WorldWideScience

Sample records for blast overpressure exposures

  1. Study of blast wave overpressures using the computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    M. L. COSTA NETO

    Full Text Available ABSTRACT The threats of bomb attacks by criminal organizations and accidental events involving chemical explosives are a danger to the people and buildings. Due the severity of these issues and the need of data required for a safety design, more research is required about explosions and shock waves. This paper presents an assessment of blast wave overpressures using a computational fluid dynamics software. Analyses of phenomena as reflection of shock waves and channeling effects were done and a comparison between numerical results and analytical predictions has been executed, based on the simulation on several models. The results suggest that the common analytical predictions aren’t accurate enough for an overpressure analysis in small stand-off distances and that poorly designed buildings may increase the shock wave overpressures due multiple blast wave reflections, increasing the destructive potential of the explosions.

  2. Occupational overpressure exposure of breachers and military personnel

    Science.gov (United States)

    Kamimori, G. H.; Reilly, L. A.; LaValle, C. R.; Olaghere Da Silva, U. B.

    2017-11-01

    Military and law enforcement personnel may be routinely and repetitively exposed to low-level blast (LLB) overpressure during training and in operations. This repeated exposure has been associated with symptoms similar to that reported for sports concussion. This study reports LLB exposure for various military and law enforcement sources in operational training environments. Peak overpressure and impulse data are presented from indoor breaching, outdoor breaching, shotgun door breaching, small arms discharge, and mortar and artillery fire missions. Data were collected using the Black Box Biometrics (B3) Blast Gauge sensors. In all cases, sensors were attached to the operators and, where possible, also statically mounted to walls or other fixed structures. Peak overpressures from below 1 psi (7 kPa) to over 12 psi (83 kPa) were recorded; all values reported are uncorrected for incidence angle to the blast exposure source. The results of these studies indicate that the current minimum safe distance calculations are often inaccurate for both indoor and outdoor breaching scenarios as true environmental exposure can consistently exceed the 4 psi (28 kPa) incident safe threshold prescribed by U.S. Army doctrine. While ballistic (shotgun) door breaching and small arms firing only expose the operator to low peak exposure levels, the sheer number of rounds fired during training may result in an excessive cumulative exposure. Mortar and artillery crew members received significantly different overpressure and impulse exposures based on their position (job) relative to the weapon. As both the artillery and mortar crews commonly fire hundreds of rounds during a single training session they are also likely to receive high cumulative exposures. These studies serve to provide the research community with estimates for typical operator exposure across a range of operational scenarios or in the discharge of various weapons systems.

  3. Critique of An Analysis of the Blast Overpressure Study Data Comparing Three Exposure Criteria, by Murphy, Khan, and Shaw

    Science.gov (United States)

    2010-08-01

    ear has in fact led to a confounded and inaccurate conclusion. 3.2 Limited Reports of Exposure A second concern is that we have no full exposure...KALAMAZOO MI 49008-5355 NO. OF NO. OF COPIES ORGANIZATION COPIES ORGANIZATION 27 1 GEORGE LUZ LUZ SOCIAL AND ENVIRONMENTAL ASSOCIATES 4910

  4. Blast overpressure induced axonal injury changes in rat brainstem and spinal cord

    Directory of Open Access Journals (Sweden)

    Srinivasu Kallakuri

    2015-01-01

    Full Text Available Introduction: Blast induced neurotrauma has been the signature wound in returning soldiers from the ongoing wars in Iraq and Afghanistan. Of importance is understanding the pathomechansim(s of blast overpressure (OP induced axonal injury. Although several recent animal models of blast injury indicate the neuronal and axonal injury in various brain regions, animal studies related to axonal injury in the white matter (WM tracts of cervical spinal cord are limited. Objective: The purpose of this study was to assess the extent of axonal injury in WM tracts of cervical spinal cord in male Sprague Dawley rats subjected to a single insult of blast OP. Materials and Methods: Sagittal brainstem sections and horizontal cervical spinal cord sections from blast and sham animals were stained by neurofilament light (NF-L chain and beta amyloid precursor protein immunocytochemistry and observed for axonal injury changes. Results: Observations from this preliminary study demonstrate axonal injury changes in the form of prominent swellings, retraction bulbs, and putative signs of membrane disruptions in the brainstem and cervical spinal cord WM tracts of rats subjected to blast OP. Conclusions: Prominent axonal injury changes following the blast OP exposure in brainstem and cervical spinal WM tracts underscores the need for careful evaluation of blast induced injury changes and associated symptoms. NF-L immunocytochemistry can be considered as an additional tool to assess the blast OP induced axonal injury.

  5. Neuro-glial and systemic mechanisms of pathological responses in rat models of primary blast overpressure compared to ‘composite’ blast.

    Directory of Open Access Journals (Sweden)

    Stanislav I. Svetlov

    2012-02-01

    Full Text Available A number of experimental models of blast brain injury have been implemented in rodents and larger animals. However, the variety of blast sources and the complexity of blast wave biophysics have made data on injury mechanisms and biomarkers difficult to analyze and compare. Recently, we showed the importance of rat position towards blast generated by an external shock tube. In this study, we further characterized blast producing moderate TBI and defined ‘composite’ blast and primary blast exposure set-ups. Schlieren optics visualized interaction between the head and a shock wave generated by external shock tube, revealing strong head acceleration upon positioning the rat on-axis with the shock tube (composite blast, but negligible skull movement upon peak overpressure exposure off-axis (primary blast. Brain injury signatures of a primary blast hitting the frontal head were assessed and compared to damage produced by composite blast. Low to negligible levels of neurodegeneration were found following primary blast compared to composite blast by silver staining. However, persistent gliosis in hippocampus and accumulation of GFAP/CNPase in circulation was detected after both primary and composite blast. Also, markers of vascular/endothelial inflammation integrin alpha/beta, sICAM, and L-selectin along with neurotrophic factor NGF-beta were increased in serum within 6 hours post-blasts and persisted for 7 days thereafter. In contrast, systemic IL-1, IL-10, fractalkine, neuroendocrine peptide Orexin A, and VEGF receptor Neuropilin-2 (NRP-2 were raised predominantly after primary blast exposure. In conclusion, biomarkers of major pathological pathways were elevated at all blast setups. The most significant and persistent changes in neuro-glial markers were found after composite blast, while primary blast instigated prominent systemic cytokine/chemokine, Orexin A, and Neuropilin-2 release, particularly when primary blast impacted rats with

  6. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    Science.gov (United States)

    2014-11-01

    correlate with se- verity of diffuse brain injury in rats. Neurosurgery 56, 582–589. 23. Robertson, C.L., Saraswati, M., and Fiskum, G. (2007). Mitochondrial...were affected in 6/9 rats in the single blast group (average severi- ty =mild) versus 8/8 rats in the double blast group (average se- verity ...D.J., Pagulayan, K., McCraw, K., Hoff, D., Hart , K., Yu, C.E., Raskind, M.A., Cook, D.G., and Min- oshima, S. (2011). Cerebrocerebellar

  7. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    Science.gov (United States)

    2015-10-01

    least four distinct forms of alkaline phosphatase nzyme present in mammals - intestinal, placental, placental- ike and TNAP (present in liver, bone...Mahota, T. M., Xu, L., Slack, N., Windle, D., and Ahmed, F. A. (2011). The patho- biology of blast injuries and blast- induced neurotrauma as...presence of 0.33 M of gene specific primers and 0.5 l of cDNA in thermal cycler as follows; 95 ◦C × 1 min, followed by 35 cycles of 95 ◦C × 30 s, 61 ◦C

  8. Protection of the lung from blast overpressure by stress wave decouplers, buffer plates or sandwich panels.

    Science.gov (United States)

    Sedman, Andrew; Hepper, A

    2018-03-19

    This paper outlines aspects of UK Ministry of Defence's research and development of blast overpressure protection technologies appropriate for use in body armour, with the aim of both propagating new knowledge and updating existing information. Two simple models are introduced not only to focus the description of the mechanism by which the lungs can be protected, but also to provide a bridge between fields of research that may hold the key to further advances in protection technology and related body armour. Protection can be provided to the lungs by decoupling the stress wave transmission into the thorax by managing the blast energy imparted through the protection system. It is proposed that the utility of the existing 'simple decoupler' blast overpressure protection is reviewed in light of recent developments in the treatment of those sustaining both overpressure and fragment injuries. It is anticipated that further advances in protection technology may be generated by those working in other fields on the analogous technologies of 'buffer plates' and 'sandwich panels'. © Crown copyright (2018), Dstl. This material is licensed under the terms of the Open Government Licence except where otherwise stated. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3 or write to the Information Policy Team, The National Archives, Kew, London TW9 4DU, or email: psi@nationalarchives.gsi.gov.uk.

  9. Blast overpressure and fallout radiation dose models for casualty assessment and other purposes. Rev. ed.

    International Nuclear Information System (INIS)

    Bentley, P.R.

    1981-12-01

    The determination of blast overpressures and fallout radiation doses at points on a sufficiently fine grid, for any part or for the whole of the UK, and for any postulated attack, is an essential element in the systematic assessment of casualties, the estimation of numbers of homeless, and the evaluation of life-saving measures generally. Models are described which provide the required blast and dose values and which are intended to supersede existing models which were introduced in 1971. The factors which affect blast and, more particularly, dose values are discussed, and the way in which various factors are modelled is described. The models are incorporated into separate computer programs which are described, the outputs of which are stored on magnetic tape for subsequent use as required. (author)

  10. Elucidation of Inflammation Processes Exacerbating Neuronal Cell Damage to the Retina and Brain Visual Centers as Quest for Therapeutic Drug Targets in Rat Model of Blast Overpressure Wave Exposure

    Science.gov (United States)

    2016-10-01

    their eye tracking thresholds are noted (cycles/degree) Using a full field flash Ganzfeld ERG device ( Color Dome; Diagnosys), isoflurane...Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for...traumatic eye injuries to soldiers is exposure to blast shock waves; and it can involve cellular damage to the retina as well as brain visual centers

  11. Computational modeling of blast exposure associated with recoilless weapons combat training

    Science.gov (United States)

    Wiri, S.; Ritter, A. C.; Bailie, J. M.; Needham, C.; Duckworth, J. L.

    2017-11-01

    Military personnel are exposed to blast as part of routine combat training with shoulder-fired recoilless rifles. These weapons fire large-caliber ammunitions capable of disabling structures and uparmored vehicles (e.g., tanks). Scientific, medical, and military leaders are beginning to recognize the blast overpressure from these shoulder-fired weapons may result in acute and even long-term physiological effects to military personnel. However, the back blast generated from the Carl Gustav and Shoulder-launched Multipurpose Assault Weapon (SMAW) shoulder-fired weapons on the weapon operator has not been quantified. By quantifying and modeling the full-body blast exposure from these weapons, better injury correlations can be constructed. Blast exposure data from the Carl Gustav and SMAW were used to calibrate a propellant burn source term for computational simulations of blast exposure on operators of these shoulder-mounted weapon systems. A propellant burn model provided the source term for each weapon to capture blast effects. Blast data from personnel-mounted gauges during weapon firing were used to create initial, high-fidelity 3D computational fluid dynamic simulations using SHAMRC (Second-order Hydrodynamic Automatic Mesh Refinement Code). These models were then improved upon using data collected from static blast sensors positioned around the military personnel while weapons were utilized in actual combat training. The final simulation models for both the Carl Gustav and SMAW were in good agreement with the data collected from the personnel-mounted and static pressure gauges. Using the final simulation results, contour maps were created for peak overpressure and peak overpressure impulse experienced by military personnel firing the weapon as well as those assisting with firing of those weapons. Reconstruction of the full-body blast loading enables a more accurate assessment of the cause of potential mechanisms of injury due to air blast even for subjects not

  12. The use of HANDIDET reg-sign non-electric detonator assemblies to reduce blast-induced overpressure at AECL's Underground Research Laboratory

    International Nuclear Information System (INIS)

    Onagi, D.P.; Keith, S.G.; Kuzyk, G.W.

    1996-01-01

    A number of aspects of the Canadian concept for nuclear fuel waste disposal are being assessed by Atomic Energy of Canada Limited (AECL) in a series of experiments at its Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, Canada. One of the major objectives of the work being carried out at the URL is to develop and evaluate the methods and technology to ensure safe, permanent disposal of Canada's nuclear fuel waste. In 1994, AECL excavated access tunnels and a laboratory room for the Quarried Block Fracture Migration Experiment (QBFME) at the 240 Level of the URL. This facility will be used to study the transport of radionuclides in natural fractures in quarried blocks of granite under in-situ groundwater conditions. The experiment is being carried out under a cooperative agreement with the Japan Atomic Energy Research Institute. The excavation of the QBFME access tunnels and laboratory was carried out using controlled blasting techniques that minimized blast-induced overpressure which could have damaged or interrupted other ongoing experiments in the vicinity. The majority of the blasts used conventional long delay non-electric detonators but a number of blasts were carried out using HANDIDET 250/6000 non-electric long delay detonator assemblies and HTD reg-sign non-electric short delay trunkline detonator assemblies. The tunnel and laboratory excavation was monitored to determine the levels of blast-induced overpressure. This paper describes the blasting and monitoring results of the blasts using HANDIDET non-electric detonator assemblies and the effectiveness of these detonators in reducing blast-induced overpressure

  13. The use of HANDIDET{reg_sign} non-electric detonator assemblies to reduce blast-induced overpressure at AECL`s Underground Research Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Onagi, D.P.; Keith, S.G.; Kuzyk, G.W. [AECL, Pinawa, Manitoba (Canada). Underground Research Lab.; Proudfoot, D.F. [ICI Explosives Canada, North Delta, British Columbia (Canada)

    1996-12-01

    A number of aspects of the Canadian concept for nuclear fuel waste disposal are being assessed by Atomic Energy of Canada Limited (AECL) in a series of experiments at its Underground Research Laboratory (URL) near Lac du Bonnet, Manitoba, Canada. One of the major objectives of the work being carried out at the URL is to develop and evaluate the methods and technology to ensure safe, permanent disposal of Canada`s nuclear fuel waste. In 1994, AECL excavated access tunnels and a laboratory room for the Quarried Block Fracture Migration Experiment (QBFME) at the 240 Level of the URL. This facility will be used to study the transport of radionuclides in natural fractures in quarried blocks of granite under in-situ groundwater conditions. The experiment is being carried out under a cooperative agreement with the Japan Atomic Energy Research Institute. The excavation of the QBFME access tunnels and laboratory was carried out using controlled blasting techniques that minimized blast-induced overpressure which could have damaged or interrupted other ongoing experiments in the vicinity. The majority of the blasts used conventional long delay non-electric detonators but a number of blasts were carried out using HANDIDET 250/6000 non-electric long delay detonator assemblies and HTD{reg_sign} non-electric short delay trunkline detonator assemblies. The tunnel and laboratory excavation was monitored to determine the levels of blast-induced overpressure. This paper describes the blasting and monitoring results of the blasts using HANDIDET non-electric detonator assemblies and the effectiveness of these detonators in reducing blast-induced overpressure.

  14. Repeated Low-Level Blast Exposure: A Descriptive Human Subjects Study.

    Science.gov (United States)

    Carr, Walter; Stone, James R; Walilko, Tim; Young, Lee Ann; Snook, Tianlu Li; Paggi, Michelle E; Tsao, Jack W; Jankosky, Christopher J; Parish, Robert V; Ahlers, Stephen T

    2016-05-01

    The relationship between repeated exposure to blast overpressure and neurological function was examined in the context of breacher training at the U.S. Marine Corps Weapons Training Battalion Dynamic Entry School. During this training, Students are taught to apply explosive charges to achieve rapid ingress into secured buildings. For this study, both Students and Instructors participated in neurobehavioral testing, blood toxin screening, vestibular/auditory testing, and neuroimaging. Volunteers wore instrumentation during training to allow correlation of human response measurements and blast overpressure exposure. The key findings of this study were from high-memory demand tasks and were limited to the Instructors. Specific tests showing blast-related mean differences were California Verbal Learning Test II, Automated Neuropsychological Assessment Metrics subtests (Match-to-Sample, Code Substitution Delayed), and Delayed Matching-to-Sample 10-second delay condition. Importantly, apparent deficits were paralleled with functional magnetic resonance imaging using the n-back task. The findings of this study are suggestive, but not conclusive, owing to small sample size and effect. The observed changes yield descriptive evidence for potential neurological alterations in the subset of individuals with occupational history of repetitive blast exposure. This is the first study to integrate subject instrumentation for measurement of individual blast pressure exposure, neurocognitive testing, and neuroimaging. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

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

    Directory of Open Access Journals (Sweden)

    Scott A Heldt

    2014-01-01

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

  16. Blast exposure causes early and persistent aberrant phospho- and cleaved-tau expression in a murine model of mild blast-induced traumatic brain injury.

    Science.gov (United States)

    Huber, Bertrand R; Meabon, James S; Martin, Tobin J; Mourad, Pierre D; Bennett, Raymond; Kraemer, Brian C; Cernak, Ibolja; Petrie, Eric C; Emery, Michael J; Swenson, Erik R; Mayer, Cynthia; Mehic, Edin; Peskind, Elaine R; Cook, David G

    2013-01-01

    Mild traumatic brain injury (mTBI) is considered the 'signature injury' of combat veterans that have served during the wars in Iraq and Afghanistan. This prevalence of mTBI is due in part to the common exposure to high explosive blasts in combat zones. In addition to the threats of blunt impact trauma caused by flying objects and the head itself being propelled against objects, the primary blast overpressure (BOP) generated by high explosives is capable of injuring the brain. Compared to other means of causing TBI, the pathophysiology of mild-to-moderate BOP is less well understood. To study the consequences of BOP exposure in mice, we employed a well-established approach using a compressed gas-driven shock tube that recapitulates battlefield-relevant open-field BOP. We found that 24 hours post-blast a single mild BOP provoked elevation of multiple phospho- and cleaved-tau species in neurons, as well as elevating manganese superoxide-dismutase (MnSOD or SOD2) levels, a cellular response to oxidative stress. In hippocampus, aberrant tau species persisted for at least 30 days post-exposure, while SOD2 levels returned to sham control levels. These findings suggest that elevated phospho- and cleaved-tau species may be among the initiating pathologic processes induced by mild blast exposure. These findings may have important implications for efforts to prevent blast-induced insults to the brain from progressing into long-term neurodegenerative disease processes.

  17. Reduction of 5in./54 Gun Blast Overpressure by Means of an Aqueous Foam- Filled Muzzle Device

    Science.gov (United States)

    1981-08-01

    Such a device is normally attached to a gun muzzle to reduce blast, but a second purpose in this testing was to obtain information about the blast...the internal pressure distribucion could be established and in- formation could be provided about the strength requirement of the device. Pres- sure

  18. DIRECT AIR BLAST EXPOSURE EFFECTS IN ANIMALS, OPERATION UPSHOT-KNOTHOLE, PROJECT 4.2

    Energy Technology Data Exchange (ETDEWEB)

    DRAEGER, R.H. (UNITED STATES NAVY - DEPARTMENT OF); LEE, R.H. (UNITED STATES NAVY - DEPARTMENT OF)

    1953-12-31

    Project 4.2 was designed to study direct (primary) air blast injury, in animals, from an atomic weapon in the range of 20 to 50 psi under circumstances affording protection against missiles, thermal and ionizing radiation and to estimate the probable direct air blast hazard in man. The pressure levels at which atomic weapons direct air blast injuries occur will determine, to a large extent, the number of blast casualties likely to be encountered. It is probable that fatal overpressures are not reached until well within the range at which indirect (secondary) blast, thermal and ionizing radiation are practically certain to prove fatal. Only in special situations affording partial protection from other injuries are blast injuries likely to be of practical importance. Two animal species of widely different body weights (700 rats and 56 dogs) were exposed, together with air pressure recorders, in aluminum cylinders, covered by sandbags and dirt but open at both ends, at seven stations distributed within the intended overpressure range of 20 to 50 psi of Shot 10« About 200 rats were likewise exposed in Shot 9. Unfortunately, the destructive effect of the air blast of Shot 10 was much greater than anticipated. Many of the exposure cylinders were displaced and their contents destroyed. Only a partial recovery of the animals was possible due to the excessive radioactive contamination which greatly limited the time in the area. Most of the animals were dead upon recovery. Those living were in a state of severe shock. Autopsy findings showed remarkably few traumatic lesions and lung hemorrhages in spite of the rough treatment and high overpressure to which they were subjected. The rats recovered from Shot 9 were exposed to a recorded pressure of 18 to 2k psi. The autopsy findings showed moderate lung hemorrhage in most of the animals undoubtedly due to direct air blast injury. The findings were typical of those seen following exposure to air blast from HE or in the shock

  19. The multi-modal responses of a physical head model subjected to various blast exposure conditions

    Science.gov (United States)

    Ouellet, S.; Phillippens, M.

    2017-11-01

    The local and global biomechanical response of the body to a blast wave is the first step of a sequence that leads to the development of stresses and strains which can exceed the tolerance of brain tissue. These stresses and strains may then lead to neuro-physical changes in the brain and contribute to initiate a cascade of events leading to injury. The specific biomechanical pathways by which the blast energy is transmitted through the head structure are, however, not clearly understood. Multiple transmission mechanisms have been proposed to explain the generation of brain stresses following the impingement of a blast wave on the head. With the use of a physical head model, the work presented here aims at demonstrating that the proposed transmission mechanisms are not mutually exclusive. They are part of a continuum of head responses where, depending on the exposure conditions, a given mechanism may or may not dominate. This article presents the joint analysis of previous blast test results generated with the brain injury protection evaluation device (BIPED) headform under four significantly different exposure conditions. The focus of the analysis is to demonstrate how the nature of the recorded response is highly dependent on the exposure characteristics and consequently, on the method used to reproduce blast exposure in a laboratory environment. The timing and magnitude of the variations in intra-cranial pressures (ICP) were analysed relative to the external pressure field in order to better understand the wave dynamics occurring within the brain structure of the headform. ICP waveforms were also analysed in terms of their energy spectral density to better identify the energy partitioning between the different modes of response. It is shown that the BIPED response is multi-modal and that the energy partitioning between its different modes of response is greatly influenced by exposure characteristics such as external peak overpressure, impulse, blast wave

  20. The multi-modal responses of a physical head model subjected to various blast exposure conditions

    Science.gov (United States)

    Ouellet, S.; Philippens, M.

    2018-01-01

    The local and global biomechanical response of the body to a blast wave is the first step of a sequence that leads to the development of stresses and strains which can exceed the tolerance of brain tissue. These stresses and strains may then lead to neuro-physical changes in the brain and contribute to initiate a cascade of events leading to injury. The specific biomechanical pathways by which the blast energy is transmitted through the head structure are, however, not clearly understood. Multiple transmission mechanisms have been proposed to explain the generation of brain stresses following the impingement of a blast wave on the head. With the use of a physical head model, the work presented here aims at demonstrating that the proposed transmission mechanisms are not mutually exclusive. They are part of a continuum of head responses where, depending on the exposure conditions, a given mechanism may or may not dominate. This article presents the joint analysis of previous blast test results generated with the brain injury protection evaluation device (BIPED) headform under four significantly different exposure conditions. The focus of the analysis is to demonstrate how the nature of the recorded response is highly dependent on the exposure characteristics and consequently, on the method used to reproduce blast exposure in a laboratory environment. The timing and magnitude of the variations in intra-cranial pressures (ICP) were analysed relative to the external pressure field in order to better understand the wave dynamics occurring within the brain structure of the headform. ICP waveforms were also analysed in terms of their energy spectral density to better identify the energy partitioning between the different modes of response. It is shown that the BIPED response is multi-modal and that the energy partitioning between its different modes of response is greatly influenced by exposure characteristics such as external peak overpressure, impulse, blast wave

  1. Porcine head response to blast

    Directory of Open Access Journals (Sweden)

    Jay eShridharani

    2012-05-01

    Full Text Available Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposed porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110-740 kPa peak incident overpressure with scaled durations from 1.3-6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. The bulk head acceleration and the pressure at the surface of the head and in the cranial cavity were measured. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within thirty seconds and the remaining two recovered within 8 minutes following bagging and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80-685 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300-2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385-3845 G’s and were well correlated with peak incident overpressure (R2=0.90. One standard deviation corridors for the surface pressure, intracranial pressure, and head acceleration are presented to provide experimental data for

  2. An Evaluation of the Compressive Properties of Helmet Pads Pre- and Post-Shock Wave Overpressure Exposure

    Science.gov (United States)

    2015-08-14

    OVERPRESSURE WOUNDS AND INJURIES IMPACT STATIC TESTS PADS(CUSHIONS) TEST AND EVALUATION TRAUMA...HELMET PADS HEAD(ANATOMY) TRAUMATIC BRAIN INJURY HELMETS SHOCK TUBES ACH(ADVANCED COMBAT HELMET) U.S...Cambridge, UK: Cambridge University Press, 1997. [5] W. C. Moss and M. J. King, "Impact response of US Army and National Football League helmet pad

  3. Rodent model of direct cranial blast injury.

    Science.gov (United States)

    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

    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 β-amyloid precursor protein (β-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.

  4. Low-cost blast wave generator for studies of hearing loss and brain injury: blast wave effects in closed spaces.

    Science.gov (United States)

    Newman, Andrew J; Hayes, Sarah H; Rao, Abhiram S; Allman, Brian L; Manohar, Senthilvelan; Ding, Dalian; Stolzberg, Daniel; Lobarinas, Edward; Mollendorf, Joseph C; Salvi, Richard

    2015-03-15

    Military personnel and civilians living in areas of armed conflict have increased risk of exposure to blast overpressures that can cause significant hearing loss and/or brain injury. The equipment used to simulate comparable blast overpressures in animal models within laboratory settings is typically very large and prohibitively expensive. To overcome the fiscal and space limitations introduced by previously reported blast wave generators, we developed a compact, low-cost blast wave generator to investigate the effects of blast exposures on the auditory system and brain. The blast wave generator was constructed largely from off the shelf components, and reliably produced blasts with peak sound pressures of up to 198dB SPL (159.3kPa) that were qualitatively similar to those produced from muzzle blasts or explosions. Exposure of adult rats to 3 blasts of 188dB peak SPL (50.4kPa) resulted in significant loss of cochlear hair cells, reduced outer hair cell function and a decrease in neurogenesis in the hippocampus. Existing blast wave generators are typically large, expensive, and are not commercially available. The blast wave generator reported here provides a low-cost method of generating blast waves in a typical laboratory setting. This compact blast wave generator provides scientists with a low cost device for investigating the biological mechanisms involved in blast wave injury to the rodent cochlea and brain that may model many of the damaging effects sustained by military personnel and civilians exposed to intense blasts. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Blast Exposure, White Matter Integrity, and Cognitive Function in Iraq and Afghanistan Combat Veterans

    Directory of Open Access Journals (Sweden)

    Erin A. Hazlett

    2017-04-01

    Full Text Available The long-term effects of blast exposure are a major health concern for combat veterans returning from the recent conflicts in Iraq and Afghanistan. We used an optimized diffusion tensor imaging tractography algorithm to assess white matter (WM fractional anisotropy (FA in blast-exposed Iraq and Afghanistan veterans (n = 40 scanned on average 3.7 years after deployment/trauma exposure. Veterans diagnosed with a blast-related mild traumatic brain injury (mTBI were compared to combat veterans with blast exposure but no TBI diagnosis. Blast exposure was associated with decreased FA in several WM tracts. However, total blast exposure did not correlate well with neuropsychological testing performance and there were no differences in FA based on mTBI diagnosis. Yet, veterans with mTBI performed worse on every neurocognitive test administered. Multiple linear regression across all blast-exposed veterans using a six-factor prediction model indicated that the amount of blast exposure accounted for 11–15% of the variability in composite FA scores such that as blast exposure increased, FA decreased. Education accounted for 10% of the variability in composite FA scores and 25–32% of FA variability in the right cingulum, such that as level of education increased, FA increased. Total blast exposure, age, and education were significant predictors of FA in the left cingulum. We did not find any effect of post-traumatic stress disorder on cognition or composite FA. In summary, our findings suggest that greater total blast exposure is a contributing factor to poor WM integrity. While FA was not associated with neurocognitive performance, we hypothesize that FA changes in the cingulum in veterans with multiple combat exposures and no head trauma prior to deployment may represent a marker of vulnerability for future deficits. Future work needs to examine this longitudinally.

  6. Controlled Low-Pressure Blast-Wave Exposure Causes Distinct Behavioral and Morphological Responses Modelling Mild Traumatic Brain Injury, Post-Traumatic Stress Disorder, and Comorbid Mild Traumatic Brain Injury-Post-Traumatic Stress Disorder.

    Science.gov (United States)

    Zuckerman, Amitai; Ram, Omri; Ifergane, Gal; Matar, Michael A; Sagi, Ram; Ostfeld, Ishay; Hoffman, Jay R; Kaplan, Zeev; Sadot, Oren; Cohen, Hagit

    2017-01-01

    The intense focus in the clinical literature on the mental and neurocognitive sequelae of explosive blast-wave exposure, especially when comorbid with post-traumatic stress-related disorders (PTSD) is justified, and warrants the design of translationally valid animal studies to provide valid complementary basic data. We employed a controlled experimental blast-wave paradigm in which unanesthetized animals were exposed to visual, auditory, olfactory, and tactile effects of an explosive blast-wave produced by exploding a thin copper wire. By combining cognitive-behavioral paradigms and ex vivo brain MRI to assess mild traumatic brain injury (mTBI) phenotype with a validated behavioral model for PTSD, complemented by morphological assessments, this study sought to examine our ability to evaluate the biobehavioral effects of low-intensity blast overpressure on rats, in a translationally valid manner. There were no significant differences between blast- and sham-exposed rats on motor coordination and strength, or sensory function. Whereas most male rats exposed to the blast-wave displayed normal behavioral and cognitive responses, 23.6% of the rats displayed a significant retardation of spatial learning acquisition, fulfilling criteria for mTBI-like responses. In addition, 5.4% of the blast-exposed animals displayed an extreme response in the behavioral tasks used to define PTSD-like criteria, whereas 10.9% of the rats developed both long-lasting and progressively worsening behavioral and cognitive "symptoms," suggesting comorbid PTSD-mTBI-like behavioral and cognitive response patterns. Neither group displayed changes on MRI. Exposure to experimental blast-wave elicited distinct behavioral and morphological responses modelling mTBI-like, PTSD-like, and comorbid mTBI-PTSD-like responses. This experimental animal model can be a useful tool for elucidating neurobiological mechanisms underlying the effects of blast-wave-induced mTBI and PTSD and comorbid mTBI-PTSD.

  7. VRPI Temporal Progression of Closed Globe Injury from Blast Exposure

    Science.gov (United States)

    2015-09-01

    significant increases in VEGF have been reported in many ocular disorders including diabetic retinopathy , diffuse macular edema, retinal vein...FRIEDLANDER SHAPED BLAST WAVES. FIGURE 2. BLAST WAVE MEASURED 1-IN IN FRONT OF ANIMAL LOCATION COMPARED TO PREDICTION OF BLAST FROM FRIEDLANDER WAVE

  8. Effects of low-level blast exposure on the nervous system: Is there really a controversy?

    Directory of Open Access Journals (Sweden)

    Gregory A Elder

    2014-12-01

    Full Text Available High-pressure blast waves can cause extensive CNS injury in humans. However, in combat settings such as Iraq and Afghanistan, lower level exposures associated with mild TBI (mTBI or subclinical exposure have been much more common. Yet controversy exists concerning what traits can be attributed to low-level blast, in large part due to the difficulty of distinguishing blast-related mTBI from post-traumatic stress disorder (PTSD. We describe how TBI is defined in humans and the problems posed in using current definitions to recognize blast-related mTBI. We next consider the problem of applying definitions of human mTBI to animal models, in particular that TBI severity in humans is defined in relation to alteration of consciousness at the time of injury, which typically cannot be assessed in animals. However, based on outcome assessments a condition of low-level blast exposure can be defined in animals that likely approximates human mTBI or subclinical exposure. We review blast injury modeling in animals noting that inconsistencies in experimental approach have contributed to uncertainty over the effects of low-level blast. Yet animal studies show that low-level blast pressure waves are transmitted to the brain. In brain low-level blast exposures cause behavioral, biochemical, pathological and physiological effects on the nervous system including the induction of PTSD-related behavioral traits in the absence of a psychological stressor. We review the relationship of blast exposure to chronic neurodegenerative diseases noting the paradoxical lowering of Abeta by blast, which along with other observations suggest that blast-related TBI is pathophysiologically distinct from non-blast TBI. Human neuroimaging studies show that blast-related mTBI is associated with a variety of chronic effects that are unlikely to be explained by co-morbid PTSD. We conclude that abundant evidence supports low-level blast as having long-term effects on the nervous system.

  9. Chronic Hormonal Imbalance and Adipose Redistribution Is Associated with Hypothalamic Neuropathology following Blast Exposure.

    Science.gov (United States)

    VandeVord, Pamela J; Sajja, Venkata Siva Sai Sujith; Ereifej, Evon; Hermundstad, Amy; Mao, Shijie; Hadden, Timothy J

    2016-01-01

    Endocrine disorders have been shown to be a consequence of blast traumatic brain injury in soldiers returning from military conflicts. Hormone deficiency and adrenocorticotropic hormone (ACTH) dysfunction can lead to symptoms such as fatigue, anxiety, irritability, insomnia, sexual dysfunction, and decreased quality of life. Given these changes following blast exposure, the current study focused on investigating chronic pathology within the hypothalamus following blast, in addition to systemic effects. An established rodent model of blast neurotrauma was used to induce mild blast-induced neurotrauma. Adipose tissue, blood, and brain samples were collected at one and three months following a single blast exposure. Adipose tissue and blood were evaluated for changes in ACTH, adiponectin, C-reactive protein, glial fibrillary acidic protein, interleukin (IL)-1β, and leptin. The hypothalamus was evaluated for injury using immunohistochemical techniques. The results demonstrated that the weight of the blast animals was significantly less, compared with the sham group. The slower rate of increase in their weight was associated with changes in ACTH, IL-1β, and leptin levels. Further, histological analysis indicated elevated levels of cleaved caspase-3 positive cells within the hypothalamus. The data suggest that long-term outcomes of brain injury occurring from blast exposure include dysfunction of the hypothalamus, which leads to compromised hormonal function, elevated biological stress-related hormones, and subsequent adipose tissue remodeling.

  10. Assessment of Mechanical Damage to Odontocete Respiratory Tract Tissues After Controlled Exposure to Blasting

    National Research Council Canada - National Science Library

    Reidenberg, Joy

    2004-01-01

    The odontocete respiratory tract is adapted to withstand the gradual pressure changes associated with diving, yet nothing is known about how it responds to the sudden pressure changes of a blast exposure...

  11. Effects of repetitive low-level blast exposure on visual systems and ocular structures

    OpenAIRE

    José E. Capó-Aponte, OD, PhD; Gina M. Jurek; David V. Walsh, OD, PhD; Leonard A. Temme, PhD; William A. Ahroon, PhD; Daniel W. Riggs, MS

    2015-01-01

    The purpose of this study was to determine whether repetitive exposure to low-level blasts during military breacher training produces acute and cumulative damage to the ocular tissues or visual system. The effects of low-level blast exposure on high-contrast visual acuity, contrast sensitivity, oculomotor function, color vision, visual field (VF), pupillary light reflex, corneal endothelial cell density (ECD), macular thickness, retinal nerve fiber layer thickness, and cup-to-disc ratio were ...

  12. Propulsion system ignition overpressure for the Space Shuttle

    Science.gov (United States)

    Ryan, R. S.; Jones, J. H.; Guest, S. H.; Struck, H. G.; Rheinfurth, M. H.; Verferaime, V. S.

    1981-01-01

    Liquid and solid rocket motor propulsion systems create an overpressure wave during ignition, caused by the accelerating gas particles pushing against or displacing the air contained in the launch pad or launch facility and by the afterburning of the fuel-rich gases. This wave behaves as a blast or shock wave characterized by a positive triangular-shaped first pulse and a negative half-sine wave second pulse. The pulse travels up the space vehicle and has the potential of either overloading individual elements or exciting overall vehicle dynamics. The latter effect results from the phasing difference of the wave from one side of the vehicle to the other. This overpressure phasing, or delta P environment, because of its frequency content as well as amplitude, becomes a design driver for certain panels (e.g., thermal shields) and payloads for the Space Shuttle. The history of overpressure effects on the Space Shuttle, the basic overpressure phenomenon, Space Shuttle overpressure environment, scale model overpressure testing, and techniques for suppressing the overpressure environments are considered.

  13. The effects of repeated low-level blast exposure on hearing in marines

    Directory of Open Access Journals (Sweden)

    Lina R Kubli

    2017-01-01

    Full Text Available Background: The study evaluates a group of Military Service Members specialized in blast explosive training called “Breachers” who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group “Breachers” was compared to a control group, “Engineers”. Methods: A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN measures, and central auditory behavioral and objective tests using early and late (P300 auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. Results: No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. Conclusions: To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing.

  14. Temporal Progression of Visual Injury from Blast Exposure

    Science.gov (United States)

    2017-09-01

    or 48 hours) and animal orientation (side-on or face-on). Experimental evaluations using multiple species is required to fully validate the...ProQuest. Computer modeling was used to understand how the findings in our experimental animal models (and those of other researchers) can be... experimental work was performed. Several modifications to the blast device were made. In Year 3, the bulk of animal studies were completed and

  15. Auditory, Vestibular and Cognitive Effects due to Repeated Blast Exposure on the Warfighter

    Science.gov (United States)

    2012-10-01

    competitions Prior disorders of hearing and balance including: o Meniere’s disease o Chronic migraine o Multiple sclerosis o Vestibular neuritis o...AD______________ AWARD NUMBER: W81XWH-08-2-0029 TITLE: Auditory, Vestibular and Cognitive...201 – 31 201 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Auditory, Vestibular and Cognitive Effects due to Repeated Blast Exposure on the

  16. Accidental hand grenade blast injuries in the Transkei region of ...

    African Journals Online (AJOL)

    The result is extensive mutilation of the body, particularly to those close to the blast. In this report the nature and .... Those who joined the liberation movements received training in firearms both within and outside the ... peak overpressures and positive-phase durations of blast waves.7 The simulated peak overpressure and ...

  17. Assessing Neuro-Systemic & Behavioral Components in the Pathophysiology of Blast-Related Brain Injury

    Directory of Open Access Journals (Sweden)

    Firas H Kobeissy

    2013-11-01

    Full Text Available Among the U.S. military personnel, blast injury is among the leading causes of brain injury. During the past decade, it has become apparent that even blast injury as a form of mild traumatic brain injury (mTBI may lead to multiple different adverse outcomes, such as neuropsychiatric symptoms and long-term cognitive disability. Blast injury is characterized by blast overpressure (BOP, blast duration, and blast impulse. While the blast injuries of a victim close to the explosion will be severe, majority of victims are usually at a distance leading to milder form described as mild blast TBI (mbTBI. A major feature of mbTBI is its complex manifestation occurring in concert at different organ levels involving systemic, cerebral, neuronal and neuropsychiatric responses; some of which are shared with other forms of brain trauma such as acute brain injury and other neuropsychiatric disorders such as PTSD. The pathophysiology of blast injury exposure involves complex cascades of chronic psychological stress, autonomic dysfunction and neuro/systemic inflammation. These factors render blast injury as an arduous challenge in terms of diagnosis and treatment as well as identification of sensitive and specific biomarkers distinguishing mTBI from other non-TBI pathologies and from neuropsychiatric disorders with similar symptoms. This is due to the distinct but shared and partially identified biochemical pathways and neuro-histopathological changes that might be linked to behavioral deficits observed. Taken together, this article aims to provide an overview of the current status of the cellular and pathological mechanisms involved in blast overpressure injury and argues for the urgent need to identify potential biomarkers that can hint at the different mechanisms involved.

  18. Blast exposure and dual sensory impairment: an evidence review and integrated rehabilitation approach.

    Science.gov (United States)

    Saunders, Gabrielle H; Echt, Katharina V

    2012-01-01

    Combat exposures to blast can result in both peripheral damage to the ears and eyes and central damage to the auditory and visual processing areas in the brain. The functional effects of the latter include visual, auditory, and cognitive processing difficulties that manifest as deficits in attention, memory, and problem solving--symptoms similar to those seen in individuals with visual and auditory processing disorders. Coexisting damage to the auditory and visual system is referred to as dual sensory impairment (DSI). The number of Operation Iraqi Freedom/Operation Enduring Freedom Veterans with DSI is vast; yet currently no established models or guidelines exist for assessment, rehabilitation, or service-delivery practice. In this article, we review the current state of knowledge regarding blast exposure and DSI and outline the many unknowns in this area. Further, we propose a model for clinical assessment and rehabilitation of blast-related DSI that includes development of a coordinated team-based approach to target activity limitations and participation restrictions in order to enhance reintegration, recovery, and quality of life.

  19. Exploration of the molecular basis of blast injury in a biofidelic model of traumatic brain injury

    Science.gov (United States)

    Thielen, P.; Mehoke, T.; Gleason, J.; Iwaskiw, A.; Paulson, J.; Merkle, A.; Wester, B.; Dymond, J.

    2018-01-01

    Biological response to blast overpressure is complex and results in various and potentially non-concomitant acute and long-term deficits to exposed individuals. Clinical links between blast severity and injury outcomes remain elusive and have yet to be fully described, resulting in a critical inability to develop associated protection and mitigation strategies. Further, experimental models frequently fail to reproduce observed physiological phenomena and/or introduce artifacts that confound analysis and reproducibility. New models are required that employ consistent mechanical inputs, scale with biological analogs and known clinical data, and permit high-throughput examination of biological responses for a range of environmental and battlefield- relevant exposures. Here we describe a novel, biofidelic headform capable of integrating complex biological samples for blast exposure studies. We additionally demonstrate its utility in detecting acute transcriptional responses in the model organism Caenorhabditis elegans after exposure to blast overpressure. This approach enables correlation between mechanical exposure and biological outcome, permitting both the enhancement of existing surrogate and computational models and the high-throughput biofidelic testing of current and future protection systems.

  20. Injury careers after blast exposure among combat veterans deployed to Iraq or Afghanistan.

    Science.gov (United States)

    Chase, Rachel P; McMahon, Shannon A; Winch, Peter J

    2015-12-01

    During the Iraq and Afghanistan wars, blasts were the most common cause of combat injuries, including traumatic brain injury (TBI). Prior to 2007, service members were not systematically screened for TBI, and estimates suggest that tens of thousands of mild TBIs went undiagnosed. This study sought to understand post-acute "injury careers," documenting the life- and health-related narratives of veterans who were at high risk of undocumented TBI due to being blast-exposed before 2007. Researchers conducted 38 in-depth interviews between May 2013 and August 2014 with Army veterans who served in combat-intense settings (n = 16) and their family members (n = 10). Respondents detailed a series of experiences in the months and years following blast exposure. We present this series as a model that draws upon the vernacular of participants who described veterans "downplaying" their injuries and later "detaching" themselves from friends, family, and communities, and "denying" or being "oblivious" to their circumstances until a "wake-up call" pushed them to "get help." Looking to the future, veterans grapple with uncertainties related to personal identity and professional or social expectations. This model is presented within a member-checked metaphor of an individual being hurled into--and emerging from--a canyon. Policies and programs addressing veteran health, particularly among those exposed to multiple blasts prior to systematic TBI documentation, must consider the personal, social, and health system challenges faced by veterans and their families throughout their injury careers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Characteristic overpressure-impulse-distance curves for vapour cloud explosions using the TNO Multi-Energy model.

    Science.gov (United States)

    Díaz Alonso, Fernando; González Ferradás, Enrique; Sánchez Pérez, Juan Francisco; Miñana Aznar, Agustín; Ruiz Gimeno, José; Martínez Alonso, Jesús

    2006-09-21

    A number of models have been proposed to calculate overpressure and impulse from accidental industrial explosions. When the blast is produced by ignition of a vapour cloud, the TNO Multi-Energy model is widely used. From the curves given by this model, data are fitted to obtain equations showing the relationship between overpressure, impulse and distance. These equations, referred herein as characteristic curves, can be fitted by means of power equations, which depend on explosion energy and charge strength. Characteristic curves allow the determination of overpressure and impulse at each distance.

  2. Improved Overpressure Recording and Modeling for Near-Surface Explosion Forensics

    Science.gov (United States)

    Kim, K.; Schnurr, J.; Garces, M. A.; Rodgers, A. J.

    2017-12-01

    The accurate recording and analysis of air-blast acoustic waveforms is a key component of the forensic analysis of explosive events. Smartphone apps can enhance traditional technologies by providing scalable, cost-effective ubiquitous sensor solutions for monitoring blasts, undeclared activities, and inaccessible facilities. During a series of near-surface chemical high explosive tests, iPhone 6's running the RedVox infrasound recorder app were co-located with high-fidelity Hyperion overpressure sensors, allowing for direct comparison of the resolution and frequency content of the devices. Data from the traditional sensors is used to characterize blast signatures and to determine relative iPhone microphone amplitude and phase responses. A Wiener filter based source deconvolution method is applied, using a parameterized source function estimated from traditional overpressure sensor data, to estimate system responses. In addition, progress on a new parameterized air-blast model is presented. The model is based on the analysis of a large set of overpressure waveforms from several surface explosion test series. An appropriate functional form with parameters determined empirically from modern air-blast and acoustic data will allow for better parameterization of signals and the improved characterization of explosive sources.

  3. Postconcussion symptoms reported by Operation Enduring Freedom/Operation Iraqi Freedom veterans with and without blast exposure, mild traumatic brain injury, and posttraumatic stress disorder.

    Science.gov (United States)

    O'Neil, Maya Elin; Callahan, Megan; Carlson, Kathleen F; Roost, Mai; Laman-Maharg, Benjamin; Twamley, Elizabeth W; Iverson, Grant L; Storzbach, Daniel

    2017-06-01

    This study examined symptom reporting related to the 10th Edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) criteria for postconcussional syndrome (PCS) in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Veterans. Our aims were to: (a) examine relationships among PCS symptoms by identifying potential subscales of the British Columbia Postconcussion Symptom Inventory (BC-PSI); and (b) examine group differences in BC-PSI items and subscales in Veterans with and without blast exposure, mild traumatic brain injury (mTBI), and posttraumatic stress disorder (PTSD). Our sample included Veterans with blast-related mTBI history (n = 47), with blast exposure but no mTBI history (n = 20), and without blast exposure (n = 23). Overall, 37 Veterans had PTSD, and 53 did not. We conducted an exploratory factor analysis (EFA) of the BC-PSI followed by multivariate analysis of variance to examine differences in BC-PSI subscale scores by blast exposure, mTBI history, and PTSD. BC-PSI factors were interpreted as cognitive, vestibular, affective, anger, and somatic. Items and factor scores were highest for Veterans with blast exposure plus mTBI, and lowest for controls. Vestibular, affective, and somatic factors were significantly higher for Veterans with blast exposure plus mTBI than for controls, but not significantly different for those with blast exposure but no mTBI. These results remained significant when PTSD symptom severity was included as a covariate. Cognitive, anger, and somatic subscales were significantly higher for Veterans with PTSD, though there was no interaction effect of PTSD and mTBI or blast history. EFA-derived subscales of the BC-PSI differentiated Veterans based on blast exposure, mTBI history, and PTSD.

  4. Exposure to a predator scent induces chronic behavioral changes in rats previously exposed to low-level blast: Implications for the relationship of blast-related TBI to PTSD

    Directory of Open Access Journals (Sweden)

    Georgina Perez-Garcia

    2016-10-01

    Full Text Available Blast-related mild traumatic brain injury (mTBI has been unfortunately common in veterans who served in the recent conflicts in Iraq and Afghanistan. The postconcussion syndrome associated with these mTBIs has frequently appeared in combination with post-traumatic stress disorder (PTSD. The presence of PTSD has complicated diagnosis since clinically PTSD and the postconcussion syndrome of mTBI have many overlapping symptoms. In particular establishing how much of the symptom complex can be attributed to the psychological trauma associated with PTSD in contrast to the physical injury of TBI has proven difficult. Indeed some have suggested that much of what is now being called blast-related postconcussion syndrome is better explained by PTSD. The relationship between the postconcussion syndrome of mTBI and PTSD is complex. Association of the two disorders might be viewed as additive effects of independent psychological and physical traumas suffered in a war zone. However we previously found that rats exposed to repetitive low-level blast exposure in the absence of a psychological stressor developed a variety of anxiety and PTSD-related behavioral traits that were present months following the last blast exposure. Here we show that a single predator scent challenge delivered 8 months after the last blast exposure induces chronic anxiety related changes in blast-exposed rats that are still present 45 days later. These observations suggest that in addition to independently inducing PTSD-related traits, blast exposure sensitizes the brain to react abnormally to a subsequent psychological stressor. These studies have implications for conceptualizing the relationship between blast-related mTBI and PTSD and suggest that blast-related mTBI in humans may predispose to the later development of PTSD in reaction to subsequent psychological stressors.

  5. Explosive signatures: Pre & post blast

    Science.gov (United States)

    Bernier, Evan Thomas

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

  6. The equilibrium of overpressurized polytropes

    Science.gov (United States)

    Huré, J.-M.; Hersant, F.; Nasello, G.

    2018-03-01

    We investigate the impact of an external pressure on the structure of self-gravitating polytropes for axially symmetric ellipsoids and rings. The confinement of the fluid by photons is accounted for through a boundary condition on the enthalpy H. Equilibrium configurations are determined numerically from a generalized `self-consistent-field' method. The new algorithm incorporates an intraloop re-scaling operator R(H), which is essential for both convergence and getting self-normalized solutions. The main control parameter is the external-to-core enthalpy ratio. In the case of uniform rotation rate and uniform surrounding pressure, we compute the mass, the volume, the rotation rate and the maximum enthalpy. This is repeated for a few polytropic indices, n. For a given axial ratio, overpressurization globally increases all output quantities, and this is more pronounced for large n. Density profiles are flatter than in the absence of an external pressure. When the control parameter asymptotically tends to unity, the fluid converges towards the incompressible solution, whatever the index, but becomes geometrically singular. Equilibrium sequences, obtained by varying the axial ratio, are built. States of critical rotation are greatly exceeded or even disappear. The same trends are observed with differential rotation. Finally, the typical response to a photon point source is presented. Strong irradiation favours sharp edges. Applications concern star-forming regions and matter orbiting young stars and black holes.

  7. A multiscale approach to blast neurotrauma modeling:Part II: Methodology for inducing blast injury to in vitro models

    Directory of Open Access Journals (Sweden)

    Gwen B. Effgen

    2012-02-01

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

  8. Face shield design against blast-induced head injuries.

    Science.gov (United States)

    Tan, Long Bin; Tse, Kwong Ming; Tan, Yuan Hong; Sapingi, Mohamad Ali Bin; Tan, Vincent Beng Chye; Lee, Heow Pueh

    2017-12-01

    Blast-induced traumatic brain injury has been on the rise in recent years because of the increasing use of improvised explosive devices in conflict zones. Our study investigates the response of a helmeted human head subjected to a blast of 1 atm peak overpressure, for cases with and without a standard polycarbonate (PC) face shield and for face shields comprising of composite PC and aerogel materials and with lateral edge extension. The novel introduction of aerogel into the laminate face shield is explored and its wave-structure interaction mechanics and performance in blast mitigation is analysed. Our numerical results show that the face shield prevented direct exposure of the blast wave to the face and help delays the transmission of the blast to reduce the intracranial pressures (ICPs) at the parietal lobe. However, the blast wave can diffract and enter the midface region at the bottom and side edges of the face shield, resulting in traumatic brain injury. This suggests that the bottom and sides of the face shield are important regions to focus on to reduce wave ingress. The laminated PC/aerogel/PC face shield yielded higher peak positive and negative ICPs at the frontal lobe, than the original PC one. For the occipital and temporal brain regions, the laminated face shield performed better than the original. The composite face shield with extended edges reduced ICP at the temporal lobe but increases ICP significantly at the parietal lobe, which suggests that a greater coverage may not lead to better mitigating effects. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Microstructural Consequences of Blast Lung Injury Characterized with Digital Volume Correlation

    Directory of Open Access Journals (Sweden)

    Hari Arora

    2017-12-01

    Full Text Available This study focuses on microstructural changes that occur within the mammalian lung when subject to blast and how these changes influence strain distributions within the tissue. Shock tube experiments were performed to generate the blast injured specimens (cadaveric Sprague-Dawley rats. Blast overpressures of 100 and 180 kPa were studied. Synchrotron tomography imaging was used to capture volumetric image data of lungs. Specimens were ventilated using a custom-built system to study multiple inflation pressures during each tomography scan. These data enabled the first digital volume correlation (DVC measurements in lung tissue to be performed. Quantitative analysis was performed to describe the damaged architecture of the lung. No clear changes in the microstructure of the tissue morphology were observed due to controlled low- to moderate-level blast exposure. However, significant focal sites of injury were observed using DVC, which allowed the detection of bias and concentration in the patterns of strain level. Morphological analysis corroborated the findings, illustrating that the focal damage caused by a blast can give rise to diffuse influence across the tissue. It is important to characterize the non-instantly fatal doses of blast, given the transient nature of blast lung in the clinical setting. This research has highlighted the need for better understanding of focal injury and its zone of influence (alveolar interdependency and neighboring tissue burden as a result of focal injury. DVC techniques show great promise as a tool to advance this endeavor, providing a new perspective on lung mechanics after blast.

  10. Military Blast Exposure and Chronic Neurodegeneration: Summary of Working Groups and Expert Panel Findings and Recommendations

    NARCIS (Netherlands)

    Brix, K.A.; Brody, D.L.; Grimes, J.B.; Yitzhak, A.; Agoston, D.; Aldag, M.; Armstrong, R.; Arun, P.; Audette, M.; Babcock, D.; Balaban, C.; Banton, R.; Bellgowan, P.; Borkholder, D.; Broglio, S.; Brokaw, E.; Cantu, R.; Carr, W.; Chapman, S.; Cmarik, J.; Colder, B.; Colombe, J.; Cook, D.; Cozzarelli, T.; Da Silva, U.O.; Daphalapurkar, N.; Dardzinski, B.; DeGraba, T.; DeMar, J.; DeWitt, D.; Dickstein, D.; Duckworth, J.; Elder, G.; Fazel-Rezai, R.; Fine, M.; Fiskum, G.; Fournier, A.; Ganpule, S.; Gill, J.; Glenn, J.F.; Greene, C.; Greig, N.; Haering, C.; Harrington, J.; Hein, A.; Helmick, K.; Hicks, R.; Hinds, S.; Hoffman, S.; Horkayne-Szakaly, I.; Iacono, D.; Ishii, E.; Jones, R.V.; Karami, G.; Krawczyk, D.; Labutta, R.; Latta, R.; Lattimore, T.; Leggieri, M.; Leonessa, F.; Lin, A.; Ling, G.; Long, M.; Lu, K.P.; Panker, S.M.; McCabe, J.; Merkle, A.; Montenigro, P.; Mueller, G.P.; Ng, L.; Nigam, S.; O'Donnell, J.; Okonkwo, D.; Pauli, I.; Perl, D.; Peskind, E.; Pfister, B.; Philippens, M.; Piehler, T.; Proctor, J.; Przekwas, A.; Qashu, F.; Raskind, M.; Razumovsky, A.; Reifman, J.; Reyes, P.; Rigby, P.; Risling, M.; Robinson, M.; Rooks, T.; Rosen, C.; Rosseau, G.; Sammons-Jackson, W.; Santago, A.; Shoge, R.; Sours, C.; Stone, J.; Templin, M.; Tepe, V.; Thielen, P.; Thomas, M.; Timmes, T.; Tortella, F.; Tucker, L.; Tweedie, D.; Hamm, D.V.; Christie Vu, B.; Wang, Y.; West, T.; Wilde, E.; Willis, A.; Wu, J.; Zai, L.; Zander, N.; Zheng, J.; Ziejewski, M.

    2017-01-01

    The potential relationship between chronic traumatic encephalopathy (CTE) and head injuries such as blast-related traumatic brain injury (TBI) is an important area of study, particularly for military and contact sports populations, yet little is known about this relationship. To address this topic,

  11. The Effects of Blast Exposure on Protein Deimination in the Brain

    Directory of Open Access Journals (Sweden)

    Peter J. Attilio

    2017-01-01

    Full Text Available Oxidative stress and calcium excitotoxicity are hallmarks of traumatic brain injury (TBI. While these early disruptions may be corrected over a relatively short period of time, long-lasting consequences of TBI including impaired cognition and mood imbalances can persist for years, even in the absence of any evidence of overt injury based on neuroimaging. This investigation examined the possibility that disordered protein deimination occurs as a result of TBI and may thus contribute to the long-term pathologies of TBI. Protein deimination is a calcium-activated, posttranslational modification implicated in the autoimmune diseases rheumatoid arthritis and multiple sclerosis, where aberrant deimination creates antigenic epitopes that elicit an autoimmune attack. The present study utilized proteomic analyses to show that blast TBI alters the deimination status of proteins in the porcine cerebral cortex. The affected proteins represent a small subset of the entire brain proteome and include glial fibrillary acidic protein and vimentin, proteins reported to be involved in autoimmune-based pathologies. The data also indicate that blast injury is associated with an increase in immunoglobulins in the brain, possibly representing autoantibodies directed against novel protein epitopes. These findings indicate that aberrant protein deimination is a biomarker for blast TBI and may therefore underlie chronic neuropathologies of head injury.

  12. Analysis of MINIE2013 Explosion Air-Blast Data

    Energy Technology Data Exchange (ETDEWEB)

    Schnurr, Julie M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Hawaii, Manoa, HI (United States); Rodgers, Arthur J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kim, Keehoon [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ford, Sean R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, Abelardo L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-14

    We report analysis of air-blast overpressure measurements from the MINIE2013 explosive experiments. The MINIE2013 experiment involved a series of nearly 70 near-surface (height-ofburst, HOB, ranging from -1 to +4 m) low-yield (W=2-20 kg TNT equivalent) chemical highexplosives tests that were recorded at local distances (230 m – 28.5 km). Many of the W and HOB combinations were repeated, allowing for quantification of the variability in air-blast features and corresponding yield estimates. We measured canonical signal features (peak overpressure, impulse per unit area, and positive pulse duration) from the air-blast data and compared these to existing air-blast models. Peak overpressure measurements showed good agreement with the models at close ranges but tended to attenuate more rapidly at longer range (~ 1 km), which is likely caused by upward refraction of acoustic waves due to a negative vertical gradient of sound speed. We estimated yields of the MINIE2013 explosions using the Integrated Yield Determination Tool (IYDT). Errors of the estimated yields were on average within 30% of the reported yields, and there were no significant differences in the accuracy of the IYDT predictions grouped by yield. IYDT estimates tend to be lower than ground truth yields, possibly because of reduced overpressure amplitudes by upward refraction. Finally, we report preliminary results on a development of a new parameterized air-blast waveform.

  13. Study of TATP: blast characteristics and TNT equivalency of small charges

    Science.gov (United States)

    Pachman, J.; Matyáš, R.; Künzel, M.

    2014-07-01

    Blast wave parameters including incident overpressure, impulse and duration of the positive phase of the incident blast wave and its time of arrival were experimentally determined for 50 g charges of low bulk density () dry TATP (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane). The results were compared with published TNT data, and TNT equivalencies were determined, resulting in the values of 70 % based on overpressure and 55 % based on impulse of the positive phase of the blast wave. Brisance by the Hess method (lead cylinder compression) was found to be about one-third of that for TNT (at density . Detonation velocities averaged around

  14. A computational model of blast loading on the human eye.

    Science.gov (United States)

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

    2014-01-01

    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.

  15. Project Sedan, Nevada Test Site, July 6, 1962. Close-In Air Blast From a Nuclear Event in NTS Desert Alluvium

    National Research Council Canada - National Science Library

    Vortman, L. J

    1964-01-01

    .... In Spite of overranging of the pressure gages, the measurements permit derivation of a lower limit of peak overpressure and an upper limit on the amount of blast Suppression resulting from charge burial...

  16. Epidemiological Study of Mild Traumatic Brain Injury Sequelae Caused by Blast Exposure During Operations Iraqi Freedom and Enduring Freedom

    Science.gov (United States)

    2014-11-01

    assessing their own cognitive abilities; instead, the strongest influence on self -assessment is self - esteem , not actual performance.41 Therefore, a...blast mTBI diagnosis. Further, based on our clinical experience and supportive data from athletic mTBI literature, we assumed that those having...toward an association between blast mTBI grade and PCS. There was no relationship between self -reported non-blast head injuries or month since worst or

  17. Nuclear blast and fall-out shelter

    International Nuclear Information System (INIS)

    Daroga, N.D.

    1984-01-01

    A nuclear blast and fall-out shelter is described with automatically controlled oxygen supply means, air reconditioning means to remove CO and CO 2 , a hand operated pump for introducing external air if required, an over-pressure outlet valve, and means for automatically measuring the proportion of CO and CO 2 in the air in the shelter and giving an alarm signal in case of danger. (author)

  18. An Investigation of the Mechanism of Traumatic Brain Injury Caused by Blast in the Open Field

    Science.gov (United States)

    Feng, Ke

    Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo, and the correlation analysis between the biomechanical responses and its injury outcomes. Such information is crucial to the development of injury criteria of bTBI. This study aims to evaluate the external and internal mechanical responses of the brain against different levels of blast loading with Yucatan swine in free field, and to conduct correlational studies with brain tissue damage. To better understand primary bTBI, we have implemented an open field experimental model to apply controlled shock waves on swine head. The applied pressure levels of shock waves were predicted by finite element modeling and verified with calibrated testing. Biomechanical responses of primary blasts such as intracranial pressure (ICP), head kinetics, strain rate of skull, were measured in vivo during the blasts. A positive correlation between incident overpressure (IOP) and its corresponding biomechanical responses of the brain was observed. A parallel group of non-instrumented animals were used to collect injury data 72 hours post experiment. Cellular responses governed by primary blasts, such as neuronal degeneration and apoptosis were studied via immunohistochemistry. Representative fluorescent-stained images were examined under microscope. A positive correlation was found between the amount of degenerative neurons and the blast level. Significant elevation of apoptosis was found in the high-level blast. Comparisons between brains with varies ICP readings demonstrate differences of the

  19. Structural dynamic and resistance to nuclear air blast

    International Nuclear Information System (INIS)

    Qureshi, S.M.

    2003-01-01

    A need exists to design protective shelters attached to specialized facilities against nuclear airbursts, explosive shocks and impacting projectiles. Designing such structures against nuclear and missile impact is a challenging task that needs to be looked into for design methodology formulation and practicability. Structures can be designed for overpressure pulsed generated by a nuclear explosion as well as the scabbing and perforation/punching of an impacting projectile. This paper discuses and formulates the methods of dynamic analysis and design required to undertake such a task. Structural resistance to peak overpressure pulse for a 20 KT weapons and smaller tactical nuclear weapons of 1 KT (16 psi, overpressure) size as a direct air blast overpressure has been considered in design of walls, beams and slabs of a special structure under review. The design of shear reinforcement as lacing is also carried out. Adopting the philosophy of strengthening and hardening can minimize the effect of air blast overpressure and projectile impact. The objective is to avoid a major structural failure. The structure then needs to be checked against ballistic penetration by a range of weapons or be required to resist explosive penetration from the charge detonated in contact with the structure. There is also a dire need to formulate protective guidelines for all existing and future critical facilities. (author)

  20. Blast Technologies

    Science.gov (United States)

    2011-06-27

    Team Leader Risa Scherer Blast Mitigation Interior and Laboratory Team Leader Blast Technologies POC’s Government Point Of Contacts (POCs): To...to yield injury assessments at higher fidelities and with higher confidence UNCLASSIFIED UNCLASSIFIED Risa Scherer Blast Mitigation Interior and

  1. Blast neurotrauma impairs working memory and disrupts prefrontal myo-inositol levels in rats.

    Science.gov (United States)

    Sajja, Venkata Siva Sai Sujith; Perrine, Shane A; Ghoddoussi, Farhad; Hall, Christina S; Galloway, Matthew P; VandeVord, Pamela J

    2014-03-01

    Working memory, which is dependent on higher-order executive function in the prefrontal cortex, is often disrupted in patients exposed to blast overpressure. In this study, we evaluated working memory and medial prefrontal neurochemical status in a rat model of blast neurotrauma. Adult male Sprague-Dawley rats were anesthetized with 3% isoflurane and exposed to calibrated blast overpressure (17 psi, 117 kPa) while sham animals received only anesthesia. Early neurochemical effects in the prefrontal cortex included a significant decrease in betaine (trimethylglycine) and an increase in GABA at 24 h, and significant increases in glycerophosphorylcholine, phosphorylethanolamine, as well as glutamate/creatine and lactate/creatine ratios at 48 h. Seven days after blast, only myo-inositol levels were altered showing a 15% increase. Compared to controls, short-term memory in the novel object recognition task was significantly impaired in animals exposed to blast overpressure. Working memory in control animals was negatively correlated with myo-inositol levels (r=-.759, p<0.05), an association that was absent in blast exposed animals. Increased myo-inositol may represent tardive glial scarring in the prefrontal cortex, a notion supported by GFAP changes in this region after blast overexposure as well as clinical reports of increased myo-inositol in disorders of memory. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The measurement of intracranial pressure and brain displacement due to short-duration dynamic overpressure loading

    Science.gov (United States)

    Iwaskiw, A. S.; Ott, K. A.; Armiger, R. S.; Wickwire, A. C.; Alphonse, V. D.; Voo, L. M.; Carneal, C. M.; Merkle, A. C.

    2018-01-01

    The experimental measurement of biomechanical responses that correlate with blast-induced traumatic brain injury (bTBI) has proven challenging. These data are critical for both the development and validation of computational and physical head models, which are used to quantify the biomechanical response to blast as well as to assess fidelity of injury mitigation strategies, such as personal protective equipment. Therefore, foundational postmortem human surrogate (PMHS) experimental data capturing the biomechanical response are necessary for human model development. Prior studies have measured short-duration pressure transmission to the brain (Kinetic phase), but have failed to reproduce and measure the longer-duration inertial loading that can occur (Kinematic phase). Four fully instrumented PMHS were subjected to short-duration dynamic overpressure in front-facing and rear-facing orientations, where intracranial pressure (ICP), global head kinematics, and brain motion (as measured by high-speed X-ray) with respect to the skull were recorded. Peak ICP results generally increased with increased dose, and a mirrored pressure response was seen when comparing the polarity of frontal bone versus occipital bone ICP sensors. The head kinematics were delayed when compared to the pressure response and showed higher peak angles for front-facing tests as compared to rear-facing. Brain displacements were approximately 2-6 mm, and magnitudes did not change appreciably between front- and rear-facing tests. These data will be used to inform and validate models used to assess bTBI.

  3. Optimizing Blasting’s Air Overpressure Prediction Model using Swarm Intelligence

    Science.gov (United States)

    Nur Asmawisham Alel, Mohd; Ruben Anak Upom, Mark; Asnida Abdullah, Rini; Hazreek Zainal Abidin, Mohd

    2018-04-01

    Air overpressure (AOp) resulting from blasting can cause damage and nuisance to nearby civilians. Thus, it is important to be able to predict AOp accurately. In this study, 8 different Artificial Neural Network (ANN) were developed for the purpose of prediction of AOp. The ANN models were trained using different variants of Particle Swarm Optimization (PSO) algorithm. AOp predictions were also made using an empirical equation, as suggested by United States Bureau of Mines (USBM), to serve as a benchmark. In order to develop the models, 76 blasting operations in Hulu Langat were investigated. All the ANN models were found to outperform the USBM equation in three performance metrics; root mean square error (RMSE), mean absolute percentage error (MAPE) and coefficient of determination (R2). Using a performance ranking method, MSO-Rand-Mut was determined to be the best prediction model for AOp with a performance metric of RMSE=2.18, MAPE=1.73% and R2=0.97. The result shows that ANN models trained using PSO are capable of predicting AOp with great accuracy.

  4. Control blasting of reinforced concrete

    International Nuclear Information System (INIS)

    Nagase, Tetsuo

    1981-01-01

    With the need of decommissioning nuclear power plants, it is urgently required to establish its methods and standards. In Shimizu Construction Co., Ltd., experimental feasibility studies have been made on explosive demolition method i.e. the controlled blasting for the massive concrete structures peculiar to nuclear power plants, considering low radiation exposure, safety and high efficiency. As such, four techniques of line drilling, cushion blasting, pre-splitting and guide hole blasting, respectively, are described with photographs. Assuming the selective demolition of activated concrete structures, the series of experiments showed the good results of clear-cut surfaces and the effect of blasting was confined properly. Moreover, the scattering of debris in blasting was able to be entirely prevented by the use of rubber belts. The generation of gas and dust was also little due to the small amount of the charge used. (J.P.N.)

  5. Numerical investigation of particle-blast interaction during explosive dispersal of liquids and granular materials

    Science.gov (United States)

    Pontalier, Q.; Lhoumeau, M.; Milne, A. M.; Longbottom, A. W.; Frost, D. L.

    2018-04-01

    Experiments show that when a high-explosive charge with embedded particles or a charge surrounded by a layer of liquid or granular material is detonated, the flow generated is perturbed by the motion of the particles and the blast wave profile differs from that of an ideal Friedlander form. Initially, the blast wave overpressure is reduced due to the energy dissipation resulting from compaction, fragmentation, and heating of the particle bed, and acceleration of the material. However, as the blast wave propagates, particle-flow interactions collectively serve to reduce the rate of decay of the peak blast wave overpressure. Computations carried out with a multiphase hydrocode reproduce the general trends observed experimentally and highlight the transition between the particle acceleration/deceleration phases, which is not accessible experimentally, since the particles are obscured by the detonation products. The dependence of the particle-blast interaction and the blast mitigation effectiveness on the mitigant to explosive mass ratio, the particle size, and the initial solid volume fraction is investigated systematically. The reduction in peak blast overpressure is, as in experiments, primarily dependent on the mass ratio of material to explosive, with the particle size, density, and initial porosity of the particle bed playing secondary roles. In the near field, the blast overpressure decreases sharply with distance as the particles are accelerated by the flow. When the particles decelerate due to drag, energy is returned to the flow and the peak blast overpressure recovers and reaches values similar to that of a bare explosive charge for low mass ratios. Time-distance trajectory plots of the particle and blast wave motion with the pressure field superimposed, illustrate the weak pressure waves generated by the motion of the particle layer which travel upstream and perturb the blast wave motion. Computation of the particle and gas momentum flux in the multiphase

  6. Impact of overpressures on subsurface exploration and reservoir management

    Science.gov (United States)

    Kukla, P.

    2009-04-01

    The presence of overpressures in the subsurface poses major problems for safety and cost efficient well design, but less well known is their importance for exploration and reservoir development. Overpressures reduce the vertical effective stress (VES, the difference between the vertical stress and fluid pressure) experienced by the sediment. As sediment compaction is primarily an irreversible function of VES, a reduction in VES will halt compaction. Similarly, a reduction in its rate of increase will reduce the rate of porosity loss. Porosity and other key rock properties will therefore reflect changes in vertical effective stress. Any measurement that senses porosity, or seismic velocity (e.g. sonic, density or resistivity logs) will provide a means of estimating overpressures. The reduction of porosity with vertical effective stress is exponential in nature. Consequently, overpressures generated early in the burial history, such as those generated by disequilibrium compaction, will have a greater impact on rock properties than those generated or emplaced during late burial. Indeed, late overpressuring, so-called inflation, may have little or no impact on rock properties and therefore methods for the prediction of overpressures from properties such as seismic velocity will not provide reliable pressure estimates. In order for fluid pressures to rise in a basin, the pressures have to be contained by rocks with sufficiently low permeability. Overpressures are transient and gradually leak away when the generation mechanism ceases to operate. In some areas, such as in parts of the central North Sea and the Middle East, fluid pressures have built up until the failure envelope of the seal is reached, leading to a subsequent loss of the sealing capacity. The failure envelope is usually considered to be determined by the minimum horizontal stress. The failure pressure for the seal systematically increases with depth and this variation will control the maximum pressures

  7. Blast tests of expedient shelters in the DICE THROW event

    International Nuclear Information System (INIS)

    Kearny, C.H.; Chester, C.V.

    1978-03-01

    To determine the worst blast environments that eight types of expedient shelters can withstand, we subjected a total of 18 shelters to the 1-kiloton blast effects of Defense Nuclear Agency's DICE THROW main event. These expedient shelters included two Russian and two Chinese types. The best shelter tested was a Small-Pole Shelter that had a box-like room of Russian design with ORNL-designed expedient blast entries and blast doors added. It was undamaged at the 53-psi peak overpressure range; the pressure rise inside was only 1.5 psi. An unmodified Russian Pole-Covered Trench Shelter was badly damaged at 6.8 psi. A Chinese ''Man'' Shelter, which skillfully uses very small poles to attain protective earth arching, survived 20 psi, undamaged. Two types of expedient shelters built of materials found in and around most American homes gave good protection at overpressures up to about 6 psi. Rug-Covered Trench Shelters were proved unsatisfactory. Water storage pits lined with ordinary plastic trash bags were proven practical at up to 53 psi, as were triangular expedient blast doors made of poles

  8. Molecular mechanisms of increased cerebral vulnerability after repeated mild blast-induced traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Alaa Kamnaksh

    2014-06-01

    Full Text Available The consequences of a mild traumatic brain injury can be especially severe if it is repeated within the period of increased cerebral vulnerability (ICV that follows the initial insult. To better understand the molecular mechanisms that contribute to ICV, we exposed rats to different levels of mild blast overpressure (5 exposures; total pressure range: 15.54–19.41 psi or 107.14–133.83 kPa at a rate of 1 per 30 min, monitored select physiological parameters, and assessed behavior. Two days post-injury or sham, we determined changes in protein biomarkers related to various pathologies in behaviorally relevant brain regions and in plasma. We found that oxygen saturation and heart rate were transiently depressed following mild blast exposure and that injured rats exhibited significantly increased anxiety- and depression-related behaviors. Proteomic analyses of the selected brain regions showed evidence of substantial oxidative stress and vascular changes, altered cell adhesion, and inflammation predominantly in the prefrontal cortex. Importantly, these pathological changes as well as indications of neuronal and glial cell loss/damage were also detected in the plasma of injured rats. Our findings illustrate some of the complex molecular changes that contribute to the period of ICV in repeated mild blast-induced traumatic brain injury. Further studies are needed to determine the functional and temporal relationship between the various pathomechanisms. The validation of these and other markers can help to diagnose individuals with ICV using a minimally invasive procedure and to develop evidence-based treatments for chronic neuropsychiatric conditions.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2012-05-16

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

  11. Explosion overpressure test series: General-Purpose Heat Source development: Safety Verification Test program

    International Nuclear Information System (INIS)

    Cull, T.A.; George, T.G.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular, radioisotope heat source that will be used in radioisotope thermoelectric generators (RTGs) to supply electric power for space missions. The first two uses will be the NASA Galileo and the ESA Ulysses missions. The RTG for these missions will contain 18 GPHS modules, each of which contains four 238 PuO 2 -fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) was conducted to assess the ability of the GPHS modules to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System vehicle (space shuttle) is a conceivable accident, the SVT plan included a series of tests that simulated the overpressure exposure the RTG and GPHS modules could experience in such an event. Results of these tests, in which we used depleted UO 2 as a fuel simulant, suggest that exposure to overpressures as high as 15.2 MPa (2200 psi), without subsequent impact, does not result in a release of fuel

  12. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs

    2014-04-01

    Full Text Available Traumatic brain injury (TBI due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.

  13. Blast Waves

    CERN Document Server

    Needham, Charles E

    2010-01-01

    The primary purpose of this text is to document many of the lessons that have been learned during the author’s more than forty years in the field of blast and shock. The writing therefore takes on an historical perspective, in some sense, because it follows the author’s experience. The book deals with blast waves propagating in fluids or materials that can be treated as fluids. It begins by distinguishing between blast waves and the more general category of shock waves. It then examines several ways of generating blast waves, considering the propagation of blast waves in one, two and three dimensions as well as through the real atmosphere. One section treats the propagation of shocks in layered gases in a more detailed manner. The book also details the interaction of shock waves with structures in particular reflections, progressing from simple to complex geometries, including planar structures, two-dimensional structures such as ramps or wedges, reflections from heights of burst, and three-dimensional st...

  14. Numerical simulation of armored vehicles subjected to undercarriage landmine blasts

    Science.gov (United States)

    Erdik, A.; Kilic, S. A.; Kilic, N.; Bedir, S.

    2016-07-01

    Landmine threats play a crucial role in the design of armored personnel carriers. Therefore, a reliable blast simulation methodology is valuable to the vehicle design development process. The first part of this study presents a parametric approach for the quantification of the important factors such as the incident overpressure, the reflected overpressure, the incident impulse, and the reflected impulse for the blast simulations that employ the Arbitrary Lagrangian-Eulerian formulation. The effects of mesh resolution, mesh topology, and fluid-structure interaction (FSI) parameters are discussed. The simulation results are compared with the calculations of the more established CONventional WEaPons (CONWEP) approach based on the available experimental data. The initial findings show that the spherical topology provides advantages over the Cartesian mesh domains. Furthermore, the FSI parameters play an important role when coarse Lagrangian finite elements are coupled with fine Eulerian elements at the interface. The optimum mesh topology and the mesh resolution of the parametric study are then used in the landmine blast simulation. The second part of the study presents the experimental blast response of an armored vehicle subjected to a landmine explosion under the front left wheel in accordance with the NATO AEP-55 Standard. The results of the simulations show good agreement with the experimental measurements.

  15. Reopening of an uranium mine in India after successful pacification of public discontent through cautious blasting

    International Nuclear Information System (INIS)

    Roy, Pijush Pal; Sawmliana, Chhangte; Singh, Rakesh Kumar

    2014-01-01

    Blasting operations at Banduhurang opencast mine of Uranium Corporation of India Limited (UCIL) were stopped for about seven months since February 2011 due to the complaints lodged by the inhabitants of nearby Dhodanga village to the district administration. The complaints were related to the disturbance caused to them as a result of blast- induced ground vibration, noise/air overpressure and flying fragments. On recommendation of the district administration, the Blasting Department of the CSIR-Central Institute of Mining and Fuel Research (CSIR-CIMFR), Dhanbad carried out a thorough scientific study and assessed the impacts of blasting on various residential structures as well as on their inhabitants. The study proved that the impacts of blasting were well within safe limit. It helped pacifying public discontent and ultimately reopening the mine. (author)

  16. Transcriptional Changes in the Mouse Retina after Ocular Blast Injury: A Role for the Immune System.

    Science.gov (United States)

    Struebing, Felix L; King, Rebecca; Li, Ying; Chrenek, Micah A; Lyuboslavsky, Polina N; Sidhu, Curran S; Iuvone, P Michael; Geisert, Eldon E

    2018-01-01

    Ocular blast injury is a major medical concern for soldiers and explosion victims due to poor visual outcomes. To define the changes in gene expression following a blast injury to the eye, we examined retinal ribonucleic acid (RNA) expression in 54 mouse strains 5 days after a single 50-psi overpressure air wave blast injury. We observe that almost 40% of genes are differentially expressed with a false discovery rate (FDR) of immune system are activated. Accompanied by lymphocyte invasion into the inner retina, blast injury also results in progressive loss of visual function and retinal ganglion cells (RGCs). Collectively, these data demonstrate how systems genetics can be used to put meaning to the transcriptome changes following ocular blast injury that eventually lead to blindness.

  17. Space Launch System Scale Model Acoustic Test Ignition Overpressure Testing

    Science.gov (United States)

    Nance, Donald; Liever, Peter; Nielsen, Tanner

    2015-01-01

    The overpressure phenomenon is a transient fluid dynamic event occurring during rocket propulsion system ignition. This phenomenon results from fluid compression of the accelerating plume gas, subsequent rarefaction, and subsequent propagation from the exhaust trench and duct holes. The high-amplitude unsteady fluid-dynamic perturbations can adversely affect the vehicle and surrounding structure. Commonly known as ignition overpressure (IOP), this is an important design-to environment for the Space Launch System (SLS) that NASA is currently developing. Subscale testing is useful in validating and verifying the IOP environment. This was one of the objectives of the Scale Model Acoustic Test, conducted at Marshall Space Flight Center. The test data quantifies the effectiveness of the SLS IOP suppression system and improves the analytical models used to predict the SLS IOP environments. The reduction and analysis of the data gathered during the SMAT IOP test series requires identification and characterization of multiple dynamic events and scaling of the event waveforms to provide the most accurate comparisons to determine the effectiveness of the IOP suppression systems. The identification and characterization of the overpressure events, the waveform scaling, the computation of the IOP suppression system knockdown factors, and preliminary comparisons to the analytical models are discussed.

  18. Kevlar Vest Protection against Blast Overpressure Brain Injury: Systemic Contributions to Injury Etiology

    Science.gov (United States)

    2015-07-01

    were averaged as the score for that rat on that day. Longer traverse times and falls from the pole indicate motor deficits. These non-parametric data...were averaged as the score for that rat on that day. Longer traverse times and falls from the pole indicate motor deficits. For Morris water maze...average of 50 mg/kg for daily treatments (e.g., Wells et al., 2003; Stirling et al., 2004; Festoff et al., 2006; Li and McCullough, 2009; Abdel Baki et

  19. Neurocognitive and Biomarker Evaluation of Combination mTBI from Blast Overpressure and Traumatic Stress

    Science.gov (United States)

    2014-11-01

    G3V881_RAT G3V881 Leucine rich repeat neuronal 6A, isoform CRA_a (Protein Lingo1) 0.70 1.30 Dipeptidyl peptidase 3 (EC 3.4.14.4) (Dipeptidyl...aminopeptidase Ill) (Dipeptidyl arylamidase Ill) (Dipeptidyl peptidase Ill) (DPP Ill) DPP3_RAT 055096 (Enkephalinase B) 0.72 1.47 F1LN92_RAT F1LN92 Protein

  20. Effectiveness of eye armor during blast loading.

    Science.gov (United States)

    Bailoor, Shantanu; Bhardwaj, Rajneesh; Nguyen, Thao D

    2015-11-01

    Ocular trauma is one of the most common types of combat injuries resulting from the interaction of military personnel with improvised explosive devices. Ocular blast injury mechanisms are complex, and trauma may occur through various injury mechanisms. However, primary blast injuries (PBI) are an important cause of ocular trauma that may go unnoticed and result in significant damage to internal ocular tissues and visual impairment. Further, the effectiveness of commonly employed eye armor, designed for ballistic and laser protection, in lessening the severity of adverse blast overpressures (BOP) is unknown. In this paper, we employed a three-dimensional (3D) fluid-structure interaction computational model for assessing effectiveness of the eye armor during blast loading on human eyes and validated results against free field blast measurements by Bentz and Grimm (2013). Numerical simulations show that the blast waves focused on the ocular region because of reflections from surrounding facial features and resulted in considerable increase in BOP. We evaluated the effectiveness of spectacles and goggles in mitigating the pressure loading using the computational model. Our results corroborate experimental measurements showing that the goggles were more effective than spectacles in mitigating BOP loading on the eye. Numerical results confirmed that the goggles significantly reduced blast wave penetration in the space between the armor and the eyes and provided larger clearance space for blast wave expansion after penetration than the spectacles. The spectacles as well as the goggles were more effective in reducing reflected BOP at higher charge mass because of the larger decrease in dynamic pressures after the impact. The goggles provided greater benefit of reducing the peak pressure than the spectacles for lower charge mass. However, the goggles resulted in moderate, sustained elevated pressure loading on the eye, that became 50-100% larger than the pressure loading

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

    International Nuclear Information System (INIS)

    1997-01-01

    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

  2. Ultrafast eclogite formation via melting-induced overpressure

    Science.gov (United States)

    Chu, Xu; Ague, Jay J.; Podladchikov, Yury Y.; Tian, Meng

    2017-12-01

    The conventional wisdom holds that metamorphic reactions take place at pressures near-lithostatic so that the thermodynamic pressure, reflected by the mineral assemblage, is directly correlated with depth. On the other hand, recent field-based observations and geodynamic simulations suggest that heterogeneous stress and significant pressure deviations above lithostatic (overpressure) can occur in Earth's crust. Here we show that eclogite, normally interpreted to form at great depths in subduction zones and Earth's mantle, may form at much shallower depths via local overpressure generated in crustal shear zones. The eclogites studied crop out as lenses hosted by felsic paragneiss in a sheared thrust slice and represent a local pressure and temperature anomaly in the Taconic orogenic belt, southern New England. Sharply-defined chemical zones in garnet, which record ∼5 kbar pressure rise and fall accompanied by a temperature increase of 150-200 °C, demonstrate extremely short timescales of diffusion. This requires anomalously fast compression (∼500 yrs) and decompression. We use coupled phase equilibria and garnet diffusion forward modeling to fit the observed garnet profiles and test the likely P- T- t paths using a Monte Carlo-type approach, accounting for off-center sectioning of garnet. The simulation shows that a ∼5 kbar pressure increase after the temperature peak is necessary to reproduce the garnet zoning. Remarkably, this post-peak-T compression (from 9 kbar to 14 kbar) lasted only ∼500 yrs. If the compression was due to burial along a lithostatic pressure gradient, the descent speed would exceed 30 m yr-1, defying any observed or modeled subduction rates. Local overpressure in response to partial melting in a confined volume (Vrijmoed et al., 2009) caused by transient shear heating can explain the ultra-fast compression without necessitating burial to great depth.

  3. Blast Shock Wave Mitigation Using the Hydraulic Energy Redirection and Release Technology

    Science.gov (United States)

    Chen, Yun; Huang, Wei; Constantini, Shlomi

    2012-01-01

    A hydraulic energy redirection and release technology has been developed for mitigating the effects of blast shock waves on protected objects. The technology employs a liquid-filled plastic tubing as a blast overpressure transformer to transfer kinetic energy of blast shock waves into hydraulic energy in the plastic tubings. The hydraulic energy is redirected through the plastic tubings to the openings at the lower ends, and then is quickly released with the liquid flowing out through the openings. The samples of the specifically designed body armor in which the liquid-filled plastic tubings were installed vertically as the outer layer of the body armor were tested. The blast test results demonstrated that blast overpressure behind the body armor samples was remarkably reduced by 97% in 0.2 msec after the liquid flowed out of its appropriate volume through the openings. The results also suggested that a volumetric liquid surge might be created when kinetic energy of blast shock wave was transferred into hydraulic energy to cause a rapid physical movement or displacement of the liquid. The volumetric liquid surge has a strong destructive power, and can cause a noncontact, remote injury in humans (such as blast-induced traumatic brain injury and post-traumatic stress disorder) if it is created in cardiovascular system. The hydraulic energy redirection and release technology can successfully mitigate blast shock waves from the outer surface of the body armor. It should be further explored as an innovative approach to effectively protect against blast threats to civilian and military personnel. PMID:22745740

  4. Blast shock wave mitigation using the hydraulic energy redirection and release technology.

    Directory of Open Access Journals (Sweden)

    Yun Chen

    Full Text Available A hydraulic energy redirection and release technology has been developed for mitigating the effects of blast shock waves on protected objects. The technology employs a liquid-filled plastic tubing as a blast overpressure transformer to transfer kinetic energy of blast shock waves into hydraulic energy in the plastic tubings. The hydraulic energy is redirected through the plastic tubings to the openings at the lower ends, and then is quickly released with the liquid flowing out through the openings. The samples of the specifically designed body armor in which the liquid-filled plastic tubings were installed vertically as the outer layer of the body armor were tested. The blast test results demonstrated that blast overpressure behind the body armor samples was remarkably reduced by 97% in 0.2 msec after the liquid flowed out of its appropriate volume through the openings. The results also suggested that a volumetric liquid surge might be created when kinetic energy of blast shock wave was transferred into hydraulic energy to cause a rapid physical movement or displacement of the liquid. The volumetric liquid surge has a strong destructive power, and can cause a noncontact, remote injury in humans (such as blast-induced traumatic brain injury and post-traumatic stress disorder if it is created in cardiovascular system. The hydraulic energy redirection and release technology can successfully mitigate blast shock waves from the outer surface of the body armor. It should be further explored as an innovative approach to effectively protect against blast threats to civilian and military personnel.

  5. Blast shock wave mitigation using the hydraulic energy redirection and release technology.

    Science.gov (United States)

    Chen, Yun; Huang, Wei; Constantini, Shlomi

    2012-01-01

    A hydraulic energy redirection and release technology has been developed for mitigating the effects of blast shock waves on protected objects. The technology employs a liquid-filled plastic tubing as a blast overpressure transformer to transfer kinetic energy of blast shock waves into hydraulic energy in the plastic tubings. The hydraulic energy is redirected through the plastic tubings to the openings at the lower ends, and then is quickly released with the liquid flowing out through the openings. The samples of the specifically designed body armor in which the liquid-filled plastic tubings were installed vertically as the outer layer of the body armor were tested. The blast test results demonstrated that blast overpressure behind the body armor samples was remarkably reduced by 97% in 0.2 msec after the liquid flowed out of its appropriate volume through the openings. The results also suggested that a volumetric liquid surge might be created when kinetic energy of blast shock wave was transferred into hydraulic energy to cause a rapid physical movement or displacement of the liquid. The volumetric liquid surge has a strong destructive power, and can cause a noncontact, remote injury in humans (such as blast-induced traumatic brain injury and post-traumatic stress disorder) if it is created in cardiovascular system. The hydraulic energy redirection and release technology can successfully mitigate blast shock waves from the outer surface of the body armor. It should be further explored as an innovative approach to effectively protect against blast threats to civilian and military personnel.

  6. Prevention of overpressurization of lithium-thionyl chloride battery cells

    Energy Technology Data Exchange (ETDEWEB)

    Ramsay, G. R.; Salmon, D. J.

    1984-12-25

    A method of preventing overpressurization of a lithium-thionyl chloride battery cell by formation of excessive SO/sub 2/ during high rate discharge. The method comprises the step of providing PCl/sub 5/ in the cathode. Alternatively, the PCl/sub 5/ may be provided in the electrolyte or in both the cathode and electrolyte as desired. The PCl/sub 5/ may be incorporated in the cathode by introduction thereof into the porous carbon structure of a preformed carbon element. Alternatively, the PCl/sub 5/ may be dry mixed with the carbon and the mixture formed into the desired cathode element.

  7. An Introductory Characterization of a Combat-Casualty-Care Relevant Swine Model of Closed Head Injury Resulting from Exposure to Explosive Blast

    Science.gov (United States)

    2009-07-08

    more recently in Operation Enduring Freedom(OEF). The polytraumatic nature of blast injuries is evidence of their effectiveness, and brain injury...The polytraumatic nature of blast injuries is evidence of their effectiveness, and brain injury is a frequent and debilitating form of this trauma...injury in OIF (Hoge et al., eration Iraqi Freedom (OIF). Soon after the invasion of Iraq in 2008), and they were multifocal and polytraumatic . The

  8. The Development of a Cryogenic Over-Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Matthew L. [Illinois Inst. of Technology, Chicago, IL (United States)

    2012-01-01

    The Dark Energy Survey (DES) project will study the accelerated expansion of the universe. In order to further study this phenomenon, scientists have devised a method of creating an array of charged couple devices (CCD) to capture images that will be studied. These CCDs must be cooled and remain at 173K to eliminate thermal gradients and dark current. Therefore, a two-phase CCD liquid nitrogen (LN2) cooling system was designed to maintain the array of CCDs at a constant temperature. However, the centrifugal pump used to supply LN2 has a mean time between failure (MTBF) of approximately two thousand-eight hundred hours (116 days). Because of the low MTBF of the centrifugal pump, a new pump is being considered to replace the existing one. This positive displacement pump is a simpler design that is expected to have a MTBF that will exceed 116 days (2800hrs). This positive displacement reciprocating pump, also known as, the cryogenic over-pressure pump (OPP), was tested in February 2012 and successfully cooled the CCD array to 173K. Though unfit for service for DES CCD cooling system, the overall concept of this pump has been proven. Typical ow rates, pressures, and temperatures trends have been captured via instrumentation and are specific to the operation of future over-pressure pumps.

  9. A Numerical Method for Blast Shock Wave Analysis of Missile Launch from Aircraft

    Directory of Open Access Journals (Sweden)

    Sebastian Heimbs

    2015-01-01

    Full Text Available An efficient empirical approach was developed to accurately represent the blast shock wave loading resulting from the launch of a missile from a military aircraft to be used in numerical analyses. Based on experimental test series of missile launches in laboratory environment and from a helicopter, equations were derived to predict the time- and position-dependent overpressure. The method was finally applied and validated in a structural analysis of a helicopter tail boom under missile launch shock wave loading.

  10. Central Mechanisms and Treatment of Blast-Induced Auditory and Vestibular Injuries

    Science.gov (United States)

    2018-01-01

    pressure of 17 - 19 psi and 4 msec positive phase duration) was generated by Valmex membrane rupture in the advanced blast simulator (ABS), which...injection of AAV-L7-GFP or Lent-L7-GFP into the cerebellum of mouse. 15 6. Products: Lay Press- none None Peer -Reviewed Scientific Journals -none...overpressure (peak static pressure of 16 psi and 4 msec positive phase duration). The effect of shockwaves on hearing was determined by testing auditory

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

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brown, C. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); May, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Compton, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Walton, O. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shingleton, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, J. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Holtmeier, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loey, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mirkarimi, P. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunlop, W. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Guyton, R. L. [National Security Technologies, Livermore, CA (United States); Huffman, E. [National Security Technologies, Livermore, CA (United States)

    2014-09-01

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

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

    Science.gov (United States)

    Aguilar, Juan R.; Desai, Sachi V.

    2011-11-01

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

  13. 46 CFR 39.20-11 - Vapor overpressure and vacuum protection-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Vapor overpressure and vacuum protection-TB/ALL. 39.20-11 Section 39.20-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS Design and Equipment § 39.20-11 Vapor overpressure and vacuum protection—TB/ALL. (a) The cargo...

  14. Experimental study of near-field entrainment of moderately overpressured jets

    Science.gov (United States)

    Solovitz, S.A.; Mastin, L.G.; Saffaraval, F.

    2011-01-01

    Particle image velocimetry (PIV) experiments have been conducted to study the velocity flow fields in the developing flow region of high-speed jets. These velocity distributions were examined to determine the entrained mass flow over a range of geometric and flow conditions, including overpressured cases up to an overpressure ratio of 2.83. In the region near the jet exit, all measured flows exhibited the same entrainment up until the location of the first shock when overpressured. Beyond this location, the entrainment was reduced with increasing overpressure ratio, falling to approximately 60 of the magnitudes seen when subsonic. Since entrainment ratios based on lower speed, subsonic results are typically used in one-dimensional volcanological models of plume development, the current analytical methods will underestimate the likelihood of column collapse. In addition, the concept of the entrainment ratio normalization is examined in detail, as several key assumptions in this methodology do not apply when overpressured.

  15. Description of Muzzle Blast by Modified Ideal Scaling Models

    Directory of Open Access Journals (Sweden)

    Kevin S. Fansler

    1998-01-01

    Full Text Available Gun blast data from a large variety of weapons are scaled and presented for both the instantaneous energy release and the constant energy deposition rate models. For both ideal explosion models, similar amounts of data scatter occur for the peak overpressure but the instantaneous energy release model correlated the impulse data significantly better, particularly for the region in front of the gun. Two parameters that characterize gun blast are used in conjunction with the ideal scaling models to improve the data correlation. The gun-emptying parameter works particularly well with the instantaneous energy release model to improve data correlation. In particular, the impulse, especially in the forward direction of the gun, is correlated significantly better using the instantaneous energy release model coupled with the use of the gun-emptying parameter. The use of the Mach disc location parameter improves the correlation only marginally. A predictive model is obtained from the modified instantaneous energy release correlation.

  16. Interspecies Scaling in Blast Neurotrauma

    Science.gov (United States)

    2015-08-27

    Armour Systems Symposium 2014 in Cambridge, England. 6.1 Introduction The increased risk of exposure to blast in both military and civilian settings...Physiological Processes in Homeothermic Animals." Annual Review of Physiology 43, 1: 301-22. Capehart, B and Bass, D. 2012. "Review: managing ...CI, Calvente, RR, Lillo, VM and Canas, JM. 2007. " Management and analysis of out-of-hospital health-related responses to simultaneous railway

  17. Prediction of globe rupture caused by primary blast: a finite element analysis.

    Science.gov (United States)

    Liu, Xiaoyu; Wang, Lizhen; Wang, Chao; Fan, Jie; Liu, Songyang; Fan, Yubo

    2015-07-01

    Although a human eye comprises less than 0.1% of the frontal body surface area, injuries to the eye are found to be disproportionally common in survivors of explosions. This study aimed to introduce a Lagrangian-Eulerian coupling model to predict globe rupture resulting from primary blast effect. A finite element model of a human eye was created using Lagrangian mesh. An explosive and its surrounding air domain were modelled using Eulerian mesh. Coupling the two models allowed simulating the blast wave generation, propagation and interaction with the eye. The results showed that the peak overpressures caused by blast wave on the corneal apex are 2080, 932.1 and 487.3 kPa for the victim distances of 0.75, 1.0 and 1.25 m, respectively. Higher stress occurred at the limbus, where the peaks for the three victim distances are 25.5, 14.1 and 6.4 MPa. The overpressure threshold of globe rupture was determined as 2000 kPa in a small-scale explosion. The findings would provide insights into the mechanism of primary blast-induced ocular injuries.

  18. Modeling of aqueous foam blast wave attenuation

    Directory of Open Access Journals (Sweden)

    Domergue L.

    2011-01-01

    Full Text Available The use of aqueous foams enables the mitigation of blast waves induced by the explosion of energetic materials. The two-phase confinement gives rise to interphase interactions between the gaseous and liquid phases, which role have been emphasized in shock-tube studies with solid foams [1, 2]. Multifluid formalism enables the thermo-mechanical disequilibria between phases to be taken into account. The flow model ensures the correct estimation of the acoustic impedance of the two-phase media. As for the numerical scheme, Riemann solvers are used to describe the microscopic fluid interactions, the summation of which provides the multiphase flux. The role of the different transfer mechanisms is evaluated in the case where the liquid ligaments of the foam matrix have been shattered into droplets by the shock impingement. Characteristics of blast waves in heterogeneous media leads to a decrease of overpressure. The numerical results have been compared favorably to experimental data [3, 4].

  19. Measurements of near-field blast effects using kinetic plates

    Science.gov (United States)

    Manner, V. W.; Pemberton, S. J.; Brown, G. W.; Tappan, B. C.; Hill, L. G.; Preston, D. N.; Neuscamman, S. J.; Glascoe, L. G.

    2014-05-01

    Few tests have been designed to measure the near-field blast impulse of ideal and non-ideal explosives, mostly because of the inherent experimental difficulties due to non-transparent fireballs and thermal effects on gauges. In order to measure blast impulse in the near-field, a new test has been developed by firing spherical charges at 152 mm (6 in) from steel plates and probing acceleration using laser velocimetry. Tests measure the velocity imparted to the steel plate in the 50 - 300 μs timeframe, and are compared with free-field overpressure measurements at 1.52 m (5 ft) and ms timescales using piezoelectric pencil gauges. Specifically, tests have been performed with C4 to probe the contributions of ideal explosives and charge size effects. Non-ideal aluminized explosive formulations have been studied to explore the role of aluminum in near-field blast effects and far-field pressure, and are compared with formulations using LiF as an inert surrogate replacement for Al. The results are compared with other near-field blast tests and cylinder tests, and the validity of this test is explored with modeling and basic theory.

  20. Detecting overpressure using the Eaton and Equivalent Depth methods in Offshore Nova Scotia, Canada

    Science.gov (United States)

    Ernanda; Primasty, A. Q. T.; Akbar, K. A.

    2018-03-01

    Overpressure is an abnormal high subsurface pressure of any fluids which exceeds the hydrostatic pressure of column of water or formation brine. In Offshore Nova Scotia Canada, the values and depth of overpressure zone are determined using the eaton and equivalent depth method, based on well data and the normal compaction trend analysis. Since equivalent depth method is using effective vertical stress principle and Eaton method considers physical property ratio (velocity). In this research, pressure evaluation only applicable on Penobscot L-30 well. An abnormal pressure is detected at depth 11804 feet as possibly overpressure zone, based on pressure gradient curve and calculation between the Eaton method (7241.3 psi) and Equivalent Depth method (6619.4 psi). Shales within Abenaki formation especially Baccaro Member is estimated as possible overpressure zone due to hydrocarbon generation mechanism.

  1. The importance of systemic response in the pathobiology of blast-induced neurotrauma

    Directory of Open Access Journals (Sweden)

    Ibolja eCernak

    2010-12-01

    Full Text Available Due to complex injurious environment where multiple blast effects interact with the body, parallel blast-induced neurotrauma is a unique clinical entity induced by systemic, local, and cerebral responses. Activation of autonomous nervous system; sudden pressure-increase in vital organs such as lungs and liver; and activation of neuroendocrine-immune system are among the most important mechanisms that contribute significantly to molecular changes and cascading injury mechanisms in the brain. It has been hypothesized that vagally mediated cerebral effects play a vital role in the early response to blast: this assumption has been supported by experiments where bilateral vagotomy mitigated bradycardia, hypotension, and apnea, and also prevented excessive metabolic alterations in the brain of animals exposed to blast. Clinical experience suggests specific blast-body-nervous system interactions such as 1 direct interaction with the head either through direct passage of the blast wave through the skull or by causing acceleration and/or rotation of the head; and 2 via hydraulic interaction, when the blast overpressure compresses the abdomen and chest, and transfers its kinetic energy to the body’s fluid phase, initiating oscillating waves that traverse the body and reach the brain. Accumulating evidence suggests that inflammation plays important role in the pathogenesis of long-term neurological deficits due to blast. These include memory decline, motor function and balance impairments, and behavioral alterations, among others. Experiments using rigid body- or head protection in animals subjected to blast showed that head protection failed to prevent inflammation in the brain or reduce neurological deficits, whereas body protection was successful in alleviating the blast-induced functional and morphological impairments in the brain.

  2. Evaluation of Beryllium, Total Chromium and Nickel in the Surface Contaminant Layer Available for Dermal Exposure After Abrasive Blasting in a Shipyard

    Science.gov (United States)

    2013-04-24

    estimate the rate of allergy in the population at 10% or higher (44), while others suggest a rate of2.5% to 5% (24). Nickel itch or nickel allergy is a...area of the surface. As described in Chapter 2 nickel allergy may be the most common allergy in the general population ( 44). With the potential...presence of nickel in the non-exposed areas personnel with allergies to nickel should be properly protected. PUBLIC HEAL TH SIGNIFICANCE Blasting

  3. Rapid Sedimentation, Overpressure, and Focused Fluid Flow, Gulf of Mexico Continental Margin

    Directory of Open Access Journals (Sweden)

    Cédric M. John

    2006-09-01

    Full Text Available Expedition 308 of the Integrated Ocean Drilling Program (IODP was the fi rst phase of a two-component project dedicated to studying overpressure and fl uid fl ow on the continental slope of the Gulf of Mexico. We examined how sedimentation, overpressure, fl uid fl ow, and deformation are coupled in a passive margin setting and investigated how extremely rapid deposition of fi ne-grained mud might lead to a rapid build-up of pore pressure in excess of hydrostatic (overpressure, underconsolidation, and sedimentary masswasting. Our tests within the Ursa region, where sediment accumulated rapidly in the late Pleistocene, included the first-ever in situ measurements of how physical properties, pressure, temperature,and pore fluid compositions vary within low-permeability mudstones that overlie a permeable, overpressured aquifer, and we documented severe overpressure in the mudstones overlying the aquifer. We also drilled and logged three references sites in the Brazos-Trinity Basin IV and documented hydrostatic pressure conditions and normalconsolidation. Post-expedition studies will address how the generation and timing of overpressure control slope stability, seafl oor seeps, and large-scale crustal fluid fl ow. The operations ofExpedition 308 provide a foundation for future long-term in situ monitoring experiments in the aquifer and bounding mudstones.

  4. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    International Nuclear Information System (INIS)

    McPhee, William S.

    2001-01-01

    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

  5. Air Blasts from Cased and Uncased Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, L. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-12

    The problem of a spherical blast in air is solved using the STUN code. For bare charges, the calculations are shown to be in excellent agreement with previous published results. It is demonstrated that, for an unconfined (uncased) chemical explosive, both range and time to effect scale inversely as the cube root of the yield and directly as the cube root of the ambient air density. It is shown that the peak overpressure decays to roughly 1/10 of ambient pressure in a scaled range of roughly 10 m/kg1/3 at sea level. At a height of 30 km, where the ambient density is a factor of 64 less, the range to the same decay increases to 40 m/kg1/3 . As a direct result of the scaling a single calculation suffices for all charge sizes and altitudes. Although the close-in results are sensitive to the nature of the explosive source and the equation of state of the air, this sensitivity is shown to virtually disappear at scaled ranges > 0.5 m/kg1/3 . For cased explosives the case thickness introduces an additional scale factor. Moreover, when the blast wave arrives at the inner case radius the case begins to expand. Fracture occurs when a critical value of the resulting hoop strain is reached, causing the case to shatter into fragments. A model is proposed to describe the size distribution of the fragments and their subsequent motion via drag interaction with the explosion products and ambient air. It is shown that a significant fraction of the charge energy is initially transmitted to the case fragments in the form of kinetic energy; for example, a 1 kg spherical charge with a 5 mm thick steel case has almost 29% of the total charge energy as initial kinetic energy of case fragments. This percentage increases with increasing case thickness and decreases with increasing charge size. The peak overpressure at a given range is 70-85% for cased explosives as compared with uncased and the peak impulse per unit area is 90-95%. The peak overpressure and

  6. Two-dimensional explosion experiments examining the interaction between a blast wave and a sand hill

    Science.gov (United States)

    Sugiyama, Y.; Izumo, M.; Ando, H.; Matsuo, A.

    2018-02-01

    Two-dimensional explosion experiments were conducted to discuss the interaction between a blast wave and sand and show the mitigation effect of the sand on the blast wave. The explosive used was a detonating cord 1.0 m in length, which was initiated in a sand hill shaped like a triangular prism and whose cross section was an isosceles triangle with base angles of 30°. Sand-hill heights of 30 and 60 mm were used as parameters to discuss the effect of sand mass upon blast-wave strength. The interaction of the blast wave with the sand/air interface causes multiple peaks in the blast wave, which are induced by successive transmissions at the interface. The increase in the sand mass further mitigates the blast parameters of peak overpressure and positive impulse. The results of this experiment can be utilized to validate the numerical method of solving the problem of interaction between a compressible fluid and a particle layer.

  7. LTC vacuum blasting maching (concrete): Baseline report: Greenbook (Chapter)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The LTC shot blast technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjuction 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.

  8. Organic matter cracking: A source of fluid overpressure in subducting sediments

    Science.gov (United States)

    Raimbourg, Hugues; Thiéry, Régis; Vacelet, Maxime; Famin, Vincent; Ramboz, Claire; Boussafir, Mohammed; Disnar, Jean-Robert; Yamaguchi, Asuka

    2017-11-01

    The pressure of deep fluids in subduction zones is a major control on plate boundary strength and earthquake genesis. The record, by methane-rich fluid inclusions, of large ( 50-100 MPa) and instantaneous pressure variations in the Shimanto Belt (Japan) points to the presence of large fluid overpressure at depth (300-500 MPa, 250 °C). To further analyze the connection between methane and fluid overpressure, we determined with Rock-Eval the potential for a worldwide selection of deep seafloor sediments to produce methane as a result of organic matter (OM) cracking due to temperature increase during subduction. The principal factor controlling the methanogenesis potential of sediments is OM proportion, while OM nature is only a subordinate factor. In turn, OM proportion is mainly controlled by the organic terrigenous input. Considering a typical sediment from ocean-continent subduction zones, containing 0.5 wt% of type III OM, cracking of OM has two major consequences: (1) Methane is produced in sufficient concentration as to oversaturate the pore-filling water. The deep fluid in accretionary prisms is therefore a mechanical mixture of water-rich and methane-rich phases; (2) CH4 production can generate large fluid overpressure, of the order of several tens of MPa, The conditions for these large overpressure are a low permeability of the upper plate (z > 10 km) where OM thermal cracking occurs. At these depths, OM thermal cracking appears as a source of overpressure larger than the last increments of smectite-to-illite reaction. Such large overpressures play potentially a role in facilitating slip along the plate interface. Conversely, the scarcity of earthquakes in ocean-ocean subduction zones such as Marianna or Barbados may be related to the low influx of detrital OM and the limited methane/overpressure generation at depth.

  9. A Quantitative Comparison of some Mechanisms Generating Overpressure in Sedimentary Basins

    Energy Technology Data Exchange (ETDEWEB)

    Wangen, Magnus

    2001-05-01

    Expulsion of fluids in low permeable rock generate overpressure. Several mechanisms are suggested for fluid expulsion and overpressure build-up, and some of them have here been studied and compared. These are mechanical compaction, aquathermal pressuring, dehydration of clays, hydrocarbon generation and cementation of the pore space. A single pressure equation for these fluid expulsion processes has been studied. In particular, the source term in this pressure equation is studied carefully, because the source term consists of separate terms representing each mechanism for pressure build-up. The amount of fluid expelled from each mechanism is obtained from these individual contributions to the source term. It is shown that the rate of change of porosity can be expressed in at least two different ways for dehydration reactions and oil generation. One way in which the reduction in the solid volume enhances the porosity, and another where the porosity remains constant. A gravity number is defined by the permeability and the Darcy flux of the expelled fluid. The gravity number is shown to be a useful indicator for overpressure build-up. The gravity number is also used to estimate the thickness a seal needs for overpressure to rise from almost hydrostatic conditions above the seal to almost lithostatic conditions below the seal. Simple expressions for the Darcy fluxes caused by mechanical compaction, dehydration of clays, hydrocarbon generation and cementation of the pore space are derived. It is shown how these expressions can be combined with the gravity number to obtain an upper bound for the permeability for overpressure build-up to take place. Mechanical compaction and cementation of the pore space are shown to be the strongest expulsion mechanisms. Although most mechanisms can generate overpressure alone given a sufficiently low permeability, it is concluded that cementation of pore space is the most likely mechanism for overpressure generation in deeply buried

  10. Displacement and stress fields around rock fractures opened by irregular overpressure variations

    Directory of Open Access Journals (Sweden)

    Shigekazu eKusumoto

    2014-05-01

    Full Text Available Many rock fractures are entirely driven open by fluids such as ground water, geothermal water, gas, oil, and magma. These are a subset of extension fractures (mode I cracks; e.g., dikes, mineral veins and joints referred to as hydrofractures. Field measurements show that many hydrofractures have great variations in aperture. However, most analytical solutions for fracture displacement and stress fields assume the loading to be either constant or with a linear variation. While these solutions have been widely used, it is clear that a fracture hosted by heterogeneous and anisotropic rock is normally subject to loading that is neither constant nor with a linear variation. Here we present new general solutions for the displacement and stress fields around hydrofractures, modelled as two-dimensional elastic cracks, opened by irregular overpressure variations given by the Fourier cosine series. Each solution has two terms. The first term gives the displacement and stress fields due to the average overpressure acting inside the crack; it is given by the initial term of the Fourier coefficients expressing the overpressure variation. The second term gives the displacement and stress fields caused by the overpressure variation; it is given by general terms of the Fourier coefficients and solved through numerical integration. Our numerical examples show that the crack aperture variation closely reflects the overpressure variation. Also, that the general displacement and stress fields close to the crack follow the overpressure variation but tend to be more uniform far from the crack. The present solutions can be used to estimate the displacement and stress fields around any fluid-driven crack, that is, any hydrofracture, as well as its aperture, provided the variation in overpressure can be described by Fourier series. The solutions add to our understanding of local stresses, displacements, and fluid transport associated with hydrofractures in the crust.

  11. Probability analysis of MCO over-pressurization during staging

    International Nuclear Information System (INIS)

    Pajunen, A.L.

    1997-01-01

    The purpose of this calculation is to determine the probability of Multi-Canister Overpacks (MCOs) over-pressurizing during staging at the Canister Storage Building (CSB). Pressurization of an MCO during staging is dependent upon changes to the MCO gas temperature and the build-up of reaction products during the staging period. These effects are predominantly limited by the amount of water that remains in the MCO following cold vacuum drying that is available for reaction during staging conditions. Because of the potential for increased pressure within an MCO, provisions for a filtered pressure relief valve and rupture disk have been incorporated into the MCO design. This calculation provides an estimate of the frequency that an MCO will contain enough water to pressurize beyond the limits of these design features. The results of this calculation will be used in support of further safety analyses and operational planning efforts. Under the bounding steady state CSB condition assumed for this analysis, an MCO must contain less than 1.6 kg (3.7 lbm) of water available for reaction to preclude actuation of the pressure relief valve at 100 psid. To preclude actuation of the MCO rupture disk at 150 psid, an MCO must contain less than 2.5 kg (5.5 lbm) of water available for reaction. These limits are based on the assumption that hydrogen generated by uranium-water reactions is the sole source of gas produced within the MCO and that hydrates in fuel particulate are the primary source of water available for reactions during staging conditions. The results of this analysis conclude that the probability of the hydrate water content of an MCO exceeding 1.6 kg is 0.08 and the probability that it will exceed 2.5 kg is 0.01. This implies that approximately 32 of 400 staged MCOs may experience pressurization to the point where the pressure relief valve actuates. In the event that an MCO pressure relief valve fails to open, the probability is 1 in 100 that the MCO would experience

  12. Rapid sedimentation and overpressure in shallow sediments of the Bering Trough, offshore southern Alaska

    Science.gov (United States)

    Daigle, Hugh; Worthington, Lindsay L.; Gulick, Sean P. S.; Van Avendonk, Harm J. A.

    2017-04-01

    Pore pressures in sediments at convergent margins play an important role in driving chemical fluxes and controlling deformation styles and localization. In the Bering Trough offshore Southern Alaska, extreme sedimentation rates over the last 140 kyr as a result of glacial advance/retreats on the continental shelf have resulted in elevated pore fluid pressures in slope sediments overlying the Pamplona Zone fold and thrust belt, the accretionary wedge resulting from subduction of the Yakutat microplate beneath the North American Plate. Based on laboratory experiments and downhole logs acquired at Integrated Ocean Drilling Program Site U1421, we predict that the overpressure in the slope sediments may be as high as 92% of the lithostatic stress. Results of one-dimensional numerical modeling accounting for changes in sedimentation rate over the last 130 kyr predicted overpressures that are consistent with our estimates, suggesting that the overpressure is a direct result of the rapid sedimentation experienced on the Bering shelf and slope. Comparisons with other convergent margins indicate that such rapid sedimentation and high overpressure are anomalous in sediments overlying accretionary wedges. We hypothesize that the shallow overpressure on the Bering shelf/slope has fundamentally altered the deformation style within the Pamplona Zone by suppressing development of faults and may inhibit seismicity by focusing faulting elsewhere or causing deformation on existing faults to be aseismic. These consequences are probably long-lived as it may take several million years for the excess pressure to dissipate.

  13. Robotic Water Blast Cleaner

    Science.gov (United States)

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

    1983-01-01

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

  14. Numerical modeling and characterization of blast waves for application in blast-induced mild traumatic brain injury research

    Science.gov (United States)

    Phillips, Michael G.

    Human exposure to blast waves, including blast-induced traumatic brain injury, is a developing field in medical research. Experiments with explosives have many disadvantages including safety, cost, and required area for trials. Shock tubes provide an alternative method to produce free field blast wave profiles. A compressed nitrogen shock tube experiment instrumented with static and reflective pressure taps is modeled using a numerical simulation. The geometry of the numerical model is simplified and blast wave characteristics are derived based upon static and pressure profiles. The pressure profiles are analyzed along the shock tube centerline and radially away from the tube axis. The blast wave parameters found from the pressure profiles provide guidelines for spatial location of a specimen. The location could be based on multiple parameters and provides a distribution of anticipated pressure profiles experience by the specimen.

  15. Brain response to primary blast wave using validated finite element models of human head and advanced combat helmet

    Directory of Open Access Journals (Sweden)

    Liying eZhang

    2013-08-01

    Full Text Available Blast-induced traumatic brain injury has emerged as a signature injury in combat casualty care. Present combat helmets are designed primarily to protect against ballistic and blunt impacts, but the current issue with helmets is protection concerning blasts. In order to delineate the blast wave attenuating capability of the Advanced Combat Helmet (ACH, a finite element (FE study was undertaken to evaluate the head response against blast loadings with and without helmet using a partially validated FE model of the human head and ACH. Four levels of overpressures (0.27-0.66 MPa from the Bowen’s lung iso-damage threshold curves were used to simulate blast insults. Effectiveness of the helmet with respect to head orientation was also investigated. The resulting biomechanical responses of the brain to blast threats were compared for human head with and without the helmet. For all Bowen’s cases, the peak intracranial pressures (ICP in the head ranged from 0.68-1.8 MPa in the coup cortical region. ACH was found to mitigate ICP in the head by 10-35%. Helmeted head resulted in 30% lower average peak brain strains and product of strain and strain rate. Among three blast loading directions with ACH, highest reduction in peak ICP (44% was due to backward blasts whereas the lowest reduction in peak ICP and brain strains was due to forward blast (27%. The biomechanical responses of a human head to primary blast insult exhibited directional sensitivity owing to the different geometry contours and coverage of the helmet construction and asymmetric anatomy of the head. Thus, direction-specific tolerances are needed in helmet design in order to offer omni-directional protection for the human head. The blasts of varying peak overpressures and durations that are believed to produce the same level of lung injury produce different levels of mechanical responses in the brain, and hence "iso-damage" curves for brain injury are likely different than the Bowen curves

  16. Reconstruction of improvised explosive device blast loading to personnel in the open

    Science.gov (United States)

    Wiri, Suthee; Needham, Charles

    2016-05-01

    Significant advances in reconstructing attacks by improvised explosive devices (IEDs) and other blast events are reported. A high-fidelity three-dimensional computational fluid dynamics tool, called Second-order Hydrodynamic Automatic Mesh Refinement Code, was used for the analysis. Computer-aided design models for subjects or vehicles in the scene accurately represent geometries of objects in the blast field. A wide range of scenario types and blast exposure levels were reconstructed including free field blast, enclosed space of vehicle cabin, IED attack on a vehicle, buried charges, recoilless rifle operation, rocket-propelled grenade attack and missile attack with single subject or multiple subject exposure to pressure levels from ˜ 27.6 kPa (˜ 4 psi) to greater than 690 kPa (>100 psi). To create a full 3D pressure time-resolved reconstruction of a blast event for injury and blast exposure analysis, a combination of intelligence data and Blast Gauge data can be used to reconstruct an actual in-theatre blast event. The methodology to reconstruct an event and the "lessons learned" from multiple reconstructions in open space are presented. The analysis uses records of blast pressure at discrete points, and the output is a spatial and temporal blast load distribution for all personnel involved.

  17. An analysis of the response of Sooty Tern eggs to sonic boom overpressures.

    Science.gov (United States)

    Ting, Carina; Garrelick, Joel; Bowles, Ann

    2002-01-01

    It has been proposed that sonic booms caused a mass hatching failure of Sooty Terns in the Dry Tortugas in Florida by cracking the eggshells. This paper investigates this possibility analytically, complementing previous empirical studies. The sonic boom is represented as a plane-wave excitation with an N-wave time signature. Two models for the egg are employed. The first model, intended to provide insight, consists of a spherical shell, with the embryo represented as a rigid, concentric sphere and the albumen as an acoustic fluid filling the intervening volume. The substrate is modeled as a doubling of the incident pressure. The second, numerical model includes the egg-shape geometry and air sac. More importantly, the substrate is modeled as a rigid boundary of infinite extent with acoustic diffraction included. The peak shell stress, embryo acceleration, and reactive force are predicted as a function of the peak sonic boom overpressure and compared with damage criteria from the literature. The predicted peak sonic boom overpressure necessary for egg damage is much higher than documented sonic boom overpressures, even for extraordinary operational conditions. Therefore, as with previous empirical studies, it is concluded that it is unlikely that sonic boom overpressures damage avian eggs.

  18. 33 CFR 154.814 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Science.gov (United States)

    2010-07-01

    ... vapor overpressure and vacuum protection. 154.814 Section 154.814 Navigation and Navigable Waters COAST... vacuum protection. (a) A facility's vapor collection system must have the capacity for collecting cargo... vessel's cargo tanks between 80 percent of the highest setting of any of the vessel's vacuum relief...

  19. Overpressure, Flow Focusing, Compaction and Slope Stability on the continental slope: Insights from IODP Expedition 308

    Science.gov (United States)

    Flemings, P. B.

    2010-12-01

    Integrated Ocean Drilling Program Expepedition 308 used direct measurements of pore pressure, analysis of hydromechanical properties, and geological analysis to illuminate how sedimentation, flow focusing, overpressure, and slope stability couple beneath the seafloor on the deepwater continental slope in the Gulf of Mexico. We used pore pressure penetrometers to measure severe overpressures (60% of the difference between lithostatic stress and hydrostatic pressure) that extend from the seafloor for 100’s of meters. We ran uniaxial consolidation experiments on whole core and found that although permeability is relatively high near the seafloor, the sediments are highly compressible. As a result, the coefficient of consolidation (the hydraulic diffusivity) is remarkably constant over a large range of effective stresses. This behavior accounts for the high overpressure that begins near the seafloor and extends to depth. Forward modeling suggests that flow is driven laterally along a permeable unit called the Blue Unit. Calculations suggest that soon after deposition, lateral flow lowered the effective stress and triggered the submarine landslides that we observe. Later in the evolution of this system, overpressure may have pre-conditioned the slope to failure by earthquakes. Results from IODP Expedition 308 illustrate how pore pressure and sedimentation control the large-scale form of continental margins, how submarine landslides form, and provide strategies for designing stable drilling programs.

  20. Experimental animal models for studies on the mechanisms of blast induced neurotrauma

    Directory of Open Access Journals (Sweden)

    Mårten eRisling

    2012-04-01

    Full Text Available A blast injury is a complex type of physical trauma resulting from the detonation of explosive compounds and has become an important issue due to the use of improvised explosive devices (IED in current military conflicts. Blast induced neurotrauma (BINT is a major concern in contemporary military medicine and includes a variety of injuries that range from mild to lethal. BINT is characterized by extreme forces and their complex propagation. Modern body protection and the development of armored military vehicles can be assumed to have changed the outcome of BINT. Primary blast injuries are caused by overpressure waves whereas secondary, tertiary and quaternary blast injuries can have more varied origins such as the impact of fragments, abnormal movements or heat. The characteristics of the blast wave can be assumed to be significantly different in open field detonations compared to explosions in a confined space, such an armored vehicle. Important parameters include peak pressure, duration and shape of the pulse. Reflections from walls and armor can make the prediction of effects in individual cases very complex. Epidemiological data do not contain information of the relative importance of the different blast mechanisms. It is therefore important to generate data in carefully designed animal models. Such models can be selective reproductions of a primary blast, penetrating injuries from fragments, acceleration movements or combinations of such mechanisms. It is of crucial importance that the physical parameters of the employed models are well characterized so that the experiments can be reproduced in different laboratory settings. Ideally, pressure recordings should be calibrated by using the same equipment in several laboratories. With carefully designed models and thoroughly evaluated animal data it should be possible to achieve a translation of data between animal and clinical data. Imaging and computer simulation represent a possible link

  1. Distinguishing the Unique Neuropathological Profile of Blast Polytrauma

    Directory of Open Access Journals (Sweden)

    W. Brad Hubbard

    2017-01-01

    Full Text Available Traumatic brain injury sustained after blast exposure (blast-induced TBI has recently been documented as a growing issue for military personnel. Incidence of injury to organs such as the lungs has decreased, though current epidemiology still causes a great public health burden. In addition, unprotected civilians sustain primary blast lung injury (PBLI at alarming rates. Often, mild-to-moderate cases of PBLI are survivable with medical intervention, which creates a growing population of survivors of blast-induced polytrauma (BPT with symptoms from blast-induced mild TBI (mTBI. Currently, there is a lack of preclinical models simulating BPT, which is crucial to identifying unique injury mechanisms of BPT and its management. To meet this need, our group characterized a rodent model of BPT and compared results to a blast-induced mTBI model. Open field (OF performance trials were performed on rodents at 7 days after injury. Immunohistochemistry was performed to evaluate cellular outcome at day seven following BPT. Levels of reactive astrocytes (GFAP, apoptosis (cleaved caspase-3 expression, and vascular damage (SMI-71 were significantly elevated in BPT compared to blast-induced mTBI. Downstream markers of hypoxia (HIF-1α and VEGF were higher only after BPT. This study highlights the need for unique therapeutics and prehospital management when handling BPT.

  2. An analytical model for gas overpressure in slug-driven explosions: Insights into Strombolian volcanic eruptions

    Science.gov (United States)

    Del Bello, Elisabetta; Llewellin, Edward W.; Taddeucci, Jacopo; Scarlato, Piergiorgio; Lane, Steve J.

    2012-02-01

    Strombolian eruptions, common at basaltic volcanoes, are mildly explosive events that are driven by a large bubble of magmatic gas (a slug) rising up the conduit and bursting at the surface. Gas overpressure within the bursting slug governs explosion dynamics and vigor and is the main factor controlling associated acoustic and seismic signals. We present a theoretical investigation of slug overpressure based on magma-static and geometric considerations and develop a set of equations that can be used to calculate the overpressure in a slug when it bursts, slug length at burst, and the depth at which the burst process begins. We find that burst overpressure is controlled by two dimensionless parameters: V', which represents the amount of gas in the slug, and A', which represents the thickness of the film of magma that falls around the rising slug. Burst overpressure increases nonlinearly as V' and A' increase. We consider two eruptive scenarios: (1) the "standard model," in which magma remains confined to the vent during slug expansion, and (2) the "overflow model," in which slug expansion is associated with lava effusion, as occasionally observed in the field. We find that slug overpressure is higher for the overflow model by a factor of 1.2-2.4. Applying our model to typical Strombolian eruptions at Stromboli, we find that the transition from passive degassing to explosive bursting occurs for slugs with volume >24-230 m3, depending on magma viscosity and conduit diameter, and that at burst, a typical Strombolian slug (with a volume of 100-1000 m3) has an internal gas pressure of 1-5 bars and a length of 13-120 m. We compare model predictions with field data from Stromboli for low-energy "puffers," mildly explosive Strombolian eruptions, and the violently explosive 5 April 2003 paroxysm. We find that model predictions are consistent with field observations across this broad spectrum of eruptive styles, suggesting a common slug-driven mechanism; we propose that

  3. Structural and biochemical abnormalities in the absence of acute deficits in mild primary blast-induced head trauma.

    Science.gov (United States)

    Walls, Michael K; Race, Nicholas; Zheng, Lingxing; Vega-Alvarez, Sasha M; Acosta, Glen; Park, Jonghyuck; Shi, Riyi

    2016-03-01

    Blast-induced neurotrauma (BINT), if not fatal, is nonetheless potentially crippling. It can produce a wide array of acute symptoms in moderate-to-severe exposures, but mild BINT (mBINT) is characterized by the distinct absence of acute clinical abnormalities. The lack of observable indications for mBINT is particularly alarming, as these injuries have been linked to severe long-term psychiatric and degenerative neurological dysfunction. Although the long-term sequelae of BINT are extensively documented, the underlying mechanisms of injury remain poorly understood, impeding the development of diagnostic and treatment strategies. The primary goal of this research was to recapitulate primary mBINT in rodents in order to facilitate well-controlled, long-term investigations of blast-induced pathological neurological sequelae and identify potential mechanisms by which ongoing damage may occur postinjury. A validated, open-ended shock tube model was used to deliver blast overpressure (150 kPa) to anesthetized rats with body shielding and head fixation, simulating the protective effects of military-grade body armor and isolating a shock wave injury from confounding systemic injury responses, head acceleration, and other elements of explosive events. Evans Blue-labeled albumin was used to visualize blood-brain barrier (BBB) compromise at 4 hours postinjury. Iba1 staining was used to visualize activated microglia and infiltrating macrophages in areas of peak BBB compromise. Acrolein, a potent posttraumatic neurotoxin, was quantified in brain tissue by immunoblotting and in urine through liquid chromatography with tandem mass spectrometry at 1, 2, 3, and 5 days postinjury. Locomotor behavior, motor performance, and short-term memory were assessed with open field, rotarod, and novel object recognition (NOR) paradigms at 24 and 48 hours after the blast. Average speed, maximum speed, and distance traveled in an open-field exploration paradigm did not show significant

  4. Volcanic Lightning, Pyroclastic Density Currents, Ballistic Fall, Vent Tremor, and One Very Loud Blast: Acoustic Analysis of the 14 July 2013 Vulcanian Eruption at Tungurahua, Ecuador.

    Science.gov (United States)

    Anderson, J.; Johnson, J. B.; Steele, A. L.; Anzieta, J. C.; Ortiz, H. D.; Hall, M. L.; Ruiz, M. C.

    2014-12-01

    Acoustic recordings reveal a variety of volcanic activities during an exceptionally loud vulcanian eruption at Tungurahua. A period of several months of mild surface activity came to an abrupt end with the emission of a powerful blast wave heard at least 180 km away. Sensors 2080 m from the vent recorded a stepped rise to its maximum overpressure of 1220 Pa (corresponding to a sound pressure level of 156 dB) and its unusually long dominant period of 5.6 s. We discuss source processes that produced the blast wave, considering that wave propagation could be nonlinear near the vent because of high overpressures. More than an hour of acoustic activity was recorded after the blast wave, including sound from falling ballistics, reflections of the blast wave from nearby mountains, pyroclastic density currents, and acoustic tremor at the vent. Glitches in the acoustic records related to plume lightning were also serendipitously observed, although thunder could not be unambiguously identified. We discuss acoustic signatures of falling ballistics and pyroclastic density currents and how array-style deployments and analytic methods can be used to reveal them. Placement of sensors high on the volcano's slopes facilitated resolving these distinct processes. This study demonstrates that near-vent, array-style acoustic installations can be used to monitor various types of volcanic activity.

  5. Laboratory tests of overpressure differential systems for smoke protection of lobbies

    Science.gov (United States)

    Szałański, Paweł; Misiński, Jacek

    2017-11-01

    Paper presents the methodology of laboratory tests for ventilation overpressure differential systems for smoke protection of lobbies. Research area consists of two spaces representing the lobby and the area under fire equipped with proper ventilation installation. This allows testing of overpressure differential systems for smoke protection of lobbies. Moreover, piece of laboratory tests results for two selected smoke protection systems for lobbies are presented. First one is standard system with constantly opened transfer-damper mounted between lobby and area under fire. Second one - system with so called "electronic transfer" based on two dampers (supplying air to a lobby and to unprotected area alternatively). Opening and closing both dampers is electronically controlled. Changes of pressure difference between lobby and fire affected area during closing and opening doors between those spaces is presented. Conclusions, concerning the possibility of meeting the time period criteria of pressure difference stabilization required by standards, are presented and discussed for both systems.

  6. Parallel Human and Animal Models of Blast- and Concussion-Induced Tinnitus and Related Traumatic Brain Injury (TBI)

    Science.gov (United States)

    2014-01-01

    small piece of occipital bone and underlying dura mater above the left DCN were removed. Following partial aspiration of the cerebellar tissue...indicated the blast exposure may cause robust neural activity changes at the auditory cortex three months after blast exposure. 5. Manganese ...activity changes in several limbic and paralimbic structures were evaluated using manganese -enhanced magnetic resonance imaging (MEMRI). Five weeks

  7. REDUCING THE BOOSTER STATIONS ENERGY CONSUMPTION BY WAY OF ELIMINATING OVERPRESSURE IN THE WATER SUPPLY NETWORK

    Directory of Open Access Journals (Sweden)

    G. N. Zdor

    2015-01-01

    Full Text Available The energy efficiency improvement of the city housing-and-utilities infrastructure and watersupply and water-disposal systems poses an occurrent problem. The water-supply systems energy consumption sizable share falls on the pump plants. The article deals with the issues of the operating regime management of the existing booster stations equipped with a group of pumping units regulated with frequency converters. One of the optimization directions of their energy consumption is the reduction of over-pressure in the water-distribution network and its sustentation within the regulatory values. The authors offer the structure and methodology of the data collection-and-analysis automated system utilization for revealing and eliminating the overpressure in the water-supply network. This system is designed for the group management of booster-stations operating regimes on the ground of data obtained from the pressure controlling devices at the consumers. The data exchange in the system is realized via GSM.The paper presents results of the tests carried out at the booster stations in some major cities of the Republic of Belarus. The authors analyze dependence of overpressure in the network on the methods of the plant output pressure sustentation (daily graph or constant pressure. The authors study the elimination effect of over-pressure in the water distribution network on changing the booster station pumping units operation regimes. The study shows that eliminating over pressure in the water distributing network leads to lowering the booster station pressure. This in its turn decreases its energy consumption by 15–20 % depending on the over pressure fixed level.

  8. Identification of low-overpressure interval and its implication to hydrocarbon migration: Case study in the Yanan sag of the Qiongdongnan Basin, South China Sea.

    Directory of Open Access Journals (Sweden)

    Qinghai Xu

    Full Text Available The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient (the ratio of the actual pore pressure versus hydrostatic pressure at the same depth over 2.27. However, there exists a widespread low-overpressure interval between the strong overpressure intervals in the Yanan Sag of western basin. The mechanisms of the low-overpressure interval are not well understood. Three main approaches, pore pressure test data and well-log analysis, pressure prediction based on the relationship between the deviation of the velocity and the pressure coefficients, and numerical modeling, were employed to illustrate the distribution and evolution of the low-overpressure interval. And we analyzed and explained the phenomenon of the low-overpressure interval that is both underlain and overlain by high overpressure internal. The low-overpressure interval between the strong overpressure intervals can be identified and modelled by drilling data of P-wave sonic and the mud weight, and the numerical modeling using the PetroMod software. Results show that the low-overpressure interval is mainly composed of sandstone sediments. The porosities of sandstone in the low-overpressure interval primarily range from 15%-20%, and the permeabilities range from 10-100 md. Analysis of the geochemical parameters of C1, iC4/nC4, ΔR3, and numerical modeling shows that oil and gas migrated upward into the sandstone in the low-overpressure interval, and then migrated along the sandstone of low-overpressure interval into the Yacheng uplift. The low-overpressure both underlain and overlain by overpressure resulted from the fluids migrating along the sandstones in the low-overpressure interval into the Yacheng uplift since 1.9Ma. The mudstone in the strong overpressure interval is good cap overlain the sandstone of low-overpressure interval, therefore up-dip pinchouts or isolated sandstone in the low-overpressure interval locating the migration path of oil

  9. Identification of low-overpressure interval and its implication to hydrocarbon migration: Case study in the Yanan sag of the Qiongdongnan Basin, South China Sea

    Science.gov (United States)

    Xu, Qinghai; Shi, Wanzhong; Xie, Yuhong; Wang, Zhenfeng; Li, Xusheng; Tong, Chuanxin

    2017-01-01

    The Qiongdongnan Basin is a strongly overpressured basin with the maximum pressure coefficient (the ratio of the actual pore pressure versus hydrostatic pressure at the same depth) over 2.27. However, there exists a widespread low-overpressure interval between the strong overpressure intervals in the Yanan Sag of western basin. The mechanisms of the low-overpressure interval are not well understood. Three main approaches, pore pressure test data and well-log analysis, pressure prediction based on the relationship between the deviation of the velocity and the pressure coefficients, and numerical modeling, were employed to illustrate the distribution and evolution of the low-overpressure interval. And we analyzed and explained the phenomenon of the low-overpressure interval that is both underlain and overlain by high overpressure internal. The low-overpressure interval between the strong overpressure intervals can be identified and modelled by drilling data of P-wave sonic and the mud weight, and the numerical modeling using the PetroMod software. Results show that the low-overpressure interval is mainly composed of sandstone sediments. The porosities of sandstone in the low-overpressure interval primarily range from 15%-20%, and the permeabilities range from 10–100 md. Analysis of the geochemical parameters of C1, iC4/nC4, ΔR3, and numerical modeling shows that oil and gas migrated upward into the sandstone in the low-overpressure interval, and then migrated along the sandstone of low-overpressure interval into the Yacheng uplift. The low-overpressure both underlain and overlain by overpressure resulted from the fluids migrating along the sandstones in the low-overpressure interval into the Yacheng uplift since 1.9Ma. The mudstone in the strong overpressure interval is good cap overlain the sandstone of low-overpressure interval, therefore up-dip pinchouts or isolated sandstone in the low-overpressure interval locating the migration path of oil and gas are good

  10. Investigations of primary blast-induced traumatic brain injury

    Science.gov (United States)

    Sawyer, T. W.; Josey, T.; Wang, Y.; Villanueva, M.; Ritzel, D. V.; Nelson, P.; Lee, J. J.

    2018-01-01

    The development of an advanced blast simulator (ABS) has enabled the reproducible generation of single-pulse shock waves that simulate free-field blast with high fidelity. Studies with rodents in the ABS demonstrated the necessity of head restraint during head-only exposures. When the head was not restrained, violent global head motion was induced by pressures that would not produce similar movement of a target the size and mass of a human head. This scaling artefact produced changes in brain function that were reminiscent of traumatic brain injury (TBI) due to impact-acceleration effects. Restraint of the rodent head eliminated these, but still produced subtle changes in brain biochemistry, showing that blast-induced pressure waves do cause brain deficits. Further experiments were carried out with rat brain cell aggregate cultures that enabled the conduct of studies without the gross movement encountered when using rodents. The suspension nature of this model was also exploited to minimize the boundary effects that complicate the interpretation of primary blast studies using surface cultures. Using this system, brain tissue was found not only to be sensitive to pressure changes, but also able to discriminate between the highly defined single-pulse shock waves produced by underwater blast and the complex pressure history exposures experienced by aggregates encased within a sphere and subjected to simulated air blast. The nature of blast-induced primary TBI requires a multidisciplinary research approach that addresses the fidelity of the blast insult, its accurate measurement and characterization, as well as the limitations of the biological models used.

  11. Performance of Hybrid Steel Fibers Reinforced Concrete Subjected to Air Blast Loading

    Directory of Open Access Journals (Sweden)

    Mohammed Alias Yusof

    2013-01-01

    Full Text Available This paper presents the results of the experimental data and simulation on the performance of hybrid steel fiber reinforced concrete (HSFRC and also normal reinforced concrete (NRC subjected to air blast loading. HSFRC concrete mix consists of a combination of 70% long steel hook end fibre and also 30% of short steel hook end fibre with a volume fraction of 1.5% mix. A total of six concrete panels were subjected to air blast using plastic explosive (PE4 weighing 1 kg each at standoff distance of 0.3 meter. The parameters measured are mode of failure under static and blast loading and also peak overpressure that resulted from detonation using high speed data acquisition system. In addition to this simulation work using AUTODYN was carried out and validated using experimental data. The experimental results indicate that hybrid steel fiber reinforced concrete panel (HSFRC possesses excellent resistance to air blast loading as compared to normal reinforced concrete (NRC panel. The simulation results were also found to be close with experimental data. Therefore the results have been validated using experimental data.

  12. Recent Results from BLAST

    International Nuclear Information System (INIS)

    Hasell, D.K.

    2005-01-01

    The Bates Large Acceptance Spectrometer Toroid experiment, BLAST, at the MIT-Bates Linear Accelerator Laboratory is designed to study in a systematic manner the spindependent electromagnetic interaction in few-nucleon systems at momentum transfers below 1 GeV/c. Utilizing a polarized electron beam, highly polarized internal gas targets of H and D, and a symmetric detector configuration, BLAST is able to make simultaneous measurements of several reaction channels for different combinations of beam helicity and target polarization (vector for H, both vector and tensor for D). BLAST will provide new data on the nucleon and deuteron form factors as well as study few body physics and pion production. Preliminary results are presented

  13. Bridging the Gap of Standardized Animals Models for Blast Neurotrauma: Methodology for Appropriate Experimental Testing.

    Science.gov (United States)

    VandeVord, Pamela J; Leonardi, Alessandra Dal Cengio; Ritzel, David

    2016-01-01

    Recent military combat has heightened awareness to the complexity of blast-related traumatic brain injuries (bTBI). Experiments using animal, cadaver, or biofidelic physical models remain the primary measures to investigate injury biomechanics as well as validate computational simulations, medical diagnostics and therapies, or protection technologies. However, blast injury research has seen a range of irregular and inconsistent experimental methods for simulating blast insults generating results which may be misleading, cannot be cross-correlated between laboratories, or referenced to any standard for exposure. Both the US Army Medical Research and Materiel Command and the National Institutes of Health have noted that there is a lack of standardized preclinical models of TBI. It is recommended that the blast injury research community converge on a consistent set of experimental procedures and reporting of blast test conditions. This chapter describes the blast conditions which can be recreated within a laboratory setting and methodology for testing in vivo models within the appropriate environment.

  14. Investigation of Thermophysical Parameters Properties for Enhancing Overpressure Mechanism Estimation. Case Study: Miri Area, West Baram Delta

    Science.gov (United States)

    Adha, Kurniawan; Yusoff, Wan Ismail Wan; Almanna Lubis, Luluan

    2017-10-01

    Determining the pore pressure data and overpressure zone is a compulsory part of oil and gas exploration in which the data can enhance the safety with profit and preventing the drilling hazards. Investigation of thermophysical parameters such as temperature and thermal conductivity can enhance the pore pressure estimation for overpressure mechanism determination. Since those parameters are dependent on rock properties, it may reflect the changes on the column of thermophysical parameters when there is abnormally in pore pressure. The study was conducted in “MRI 1” well offshore Sarawak, where a new approach method designed to determine the overpressure generation. The study was insisted the contribution of thermophysical parameters for supporting the velocity analysis method, petrophysical analysis were done in these studies. Four thermal facies were identified along the well. The overpressure developed below the thermal facies 4, where the pressure reached 38 Mpa and temperature was increasing significantly. The velocity and the thermal conductivity cross plots shows a linear relationship since the both parameters mainly are the function of the rock compaction. When the rock more compact, the particles were brought closer into contact and making the sound wave going faster while the thermal conductivity were increasing. In addition, the increment of temperature and high heat flow indicated the presence of fluid expansion mechanism. Since the shale sonic velocity and density analysis were the common methods in overpressure mechanism and pore pressure estimation. As the addition parameters for determining overpressure zone, the presence of thermophysical analysis was enhancing the current method, where the current method was the single function of velocity analysis. The presence of thermophysical analysis will improve the understanding in overpressure mechanism determination as the new input parameters. Thus, integrated of thermophysical technique and velocity

  15. Analysis on the overpressure characterization with respect to depositional environment facies: Case Study in Miri Area, Baram Delta

    Science.gov (United States)

    Mhd Hanapiah, N.; Yusoff, W. I. Wan; Zakariah, M. N. A.

    2017-10-01

    Overpressure studies in oil and gas exploration and production are carried out in order to mitigate any losses that could happen while drilling. These concerns can be addressed by enhancing the understanding of overpressure characterization in the fields. This research emphasizes in determining the pore pressure trend in Miri area to assist pore pressure prediction for future hydrocarbon exploration and production. Generally, pore pressure trends are related to mechanisms that contribute to the overpressure generation. In the region predominant overpressure are disequilibrium compaction within the prodelta shales meanwhile in outer shelf overpressure generation controlled by fluid expansion in deltaic sequence of inner shelf area. The objective of this research is to analyze the pore pressure profile of wells for determining vertical trends of pore pressure for various depositional environment facies of Miri area. Integration of rock physics and pore pressure analysis and relating the trends to environment depositional environment facies within shale underlying sand interval. Analysis done shows that overpressure top is characterize by depositional environment facies within shale underlying sand interval.

  16. Differences in postinjury auditory system pathophysiology after mild blast and nonblast acute acoustic trauma.

    Science.gov (United States)

    Race, Nicholas; Lai, Jesyin; Shi, Riyi; Bartlett, Edward L

    2017-08-01

    Hearing difficulties are the most commonly reported disabilities among veterans. Blast exposures during explosive events likely play a role, given their propensity to directly damage both peripheral (PAS) and central auditory system (CAS) components. Postblast PAS pathophysiology has been well documented in both clinical case reports and laboratory investigations. In contrast, blast-induced CAS dysfunction remains understudied but has been hypothesized to contribute to an array of common veteran behavioral complaints, including learning, memory, communication, and emotional regulation. This investigation compared the effects of acute blast and nonblast acoustic impulse trauma in adult male Sprague-Dawley rats. An array of audiometric tests were utilized, including distortion product otoacoustic emissions (DPOAE), auditory brain stem responses (ABR), middle latency responses (MLR), and envelope following responses (EFRs). Generally, more severe and persistent postinjury central auditory processing (CAP) deficits were observed in blast-exposed animals throughout the auditory neuraxis, spanning from the cochlea to the cortex. DPOAE and ABR results captured cochlear and auditory nerve/brain stem deficits, respectively. EFRs demonstrated temporal processing impairments suggestive of functional damage to regions in the auditory brain stem and the inferior colliculus. MLRs captured thalamocortical transmission and cortical activation impairments. Taken together, the results suggest blast-induced CAS dysfunction may play a complementary pathophysiological role to maladaptive neuroplasticity of PAS origin. Even mild blasts can produce lasting hearing impairments that can be assessed with noninvasive electrophysiology, allowing these measurements to serve as simple, effective diagnostics. NEW & NOTEWORTHY Blasts exposures often produce hearing difficulties. Although cochlear damage typically occurs, the downstream effects on central auditory processing are less clear

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    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.

  18. Characterization of viscoelastic materials for low-magnitude blast mitigation

    Science.gov (United States)

    Bartyczak, S.; Mock, W.

    2014-05-01

    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.

  19. Mild blast events alter anxiety, memory, and neural activity patterns in the anterior cingulate cortex.

    Directory of Open Access Journals (Sweden)

    Kun Xie

    Full Text Available There is a general interest in understanding of whether and how exposure to emotionally traumatizing events can alter memory function and anxiety behaviors. Here we have developed a novel laboratory-version of mild blast exposure comprised of high decibel bomb explosion sound coupled with strong air blast to mice. This model allows us to isolate the effects of emotionally fearful components from those of traumatic brain injury or bodily injury typical associated with bomb blasts. We demonstrate that this mild blast exposure is capable of impairing object recognition memory, increasing anxiety in elevated O-maze test, and resulting contextual generalization. Our in vivo neural ensemble recording reveal that such mild blast exposures produced diverse firing changes in the anterior cingulate cortex, a region processing emotional memory and inhibitory control. Moreover, we show that these real-time neural ensemble patterns underwent post-event reverberations, indicating rapid consolidation of those fearful experiences. Identification of blast-induced neural activity changes in the frontal brain may allow us to better understand how mild blast experiences result in abnormal changes in memory functions and excessive fear generalization related to post-traumatic stress disorder.

  20. Blasting agents and initiation systems

    Energy Technology Data Exchange (ETDEWEB)

    Fiscor, S.

    2000-01-01

    Although blasting differs between and within each industry, as a whole, the mines and quarries are making a shift from a purely ammonium nitrate/fuel oil (ANFO) mixture to a blend of emulsion and ANFO on a straight emulsion. Non-electric (shock tube) initiation systems have provided a viable alternative to the electric detonator (blasting cap). Explosives manufacturers are seeing their roles changes to being blasting contractors or consultants rather than just suppliers. The article discusses these trends and gives examples of typical blasting techniques and amounts of blasting agent used at large USA surface coal mines. Electric caps are still used in blasting underground coal. The Ensign Bickford Co. (EBCo) is developing electronic detonators and has been field testing an electronic initiator, the DIGIDET detonator, for the last four years. When commercially available, electronic detonators will be accurate but will come with a hefty price tag. 2 photos.

  1. Characterization of the Scale Model Acoustic Test Overpressure Environment using Computational Fluid Dynamics

    Science.gov (United States)

    Nielsen, Tanner; West, Jeff

    2015-01-01

    The Scale Model Acoustic Test (SMAT) is a 5% scale test of the Space Launch System (SLS), which is currently being designed at Marshall Space Flight Center (MSFC). The purpose of this test is to characterize and understand a variety of acoustic phenomena that occur during the early portions of lift off, one being the overpressure environment that develops shortly after booster ignition. The pressure waves that propagate from the mobile launcher (ML) exhaust hole are defined as the ignition overpressure (IOP), while the portion of the pressure waves that exit the duct or trench are the duct overpressure (DOP). Distinguishing the IOP and DOP in scale model test data has been difficult in past experiences and in early SMAT results, due to the effects of scaling the geometry. The speed of sound of the air and combustion gas constituents is not scaled, and therefore the SMAT pressure waves propagate at approximately the same speed as occurs in full scale. However, the SMAT geometry is twenty times smaller, allowing the pressure waves to move down the exhaust hole, through the trench and duct, and impact the vehicle model much faster than occurs at full scale. The DOP waves impact portions of the vehicle at the same time as the IOP waves, making it difficult to distinguish the different waves and fully understand the data. To better understand the SMAT data, a computational fluid dynamics (CFD) analysis was performed with a fictitious geometry that isolates the IOP and DOP. The upper and lower portions of the domain were segregated to accomplish the isolation in such a way that the flow physics were not significantly altered. The Loci/CHEM CFD software program was used to perform this analysis.

  2. Blast Mitigation Using Water Mist

    National Research Council Canada - National Science Library

    Bailey, Jean L; Farley, John P; Williams, Frederick W; Lindsay, Michael S; Schwer, Douglas A

    2006-01-01

    A series of experiments demonstrating the mitigation of water mist on the over-pressure effects of a TNT detonation have been conducted A series of TNT charges, 0.9 kg (2 lb), 2.2 kg (5 lb) and 3.2 kg (7 lb...

  3. An analytical solution describing the shape of a yield stress material subjected to an overpressure

    DEFF Research Database (Denmark)

    Hovad, Emil; Spangenberg, Jon; Larsen, P.

    2016-01-01

    Many fluids and granular materials are able to withstand a limited shear stress without flowing. These materials are known as yields stress materials. Previously, an analytical solution was presented to quantify the yield stress for such materials. The yields stress is obtained based on the density...... as well as the spread length and height of the material when deformed in a box due to gravity. In the present work, the analytical solution is extended with the addition of an overpressure that acts over the entire body of the material. This extension enables finding the shape of a yield stress material...

  4. Experimental study of the overpressures generated by the detonation of spherical air-hydrocarbon gaseous mixtures

    International Nuclear Information System (INIS)

    Brossard, J.

    1978-01-01

    The characteristics of the pressure waves transmitted by detonation of gaseous mixtures to the surrounding air were measured by tests made near the ground level in 1 to 54 m 3 spherical balloons containing air-acetylene or air-ethylene mixtures. As concerns the peak overpressure Δp, a theoretical dimensional analysis in accordance with the experimental results shows that Δp can be expressed as a function of two independent variables, which are the radial distance R and the volume V of the balloon . A semi-empirical formula, including ground effects, is proposed and its present validity range is given. (author)

  5. BeoBLAST: distributed BLAST and PSI-BLAST on a Beowulf cluster.

    Science.gov (United States)

    Grant, J D; Dunbrack, R L; Manion, F J; Ochs, M F

    2002-05-01

    BeoBLAST is an integrated software package that handles user requests and distributes BLAST and PSI-BLAST searches to nodes of a Beowulf cluster, thus providing a simple way to implement a scalable BLAST system on top of relatively inexpensive computer clusters. Additionally, BeoBLAST offers a number of novel search features through its web interface, including the ability to perform simultaneous searches of multiple databases with multiple queries, and the ability to start a search using the PSSM generated from a previous PSI-BLAST search on a different database. The underlying system can also handle automated querying for high throughput work. Source code is available under the GNU public license at http://bioinformatics.fccc.edu/

  6. Tunnel blasting - recent developments

    Energy Technology Data Exchange (ETDEWEB)

    White, T.E.

    1999-05-01

    While tunnelling machines are more efficient than previously, there are still areas where blasting is a more efficient method of advance. Drilling and design methods are increasingly sophisticated, as is choice of explosive. Explosive deployment must be carefully calculated so as to avoid desensitisation. Nitroglycerine may be used as slurries; bulk mixing on site of ANFO is also practised in mining in the UK. Electric detonators, Nonel tubes, and electronic detonators are also increasingly employed.

  7. New-construction techniques and HVAC overpressurization for radon reduction in schools

    International Nuclear Information System (INIS)

    Saum, D.; Witter, K.A.; Craig, A.B.

    1988-01-01

    Construction of a school in Fairfax County, Virginia, is being carefully monitored since elevated indoor radon levels have been identified in many existing houses near the site. Soil gas radon concentrations measured prior to pouring of the slabs were also indicative of a potential radon problem should the soil gas enter the school; however, subslab radon measurements collected thus far are lower than anticipated. Radon-resistant features have been incorporated into construction of the school and include the placing of at least 100 mm of clean coarse aggregate under the slab and a plastic film barrier between the aggregate and the slab, the sealing of all expansion joints, the sealing or plugging of all utility penetrations where possible, and the painting of interior block walls. In addition, the school's heating, ventilating, and air-conditioning (HVAC) system has been designed to operate continuously in overpressurization to help reduce pressure-driven entry of radon-containing soil gas into the building. Following completion, indoor radon levels in the school will be monitored to determine the effectiveness of these radon-resistant new-construction techniques and HVAC overpressurization in limiting radon entry into the school

  8. Experimental animal models for studies on the mechanisms of blast-induced neurotrauma.

    Science.gov (United States)

    Risling, Mårten; Davidsson, Johan

    2012-01-01

    A blast injury is a complex type of physical trauma resulting from the detonation of explosive compounds and has become an important issue due to the use of improvised explosive devices (IED) in current military conflicts. Blast-induced neurotrauma (BINT) is a major concern in contemporary military medicine and includes a variety of injuries that range from mild to lethal. Extreme forces and their complex propagation characterize BINT. Modern body protection and the development of armored military vehicles can be assumed to have changed the outcome of BINT. Primary blast injuries are caused by overpressure waves whereas secondary, tertiary, and quaternary blast injuries can have more varied origins such as the impact of fragments, abnormal movements, or heat. The characteristics of the blast wave can be assumed to be significantly different in open field detonations compared to explosions in a confined space, such an armored vehicle. Important parameters include peak pressure, duration, and shape of the pulse. Reflections from walls and armor can make the prediction of effects in individual cases very complex. Epidemiological data do not contain information of the comparative importance of the different blast mechanisms. It is therefore important to generate data in carefully designed animal models. Such models can be selective reproductions of a primary blast, penetrating injuries from fragments, acceleration movements, or combinations of such mechanisms. It is of crucial importance that the physical parameters of the employed models are well characterized so that the experiments can be reproduced in different laboratory settings. Ideally, pressure recordings should be calibrated by using the same equipment in several laboratories. With carefully designed models and thoroughly evaluated animal data it should be possible to achieve a translation of data between animal and clinical data. Imaging and computer simulation represent a possible link between experiments

  9. A Monte Carlo Approach to Modeling the Breakup of the Space Launch System EM-1 Core Stage with an Integrated Blast and Fragment Catalogue

    Science.gov (United States)

    Richardson, Erin; Hays, M. J.; Blackwood, J. M.; Skinner, T.

    2014-01-01

    The Liquid Propellant Fragment Overpressure Acceleration Model (L-FOAM) is a tool developed by Bangham Engineering Incorporated (BEi) that produces a representative debris cloud from an exploding liquid-propellant launch vehicle. Here it is applied to the Core Stage (CS) of the National Aeronautics and Space Administration (NASA) Space Launch System (SLS launch vehicle). A combination of Probability Density Functions (PDF) based on empirical data from rocket accidents and applicable tests, as well as SLS specific geometry are combined in a MATLAB script to create unique fragment catalogues each time L-FOAM is run-tailored for a Monte Carlo approach for risk analysis. By accelerating the debris catalogue with the BEi blast model for liquid hydrogen / liquid oxygen explosions, the result is a fully integrated code that models the destruction of the CS at a given point in its trajectory and generates hundreds of individual fragment catalogues with initial imparted velocities. The BEi blast model provides the blast size (radius) and strength (overpressure) as probabilities based on empirical data and anchored with analytical work. The coupling of the L-FOAM catalogue with the BEi blast model is validated with a simulation of the Project PYRO S-IV destruct test. When running a Monte Carlo simulation, L-FOAM can accelerate all catalogues with the same blast (mean blast, 2 s blast, etc.), or vary the blast size and strength based on their respective probabilities. L-FOAM then propagates these fragments until impact with the earth. Results from L-FOAM include a description of each fragment (dimensions, weight, ballistic coefficient, type and initial location on the rocket), imparted velocity from the blast, and impact data depending on user desired application. LFOAM application is for both near-field (fragment impact to escaping crew capsule) and far-field (fragment ground impact footprint) safety considerations. The user is thus able to use statistics from a Monte Carlo

  10. High productivity vacuum blasting system

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    2000-01-01

    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

  11. PREVALENCE OF RICE BLAST AND VARIETAL

    African Journals Online (AJOL)

    search-screening site grown to an improved vari- ety, Tox 3050, was heavily blasted. There was no blast incidence at Damongo. in Upper East. Region, there was severe incidence of blast in farmers' fields at Bawku and PVS nurseries and farmers' fields at Nyorigu. There was no blast at. Manga, Navrongo, Tono, Sandema, ...

  12. HIGH PRODUCTIVITY VACUUM BLASTING SYSTEM

    International Nuclear Information System (INIS)

    McPhee, William S.

    1999-01-01

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

  13. BOMB BLAST: PATTERN AND NATURE OF INJURIES

    OpenAIRE

    Brahmaji Master; Chandra Sekhar; Rangaiah

    2015-01-01

    Bomb blast cause injury on large groups of people by multiple mechanisms. Bomb blast injuries differ from the conventional description of trauma complexity. Primary injuries are caused by blast wave and over pressure. Secondary injuries are caused by flyin g debris and cause shrapnel wounds. Tertiary injuries are caused by blast wind due to forceful impact and quaternary injuries are caused by other vectors like heat, radiation etc. Combined injuries, especially blast and...

  14. Simulating the blast wave from detonation of a charge using a balloon of compressed air

    Science.gov (United States)

    Blanc, L.; Santana Herrera, S.; Hanus, J. L.

    2017-11-01

    This paper investigates a simple numerical method, based on the release of a pressurized spherical air volume, to predict or reproduce the main characteristics of the blast environment from the detonation of solid or gaseous charges. This approach aims to give an alternative to the use of a steady-state detonation model and a Jones-Wilkins-Lee equation of state to describe the expansion of the detonation products, especially when the explosive parameters are unknown and a TNT equivalent is used. The validity of the proposed approach is assessed through the comparison of predicted overpressure and impulse at different distances from the explosion with that of TNT and stoichiometric propane-oxygen explosions. It is also shown that, for gaseous detonations, a better agreement is obtained with the rationally optimized compressed balloon than with the use of a Jones-Wilkins-Lee model and a TNT equivalent mass.

  15. Applicability of preparative overpressured layer chromatography and direct bioautography in search of antibacterial chamomile compounds.

    Science.gov (United States)

    Móricz, Agnes M; Ott, Péter G; Alberti, Agnes; Böszörményi, Andrea; Lemberkovics, Eva; Szoke, Eva; Kéry, Agnes; Mincsovics, Emil

    2013-01-01

    In situ sample preparation and preparative overpressured layer chromatography (OPLC) fractionation on a 0.5 mm thick adsorbent layer of chamomile flower methanol extract prepurified by conventional gravitation accelerated column chromatography were applied in searching for bioactive components. Sample cleanup in situ on the adsorbent layer subsequent to sample application was performed using mobile phase flow in the opposite direction (the input and output of the eluent was exchanged). The antibacterial effect of the fractions obtained from the stepwise gradient OPLC separation with the flow in the normal direction was evaluated by direct bioautography against two Gram-negative bacteria: the luminescence gene tagged plant pathogenic Pseudomonas syringae pv. maculicola, and the naturally luminescent marine bacterium Vibrio fischeri. The fractions having strong activity were analyzed by SPME-GC/MS and HPLC/MS/MS. Mainly essential oil components, coumarins, flavonoids, phenolic acids, and fatty acids were tentatively identified in the fractions.

  16. Compaction of TOC-rich shales due to kerogen conversion. Implications for fluid flow and overpressure

    International Nuclear Information System (INIS)

    Hanebeck, D.; Krooss, B.M.; Leythaeuser, D.

    1998-01-01

    TOC-rich shales (10% TOC) have been artificially matured at temperatures between 200 and 350 deg C under controlled axial stress (20 - 40 MPa) for up to 350 hours. The volume change of the cylindrical samples was monitored continuously throughout the experiment. The performed experiments showed that the compaction associated with the thermal decomposition of the kerogen is significantly larger under hydrous than under dry pyrolysis conditions. This observation points at an important role of water in the conversion of kerogen. Semi quantitative permeability tests indicated that sample permeability had decreased at least one order of magnitude after the compaction pyrolysis experiments. This permeability reduction in combination with the observed compaction is the most probable mechanism for overpressure formation in TOC-rich source rock sequences. (author)

  17. Maximum overpressure in gastight containers of the storage and transport of dangerous liquids

    International Nuclear Information System (INIS)

    Steen, H.

    1977-11-01

    For a design of containers suitable under safety aspects for the transport and storage of dangerous liquids the maximum overpressure to be expected is an important value. The fundamentals for the determination of the internal pressure are pointed out for the simplified model of a rigid (i.e. not elastically or plastically deforming) and gastight container. By assuming of extreme storage and transport conditions (e.g. for the maximum liquid temperatures due to sun radiation) the figures of the maximum overpressure are calculated for about hundred liquids being of practical interest. The results show a significant influence of the compression of air in the ullage space caused by liquid expansion due to temperature rise (compression effect), particularly for liquids with a higher boiling point. The influence of the solubility of air in the liquid on the internal pressure can be neglected under the assumed transport conditions. The estimation of the volume increase of the container due to the effect of the internal pressure leads to the limitation, that the assumption of a rigid container is only justified for cylindrical and spherical steel tanks. The enlargement of the container volume due to a heating of the container shell does play no significant roll for all metal containers under the assumed conditions of storage and transport. The results obtained bear out essentially the stipulations for the test pressure and the filling limits laid down in the older German regulations for the transport of dangerous liquids in rail tank waggons and road tank vehicles without pressure relief valves. For the recently fixed and internationally harmonized regulations for tankcontainers the considerations and the results pointed out in this paper give rise to a review. (orig.) [de

  18. Overpressures: Causal Mechanisms, Conventional and Hydromechanical Approaches Surpressions : origine, approches conventionnelle et hydromécanique

    Directory of Open Access Journals (Sweden)

    Grauls D.

    2006-12-01

    Full Text Available Abnormal fluid pressure regimes are commonly encountered at depth in most sedimentary basins. Relationships between effective vertical stress and porosity have been applied, since 1970 to the Gulf Coast area, to assess the magnitude of overpressures. Positive results have been obtained from seismic and basin-modeling techniques in sand-shale, vertical-stress-dominated tertiary basins, whenever compaction disequilibrium conditions apply. However, overpressures resulting from other and/or additional causes (tectonic stress, hydrocarbon generation, thermal stress, fault-related transfer, hydrofracturing. . . cannot be quantitatively assessed using this approach. A hydromechanical approach is then proposed in addition to conventional methods. At any depth, the upper bound fluid pressure is controlled by in situ conditions related to hydrofracturing or fault reactivation. Fluid-driven fracturing implies an episodically open system, under a close to zerominimum effective stress regime. Sound knowledge of present-day tectonic stress regimes allows a direct estimation of minimum stress evolution. A quantitative fluid pressure assessment at depth is therefore possible, as in undrained or/and compartmented geological systems, pressure regimes, whatever their origin, tend to rapidly reach a value close to the minimum principal stress. Therefore, overpressure assessment will be improved, as this methodology can be applied to various geological settings and situations where present-day overpressures originated from other causal mechanisms, very often combined. However, pressure trends in transition zones are more difficult to assess correctly. Additional research on cap rocks and fault seals is therefore required to improve their predictability. In addition to overpressure assessment, the minimum principal stress concept allows a better understanding of petroleum system, as fault-related hydrocarbon dynamic transfers, hydrofractured domains and cap

  19. CO2 pellet blasting studies

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1997-01-01

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

  20. The role of overpressure and seismic activity for the generation of the Tampen Slide, North Sea Trough Mouth Fan

    Science.gov (United States)

    Bellwald, Benjamin; Urlaub, Morelia; Oline Hjelstuen, Berit; Petter Sejrup, Hans; Sørensen, Mathilde; Forsberg, Carl Fredrik; Vanneste, Maarten

    2017-04-01

    Trough mouth fans (TMFs) are environments characterized by high sediment supply during glacial stages and repeated slope failure. The Tampen Slide, which removed 1800 km3 of sediment at 130 ka BP, is one of several paleo-slides at the North Sea TMF deposited at the outlet of the Norwegian Channel, SE Nordic Sea margin. Here we use 2D Finite Element Modeling to evaluate the effects of variations in sedimentation rates and sediment properties on overpressure generation and slope stability of this TMF system. The model domain, 40 km in length and 2 km in height, is dominated by deposits of glacigenic debris flows and glacimarine processes. We use geotechnical values measured on samples of glacial debris and (glaci)marine deposits from over the Ormen Lange gas field area. Slope stability has been modeled for constant temporal sediment loading, episodic changes in sedimentation rates and abrupt pulses in sediment delivery for the 61 ka of marine isotope stage 6. The models show that increased sedimentation rates during glacial stages generate insufficient overpressure to trigger the Tampen Slide. Furthermore, the simulated overpressures do not significantly differ at the end of the model runs characterized by different sedimentation patterns. The results also highlight the importance of a basal glacimarine layer underneath the rapidly-deposited sediments for the build-up of overpressure. Consequently, this glacimarine layer has the inherited potential to act as a weak layer facilitating instability. However, as overpressure due to sediment deposition alone does not result in slope failure, we couple the preconditioned slope with earthquake ground shaking. Based on attenuation models, an earthquake of M6.9 or larger at a short distance from the Tampen Slide headwall could have triggered the Tampen Slide. Therefore we suggest glacial sedimentation and a glacimarine layer to represent preconditioning factors, and seismic shaking as the controlling factor for the Tampen

  1. Assessment and Treatment of Blast-Induced Auditory and Vestibular Injuries

    Science.gov (United States)

    2017-06-01

    unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Hearing loss and balance disorders are widespread among OIF/OEF veterans as a result of blast...key military medical issue. The debilitating consequences of acute blast-induced auditory and vestibular disorders (e.g. hearing loss, tinnitus, and...persisted over several months (Fig. 1). Compared to sham controls at 28 days post exposure, significantly elevated ABR thresholds and decreased wave

  2. Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave Overpressure Impacts

    Science.gov (United States)

    2017-11-01

    shown that peak pressure can be reproduced with standard deviations between 6% and 28% (of the pressure value).25 The average intensity of the blast...region of interest feature and calculating the mean intensity using the histogram feature. 2.6 Statistics All data are expressed as mean ± standard ... deviation unless noted. One-way analysis of variance (ANOVA) with a Tukey Means Comparison was conducted with a significance level of p < 0.05

  3. The BLAST experiment

    International Nuclear Information System (INIS)

    Hasell, D.; Akdogan, T.; Alarcon, R.; Bertozzi, W.; Booth, E.; Botto, T.; Calarco, J.R.; Clasie, B.; Crawford, C.; DeGrush, A.; Dow, K.; Dutta, D.; Farkhondeh, M.; Fatemi, R.; Filoti, O.; Franklin, W.; Gao, H.; Geis, E.; Gilad, S.; Hersman, W.

    2009-01-01

    The Bates large acceptance spectrometer toroid (BLAST) experiment was operated at the MIT-Bates Linear Accelerator Center from 2003 until 2005. The detector and experimental program were designed to study, in a systematic manner, the spin-dependent electromagnetic interaction in few-nucleon systems. As such the data will provide improved measurements for neutron, proton, and deuteron form factors. The data will also allow details of the reaction mechanism, such as the role of final state interactions, pion production, and resonances to be studied. The experiment used: a longitudinally polarized electron beam stored in the South Hall Storage Ring; a highly polarized, isotopically pure, internal gas target of hydrogen or deuterium provided by an atomic beam source; and a symmetric, general purpose detector based on a toroidal spectrometer with tracking, time-of-flight, Cherenkov, and neutron detectors. Details of the experiment and operation are presented.

  4. Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, Gene [Muons, Inc., Batavia, IL (United States); Johnson, Rolland [Muons, Inc., Batavia, IL (United States)

    2016-02-18

    High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi2Sr2CaCu2Ox (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 105 A/cm2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (Jc ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would

  5. Behavioral Outcomes Differ Between Rotational Acceleration and Blast Mechanisms of Mild Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Brian D. Stemper

    2016-03-01

    Full Text Available Mild traumatic brain injury (mTBI can result from a number of mechanisms, including blunt impact, head rotational acceleration, exposure to blast, and penetration of projectiles. Mechanism is likely to influence the type, severity, and chronicity of outcomes. The objective of this study was to determine differences in the severity and time-course of behavioral outcomes following blast and rotational mTBI. The Medical College of Wisconsin (MCW Rotational Injury model and a shock tube model of primary blast injury were used to induce mTBI in rats and behavioral assessments were conducted within the first week, as well as 30 and 60 days following injury. Acute recovery time demonstrated similar increases over protocol-matched shams, indicating acute injury severity equivalence between the two mechanisms. Post-injury behavior in the elevated plus maze demonstrated differing trends, with rotationally injured rats acutely demonstrating greater activity, whereas blast-injured rats had decreased activity that developed at chronic time points. Similarly, blast-injured rats demonstrated trends associated with cognitive deficits that were not apparent following rotational injuries. These findings demonstrate that rotational and blast injury result in behavioral changes with different qualitative and temporal manifestations. Whereas rotational injury was characterized by a rapidly emerging phenotype consistent with behavioral disinhibition, blast injury was associated with emotional and cognitive differences that were not evident acutely, but developed later, with an anxiety-like phenotype still present in injured animals at our most chronic measurements.

  6. Viscoelastic Materials Study for the Mitigation of Blast-Related Brain Injury

    Science.gov (United States)

    Bartyczak, Susan; Mock, Willis, Jr.

    2011-06-01

    Recent preliminary research into the causes of blast-related brain injury indicates that exposure to blast pressures, such as from 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 sufficient to protect the warfighter from this danger and the effects are debilitating, costly, and long-lasting. Commercially available viscoelastic materials, designed to dampen vibration caused by shock waves, might be useful as helmet liners to dampen blast waves. The objective of this research is to develop an experimental technique to test these commercially available materials when subject to blast waves and evaluate their blast mitigating behavior. A 40-mm-bore gas gun is being used as a shock tube to generate blast waves (ranging from 1 to 500 psi) in a test fixture at the gun muzzle. A fast opening valve is used to release nitrogen gas from the breech to impact instrumented targets. The targets consist of aluminum/ viscoelastic polymer/ aluminum materials. Blast attenuation is determined through the measurement of pressure and accelerometer data in front of and behind the target. The experimental technique, calibration and checkout procedures, and results will be presented.

  7. Blast biology: a study of the primary and tertiary effects of blast in open underground protective shelters. Project 33. 1 of Operation Plumbbob

    Energy Technology Data Exchange (ETDEWEB)

    Ricmond, D.R.; Taborelli, R.V.; Bowen, I.G.

    1959-02-01

    Dogs, pigs, rabbits, guinea pigs, and mice were exposed to nuclear detonations in two open underground partitioned shelters. The shelters were of similar construction, and each was exposed to separate detonations. Each inner chamber filled through its own orifice; thus four separate pressure environments were obtained. An aerodynamic mound was placed over the escape hatch of each structure to determine its effect on the pressure-curve shape inside the chamber. In one test a sieve plate bolted across the top of the mound was evaluated. Wind protective baffles of solid plate and of heavy wire screen were installed in the shelters to compare primary and tertiary blast effects on dogs. The shelters also contained static and dynamic pressure gages, radiation detectors, telemetering devices, and, in one test, air-temperature measuring instruments, dust-collecting trays, and eight pigs for the biological assessment of thermal effects. One dog was severely injured from tertiary blast effects associated with a maximal dynamic pressure (Q) of 10.5 psi, and one was undamaged with a maximal Q of 2 psi. Primary blast effects resulting from peak overpressures of 30.3, 25.5, 9.5, and 4.1 psi were minimal. The mortality was 19% of the mice exposed to a peak pressure of 30.3 psi and 5 and 3% of the guinea pigs and mice exposed to a peak pressure of 25.5 psi. Many of the rabbits, guinea pigs, and mice sustained slight lung hemorrhages at maximum pressues of 25.5 and 30.3 psi. Eardrum perforation data for all species, except mice, were recorded. Following shot 2, thermal effects were noted. Animals of the groups saved for observation have died from ionizing-radiation effects.

  8. Pulmonary effects of combined blast injury and radiation poisoning.

    Science.gov (United States)

    Johnston, A McD

    2004-09-01

    In situations with relatively small numbers of patients with pulmonary blast injury aggressive modern intensive care treatment may allow a return to normal function. The additional effects of radiation poisoning are more difficult to factor in, but new treatments such as colony stimulating factors may improve the outlook for a group with moderate to severe radiation exposure who would previously have died of infection or haemorrhage.

  9. Internal Jugular Vein Compression: A Novel Approach to Mitigate Blast Induced Hearing Injury.

    Science.gov (United States)

    Sindelar, Brian; Shinners, Michael; Sherman, Sydney; Novak, Kevin; Erickson, Kristine; Patel, Vimal; Kubilis, Paul; Smith, David; Finan, John; Bailes, Julian E

    2017-04-01

    Internal jugular vein (IJV) compression before blast injury will lead to reduced risk of traumatic hearing injury following exposure to a blast injury. IJV compression and its effects on not only intracranial, but also intracochlear pressure may potentiate blast induced hearing injury, therefore, precluding its use as a prophylactic therapy for blast induced traumatic brain injury. Twenty Sprague Dawley rats were exposed to a 17.9 ± 0.4 PSI (195.8 dB SPL) right sided shock wave in which 10 had application of a custom IJV compression collar before injury. All rodents received baseline and post blast injury otoacoustic emission (OAE) and auditory brainstem response (ABR) testing followed by cochlear histology. IJV compression was shown to significantly reduce ABR and OAE threshold shifts in comparison to the non-intervention group by: 14.9 ± 4.8 dB (right ear ABR 0.5 kHz Day 1 post blast, p = 0.01), 13.1 ± 4.9 dB (right ear ABR 4 kHz Day 1 post blast, p = 0.04), 16.5 ± 4.5 dB (right ear ABR click Day 1 post blast, p = 0.003), 12.1 ± 4.6 dB (right ear ABR click Day 6 post blast, p = 0.04), and 14.0 ± 3.2 dB (both ears OAE 3.2-10 kHz, p collar application had a greater number of total hair cells per mm from 70 to 100% distance from the cochlear apex following blast injury in comparison to those without intervention (blast: 211.8 ± 27.5 versus blast+collar: 355.5 ± 39.5 [p = 0.0002]). This study supports the use of IJV compression in a pre-clinical model as a new prophylactic mechanism to combat blast induced hearing injury.

  10. Blast-induced Mild Traumatic Brain Injury

    Science.gov (United States)

    2010-01-01

    directly to the brain after craniotomy 154 or 240 kPa Unknown 2.8 or 20 kPa 40 kPa 1 or 10 MPa Redistribution of phosphorylated neurofilament H...m a: 1𔃻) .... !l ~ Blast-induced Mild Traumatic Brain Injury 767 colleagues55 compared neuropsychological test results in a group of primarily...patterns between blast and non-blast-injured subjects, thus providing no support at the neuropsychological level that blast is different. However

  11. Service robot for hull-blasting

    OpenAIRE

    Ortiz Zaragoza, Francisco José; Iborra García, Andrés José; Álvarez Torres, María Bárbara; Marín García, Fulgencio; Fernández Meroño, José María

    2001-01-01

    Present grit blasting technology for hull cleaning is very pollutant, environmentally unaffordable, and it is progressively forbidden in the most environmental countries (mainly north of Europe). At the time being, the above methodology has been partially substituted by ultra highpressure water blasting, however they do not show as good performance as the grit blasting systems. This paper describes a service robot for hull blasting. The technology we developed consists of the cleanin...

  12. Effects of filament size on critical current density in overpressure processed Bi-2212 round wire.

    Science.gov (United States)

    Jiang, Jianyi; Francis, Ashleigh; Alicea, Ryan; Matras, Maxime; Kametani, Fumitake; Trociewitz, Ulf P; Hellstrom, Eric E; Larbalestier, David C

    2017-06-01

    Bi 2 Sr 2 CaCu 2 O x (Bi-2212) conductor is the only high temperature superconductor manufactured as a round wire and is a very promising conductor for very high field applications. One of the key design parameters of Bi-2212 wire is its filament size, which has been previously reported to affect the critical current density ( J c ) and ac losses. Work with 1 bar heat treatment showed that the optimal filament diameter was about 15 μm but it was not well understood at that time that gas bubbles were the main current limiting mechanism. Here we investigated a recent Bi-2212 wire with a 121×18 filament architecture with varying wire diameter (1.0 to 1.5 mm) using 50 bar overpressure processing. This wire is part of a 1.2 km piece length of 1.0 mm diameter made by Oxford Superconducting Technology. We found that J c is independent of the filament size in the range from 9 to 14 μm, although the n value increased with increasing filament size. A new record J c (4.2 K, 15 T) of 4200 A/mm 2 and J E (4.2 K, 15 T) of 830 A/mm 2 were achieved.

  13. Structural response of reactor-core hexcan subassemblies subjected to dynamic overpressurization under accident conditions

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.; Kulak, R.F.

    1993-01-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall

  14. Dynamic structural response of reactor-core subassemblies (hexcans) due to accident overpressurization

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.; Kulak, R.F.

    1993-01-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall

  15. Dynamic structural response of reactor-core subassemblies (hexcans) due to accident overpressurization

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.; Kulak, R.F.

    1993-01-01

    This paper presents a two-dimensional structural analysis for the evaluation of a single core subassembly due to internal overpressure associated with possible failure of fuel pins having high fission gas plenum pressure. Structural models are developed for the subassemblies and their surroundings with emphasis on the critical physical aspects of the problem. With these models the strains, deformations and the extent of permanent damage (plastic strain) to the subassemblies can be assessed. The nonlinear structural analyses was performed with a finite element program called STRAW (Structural Transient Response of Assembly Wrappers). This finite element program is applicable to nonlinear large displacement problems. The results of this study indicate that the permanent deformation (damage) is strongly influenced by the rise time (time to reach peak pressure) of the pressure pulse and the pressure in the fuel pin. The rise time is influenced by the opening time of the flow path for release of gas from the fuel pin plenum. Several examples are illustrated with various rise times and pressure magnitudes and the resulting permanent deformation of the hexcan wall. (author)

  16. Seismic chimneys in the Southern Viking Graben - Implications for palaeo fluid migration and overpressure evolution

    Science.gov (United States)

    Karstens, Jens; Berndt, Christian

    2015-02-01

    Detailed understanding of natural fluid migration systems is essential to minimize risks during hydrocarbon exploration and to evaluate the long-term efficiency of the subsurface storage of waste water and gas from hydrocarbon production as well as CO2. The Southern Viking Graben (SVG) hosts numerous focused fluid flow structures in the shallow (expressions of vertical fluid conduits are variously known as seismic chimneys or pipes. Seismic pipes are known to form large clusters. Seismic chimneys have so far been described as solitary structures. Here, we show that the study area in the SVG hosts more than 46 large-scale vertical chimney structures, which can be divided in three categories implying different formation processes. Our analysis reveals that seal-weakening, formation-wide overpressure and the presence of free gas are required to initiate the formation of vertical fluid conduits in the SVG. The presence of numerous vertical fluid conduits implies inter-stratigraphic hydraulic connectivity, which significantly affects the migration of fluids in the subsurface. Chimney structures are important for understanding the transfer of pore pressure anomalies to the shallow parts of the basin.

  17. Overpressure generation by load transfer following shale framework weakening due to smectite diagenesis

    Science.gov (United States)

    Lahann, R.W.; Swarbrick, R.E.

    2011-01-01

    Basin model studies which have addressed the importance of smectite conversion to illite as a source of overpressure in the Gulf of Mexico have principally relied on a single-shale compaction model and treated the smectite reaction as only a fluid-source term. Recent fluid pressure interpretation and shale petrology studies indicate that conversion of bound water to mobile water, dissolution of load-bearing grains, and increased preferred orientation change the compaction properties of the shale. This results in substantial changes in effective stress and fluid pressure. The resulting fluid pressure can be 1500-3000psi higher than pressures interpreted from models based on shallow compaction trends. Shale diagenesis changes the mineralogy, volume, and orientation of the load-bearing grains in the shale as well as the volume of bound water. This process creates a weaker (more compactable) grain framework. When these changes occur without fluid export from the shale, some of the stress is transferred from the grains onto the fluid. Observed relationships between shale density and calculated effective stress in Gulf of Mexico shelf wells confirm these changes in shale properties with depth. Further, the density-effective stress changes cannot be explained by fluid-expansion or fluid-source processes or by prediagenesis compaction, but are consistent with a dynamic diagenetic modification of the shale mineralogy, texture, and compaction properties during burial. These findings support the incorporation of diagenetic modification of compaction properties as part of the fluid pressure interpretation process. ?? 2011 Blackwell Publishing Ltd.

  18. The Foulness multi-ton air blast simulator. Part 2. Recent developments - the linear charge driven facility

    International Nuclear Information System (INIS)

    Clare, P.M.

    1978-02-01

    The gun-driven facility for simulating nuclear air blast has been described in Part 1 (AWRE Report 031/74). It was, however, subject to certain limitations in providing the requisite blast parameters for nuclear hardening. The efficiency of the simulator has been improved beyond that of the gun-driven facility to produce blast waves of higher peak overpressure, longer positive duration and greater equivalent yield. This has been done by firing in the 1.8 m (6 ft) diameter section of the tunnel instead of in the guns. Various line charge arrangements were investigated and the pressures and strains developed in the 1.8 m (6 ft) diameter section were measured. The shock loading on the tube walls was less than that produced by firing in the guns and consisted of a short duration shock decaying to a lower amplitude pressure pulse of longer duration (1 ms), followed by a few reflected shocks which the tube walls were well able to withstand. The equipment is described and results discussed. (author)

  19. 30 CFR 75.1323 - Blasting circuits.

    Science.gov (United States)

    2010-07-01

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

  20. BLEVE blast by expansion-controlled evaporation

    NARCIS (Netherlands)

    Berg, A.C. van den; Voort, M.M. van der; Weerheijm, J.; Versloot, N.H.A.

    2006-01-01

    This report presents a new method to calculate the blast effects originating from an exploding vessel of liquefied gas. Adequate blast calculation requires full knowledge of the blast source characteristics, that is, the release and subsequent evaporation rate of the flashing liquid. Because the

  1. Simulating geometrically complex blast scenarios

    Directory of Open Access Journals (Sweden)

    Ian G. Cullis

    2016-04-01

    Full Text Available The effects of blast waves generated by energetic and non-energetic sources are of continuing interest to the ballistics research community. Modern conflicts are increasingly characterised by asymmetric urban warfare, with improvised explosive devices (IEDs often playing a dominant role on the one hand and an armed forces requirement for minimal collateral effects from their weapons on the other. These problems are characterised by disparate length- and time-scales and may also be governed by complex physics. There is thus an increasing need to be able to rapidly assess and accurately predict the effects of energetic blast in topologically complex scenarios. To this end, this paper presents a new QinetiQ-developed advanced computational package called EAGLE-Blast, which is capable of accurately resolving the generation, propagation and interaction of blast waves around geometrically complex shapes such as vehicles and buildings. After a brief description of the numerical methodology, various blast scenario simulations are described and the results compared with experimental data to demonstrate the validation of the scheme and its ability to describe these complex scenarios accurately and efficiently. The paper concludes with a brief discussion on the use of the code in supporting the development of algorithms for fast running engineering models.

  2. Domain enhanced lookup time accelerated BLAST

    Directory of Open Access Journals (Sweden)

    Boratyn Grzegorz M

    2012-04-01

    Full Text Available Abstract Background BLAST is a commonly-used software package for comparing a query sequence to a database of known sequences; in this study, we focus on protein sequences. Position-specific-iterated BLAST (PSI-BLAST iteratively searches a protein sequence database, using the matches in round i to construct a position-specific score matrix (PSSM for searching the database in round i + 1. Biegert and Söding developed Context-sensitive BLAST (CS-BLAST, which combines information from searching the sequence database with information derived from a library of short protein profiles to achieve better homology detection than PSI-BLAST, which builds its PSSMs from scratch. Results We describe a new method, called domain enhanced lookup time accelerated BLAST (DELTA-BLAST, which searches a database of pre-constructed PSSMs before searching a protein-sequence database, to yield better homology detection. For its PSSMs, DELTA-BLAST employs a subset of NCBI’s Conserved Domain Database (CDD. On a test set derived from ASTRAL, with one round of searching, DELTA-BLAST achieves a ROC5000 of 0.270 vs. 0.116 for CS-BLAST. The performance advantage diminishes in iterated searches, but DELTA-BLAST continues to achieve better ROC scores than CS-BLAST. Conclusions DELTA-BLAST is a useful program for the detection of remote protein homologs. It is available under the “Protein BLAST” link at http://blast.ncbi.nlm.nih.gov. Reviewers This article was reviewed by Arcady Mushegian, Nick V. Grishin, and Frank Eisenhaber.

  3. Blast wave parameters at diminished ambient pressure

    Science.gov (United States)

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

    2015-04-01

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

  4. Parallel BLAST on split databases.

    Science.gov (United States)

    Mathog, David R

    2003-09-22

    BLAST programs often run on large SMP machines where multiple threads can work simultaneously and there is enough memory to cache the databases between program runs. A group of programs is described which allows comparable performance to be achieved with a Beowulf configuration in which no node has enough memory to cache a database but the cluster as an aggregate does. To achieve this result, databases are split into equal sized pieces and stored locally on each node. Each query is run on all nodes in parallel and the resultant BLAST output files from all nodes merged to yield the final output. Source code is available from ftp://saf.bio.caltech.edu/

  5. Control buildings for blast resistance

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.A.

    1982-08-01

    Offers advice on interior design for blast-resistant control buildings. Suggests that for the comfort and safety of occupants, special attention must be paid to internal finishes and color schemes. Considers external treatment (e.g. panels, cladding fixings, thermal insulation), air intakes and exhausts, internal finishes (e.g. stud lining method), and internal walls and partitions. Presents diagrams showing construction method for a control building; elimination of ''cold bridge'' at eaves level; staggering door openings to minimize blast effects; and flexure of concrete walls without affecting the inner lining.

  6. Blast Responses and Vibration of Flood-Defense Structures under High-Intensity Blast Loadings

    Directory of Open Access Journals (Sweden)

    Yonghee Ryu

    2018-01-01

    Full Text Available This study presented the blast behavior of flood-defense structures subjected to high-intensity loadings such as blast shock waves. In order to understand the blast behavior of weir structures, PHAST program was used to predict blast loadings in consideration of material reactivity and congestion levels. Environment factors such as weather data and atmospheric parameters were also considered in this study. Then, nonlinear dynamic analyses were performed using the ABAQUS platform to evaluate structural responses and blast vibration of concrete weir structures subjected to various types of blast loadings, due to uncertainties of the magnitude and durations of blast loads as a function of distance from the explosion. It was shown that the blast damage to concrete weir structure was significantly influenced by congestion levels or material reactivity. Also, the stress concentration under blast loading was observed at the connection area between the concrete weir body and stilling basin.

  7. On the Accurate Determination of Shock Wave Time-Pressure Profile in the Experimental Models of Blast-Induced Neurotrauma

    Directory of Open Access Journals (Sweden)

    Maciej Skotak

    2018-02-01

    Full Text Available Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime. These observations were despite the fact that typical overpressures in our experiments do not exceed 50 psi for sensors that are rated at 1,000 psi maximum pressure. We demonstrate that sampling rate of 1,000 kHz is necessary to capture the correct rise time values, but there were no statistically significant differences between peak overpressure and impulse values for low-intensity shock waves (Mach number <2 at lower rates. We discuss two sources of experimental errors originating from mechanical vibration and electromagnetic interference on the quality of a waveform recorded using state-of-the-art high-frequency pressure sensors. The implementation of preventive measures, pressure acquisition artifacts, and data interpretation with examples, are provided in this paper that will help the community at large to avoid these mistakes. In order to facilitate inter-laboratory data comparison, common reporting standards should be developed by the blast TBI research community. We noticed the majority of published literature on the subject limits reporting to peak overpressure; with much less attention directed toward other important parameters, i.e., duration, impulse, and dynamic pressure. These parameters should be included as a mandatory requirement in publications so the results can be properly

  8. Longitudinal variations of laryngeal overpressure and voice-related quality of life in spasmodic dysphonia.

    Science.gov (United States)

    Yeung, Jeffrey C; Fung, Kevin; Davis, Eric; Rai, Sunita K; Day, Adam M B; Dzioba, Agnieszka; Bornbaum, Catherine; Doyle, Philip C

    2015-03-01

    Adductor spasmodic dysphonia (AdSD) is a voice disorder characterized by variable symptom severity and voice disability. Those with the disorder experience a wide spectrum of symptom severity over time, resulting in varied degrees of perceived voice disability. This study investigated the longitudinal variability of AdSD, with a focus on auditory-perceptual judgments of a dimension termed laryngeal overpressure (LO) and patient self-assessments of voice-related quality of life (V-RQOL). Longitudinal, correlational study. Ten adults with AdSD were followed over three time periods. At each, both voice samples and self-ratings of V-RQOL were gathered prior to their scheduled Botox injection. Voice recordings subsequently were perceptually evaluated by eight listeners for LO using a visual analog scale. LO ratings for all-voiced and Rainbow Passage sentence stimuli were found to be highly correlated. However, only the LO ratings obtained from judgments of AV stimuli were found to correlate moderately with self-ratings of voice disability for both the physical functioning and social-emotional subscores, as well as the total V-RQOL score. Based on perceptual judgments, LO appears to provide a reliable means of quantifying the severity of voice abnormalities in AdSD. Variability in self-ratings of the V-RQOL suggest that perceived disability related to AdSD should be actively monitored. Further, auditory-perceptual judgments may provide an accurate index of the potential impact of the disorder on the speaker. Similarly, LO was supported as a simple clinical measure that serves as a reliable index of voice change over time. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

  9. Over-pressure test on BARCOM pre-stressed concrete containment

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, R.M.; Singh, Tarvinder; Thangamani, I.; Trivedi, Neha; Singh, Ram Kumar, E-mail: rksingh@barc.gov.in

    2014-04-01

    Bhabha Atomic Research Centre (BARC), Trombay has organized an International Round Robin Analysis program to carry out the ultimate load capacity assessment of BARC Containment (BARCOM) test model. The test model located in BARC facilities Tarapur; is a 1:4 scale representation of 540 MWe Pressurized Heavy Water Reactor (PHWR) pre-stressed concrete inner containment structure of Tarapur Atomic Power Station (TAPS) unit 3 and 4. There are a large number of sensors installed in BARCOM that include vibratory wire strain gauges of embedded and spot-welded type, surface mounted electrical resistance strain gauges, dial gauges, earth pressure cells, tilt meters and high resolution digital camera systems for structural response, crack monitoring and fracture parameter measurement to evaluate the local and global behavior of the containment test model. The model has been tested pneumatically during the low pressure tests (LPTs) followed by proof test (PT) and integrated leakage rate test (ILRT) during commissioning. Further the over pressure test (OPT) has been carried out to establish the failure mode of BARCOM Test-Model. The over-pressure test will be completed shortly to reach the functional failure of the test model. Pre-test evaluation of BARCOM was carried out with the results obtained from the registered international round robin participants in January 2009 followed by the post-test assessment in February 2011. The test results along with the various failure modes related to the structural members – concrete, rebars and tendons identified in terms of prescribed milestones are presented in this paper along with the comparison of the pre-test predictions submitted by the registered participants of the Round Robin Analysis for BARCOM test model.

  10. Evaluation of Novel Polyunsaturated Fatty Acid Derived Lipid Mediators of Inflammation to Ameliorate the Deleterious Effects of Blast Overpressure on Eye and Brain Visual Processing Centers in Rats

    Science.gov (United States)

    2014-10-01

    animal was lost to histopathology, due to its unexpected death shortly after being ERG tested for the final time. A total of 108 eye and 432 brain...Moderate 5 = Severe 6 = Catastrophic ( pitch black) Judged by intensity of silver stain coloration * * * * Efficacy Order Right: RVD1 > PDX...PDX SHAM + RVD1 Brain optic tracts Brain optic tract injury scoring scale: 1 = None 2 = Slight 3 = Mild 4 = Moderate 5 = Severe 6 = Catastrophic ( pitch

  11. Evaluation of Novel Polyunsaturated Fatty Acid Derived Lipid Mediators of Inflammation to Ameliorate the Deleterious Effects of Blast Overpressure on Eye and Brain Visual Processing Centers in Rats

    Science.gov (United States)

    2013-10-01

    we have with the procedure is many rats come out of the shock tube exhibiting severe signs of apnea . If breathing has ceased, we immediately...afterwards, yielding an excellent survival rate. This procedure, however, could still have produced transient ischemia in rats afflicted with apnea ...conditioning phase, but failed to master the test (8) or prematurely died afterward (3). This represents a total of 286 visual discrimination test trials

  12. Fragment Size Distribution of Blasted Rock Mass

    Science.gov (United States)

    Jug, Jasmin; Strelec, Stjepan; Gazdek, Mario; Kavur, Boris

    2017-12-01

    Rock mass is a heterogeneous material, and the heterogeneity of rock causes sizes distribution of fragmented rocks in blasting. Prediction of blasted rock mass fragmentation has a significant role in the overall economics of opencast mines. Blasting as primary fragmentation can significantly decrease the cost of loading, transport, crushing and milling operations. Blast fragmentation chiefly depends on the specific blast design (geometry of blast holes drilling, the quantity and class of explosive, the blasting form, the timing and partition, etc.) and on the properties of the rock mass (including the uniaxial compressive strength, the rock mass elastic Young modulus, the rock discontinuity characteristics and the rock density). Prediction and processing of blasting results researchers can accomplish by a variety of existing software’s and models, one of them is the Kuz-Ram model, which is possibly the most widely used approach to estimating fragmentation from blasting. This paper shows the estimation of fragmentation using the "SB" program, which was created by the authors. Mentioned program includes the Kuz-Ram model. Models of fragmentation are confirmed and calibrated by comparing the estimated fragmentation with actual post-blast fragmentation from image processing techniques. In this study, the Kuz-Ram fragmentation model has been used for an open-pit limestone quarry in Dalmatia, southern Croatia. The resulting calibrated value of the rock factor enables the quality prognosis of fragmentation in further blasting works, with changed drilling geometry and blast design parameters. It also facilitates simulation in the program to optimize blasting works and get the desired fragmentations of the blasted rock mass.

  13. Mask materials for powder blasting

    NARCIS (Netherlands)

    Wensink, H.; Jansen, Henricus V.; Berenschot, Johan W.; Elwenspoek, Michael Curt

    Powder blasting, or abrasive jet machining (AJM), is a technique in which a particle jet is directed towards a target for mechanical material removal. It is a fast, cheap and accurate directional etch technique for brittle materials such as glass, silicon and ceramics. The particle jet (which

  14. INCREASED RELIABILITY OF ELECTRIC BLASTING

    OpenAIRE

    Kashuba, Oleh Ivanovych; Skliarov, L I; Skliarov, A L

    2017-01-01

    The problems of improving reliability of an electric blasting method using electric detonators with nichrome filament bridges. It was revealed that in the calculation of the total resistance of the explosive network it is necessary to increase to 24% of the nominal value

  15. An analysis of the heap construction by long hole blasting for in-situ leaching of blasted ore

    International Nuclear Information System (INIS)

    Yang Shijiao

    1999-01-01

    The author establishes specific requirements for heap construction by blasting on the basis of the mechanism for in situ leaching of blasted ore, analyses the feasibility of heap construction by long hole blasting, selection of the blast plan and the relevant technological problems, and gives a case of heap construction by long hole blasting in Renhua uranium mine

  16. Computational modeling of blast wave interaction with a human body and assessment of traumatic brain injury

    Science.gov (United States)

    Tan, X. G.; Przekwas, A. J.; Gupta, R. K.

    2017-11-01

    The modeling of human body biomechanics resulting from blast exposure poses great challenges because of the complex geometry and the substantial material heterogeneity. We developed a detailed human body finite element model representing both the geometry and the materials realistically. The model includes the detailed head (face, skull, brain and spinal cord), the neck, the skeleton, air cavities (lungs) and the tissues. Hence, it can be used to properly model the stress wave propagation in the human body subjected to blast loading. The blast loading on the human was generated from a simulated C4 explosion. We used the highly scalable solvers in the multi-physics code CoBi for both the blast simulation and the human body biomechanics. The meshes generated for these simulations are of good quality so that relatively large time-step sizes can be used without resorting to artificial time scaling treatments. The coupled gas dynamics and biomechanics solutions were validated against the shock tube test data. The human body models were used to conduct parametric simulations to find the biomechanical response and the brain injury mechanism due to blasts impacting the human body. Under the same blast loading condition, we showed the importance of inclusion of the whole body.

  17. Reconstruction of fluid (over-)pressure evolution from sub-seismic fractures in folds and foreland basins

    Science.gov (United States)

    Beaudoin, Nicolas; Lacombe, Olivier; Bellahsen, Nicolas; Emmanuel, Laurent

    2013-04-01

    Deciphering the evolution of pressure, temperature and chemistry of fluids during fold history is a challenging problem. While temperature and chemistry of paleo-fluids can be determined using vein mineralizations in fault zones and/or in diffuse sub-seismic fracture sets, few methods exist to constrain the evolution through time of fluid pressure, especially when no hydrocarbons are encountered. This contribution aims at presenting and discussing a new approach to reconstruct the evolution of fluid pressure based on paleostress analyses. The combination of stress inversion of fault slip data and calcite twin data with rock mechanics data allows determining both the orientations and the magnitudes of principal stresses during basin evolution. Assuming no burial change through time, the comparison of the computed magnitudes of the effective vertical stress with its theoretical value (calculated with respect to the paleo-overburden and hydrostatic fluid pressure) may be used to quantitatively estimate fluid overpressure in limestones at different steps of the tectonic history. Alternatively, if hydrostatic fluid pressure is assumed to prevail in the system from step to step, results likely reflect overburden variations. The application focuses on the diffuse fracture populations observed in limestones of the famous Mississippian-Permian Madison and Phosphoria formations in Laramide basement-cored folds of the Rocky Mountains: the Sheep Mountain and the Rattlesnake Mountain anticlines (Bighorn Basin, Wyoming, USA). The location of these basement-folds on each edge of the Bighorn Basin ensures that depositional and erosional events can be neglected before folding, and thus grants the opportunity to constrain and to discuss the level of fluid overpressure during both the Sevier (thin-skinned) and Laramide (thick-skinned) related Layer-Parallel Shortening (LPS) phases at both fold scale and basin scale. Results highlight an initial fluid overpressure in limestones buried

  18. High-speed imaging and small-scale explosive characterization techniques to understand effects of primary blast-induced injury on nerve cell structure and function

    Science.gov (United States)

    Piehler, T.; Banton, R.; Zander, N.; Duckworth, J.; Benjamin, R.; Sparks, R.

    2018-01-01

    Traumatic brain injury (TBI) is often associated with blast exposure. Even in the absence of penetrating injury or evidence of tissue injury on imaging, blast TBI may trigger a series of neural/glial cellular and functional changes. Unfortunately, the diagnosis and proper treatment of mild traumatic brain injury (mTBI) caused by explosive blast is challenging, as it is not easy to clinically distinguish blast from non-blast TBI on the basis of patient symptoms. Damage to brain tissue, cell, and subcellular structures continues to occur slowly and in a manner undetectable by conventional imaging techniques. The threshold shock impulse levels required to induce damage and the cumulative effects upon multiple exposures are not well characterized. Understanding how functional and structural damage from realistic blast impact at cellular and tissue levels at variable timescales after mTBI events may be vital for understanding this injury phenomenon and for linking mechanically induced structural changes with measurable effects on the nervous system. Our working hypothesis is that there is some transient physiological dysfunction occurring at cellular and subcellular levels within the central nervous system due to primary blast exposure. We have developed a novel in vitro indoor experimental system that uses real military explosive charges to more accurately represent military blast exposure and to probe the effects of primary explosive blast on dissociated neurons. We believe this system offers a controlled experimental method to analyze and characterize primary explosive blast-induced cellular injury and to understand threshold injury phenomenon. This paper will also focus on the modeling aspect of our work and how it relates to the experimental work.

  19. Dyke thicknesses follow a Weibull distribution controlled by host-rock strength and magmatic overpressure

    Science.gov (United States)

    Krumbholz, M.; Hieronymus, C.; Burchardt, S.; Troll, V. R.; Tanner, D. C.; Friese, N.

    2012-04-01

    thickness, irrespective of the tectonic setting, type of magmatic sheet intrusion (e.g. regional dykes and inclined sheets), or magma type. Moreover, the Weibull distribution of dyke thickness can be easily explained by the interplay of host-rock strength (i.e. the distribution of weaknesses) and magmatic overpressure.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-07-01

    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.

  1. CrocoBLAST: Running BLAST efficiently in the age of next-generation sequencing.

    Science.gov (United States)

    Tristão Ramos, Ravi José; de Azevedo Martins, Allan Cézar; da Silva Delgado, Gabrielle; Ionescu, Crina-Maria; Ürményi, Turán Peter; Silva, Rosane; Koca, Jaroslav

    2017-11-15

    CrocoBLAST is a tool for dramatically speeding up BLAST+ execution on any computer. Alignments that would take days or weeks with NCBI BLAST+ can be run overnight with CrocoBLAST. Additionally, CrocoBLAST provides features critical for NGS data analysis, including: results identical to those of BLAST+; compatibility with any BLAST+ version; real-time information regarding calculation progress and remaining run time; access to partial alignment results; queueing, pausing, and resuming BLAST+ calculations without information loss. CrocoBLAST is freely available online, with ample documentation (webchem.ncbr.muni.cz/Platform/App/CrocoBLAST). No installation or user registration is required. CrocoBLAST is implemented in C, while the graphical user interface is implemented in Java. CrocoBLAST is supported under Linux and Windows, and can be run under Mac OS X in a Linux virtual machine. jkoca@ceitec.cz. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  2. Blast-Induced Tinnitus and Elevated Central Auditory and Limbic Activity in Rats: A Manganese-Enhanced MRI and Behavioral Study.

    Science.gov (United States)

    Ouyang, Jessica; Pace, Edward; Lepczyk, Laura; Kaufman, Michael; Zhang, Jessica; Perrine, Shane A; Zhang, Jinsheng

    2017-07-07

    Blast-induced tinitus is the number one service-connected disability that currently affects military personnel and veterans. To elucidate its underlying mechanisms, we subjected 13 Sprague Dawley adult rats to unilateral 14 psi blast exposure to induce tinnitus and measured auditory and limbic brain activity using manganese-enhanced MRI (MEMRI). Tinnitus was evaluated with a gap detection acoustic startle reflex paradigm, while hearing status was assessed with prepulse inhibition (PPI) and auditory brainstem responses (ABRs). Both anxiety and cognitive functioning were assessed using elevated plus maze and Morris water maze, respectively. Five weeks after blast exposure, 8 of the 13 blasted rats exhibited chronic tinnitus. While acoustic PPI remained intact and ABR thresholds recovered, the ABR wave P1-N1 amplitude reduction persisted in all blast-exposed rats. No differences in spatial cognition were observed, but blasted rats as a whole exhibited increased anxiety. MEMRI data revealed a bilateral increase in activity along the auditory pathway and in certain limbic regions of rats with tinnitus compared to age-matched controls. Taken together, our data suggest that while blast-induced tinnitus may play a role in auditory and limbic hyperactivity, the non-auditory effects of blast and potential traumatic brain injury may also exert an effect.

  3. Alkaline carbonates in blast furnace process

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-10-01

    Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

  4. Acute Inflammatory Response in Rodent Brain and Blood Following a Blast Induced Traumatic Brain Injury

    Science.gov (United States)

    2014-11-01

    dehydrated with 30% sucrose before storing at -80 °C. Thirty micron coronal sections were stained with a primary antibody against microglia ...strongly Iba-1 stained cells as compared to controls. These results indicate blast exposure induces activation of microglia in the hippocampus... Neuroinflammation after traumatic brain injury: Opportunities for therapeutic intervention. Brain, behaviour and Immunity 26: 1191-1201. Loane, D. J

  5. A new AVA attribute based on P-wave and S-wave reflectivities for overpressure prediction

    Science.gov (United States)

    Aleardi, Mattia; Mapelli, Luca; Mazzotti, Alfredo

    2017-05-01

    Pore pressure prediction is a key step for safe well drilling operations and is usually performed by deriving a velocity-pressure relationship calibrated to a reference well. However, in the last few decades, other seismic-based methods, such as the Amplitude versus Angle (AVA) technique, have been extended to predict anomalous pressure values. Concerning AVA analysis, in this work, we show that the expected pressure effect on the elastic rock properties is very different from the fluid effect, thus making the classical AVA attributes used for fluid prediction ineffective at highlighting pressure anomalies. Therefore, we propose a new AVA attribute to evidence the decrease in P-wave and S-wave reflectivity that usually occurs when passing from an overlying formation to an underlying overpressured one. This attribute can be easily derived from the intercept and gradient values extracted from the recorded seismic pre-stack data by means of the Shuey equation. To demonstrate the applicability of this new attribute for pore pressure prediction we show examples on synthetic seismic data and three applications to different field datasets over already drilled prospects. In the case of overpressured layers, this attribute shows anomalous responses, thus demonstrating its effectiveness in highlighting anomalous pore pressure regimes. In contrast, no anomalous attribute values are observed in cases characterized by a hydrostatic pore pressure regime.

  6. Statistics of peak overpressure and shock steepness for linear and nonlinear N-wave propagation in a kinematic turbulence.

    Science.gov (United States)

    Yuldashev, Petr V; Ollivier, Sébastien; Karzova, Maria M; Khokhlova, Vera A; Blanc-Benon, Philippe

    2017-12-01

    Linear and nonlinear propagation of high amplitude acoustic pulses through a turbulent layer in air is investigated using a two-dimensional KZK-type (Khokhlov-Zabolotskaya-Kuznetsov) equation. Initial waves are symmetrical N-waves with shock fronts of finite width. A modified von Kármán spectrum model is used to generate random wind velocity fluctuations associated with the turbulence. Physical parameters in simulations correspond to previous laboratory scale experiments where N-waves with 1.4 cm wavelength propagated through a turbulence layer with the outer scale of about 16 cm. Mean value and standard deviation of peak overpressure and shock steepness, as well as cumulative probabilities to observe amplified peak overpressure and shock steepness, are analyzed. Nonlinear propagation effects are shown to enhance pressure level in random foci for moderate initial amplitudes of N-waves thus increasing the probability to observe highly peaked waveforms. Saturation of the pressure level is observed for stronger nonlinear effects. It is shown that in the linear propagation regime, the turbulence mainly leads to the smearing of shock fronts, thus decreasing the probability to observe high values of steepness, whereas nonlinear effects dramatically increase the probability to observe steep shocks.

  7. Research on the water hammer protection of the long distance water supply project with the combined action of the air vessel and over-pressure relief valve

    International Nuclear Information System (INIS)

    Li, D D; Jiang, J; Zhao, Z; Yi, W S; Lan, G

    2013-01-01

    We take a concrete pumping station as an example in this paper. Through the calculation of water hammer protection with a specific pumping station water supply project, and the analysis of the principle, mathematical models and boundary conditions of air vessel and over-pressure relief valve we show that the air vessel can protect the water conveyance system and reduce the transient pressure damage due to various causes. Over-pressure relief valve can effectively reduce the water hammer because the water column re-bridge suddenly stops the pump and prevents pipeline burst. The paper indicates that the combination set of air vessel and over-pressure relief valve can greatly reduce the quantity of the air valve and can eliminate the water hammer phenomenon in the pipeline system due to the vaporization and water column separation and re-bridge. The conclusion could provide a reference for the water hammer protection of long-distance water supply system

  8. CO2 blasting in Europe

    International Nuclear Information System (INIS)

    Vankerckhoven, Patrick

    1995-01-01

    Carbon dioxide blasting can be used during the lifetime of nuclear facilities to remove deposited contamination and reduce the dose to personnel during repair and maintenance. By contrast with conventional mechanical or chemical decontamination methods, it does not leave additional secondary wastes. During the process, liquid CO 2 is expanded and converted into dry snow which is compressed and extruded to form small dry ice pellets. These low temperature pellets are blasted at high speed in a stream of compressed air against the surface to be treated where the mechanical and thermal shock embrittles the contaminating layer and severs its bond with the surface. The dry ice sublimes into the atmosphere as CO 2 gas and the loosened contamination can be removed via a ventilation and filtration system. Some examples of the effective use of CO 2 blasting are given. They include decontamination of: a supercompactor used on radioactive waste drums; the walls and floors of a nuclear fuel fabrication plant; the vacuum vessel of the Joint European Torus, hot cells; a phosphate fertilizer plant contaminated by radium 226. (UK)

  9. Air blast circuit breaker noise and hearing loss: a multifactorial model for risk assessment.

    Science.gov (United States)

    McBride, D I; Williams, S

    2000-04-01

    The assessment of the risk to hearing from impulse noise exposure may be a problem for the occupational physician because existing legislative and international noise exposure standards deal primarily with continuous noise, and are not valid in excess of the peak exposure limit of 200 pa (140 dB). Noise exposure in excess of this level, for example that due to firearms, is frequently perceived as harmful, but this is not necessarily the case, as impulse noise standards do, in fact, allow exposure with a maximum in the order of 6.3 kPa (170 dB). To illustrate this, a cross-sectional group of electrical transmission workers have been studied who were exposed to significant levels of impulse noise from air blast circuit breakers and firearms. Important hearing loss factors have been identified by means of a specially designed questionnaire. Using the Health & Safety Executive definition, the risk of hearing loss was determined by calculating prevalence odds ratios (ORs) for exposure to these factors. The OR for those with fewer than eight unprotected air blast circuit breaker exposures was 2.27 (95% confidence interval (CI), 1.01-5.08), whilst for those with more than eight exposures the OR was 2.10 (95% CI, 0.97-4.54). For firearm exposure, ORs of 1.61 (95% CI, 0.95-2.74) were noted in the medium exposure group and 2.05 (95% CI, 1.08-3.86) in the high exposure group. When all the factors were included in the model, the most significant factor was age. The study gives support to the impulse noise exposure criteria, confirming the borderline risk from air blast circuit breaker noise exposure and the relative safety of moderate gunfire exposure.

  10. The Vestibular Effects of Repeated Low-Level Blasts.

    Science.gov (United States)

    Littlefield, Philip D; Pinto, Robin L; Burrows, Holly L; Brungart, Douglas S

    2016-01-01

    The objective of this study was to use a prospective cohort of United States Marine Corps (USMC) instructors to identify any acute or long-term vestibular dysfunction following repeated blast exposures during explosive breaching training. They were assessed in clinic and on location during training at the USMC Methods of Entry School, Quantico, VA. Subjects received comprehensive baseline vestibular assessments and these were repeated in order to identify longitudinal changes. They also received shorter assessments immediately following blast exposure in order to identify acute findings. The main outcome measures were the Neurobehavioral Symptom Inventory, vestibular Visual Analog Scale (VAS) of subjective vestibular function, videonystagmography (VNG), vestibular evoked myogenic potentials (VEMP), rotary chair (including the unilateral centrifugation test), computerized dynamic posturography, and computerized dynamic visual acuity. A total of 11 breachers and 4 engineers were followed for up to 17 months. No acute effects or longitudinal deteriorations were identified, but there were some interesting baseline group differences. Upbeat positional nystagmus was common, and correlated (p<0.005) with a history of mild traumatic brain injury (mTBI). Several instructors had abnormally short low-frequency phase leads on rotary chair testing. This study evaluated breaching instructors over a longer test period than any other study, and the results suggest that this population appears to be safe from a vestibular standpoint at the current exposure levels. Upbeat positional nystagmus correlated with a history of mTBI in this population, and this has not been described elsewhere. The data trends also suggest that this nystagmus could be an acute blast effect. However, the reasons for the abnormally short phase leads seen in rotary chair testing are unclear at this time. Further investigation seems warranted.

  11. The complexity of biomechanics causing primary blast-induced traumatic brain injury: a review of potential mechanisms.

    Directory of Open Access Journals (Sweden)

    Amy eCourtney

    2015-10-01

    Full Text Available Primary blast induced traumatic brain injury (bTBI is a prevalent battlefield injury in recent conflicts, yet biomechanical mechanisms of bTBI remain unclear. Elucidating specific biomechanical mechanisms is essential to developing animal models for testing candidate therapies and for improving protective equipment. Three hypothetical mechanisms of primary bTBI have received the most attention. Because translational and rotational head accelerations are primary contributors to TBI from non-penetrating blunt force head trauma, the acceleration hypothesis suggests that blast-induced head accelerations may cause bTBI. The hypothesis of direct cranial transmission suggests that a pressure transient traverses the skull into the brain and directly injures brain tissue. The thoracic hypothesis of bTBI suggests that some combination of a pressure transient reaching the brain via the thorax and a vagally mediated reflex result in bTBI. These three mechanisms may not be mutually exclusive, and quantifying exposure thresholds (for blasts of a given duration is essential for determining which mechanisms may be contributing for a level of blast exposure. Progress has been hindered by experimental designs which do not effectively expose animal models to a single mechanism and by over-reliance on poorly validated computational models. The path forward should be predictive validation of computational models by quantitative confirmation with blast experiments in animal models, human cadavers, and biofidelic human surrogates over a range of relevant blast magnitudes and durations coupled with experimental designs which isolate a single injury mechanism.

  12. Blast-mediated traumatic amputation: evidence for a revised, multiple injury mechanism theory.

    Science.gov (United States)

    Singleton, James A G; Gibb, I E; Bull, A M J; Clasper, J C

    2014-06-01

    The accepted mechanism of blast-mediated traumatic amputation (TA) is blast wave induced fracture followed by limb avulsion from the blast wind, generating a transosseous amputation. Blast-mediated through-joint TAs were considered extremely rare with published prevalence <2%. Previous studies have also suggested that TA is frequently associated with fatal primary blast lung injury (PBLI). However, recent evidence suggests that the mechanism of TA and the link with fatal primary blast exposure merit review. A trauma registry (UK Joint Theatre Trauma Registry) and postmortem CT (PM-CT) database were used to identify casualties (survivors and deaths) sustaining a blast-mediated TA in the 2 years from August 2008. TA metrics and associated significant injuries were recorded. Detailed anatomical data on extremity predebridement osseous and soft tissue injuries were only consistently available for deaths through comprehensive PM-CT imaging. 146 cases (75 survivors and 71 deaths) sustaining 271 TAs (130 in survivors and 141 in deaths) were identified. The lower limb was most commonly affected (117/130 in survivors, 123/141 in deaths). The overall through-joint TA rate was 47/271 (17.3%) and 34/47 through-joint injuries (72.3%) were through knee. More detailed anatomical analysis facilitated by PM-CT imaging revealed only 9/34 through-joint TAs had a contiguous fracture (ie, intra-articular involving the joint through which TA occurred), 18/34 had no fracture and 7/34 had a non-contiguous (ie, remote from the level of TA) fracture. No relationship between PBLI and TA was evident. The previously reported link between TA and PBLI was not present, calling into question the significance of primary blast injury in causation of blast mediated TAs. Furthermore, the accepted mechanism of injury can't account for the significant number of through-joint TAs. The high rate of through-joint TAs with either no associated fracture or a non-contiguous fracture (74%) is supportive of

  13. The use of blast furnace slag

    Directory of Open Access Journals (Sweden)

    V. Václavík

    2012-10-01

    Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  14. Blast mitigation experimental and numerical studies

    CERN Document Server

    2013-01-01

    Presents experimental methods of material and structural response to dynamic blast loads Includes computational analysis of material and structural response to dynamic blast loads Offers mitigation measures for structures in various environments Relates lab experiments to larger field tests Features more than 150 illustrations

  15. Swift GRBs and the blast wave model

    NARCIS (Netherlands)

    Curran, P.A.; van der Horst, A.J.; Starling, R.L.C.; Wijers, R.A.M.J.

    2009-01-01

    The complex structure of the light curves of Swift GRBs has made their interpretation and that of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to constrain the blast wave parameters: electron energy distribution, p, density profile of the circumburst medium,

  16. Increased sensibility to acute acoustic and blast trauma among patients with acoustic neuroma.

    Science.gov (United States)

    Mielczarek, Marzena; Olszewski, Jurek

    2018-01-15

    The article shows 2 cases of unusual presentation of acute acoustic trauma and blast injury due to occupational exposure. In the case of both patients the range of impaired frequencies in pure tone audiograms was atypical for this kind of causative factor. Both patients had symmetrical hearing before the accident (which was confirmed by provided results of hearing controls during their employment). A history of noise/blast exposure, the onset of symptoms directly after harmful exposure, symmetrical hearing before the trauma documented with audiograms, directed initial diagnosis towards acoustic/blast trauma, however, of atypical course. Acute acoustic and blast trauma and coexisting acoustic neuroma (AN) contributed to, and mutually modified, the course of sudden hearing loss. In the literature there are some reports pointing to a higher sensitivity to acoustic trauma in the case of patients with AN and, on the other hand, indicating noise as one of the causative factors in AN. Int J Occup Med Environ Health 2018;31(3):361-369. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  17. A state of the art report on the decontamination technology for dry ice blasting

    Energy Technology Data Exchange (ETDEWEB)

    Shin, J. M.; Kim, K. H.; Park, J. J.; Lee, H. H.; Yang, M. S.; Nam, S. H.; Kim, M. J

    2000-05-01

    DUPIC fuel fabrication process is a dry processing technology to manufacture CANDU compatible fuel through a direct reprocessing fabrication process from spent PWR fuel. DUPIC fuel fabrication process consists of the slitting of the spent PWR fuel rods, OREOX processing, homogeneous mixing, pelletizing and sintering. All these processes should be conducted by remote means in a M6 hot cell at IMEF. Since DUPIC fuel fabrication process includes powder handling process of highly radioactive spent fuel, decontamination of highly radioactive particulates from all types of surfaces such as DUPIC fuel manufacturing equipment, hot cell floor, tools is very important to improve the safety of hot cell and reduce the dose exposure to operator, This report describes various technologies for dry ice blasting. It provides the fundamentals of dry ice blasting decontamination and technical review of dry ice blasting on the radioactive decontamination.

  18. A state of the art report on the decontamination technology for dry ice blasting

    International Nuclear Information System (INIS)

    Shin, J. M.; Kim, K. H.; Park, J. J.; Lee, H. H.; Yang, M. S.; Nam, S. H.; Kim, M. J.

    2000-05-01

    DUPIC fuel fabrication process is a dry processing technology to manufacture CANDU compatible fuel through a direct reprocessing fabrication process from spent PWR fuel. DUPIC fuel fabrication process consists of the slitting of the spent PWR fuel rods, OREOX processing, homogeneous mixing, pelletizing and sintering. All these processes should be conducted by remote means in a M6 hot cell at IMEF. Since DUPIC fuel fabrication process includes powder handling process of highly radioactive spent fuel, decontamination of highly radioactive particulates from all types of surfaces such as DUPIC fuel manufacturing equipment, hot cell floor, tools is very important to improve the safety of hot cell and reduce the dose exposure to operator, This report describes various technologies for dry ice blasting. It provides the fundamentals of dry ice blasting decontamination and technical review of dry ice blasting on the radioactive decontamination

  19. Measurement and Modelling of Blast Movement to Reduce Ore ...

    African Journals Online (AJOL)

    user

    with comprehensive monitoring using high speed video and blast movement markers. 2. Develop site specific models ... The Blast Movement Monitor (BMM) is a system developed and patented by the JKMRC, University .... at Ahafo mine, the current practice was to mine to pre-blast grade boundaries (from blast hole drilling.

  20. prevalence of rice blast and varietal screening in ghana

    African Journals Online (AJOL)

    search-screening site grown to an improved vari- ety, Tox 3050, was heavily blasted. There was no blast incidence at Damongo. In Upper Iiast. Region, there was severe incidence of blast in farmers' fields at Bawku and PVS nurseries and farmers' fields at Nyorigu. There was no blast at. Manga, Navrongo, Tono, Sandema, ...

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

    Science.gov (United States)

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

    2012-06-01

    We developed and characterized a mouse model of primary ocular blast injury. The device consists of: a pressurized air tank attached to a regulated paintball gun with a machined barrel; a chamber that protects the mouse from direct injury and recoil, while exposing the eye; and a secure platform that enables fine, controlled movement of the chamber in relation to the barrel. Expected pressures were calculated and the optimal pressure transducer, based on the predicted pressures, was positioned to measure output pressures at the location where the mouse eye would be placed. Mice were exposed to one of three blast pressures (23.6, 26.4, or 30.4 psi). Gross pathology, intraocular pressure, optical coherence tomography, and visual acuity were assessed 0, 3, 7, 14, and 28 days after exposure. Contralateral eyes and non-blast exposed mice were used as controls. We detected increased damage with increased pressures and a shift in the damage profile over time. Gross pathology included corneal edema, corneal abrasions, and optic nerve avulsion. Retinal damage was detected by optical coherence tomography and a deficit in visual acuity was detected by optokinetics. Our findings are comparable to those identified in Veterans of the recent wars with closed eye injuries as a result of blast exposure. In summary, this is a relatively simple system that creates injuries with features similar to those seen in patients with ocular blast trauma. This is an important new model for testing the short-term and long-term spectrum of closed globe blast injuries and potential therapeutic interventions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Status of the BLAST experiment

    International Nuclear Information System (INIS)

    Hasell, D.K.

    2004-01-01

    The BLAST experiment is beginning operation at the MIT-Bates Linear Accelerator Laboratory. The experiment will study the spin dependent electro-magnetic interaction in few nucleon systems at momentum transfers between 0.1 and 1.0 GeV 2 . This will provide improved measurements of the nucleon form factors, particularly G E n , as well as study the structure of D and 3 He. Other reaction channels such as pion production and inclusive scattering will also be studied. The experiment, physics goals, and current status are described briefly. (orig.)

  3. Analysis on the effect of risk from containment failure by over-pressurization during the operation of containment filtered venting system

    International Nuclear Information System (INIS)

    Ham, Jaehyun; Kang, Hyun Gook; Chang, Soon Heung

    2015-01-01

    Passive safety systems which are operated without power source are suggested as a solution SBO. For containment protection system, Containment Filtered Venting System (CFVS) is suggested. CFVS controls the containment pressure by releasing the containment gas through filter passively without any power source. But because still small amount of radioactive material have no choice but to release to the environment, starting time and operation method of CFVS have to be determined carefully. Later starting time brings not only lower release but also higher risk from containment failure by over-pressurization, so it is a problem. In this research, the effect of risk from containment failure by over-pressurization during the operation of containment filtered venting system was analyzed. In this research, optimized values for variables of the CFVS operation method are found as 0.67 MPa, 9 cm, 0.1 MPa each for open pressure, pressure interval, and vent pipe diameter when DF as a function of time and risk from containment over-pressurization failure are considered. Generally in this research, release without risk get lower values in higher pressure, and lower vent pipe diameter. Release with risk get sharply high values when the containment pressure exceeds the design pressure because of the effect of risk from containment failure by over-pressurization. In conclusion, highest pressure, and lowest vent pipe diameter which are not influenced by risk is the optimized values for CFVS operation method because amount of risk is much larger than release through the CFVS

  4. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Salem nuclear power plant, Unit 1

    International Nuclear Information System (INIS)

    Laudenbach, D.H.

    1979-03-01

    The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Salem nuclear power plant, Unit 1. Design basis criteria used to evaluate the acceptability of the system include operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria

  5. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Yankee Rowe nuclear power plant

    International Nuclear Information System (INIS)

    Latorre, V.R.; Mayn, B.G.

    1979-08-01

    This report documents the technical evaluation of the electrical, instrumentation, and control design aspects for the low temperature overpressure protection system of the Yankee Rowe nuclear power plant. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria

  6. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Maine Yankee nuclear power plant

    International Nuclear Information System (INIS)

    Latorre, V.R.; Mayn, B.G.

    1979-08-01

    This report documents the technical evaluation of the electrical, instrumentation, and control design aspects for the low temperature overpressure protection system of the Maine Yankee nuclear power plant. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria

  7. Modeling and simulation of blast-induced, early-time intracranial wave physics leading to traumatic brain injury.

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Corey C. (University of New Mexico, Albuquerque, NM); Taylor, Paul Allen

    2008-02-01

    The objective of this modeling and simulation study was to establish the role of stress wave interactions in the genesis of traumatic brain injury (TBI) from exposure to explosive blast. A high resolution (1 mm{sup 3} voxels), 5 material model of the human head was created by segmentation of color cryosections from the Visible Human Female dataset. Tissue material properties were assigned from literature values. The model was inserted into the shock physics wave code, CTH, and subjected to a simulated blast wave of 1.3 MPa (13 bars) peak pressure from anterior, posterior and lateral directions. Three dimensional plots of maximum pressure, volumetric tension, and deviatoric (shear) stress demonstrated significant differences related to the incident blast geometry. In particular, the calculations revealed focal brain regions of elevated pressure and deviatoric (shear) stress within the first 2 milliseconds of blast exposure. Calculated maximum levels of 15 KPa deviatoric, 3.3 MPa pressure, and 0.8 MPa volumetric tension were observed before the onset of significant head accelerations. Over a 2 msec time course, the head model moved only 1 mm in response to the blast loading. Doubling the blast strength changed the resulting intracranial stress magnitudes but not their distribution. We conclude that stress localization, due to early time wave interactions, may contribute to the development of multifocal axonal injury underlying TBI. We propose that a contribution to traumatic brain injury from blast exposure, and most likely blunt impact, can occur on a time scale shorter than previous model predictions and before the onset of linear or rotational accelerations traditionally associated with the development of TBI.

  8. PROGRESS IN THERMO-ABRASIVE BLASTING SYSTEMS

    Directory of Open Access Journals (Sweden)

    I.A. Gorlach

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Quality of surface preparation of components and structures for further painting and/or coating is important in many fields of engineering. One of the most widely used methods of surface preparation is abrasive blasting. In the last few years, a new method for surface preparation has evolved, namely thermo-abrasive blasting. This technique utilises a high enthalpy thermal jet, generated by the thermo-abrasive blasting gun, to propel abrasive particles. Thermo-abrasive blasting has a number of advantages over conventional abrasive blasting, which were assessed during trials. This paper describes a progress in the applications of thermo-abrasive blasting as well as future potentials for South African industry. The performance data and economic comparison of conventional and thermo-abrasive blasting are also presented in this paper.

    AFRIKAANSE OPSOMMING: Die gehalte van voorbereiding van komponent- en struktuuroppervlaktes is oral belangrik in ingenieurswesetoepassings. Wat vrywel tot die hede dikwels gebruik was, is straalskuring. Onlangs het 'n nuwe metode tot stand gekom naamlik termostraalskuring. Die metode maak gebruik van 'n hoë entalpie termostaat om skuurmiddel aan te dryf. Die nuwe metode besit sekere voordele in vergelyking met tradisionele straalskuring. Praktykbevestiging is hiervan met toetse verkry. Hierdie stuk bespreek ook die praktyktoepassings van termostraalskuring en die gepaardgaande voordele vir die Suid-Afrikaanse nywerheid. Toepassingsdata en ekomiese vergelyking van konvensionele- en termostraalskuring word ook behandel.

  9. Direct simulations of outdoor blast wave propagation from source to receiver

    Science.gov (United States)

    Nguyen-Dinh, M.; Lardjane, N.; Duchenne, C.; Gainville, O.

    2017-07-01

    Outdoor blast waves generated by impulsive sources are deeply affected by numerous physical conditions such as source shape or height of burst in the near field, as well as topography, ground nature, or atmospheric conditions at larger distances. Application of classical linear acoustic methods may result in poor estimates of peak overpressures at intermediate ranges in the presence of these conditions. Here, we show, for the first time, that converged direct fully nonlinear simulations can be produced at a reasonable CPU cost in two-dimensional axisymmetric geometry from source location to more than 500 m/kg^{1/3}. The numerical procedure is based on a high-order finite-volume method with adaptive mesh refinement for solving the nonlinear Euler equations with a detonation model. It is applied to a real outdoor pyrotechnic site. A digital terrain model is built, micro-meteorological conditions are included through an effective sound speed, and a ground roughness model is proposed in order to account for the effects of vegetation and unresolved scales. Two-dimensional axisymmetric simulations are performed for several azimuths, and a comparison is made with experimental pressure signals recorded at scaled distances from 36 to 504 m/kg^{1/3}. The relative importance of the main physical effects is discussed.

  10. Disruption of caudate working memory activation in chronic blast-related traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Mary R. Newsome

    2015-01-01

    Full Text Available Mild to moderate traumatic brain injury (TBI due to blast exposure is frequently diagnosed in veterans returning from the wars in Iraq and Afghanistan. However, it is unclear whether neural damage resulting from blast TBI differs from that found in TBI due to blunt-force trauma (e.g., falls and motor vehicle crashes. Little is also known about the effects of blast TBI on neural networks, particularly over the long term. Because impairment in working memory has been linked to blunt-force TBI, the present functional magnetic resonance imaging (fMRI study sought to investigate whether brain activation in response to a working memory task would discriminate blunt-force from blast TBI. Twenty-five veterans (mean age = 29.8 years, standard deviation = 6.01 years, 1 female who incurred TBI due to blast an average of 4.2 years prior to enrollment and 25 civilians (mean age = 27.4 years, standard deviation = 6.68 years, 4 females with TBI due to blunt-force trauma performed the Sternberg Item Recognition Task while undergoing fMRI. The task involved encoding 1, 3, or 5 items in working memory. A group of 25 veterans (mean age = 29.9 years, standard deviation = 5.53 years, 0 females and a group of 25 civilians (mean age = 27.3 years, standard deviation = 5.81 years, 0 females without history of TBI underwent identical imaging procedures and served as controls. Results indicated that the civilian TBI group and both control groups demonstrated a monotonic relationship between working memory set size and activation in the right caudate during encoding, whereas the blast TBI group did not (p < 0.05, corrected for multiple comparisons using False Discovery Rate. Blast TBI was also associated with worse performance on the Sternberg Item Recognition Task relative to the other groups, although no other group differences were found on neuropsychological measures of episodic memory, inhibition, and general processing speed. These results

  11. A Blast Wave Model With Viscous Corrections

    Science.gov (United States)

    Yang, Z.; Fries, R. J.

    2017-04-01

    Hadronic observables in the final stage of heavy ion collision can be described well by fluid dynamics or blast wave parameterizations. We improve existing blast wave models by adding shear viscous corrections to the particle distributions in the Navier-Stokes approximation. The specific shear viscosity η/s of a hadron gas at the freeze-out temperature is a new parameter in this model. We extract the blast wave parameters with viscous corrections from experimental data which leads to constraints on the specific shear viscosity at kinetic freeze-out. Preliminary results show η/s is rather small.

  12. CO{sub 2} pellet blasting studies

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, K.E.

    1997-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Although most trauma centers have experience with the imaging and management of gunshot wounds, in most regions blast wounds such as the ones encountered in terrorist attacks with the use of improvised explosive devices (IEDs) are infrequently encountered outside the battlefield. As global terrorism becomes a greater concern, it is important that radiologists, particularly those working in urban trauma centers, be aware of the mechanisms of injury and the spectrum of primary, secondary, tertiary, and quaternary blast injury patterns. Primary blast injuries are caused by barotrauma from the initial increased pressure of the explosive detonation and the rarefaction of the atmosphere immediately afterward. Secondary blast injuries are caused by debris carried by the blast wind and most often result in penetrating trauma from small shrapnel. Tertiary blast injuries are caused by the physical displacement of the victim and the wide variety of blunt or penetrating trauma sustained as a result of the patient impacting immovable objects such as surrounding cars, walls, or fences. Quaternary blast injuries include all other injuries, such as burns, crush injuries, and inhalational injuries. Radiography is considered the initial imaging modality for assessment of shrapnel and fractures. Computed tomography is the optimal test to assess penetrating chest, abdominal, and head trauma. The mechanism of blast injuries and the imaging experience of the victims of the Boston Marathon bombing are detailed, as well as musculoskeletal, neurologic, gastrointestinal, and pulmonary injury patterns from blast injuries. ©RSNA, 2016.

  14. Efficacy of visor and helmet for blast protection assessed using a computational head model

    Science.gov (United States)

    Singh, D.; Cronin, D. S.

    2017-11-01

    Head injury resulting from blast exposure has been identified as a challenge that may be addressed, in part, through improved protective systems. Existing detailed head models validated for blast loading were applied to investigate the influence of helmet visor configuration, liner properties, and shell material stiffness. Response metrics including head acceleration and intracranial pressures (ICPs) generated in brain tissue during primary blast exposure were used to assess and compare helmet configurations. The addition of a visor was found to reduce peak head acceleration and positive ICPs. However, negative ICPs associated with a potential for injury were increased when a visor and a foam liner were present. In general, the foam liner material was found to be more significant in affecting the negative ICP response than positive ICP or acceleration. Shell stiffness was found to have relatively small effects on either metric. A strap suspension system, modeled as an air gap between the head and helmet, was more effective in reducing response metrics compared to a foam liner. In cases with a foam liner, lower-density foam offered a greater reduction of negative ICPs. The models demonstrated the "underwash" effect in cases where no foam liner was present; however, the reflected pressures generated between the helmet and head did not translate to significant ICPs in adjacent tissue, when compared to peak ICPs from initial blast wave interaction. This study demonstrated that the efficacy of head protection can be expressed in terms of load transmission pathways when assessed with a detailed computational model.

  15. Effects of Overpressures in Group Shelters on Animals and Dummies. Part 1

    Science.gov (United States)

    1953-09-01

    granuloma . 3.3.2 Experlment-l Animals from Shot I The animals used in the first experimental exposure were of a mixed-breed type, obtained at random, and were...finger-like segments and apical portion of the lobus intermedius which lies over the dome of the diaphragm and 1 neath the heart in such a manner that...ES Fig. 3.6-Posterior view of lungs and heart of Animal D-10 (position 602-7). Large hemorrhages are £ visible In the apical arid cardiac lobes

  16. On firework blasts and qualitative parameter dependency.

    Science.gov (United States)

    Zohdi, T I

    2016-01-01

    In this paper, a mathematical model is developed to qualitatively simulate the progressive time-evolution of a blast from a simple firework. Estimates are made for the blast radius that one can expect for a given amount of detonation energy and pyrotechnic display material. The model balances the released energy from the initial blast pulse with the subsequent kinetic energy and then computes the trajectory of the material under the influence of the drag from the surrounding air, gravity and possible buoyancy. Under certain simplifying assumptions, the model can be solved for analytically. The solution serves as a guide to identifying key parameters that control the evolving blast envelope. Three-dimensional examples are given.

  17. Material Systems for Blast-Energy Dissipation

    Energy Technology Data Exchange (ETDEWEB)

    James Schondel; Henry S. Chu

    2010-10-01

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

  18. Nucleon and Deuteron Form Factors from BLAST

    International Nuclear Information System (INIS)

    Hasell, D. K.

    2009-01-01

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

  19. Basic Local Alignment Search Tool (BLAST)

    Data.gov (United States)

    U.S. Department of Health & Human Services — BLAST finds regions of similarity between biological sequences. The program compares nucleotide or protein sequences to sequence databases and calculates the...

  20. A Software Framework for Blast Event Simulation

    National Research Council Canada - National Science Library

    Swensen, D. A; Denison, M. K; Guilkey, James; Harman, Todd; Goetz, Richard

    2006-01-01

    .... The BCF will provide a virtual test-bed where disparate computational models can seamlessly interact with one another to provide a unified modeling solution for blast-vehicle-occupant scenarios...

  1. Blast effects physical properties of shock waves

    CERN Document Server

    2018-01-01

    This book compiles a variety of experimental data on blast waves. The book begins with an introductory chapter and proceeds to the topic of blast wave phenomenology, with a discussion Rankine-Hugoniot equations and the Friedlander equation, used to describe the pressure-time history of a blast wave. Additional topics include arrival time measurement, the initiation of detonation by exploding wires, a discussion of TNT equivalency, and small scale experiments. Gaseous and high explosive detonations are covered as well. The topics and experiments covered were chosen based on the comparison of used scale sizes, from small to large. Each characteristic parameter of blast waves is analyzed and expressed versus scaled distance in terms of energy and mass. Finally, the appendix compiles a number of polynomial laws that will prove indispensable for engineers and researchers.

  2. Prevention of Blast-Related Injuries

    Science.gov (United States)

    2017-09-01

    Award Number: W81XWH-12-2-0038 TITLE: Prevention of Blast-Related Injuries PRINCIPAL INVESTIGATOR: Albert I. King CONTRACTING ORGANIZATION...CONTRACT NUMBER Prevention of Blast-Related Injuries 5b. GRANT NUMBER W81XWH-12-2-0038 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Albert King, John...TR-7340). Army research lab Aberdeen proving ground MD weapons and materials research directorate. (2015) 11. Reneer, D.V., Hisel, R.D., Hoffman

  3. Blasting at a Superfund chemical waste site

    International Nuclear Information System (INIS)

    Burns, D.R.

    1991-01-01

    During the summer of 1989, Maine Drilling and Blasting of Gardiner, Maine was contracted by Cayer Corporation of Harvard, Massachusetts to drill and blast an interceptor trench at the Nyanza Chemical Superfund Site in Ashland, Massachusetts. The interceptor trench was to be 1,365 feet long and to be blasted out of granite. The trench was to be 12 feet wide at the bottom with 1/1 slopes, the deepest cut being 30 feet deep. A French drain 12 feet wide by 15 to 35 feet deep was blasted below the main trench on a 2% slope from its center to each end. A French drain is an excavation where the rock is blasted but not dug. The trench would be used as a perimeter road with any ground water flow going through the French drain flowing to both ends of the trench. Being a Superfund project turned a simple blasting project into a regulatory nightmare. The US Environmental Protection Agency performed all the chemical related functions on site. The US Army Corps of Engineers was overseeing all related excavation and construction on site, as was the Massachusetts Department of Environmental Quality Engineering, the local Hazardous Wastes Council, and the local Fire Department. All parties had some input with the blasting and all issues had to be addressed. The paper outlines the project, how it was designed and completed. Also included is an outline of the blast plan to be submitted for approval, an outline of the Safety/Hazardous Waste training and a description of all the problems which arose during the project by various regulatory agencies

  4. The Biological Basis of Chronic Traumatic Encephalopathy following Blast Injury: A Literature Review.

    Science.gov (United States)

    Aldag, Matt; Armstrong, Regina C; Bandak, Faris; Bellgowan, Patrick S F; Bentley, Timothy; Biggerstaff, Sean; Caravelli, Katrina; Cmarik, Joan; Crowder, Alicia; DeGraba, Thomas J; Dittmer, Travis A; Ellenbogen, Richard G; Greene, Colin; Gupta, Raj K; Hicks, Ramona; Hoffman, Stuart; Latta, Robert C; Leggieri, Michael J; Marion, Donald; Mazzoli, Robert; McCrea, Michael; O'Donnell, John; Packer, Mark; Petro, James B; Rasmussen, Todd E; Sammons-Jackson, Wendy; Shoge, Richard; Tepe, Victoria; Tremaine, Ladd A; Zheng, James

    2017-09-01

    The United States Department of Defense Blast Injury Research Program Coordinating Office organized the 2015 International State-of-the-Science meeting to explore links between blast-related head injury and the development of chronic traumatic encephalopathy (CTE). Before the meeting, the planning committee examined articles published between 2005 and October 2015 and prepared this literature review, which summarized broadly CTE research and addressed questions about the pathophysiological basis of CTE and its relationship to blast- and nonblast-related head injury. It served to inform participants objectively and help focus meeting discussion on identifying knowledge gaps and priority research areas. CTE is described generally as a progressive neurodegenerative disorder affecting persons exposed to head injury. Affected individuals have been participants primarily in contact sports and military personnel, some of whom were exposed to blast. The symptomatology of CTE overlaps with Alzheimer's disease and includes neurological and cognitive deficits, psychiatric and behavioral problems, and dementia. There are no validated diagnostic criteria, and neuropathological evidence of CTE has come exclusively from autopsy examination of subjects with histories of exposure to head injury. The perivascular accumulation of hyperphosphorylated tau (p-tau) at the depths of cortical sulci is thought to be unique to CTE and has been proposed as a diagnostic requirement, although the contribution of p-tau and other reported pathologies to the development of clinical symptoms of CTE are unknown. The literature on CTE is limited and is focused predominantly on head injuries unrelated to blast exposure (e.g., football players and boxers). In addition, comparative analyses of clinical case reports has been challenging because of small case numbers, selection biases, methodological differences, and lack of matched controls, particularly for blast-exposed individuals. Consequently, the

  5. Investigation of head response to blast loading.

    Science.gov (United States)

    Lockhart, Philip; Cronin, Duane; Williams, Kevin; Ouellet, Simon

    2011-02-01

    Head injury resulting from blast loading, specifically mild traumatic brain injury, has been identified as a possible and important blast-related injury for soldiers in modern conflict zones. A study was undertaken to evaluate head response to blast loading scenarios using an explicit finite element numerical model and to comment on the potential for head injury. The blast loading and simplified human body numerical models were validated using impulse, peak acceleration and the Head Injury Criterion from experimental blast test data. A study was then undertaken to evaluate head response at varying distances and orientations from the explosive. The accelerations and injury metrics for the head increased with decreasing distance to the explosive, as expected, but were also significant at intermediate distances from the explosive for larger charge sizes and intermediate heights of burst. Varying lateral position with constant standoff did not have a significant effect on the head kinematic response. The head injury criteria considered were exceeded in close proximity to the explosive (blast loading, aggressive loading is predicted at small standoff distances and confirmed by the resulting head kinematics.

  6. Ultra Safe And Secure Blasting System

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M M

    2009-07-27

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

  7. The second generation of electronic blasting systems

    Energy Technology Data Exchange (ETDEWEB)

    Hammelmann, F.; Petzold, J. [Dynamit Nobel GmbH (Germany)

    2001-07-01

    8 years after the market introduction of the first commercial electronic detonator - DYNATRONIC - the paper describes a new area of electronic blasting systems Made in Germany: i-kon. The results of a joint development between Dynamit Nobel and Orica is a unique universal electronic detonator, which is as simple to use as a standard non-electric detonator. The delay time or delay interval is not factory preprogrammed and the system is not based on a numbered system like conventional detonators. The miner or Blaster decides on site which delay timing he likes to use and is programming the whole blast on site. The new i-kon system allows delay times between 0 and 8000 ms by increments of 1 ms. With the control equipment it is possible to blast up to 1600 detonators in a single blast. The paper describes the construction and functionality of this new electronic blasting system - manufactured and developed by Precision Blasting Systems, a joint venture between Orica and Dynamic Nobel. (orig.)

  8. Raydet non-electric blast initiation system for efficient and environment-friendly surface blasts

    Energy Technology Data Exchange (ETDEWEB)

    Sarathy, M.O. [IDL Chemicals Ltd., Hyderabad (India). Technical Services Cell

    1995-08-01

    This paper discusses the advantages of using the Raydet shock tube based blast initiation system and reviews research work carried out on release of explosive energy in the drillhole, effect of stemming retention (stemming effectiveness) and advantages of `true bottom hole initiation` of drillholes in surface blasting. Some case studies are presented. 6 refs., 5 figs., 1 tab.

  9. Reducing Drill and Blast Cost through Blast Optimisation – A Case ...

    African Journals Online (AJOL)

    Michael O. Mensah

    2015-12-02

    Dec 2, 2015 ... gold mine in Ghana, and further developed a suitable, cost-effective drill and blast geometric parameters for the mine. The study was conducted on three ... explosive type, density and costs; labour; oversize. (relative boulders), toes and ... garnering input data, and in its direct linkage between blast design ...

  10. BLAST-EXPLORER helps you building datasets for phylogenetic analysis

    Directory of Open Access Journals (Sweden)

    Claverie Jean-Michel

    2010-01-01

    Full Text Available Abstract Background The right sampling of homologous sequences for phylogenetic or molecular evolution analyses is a crucial step, the quality of which can have a significant impact on the final interpretation of the study. There is no single way for constructing datasets suitable for phylogenetic analysis, because this task intimately depends on the scientific question we want to address, Moreover, database mining softwares such as BLAST which are routinely used for searching homologous sequences are not specifically optimized for this task. Results To fill this gap, we designed BLAST-Explorer, an original and friendly web-based application that combines a BLAST search with a suite of tools that allows interactive, phylogenetic-oriented exploration of the BLAST results and flexible selection of homologous sequences among the BLAST hits. Once the selection of the BLAST hits is done using BLAST-Explorer, the corresponding sequence can be imported locally for external analysis or passed to the phylogenetic tree reconstruction pipelines available on the Phylogeny.fr platform. Conclusions BLAST-Explorer provides a simple, intuitive and interactive graphical representation of the BLAST results and allows selection and retrieving of the BLAST hit sequences based a wide range of criterions. Although BLAST-Explorer primarily aims at helping the construction of sequence datasets for further phylogenetic study, it can also be used as a standard BLAST server with enriched output. BLAST-Explorer is available at http://www.phylogeny.fr

  11. SparkBLAST: scalable BLAST processing using in-memory operations.

    Science.gov (United States)

    de Castro, Marcelo Rodrigo; Tostes, Catherine Dos Santos; Dávila, Alberto M R; Senger, Hermes; da Silva, Fabricio A B

    2017-06-27

    The demand for processing ever increasing amounts of genomic data has raised new challenges for the implementation of highly scalable and efficient computational systems. In this paper we propose SparkBLAST, a parallelization of a sequence alignment application (BLAST) that employs cloud computing for the provisioning of computational resources and Apache Spark as the coordination framework. As a proof of concept, some radionuclide-resistant bacterial genomes were selected for similarity analysis. Experiments in Google and Microsoft Azure clouds demonstrated that SparkBLAST outperforms an equivalent system implemented on Hadoop in terms of speedup and execution times. The superior performance of SparkBLAST is mainly due to the in-memory operations available through the Spark framework, consequently reducing the number of local I/O operations required for distributed BLAST processing.

  12. Probabilistic Fracture Mechanics Analysis of Boling Water Reactor Vessel for Cool-Down and Low Temperature Over-Pressurization Transients

    Directory of Open Access Journals (Sweden)

    Jeong Soon Park

    2016-04-01

    Full Text Available The failure probabilities of the reactor pressure vessel (RPV for low temperature over-pressurization (LTOP and cool-down transients are calculated in this study. For the cool-down transient, a pressure–temperature limit curve is generated in accordance with Section XI, Appendix G of the American Society of Mechanical Engineers (ASME code, from which safety margin factors are deliberately removed for the probabilistic fracture mechanics analysis. Then, sensitivity analyses are conducted to understand the effects of some input parameters. For the LTOP transient, the failure of the RPV mostly occurs during the period of the abrupt pressure rise. For the cool-down transient, the decrease of the fracture toughness with temperature and time plays a main role in RPV failure at the end of the cool-down process. As expected, the failure probability increases with increasing fluence, Cu and Ni contents, and initial reference temperature-nil ductility transition (RTNDT. The effect of warm prestressing on the vessel failure probability for LTOP is not significant because most of the failures happen before the stress intensity factor reaches the peak value while its effect reduces the failure probability by more than one order of magnitude for the cool-down transient.

  13. Measured air overpressures, soil-particle pressures, and slumps during the pre-ASIAGO U2Ar stemming experiment

    Energy Technology Data Exchange (ETDEWEB)

    Freynik, H.S. Jr.; Roach, D.R.; Dittbenner, G.R.

    1978-01-04

    On November 15, 1976, Lawrence Livermore Laboratory completed its first comprehensive stemming experiment for measuring downhole parameters while varying fill material and rate. Stemming can be defined as backfilling a hole in which a device has been placed to prevent leakage of radioactive materials or gases to the surface. A computer code is being developed for stemming operations, and this experiment was designed to measure parameters under different stemming conditions so the code could be verified and modified. The experiment was conducted in the lower half of a steel-cased, 4-ft-diam, 2000-ft-deep hole at Nevada Test Site. The two stemming materials used in the experiment, Overton sand and LLL II mix, were tested at three fill rates. Significant results of this experiment included successful measurement of downhole air overpressures, vertical and horizontal soil-particle pressures, and temperature. Vertical soil-particle pressures were higher than expected. All surface measurements were valid. The slump-displacement measurements system provided a timing mark to indicate the occurrence of a slump. A major slump occurred on the third day of stemming; a minor slump occurred on the fourth day.

  14. Research on Effects of Blast Casting Vibration and Vibration Absorption of Presplitting Blasting in Open Cast Mine

    Directory of Open Access Journals (Sweden)

    Li Ma

    2016-01-01

    Full Text Available The impact energy produced by blast casting is able to break and cast rocks, yet the strong vibration effects caused at the same time would threaten the safety of mines. Based on the theory of Janbu’s Limit Equilibrium Method (LEM, pseudo-static method has been incorporated to analyze the influence of dynamic loads of blasting on slope stability. The horizontal loads produced by blast vibrations cause an increase in sliding forces, and this leads to a lower slope stability coefficient. When the tensile stresses of the two adjacent blast holes are greater than the tensile strength of rock mass, the radical oriented cracks are formed, which is the precondition for the formation of presplit face. Thus, the formula for calculating the blast hole spacing of presplit blasting can be obtained. Based on the analysis of the principles of vibration tester and vibration pick-up in detecting blast vibrations, a detection scheme of blast vibration is worked out by taking the blast area with precrack rear and non-precrack side of the detection object. The detection and research results of blast vibration show that presplit blasting can reduce the attenuation coefficient of stress wave by half, and the vibration absorption ratio could reach 50.2%; the impact of dynamic loads on the end-wall slope stability coefficient is 1.98%, which proves that presplit blasting plays an important role in shock absorption of blast casting.

  15. Experimental Measures of Blast and Acoustic Trauma in Marine Mammals

    National Research Council Canada - National Science Library

    Ketten, Darlene R

    2004-01-01

    .... To determine onset of damage zones for blast trauma in marine mammals, fresh post-mortem specimens were implanted with pressure gages, CT scanned, and exposed to underwater blast pressures of 10-300 psi...

  16. Development of a Comprehensive Blast-Related Auditory Injury Database (BRAID)

    Science.gov (United States)

    2016-05-01

    uals deployed to battle zones are increasingly at risk for NIHL, tinnitus, and other otologic injuries [4]. The effects of blast exposure on the...They attributed this higher rate to the fact that their data were extracted from an audiology clinic database. Mrena et al. assessed the otologic and...analyzed definitive clinical data, whereas we have examined occupational hearing conservation screening data. Military and civilian otologic and audio

  17. Primary Blast Injury Criteria for Animal/Human TBI Models using Field Validated Shock Tubes

    Science.gov (United States)

    2016-09-01

    exposure to shock wave. We used experimental measures to probe the response of the body to blast loading via implantation of intracranial pressure (ICP...Representative pressure profiles measured by incident ( loading ), intracranial and carotid artery sensors (response) implanted in a rat exposed to 130 kPa...if these changes can be used as convenient markers of injury which can be used in the field and inform affected personnel immediately upon the

  18. Formation and destruction mechanism as well as major controlling factors of the Silurian shale gas overpressure in the Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Shuangjian Li

    2016-08-01

    Full Text Available Taking the Well JY1 and Well PY1 in the Eastern Sichuan Basin as examples, the formation mechanism of shale gas overpressure was studied by using the cross plot of acoustic versus density logging data. During the processes of hydrocarbon generation and the uplifting, the pressure evolution of fluids in shale gas layers was reconstructed by fluid inclusions and PVTSIM software. The major factors controlling the evolution of shale gas overpressure were established according to the study of fracture, the timing of the uplifting, and episodes of tectonic deformation. Our results showed that the main mechanism of overpressure in the Silurian shale gas reservoirs in the Sichuan Basin was the fluid expansion, which was caused by hydrocarbon generation. Since the Yanshanian, the strata were uplifted and fluid pressure generally showed a decreasing trend. However, due to the low compression rebound ratio of shale gas reservoir rocks, poor connectivity of reservoir rocks, and low content of formation water and so on, such factors made fluid pressure decrease, but these would not be enough to make up the effects of strata erosion resulting in a further increase in fluid pressure in shale gas reservoirs during the whole uplifting processes. Since the Yanshanian, the Well PY1 zone had been reconstructed by at least three episodes of tectonic movement. The initial timing of the uplifting is 130 Ma. Compared to the former, the Well JY1 zone was firstly uplifted at 90 Ma, which was weakly reconstructed. As a result, low-angle fractures and few high resistance fractures developed in the Well JY1, while high-angle fractures and many high resistance fractures developed in the Well PY1. In totality, the factors controlling the overpressure preservation in shale gas reservoirs during the late periods include timing of late uplifting, superposition and reconstruction of stress fields, and development of high-angle fractures.

  19. Primary Blast-Induced Changes in Akt and GSK3β Phosphorylation in Rat Hippocampus

    Directory of Open Access Journals (Sweden)

    Yushan Wang

    2017-08-01

    Full Text Available Traumatic brain injury (TBI due to blast from improvised explosive devices has been a leading cause of morbidity and mortality in recent conflicts in Iraq and Afghanistan. However, the mechanisms of primary blast-induced TBI are not well understood. The Akt signal transduction pathway has been implicated in various brain pathologies including TBI. In the present study, the effects of simulated primary blast waves on the phosphorylation status of Akt and its downstream effector kinase, glycogen synthase kinase 3β (GSK3β, in rat hippocampus, were investigated. Male Sprague-Dawley (SD rats (350–400 g were exposed to a single pulse shock wave (25 psi; ~7 ms duration and sacrificed 1 day, 1 week, or 6 weeks after exposure. Total and phosphorylated Akt, as well as phosphorylation of its downstream effector kinase GSK3β (at serine 9, were detected with western blot analysis and immunohistochemistry. Results showed that Akt phosphorylation at both serine 473 and threonine 308 was increased 1 day after blast on the ipsilateral side of the hippocampus, and this elevation persisted until at least 6 weeks postexposure. Similarly, phosphorylation of GSK3β at serine 9, which inhibits GSK3β activity, was also increased starting at 1 day and persisted until at least 6 weeks after primary blast on the ipsilateral side. In contrast, p-Akt was increased at 1 and 6 weeks on the contralateral side, while p-GSK3β was increased 1 day and 1 week after primary blast exposure. No significant changes in total protein levels of Akt and GSK were observed on either side of the hippocampus at any time points. Immunohistochemical results showed that increased p-Akt was mainly of neuronal origin in the CA1 region of the hippocampus and once phosphorylated, the majority was translocated to the dendritic and plasma membranes. Finally, electrophysiological data showed that evoked synaptic N-methyl-d-aspartate (NMDA receptor activity was

  20. A Study on the Generation and Preservation of Shallow Overpressures and the Effects on the Slope Instability in the Ursa Basin, deepwater Gulf of Mexico

    Science.gov (United States)

    Binh, N. T.; Tokunaga, T.; Flemings, P. B.; Sawyer, D. E.; Urgeles, R.; Nakamura, T.; Koizumi, K.; Nakajima, M.; Kubota, M.; Kameya, H.; Taniue, M.

    2008-12-01

    Understanding the evolution of abnormally high fluid pressures within sedimentary formations is critical for analyzing slope stability and assessing drilling risks. We constructed a numerical model to analyze the change of fluid flow patterns, the development of shallow overpressures, and the resulting slope instability from late Pleistocene to recent sediments in the Ursa basin, deepwater Gulf of Mexico. Our analysis showed that high pore pressure ratios (ratio between differences of pore pressure and hydrostatic pressure and overburden hydrostatic effective stress) existed from the onset of sediment deposition. Lateral fluid flow from the area where overburden is thick toward the area where it is thin have occurred at least since 30 ka. Even though almost continuous sedimentation was assumed in the model, the simulation results show that overconsolidated sediments exist in the area where overburden is thin because of unloading due to lateral flow. Ko (the ratio of horizontal to vertical effective stress) is larger in overconsolidated sediments compared with normally consolidated sediments. Thus, this phenomenon can explain the isotropic stress state reported in the area. Overpressure quickly generated at around 22 ka due to the high sedimentation rate of fine grained sediments. This high overpressure and lower effective stress might have resulted in sediments having shear strengths low enough for gravity sliding to occur. The predicted timing of a failure between the sites U1324 and U1323 below seismic horizon S20 was about 19 ka and was consistent with geological data.

  1. Explosion impacts during transport of hazardous cargo: GIS-based characterization of overpressure impacts and delineation of flammable zones for ammonia.

    Science.gov (United States)

    Inanloo, Bahareh; Tansel, Berrin

    2015-06-01

    The aim of this research was to investigate accidental releases of ammonia followed by an en-route incident in an attempt to further predict the consequences of hazardous cargo accidents. The air dispersion model Areal Locations of Hazardous Atmospheres (ALOHA) was employed to track the probable outcomes of a hazardous material release of a tanker truck under different explosion scenarios. The significance of identification of the flammable zones was taken into consideration; in case the flammable vapor causes an explosion. The impacted areas and the severity of the probable destructions were evaluated for an explosion by considering the overpressure waves. ALOHA in conjunction with ArcGIS was used to delineate the flammable and overpressure impact zones for different scenarios. Based on the results, flammable fumes were formed in oval shapes having a chief axis along the wind direction at the time of release. The expansions of the impact areas under the overpressure value which can lead to property damage for 2 and 20 tons releases, under very stable and unstable atmospheric conditions were estimated to be around 1708, 1206; 3742, 3527 feet, respectively, toward the wind direction. A sensitivity analysis was done to assess the significance of wind speed on the impact zones. The insight provided by this study can be utilized by decision makers in transportation of hazardous materials as a guide for possible rerouting, rescheduling, or limiting the quantity of hazardous cargo to reduce the possible impacts after hazardous cargo accidents during transport. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Blast shockwaves propagate Ca2+ activity via purinergic astrocyte networks in human central nervous system cells

    Science.gov (United States)

    Ravin, Rea; Blank, Paul S.; Busse, Brad; Ravin, Nitay; Vira, Shaleen; Bezrukov, Ludmila; Waters, Hang; Guerrero-Cazares, Hugo; Quinones-Hinojosa, Alfredo; Lee, Philip R.; Fields, R. Douglas; Bezrukov, Sergey M.; Zimmerberg, Joshua

    2016-01-01

    In a recent study of the pathophysiology of mild, blast-induced traumatic brain injury (bTBI) the exposure of dissociated, central nervous system (CNS) cells to simulated blast resulted in propagating waves of elevated intracellular Ca2+. Here we show, in dissociated human CNS cultures, that these calcium waves primarily propagate through astrocyte-dependent, purinergic signaling pathways that are blocked by P2 antagonists. Human, compared to rat, astrocytes had an increased calcium response and prolonged calcium wave propagation kinetics, suggesting that in our model system rat CNS cells are less responsive to simulated blast. Furthermore, in response to simulated blast, human CNS cells have increased expressions of a reactive astrocyte marker, glial fibrillary acidic protein (GFAP) and a protease, matrix metallopeptidase 9 (MMP-9). The conjoint increased expression of GFAP and MMP-9 and a purinergic ATP (P2) receptor antagonist reduction in calcium response identifies both potential mechanisms for sustained changes in brain function following primary bTBI and therapeutic strategies targeting abnormal astrocyte activity. PMID:27162174

  3. A blast absorber test: measurement and model results

    NARCIS (Netherlands)

    Eerden, F.J.M. van der; Berg, F. van den; Hof, J. van 't; Arkel, E. van

    2006-01-01

    A blast absorber test was conducted at the Aberdeen Test Centre from 13 to 17 June 2005. The test was set up to determine the absorbing and shielding effect of a gravel pile, of 1.5 meters high and 15 by 15 meters wide, on blasts from large weapons: e.g. armor, artillery or demolition. The blast was

  4. Inheritance of blast resistance and identification of SSR marker ...

    Indian Academy of Sciences (India)

    2013-08-02

    Aug 2, 2013 ... An F2 population was developed from a cross between rice. (Oryza sativa L.) genotypes, EK 70 (highly susceptible to blast) and RDN 98-2-3-5-14 (resistant to blast), to study the inheritance of blast resistance and to identify the marker associated with resistance. The F2 population segregated in 3:1 ratio for ...

  5. Blast Impact Prediction Studies at Ghana Manganese Company ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Amegbey, N. and Afum, B. O. (2015), Blast Impact Prediction Studies at Ghana Manganese Company (GMC). Ltd, Nsuta ... conduct safe blasting operations in the Pit C North, studies were undertaken to assess the environmental impacts of blast associated with ..... Technology for Construction and Mining,.

  6. Modelling human eye under blast loading.

    Science.gov (United States)

    Esposito, L; Clemente, C; Bonora, N; Rossi, T

    2015-01-01

    Primary blast injury (PBI) is the general term that refers to injuries resulting from the mere interaction of a blast wave with the body. Although few instances of primary ocular blast injury, without a concomitant secondary blast injury from debris, are documented, some experimental studies demonstrate its occurrence. In order to investigate PBI to the eye, a finite element model of the human eye using simple constitutive models was developed. The material parameters were calibrated by a multi-objective optimisation performed on available eye impact test data. The behaviour of the human eye and the dynamics of mechanisms occurring under PBI loading conditions were modelled. For the generation of the blast waves, different combinations of explosive (trinitrotoluene) mass charge and distance from the eye were analysed. An interpretation of the resulting pressure, based on the propagation and reflection of the waves inside the eye bulb and orbit, is proposed. The peculiar geometry of the bony orbit (similar to a frustum cone) can induce a resonance cavity effect and generate a pressure standing wave potentially hurtful for eye tissues.

  7. Blasting response of the Eiffel Tower

    Science.gov (United States)

    Horlyck, Lachlan; Hayes, Kieran; Caetano, Ryan; Tahmasebinia, Faham; Ansourian, Peter; Alonso-Marroquin, Fernando

    2016-08-01

    A finite element model of the Eiffel Tower was constructed using Strand7 software. The model replicates the existing tower, with dimensions justified through the use of original design drawings. A static and dynamic analysis was conducted to determine the actions of the tower under permanent, imposed and wind loadings, as well as under blast pressure loads and earthquake loads due to an explosion. It was observed that the tower utilises the full axial capacity of individual members by acting as a `truss of trusses'. As such, permanent and imposed loads are efficiently transferred to the primary columns through compression, while wind loads induce tensile forces in the windward legs and compressive forces in the leeward. Under blast loading, the tower experienced both ground vibrations and blast pressures. Ground vibrations induced a negligibly small earthquake loading into the structure which was ignored in subsequent analyses. The blast pressure was significant, and a dynamic analysis of this revealed that further research is required into the damping qualities of the structure due to soil and mechanical properties. In the worst case scenario, the blast was assumed to completely destroy several members in the adjacent leg. Despite this weakened condition, it was observed that the tower would still be able to sustain static loads, at least for enough time for occupant evacuation. Further, an optimised design revealed the structure was structurally sound under a 46% reduction of the metal tower's mass.

  8. Divide and Conquer (DC BLAST: fast and easy BLAST execution within HPC environments

    Directory of Open Access Journals (Sweden)

    Won Cheol Yim

    2017-06-01

    Full Text Available Bioinformatics is currently faced with very large-scale data sets that lead to computational jobs, especially sequence similarity searches, that can take absurdly long times to run. For example, the National Center for Biotechnology Information (NCBI Basic Local Alignment Search Tool (BLAST and BLAST+ suite, which is by far the most widely used tool for rapid similarity searching among nucleic acid or amino acid sequences, is highly central processing unit (CPU intensive. While the BLAST suite of programs perform searches very rapidly, they have the potential to be accelerated. In recent years, distributed computing environments have become more widely accessible and used due to the increasing availability of high-performance computing (HPC systems. Therefore, simple solutions for data parallelization are needed to expedite BLAST and other sequence analysis tools. However, existing software for parallel sequence similarity searches often requires extensive computational experience and skill on the part of the user. In order to accelerate BLAST and other sequence analysis tools, Divide and Conquer BLAST (DCBLAST was developed to perform NCBI BLAST searches within a cluster, grid, or HPC environment by using a query sequence distribution approach. Scaling from one (1 to 256 CPU cores resulted in significant improvements in processing speed. Thus, DCBLAST dramatically accelerates the execution of BLAST searches using a simple, accessible, robust, and parallel approach. DCBLAST works across multiple nodes automatically and it overcomes the speed limitation of single-node BLAST programs. DCBLAST can be used on any HPC system, can take advantage of hundreds of nodes, and has no output limitations. This freely available tool simplifies distributed computation pipelines to facilitate the rapid discovery of sequence similarities between very large data sets.

  9. Blast-induced traumatic brain injury: a new trend of blast injury research.

    Science.gov (United States)

    Zhao, Yan; Wang, Zheng-Guo

    2015-01-01

    Blast injury has become the major life- and function-threatening injuries in recent warfares. There is increased research interest in the mental disorders caused by blast-induced traumatic brain injury (bTBI), which has been proved as one of the "signature wounds" in modern battlefield. We reviewed the recent progresses in bTBI-related researches and concluded that the new era of blast injury research has shifted from the traditional physical impairments to cognitive dysfunctional/mental disorders that are proved to be more related to the outcome of combat casualty care.

  10. Concepts and strategies for clinical management of blast-induced traumatic brain injury and posttraumatic stress disorder.

    Science.gov (United States)

    Chen, Yun; Huang, Wei; Constantini, Shlomi

    2013-01-01

    After exposure of the human body to blast, kinetic energy of the blast shock waves might be transferred into hydraulic energy in the cardiovascular system to cause a rapid physical movement or displacement of blood (a volumetric blood surge). The volumetric blood surge moves through blood vessels from the high-pressure body cavity to the low-pressure cranial cavity, causing damage to tiny cerebral blood vessels and the blood-brain barrier (BBB). Large-scale cerebrovascular insults and BBB damage that occur globally throughout the brain may be the main causes of non-impact, blast-induced brain injuries, including the spectrum of traumatic brain injury (TBI) and posttraumatic stress disorder (PTSD). The volumetric blood surge may be a major contributor not only to blast-induced brain injuries resulting from physical trauma, but may also be the trigger to psychiatric disorders resulting from emotional and psychological trauma. Clinical imaging technologies, which are able to detect tiny cerebrovascular insults, changes in blood flow, and cerebral edema, may help diagnose both TBI and PTSD in the victims exposed to blasts. Potentially, prompt medical treatment aiming at prevention of secondary neuronal damage may slow down or even block the cascade of events that lead to progressive neuronal damage and subsequent long-term neurological and psychiatric impairment.

  11. High prevalence of chronic pituitary and target-organ hormone abnormalities after blast-related mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Charles W. Wilkinson

    2012-02-01

    Full Text Available Studies of traumatic brain injury from all causes have found evidence of chronic hypopituitarism, defined by deficient production of one or more pituitary hormones at least one year after injury, in 25-50% of cases. Most studies found the occurrence of posttraumatic hypopituitarism (PTHP to be unrelated to injury severity. Growth hormone deficiency (GHD and hypogonadism were reported most frequently. Hypopituitarism, and in particular adult GHD, is associated with symptoms that resemble those of PTSD, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction, cognitive deficiencies, and decreased quality of life. However, the prevalence of PTHP after blast-related mild TBI (mTBI, an extremely common injury in modern military operations, has not been characterized. We measured concentrations of 12 pituitary and target-organ hormones in two groups of male US Veterans of combat in Iraq or Afghanistan. One group consisted of participants with blast-related mTBI whose last blast exposure was at least one year prior to the study. The other consisted of Veterans with similar military deployment histories but without blast exposure. Eleven of 26, or 42% of participants with blast concussions were found to have abnormal hormone levels in one or more pituitary axes, a prevalence similar to that found in other forms of TBI. Five members of the mTBI group were found with markedly low age-adjusted insulin-like growth factor-I (IGF-I levels indicative of probable GHD, and three had testosterone and gonadotropin concentrations consistent with hypogonadism. If symptoms characteristic of both PTHP and PTSD can be linked to pituitary dysfunction, they may be amenable to treatment with hormone replacement. Routine screening for chronic hypopituitarism after blast concussion shows promise for appropriately directing diagnostic and therapeutic decisions that otherwise may remain unconsidered and for markedly facilitating recovery and

  12. Spalling of concrete subjected to blast loading

    Directory of Open Access Journals (Sweden)

    Foglar M.

    2013-09-01

    Full Text Available This paper presents outcomes of the blast field tests of FRC and reinforced concrete specimens, which were performed in cooperation with the Czech Army corps and Police of the Czech Republic in the military training area Boletice. The numerical evaluation of the experiments focused on the spalling of concrete subjected to blast loading started after the first set of the tests, took almost 3 years and required further small-scale experiments performed in the labs of the Czech Technical University.

  13. Work Management Manual - Blast and Paint General

    Science.gov (United States)

    1983-08-01

    material which accelerates the har- dening of certain coatinss. Acoustic paint - paint which absorbs or deadens sound . Acrylic resin-a clear resin...AUG 1983 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Work Managemaent Manual - Blast and Paint General 5a. CONTRACT NUMBER...WORK MANAGEMENT MANUAL BLAST/ PAINT GENERAL INDEX SECTION PAGE 1.0 .1 .2 .3 .4 2.0 .1 .2 .3 .4 .5 .6 .8 .9 3.0 .1 4.0 .1 5.0 .1 7.0 .1 .3 8.0 SCOPE PLANT

  14. Temporal Progression of Visual Injury from Blast Exposure

    Science.gov (United States)

    2016-09-01

    Doctorate of Philosophy , Bioengineering May 2007 Advisor: Susan S. Margulies, Ph.D. Dissertation: Mechanics of Head Impact in Infants University of...Foundation 2016 SBIR Phase II: Biodegradable polymer film for sustained delivery of antibiotics to the surface of the eye Total Award: Role: co-PI

  15. Blast noise classification with common sound level meter metrics.

    Science.gov (United States)

    Cvengros, Robert M; Valente, Dan; Nykaza, Edward T; Vipperman, Jeffrey S

    2012-08-01

    A common set of signal features measurable by a basic sound level meter are analyzed, and the quality of information carried in subsets of these features are examined for their ability to discriminate military blast and non-blast sounds. The analysis is based on over 120 000 human classified signals compiled from seven different datasets. The study implements linear and Gaussian radial basis function (RBF) support vector machines (SVM) to classify blast sounds. Using the orthogonal centroid dimension reduction technique, intuition is developed about the distribution of blast and non-blast feature vectors in high dimensional space. Recursive feature elimination (SVM-RFE) is then used to eliminate features containing redundant information and rank features according to their ability to separate blasts from non-blasts. Finally, the accuracy of the linear and RBF SVM classifiers is listed for each of the experiments in the dataset, and the weights are given for the linear SVM classifier.

  16. RegExpBlasting (REB), a Regular Expression Blasting algorithm based on multiply aligned sequences

    OpenAIRE

    Rubino, Francesco; Attimonelli, Marcella

    2009-01-01

    Background One of the most frequent uses of bioinformatics tools concerns functional characterization of a newly produced nucleotide sequence (a query sequence) by applying Blast or FASTA against a set of sequences (the subject sequences). However, in some specific contexts, it is useful to compare the query sequence against a cluster such as a MultiAlignment (MA). We present here the RegExpBlasting (REB) algorithm, which compares an unclassified sequence with a dataset of patterns defined by...

  17. [Certain theoretical-methodological problems of forensic medical expertise of the blast injury].

    Science.gov (United States)

    Popov, V L

    2015-01-01

    This article is devoted to the analysis of the theoretical problems facing forensic medical expertise of the blast injury. The original notions of the blast, injurious blast factors, and their traumatic consequences are proposed together with the classification of the blasts and their injurious factors. The principal lines of the further research on the forensic medical aspects of the blast injury are formulated.

  18. Consideration on local blast vibration control by delay blasting; Danpatsu happa ni yoru kyokuchiteki shindo seigyo ni kansuru ichikosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, Gento; Adachi, Tsuyoshi; Yamatomi, Jiro [The University of Tokyo School of Engineering Department of Geosystem Engineering, Tokyo (Japan); Hoshino, Tatsuya [Mitsui Mining and Smelting Corp., Tokyo (Japan)

    1999-10-31

    In this research, local blast vibration control based on the theory of superposition of waves was investigated. Firstly, the influence of delay time errors of conventional electric detonators upon the level of local blast vibration was examined. Secondly, for a further effective local blast vibration control, a new delay blasting design concept 'combined delay blasting' that postulates the use of electronic detonators, which virtually have no delay time errors, is proposed. For a delay blasting with uniform detonation time intervals, an optimum time interval to minimize the local PPV (Peak Particle Velocity) is obtained based on the relationship between the PPV and the time interval, which is derived by superposing identical vibration time histories of each single hole shot. However, due to the scattering of the actual delay time caused by errors, PPV of a production blast seldom coincides with the estimated one. Since the expected value and the variance of PPV mainly depend on sensitivity of PPV around the nominal delay time, it is proposed that not only the optimum but also several sub-optimum candidates of delay time should be examined taking error into consideration. Concerning the 'combined delay blasting', its concept and some simulation results are presented. The estimated reduction effect of blast vibration of a delay blast based on this concept was quite favorable, indicating a possibility for further effective local blast vibration control. (author)

  19. Development and validation of a numerical model of the swine head subjected to open-field blasts

    Science.gov (United States)

    Kalra, A.; Zhu, F.; Feng, K.; Saif, T.; Kallakuri, S.; Jin, X.; Yang, K.; King, A.

    2017-11-01

    A finite element model of the head of a 55-kg Yucatan pig was developed to calculate the incident pressure and corresponding intracranial pressure due to the explosion of 8 lb (3.63 kg) of C4 at three different distances. The results from the model were validated by comparing findings with experimentally obtained data from five pigs at three different blast overpressure levels: low (150 kPa), medium (275 kPa), and high (400 kPa). The peak values of intracranial pressures from numerical model at different locations of the brain such as the frontal, central, left temporal, right temporal, parietal, and occipital regions were compared with experimental values. The model was able to predict the peak pressure with reasonable percentage differences. The differences for peak incident and intracranial pressure values between the simulation results and the experimental values were found to be less than 2.2 and 29.3%, respectively, at all locations other than the frontal region. Additionally, a series of parametric studies shows that the intracranial pressure was very sensitive to sensor locations, the presence of air bubbles, and reflections experienced during the experiments. Further efforts will be undertaken to correlate the different biomechanical response parameters, such as the intracranial pressure gradient, stress, and strain results obtained from the validated model with injured brain locations once the histology data become available.

  20. Developments in vapour cloud explosion blast modeling

    NARCIS (Netherlands)

    Mercx, W.P.M.; Berg, A.C. van den; Hayhurst, C.J.; Robertson, N.J.; Moran, K.C.

    2000-01-01

    TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be

  1. Acceleration from short-duration blast

    Science.gov (United States)

    Ritzel, D. V.; Van Albert, S.; Sajja, V.; Long, J.

    2018-01-01

    The blast-induced motion of spheres has been studied experimentally where the shock wave is rapidly decaying during the period that quasi-steady acceleration would be developed in the case of a step-function shock wave as considered in most shock-tube studies. The motion of sphere models ranging from 39 to 251 mm in diameter and having a range of densities was assessed using the "free-flight" method in a simulator specially designed to replicate the decaying shock wave profile of spherical blast including negative phase and positive entropy gradient. A standardized blast-wave simulation of 125 kPa and 6-ms positive-phase duration was applied for all experiments. In all cases, there are three phases to the motion: a relatively low "kickoff" velocity from the shock diffraction, acceleration or deceleration during the positive duration, then deceleration through the negative phase and subsequent quiescent air. The unexpected deceleration of larger spheres after their kickoff velocity during the decaying yet high-speed flow of the blast wave seems associated with the persistence of a ring vortex on the downstream side of the sphere. The flow is entirely unsteady with initial forces dominated by the shock diffraction; therefore, the early motion of spheres under such conditions is not governed by quasi-steady drag as in classical aerodynamics. The work will help establish scaling rules for model studies of blast-induced motion relevant to improvised explosive devices, and preliminary results are shown for motion imparted to a human skull surrogate.

  2. Mathematical model and software for control of commissioning blast furnace

    Science.gov (United States)

    Spirin, N. A.; Onorin, O. P.; Shchipanov, K. A.; Lavrov, V. V.

    2016-09-01

    Blowing-in is a starting period of blast furnace operation after construction or major repair. The current approximation methods of blowing-in burden analysis are based on blowing-in practice of previously commissioned blast furnaces. This area is theoretically underexplored; there are no common scientifically based methods for selection of the burden composition and blast parameters. The purpose of this paper is development and scientific substantiation of the methods for selection of the burden composition and blast parameters in the blast furnace during the blowing-in period. Research methods are based on physical regularities of main processes running in the blast furnace, system analysis, and application of modern principles for development and construction of mathematical models, algorithms and software designed for automated control of complex production processes in metallurgy. As consequence of the research made by the authors the following results have been achieved: 1. A set of mathematical models for analysis of burden arrangement throughout the height of the blast furnace and for selection of optimal blast and gas dynamic parameters has been developed. 2. General principles for selection of the blowing-in burden composition and blast and gas dynamic parameters have been set up. 3. The software for the engineering and process staff of the blast furnace has been developed and introduced in the industry.

  3. Solar power satellite system definition study. Part 2, volume 8: SPS launch vehicle ascent and entry sonic overpressure and noise effects

    Science.gov (United States)

    1977-01-01

    Recoverable launch vehicle concepts for the Solar Power Satellite program were identified. These large launch vehicles are powered by proposed engines in the F-1 thrust level class. A description of the candidate launch vehicles and their operating mode was provided. Predictions of the sonic over pressures during ascent and entry for both types of vehicles, and prediction of launch noise levels in the vicinity of the launch site were included. An overall assessment and criteria for sonic overpressure and noise levels was examined.

  4. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach Nuclear Power Plant, Units 1 and 2

    International Nuclear Information System (INIS)

    Laudenbach, D.H.

    1979-03-01

    The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach nuclear power plant, Units 1 and 2. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory

  5. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach Nuclear Power Plant, Units 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Laudenbach, D.H.

    1979-03-01

    The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach nuclear power plant, Units 1 and 2. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory.

  6. Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Haddam Neck Nuclear Power Plant

    International Nuclear Information System (INIS)

    Laudenbach, D.H.

    1979-03-01

    The technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Haddam Neck Nuclear Power Plant is presented. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory

  7. Three, Two, One ... Blast Off!

    Science.gov (United States)

    Hawkins, Susan; Rogers, Meredith Park

    2014-01-01

    This lesson addresses the three dimensions of science learning as laid out in the "Next Generation Science Standards"--science and engineering process skills, crosscutting concepts, and disciplinary core ideas--in addition to embedding practical exposure to NOS tenets in an inquiry-based activity. In addition to the efficiency component,…

  8. Aeromedical evacuation-relevant hypobaria worsens axonal and neurologic injury in rats after underbody blast-induced hyperacceleration.

    Science.gov (United States)

    Proctor, Julie L; Mello, Kaitlin T; Fang, Raymond; Puche, Adam C; Rosenthal, Robert E; Fourney, William L; Leiste, Ulrich H; Fiskum, Gary

    2017-07-01

    Occupants of military vehicles targeted by explosive devices often suffer from traumatic brain injury (TBI) and are typically transported by the aeromedical evacuation (AE) system to a military medical center within a few days. This study tested the hypothesis that exposure of rats to AE-relevant hypobaria worsens cerebral axonal injury and neurologic impairment caused by underbody blasts. Anesthetized adult male rats were secured within cylinders attached to a metal plate, simulating the hull of an armored vehicle. An explosive located under the plate was detonated, resulting in a peak vertical acceleration force on the plate and occupant rats of 100G. Rats remained under normobaria or were exposed to hypobaria equal to 8,000 feet in an altitude chamber for 6 hours, starting at 6 hours to 6 days after blast. At 7 days, rats were tested for vestibulomotor function using the balance beam walking task and euthanized by perfusion. The brains were then analyzed for axonal fiber injury. The number of internal capsule silver-stained axonal fibers was greater in animals exposed to 100G blast than in shams. Animals exposed to hypobaria starting at 6 hours to 6 days after blast exhibited more silver-stained fibers than those not exposed to hypobaria. Rats exposed to 100% oxygen (O2) during hypobaria at 24 hours postblast displayed greater silver staining and more balance beam foot-faults, in comparison with rats exposed to hypobaria under 21% O2. Exposure of rats to blast-induced acceleration of 100G increases cerebral axonal injury, which is significantly exacerbated by exposure to hypobaria as early as 6 hours and as late as 6 days postblast. Rats exposed to underbody blasts and then to hypobaria under 100% O2 exhibit increased axonal damage and impaired motor function compared to those subjected to blast and hypobaria under 21% O2. These findings raise concern about the effects of AE-related hypobaria on TBI victims, the timing of AE after TBI, and whether these effects

  9. Proceedings of the seventeenth annual conference on explosives and blasting technique. Volume 1

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Papers from this conference dealt with the following topics: surface and underground mine blasting, control of blast effects in sensitive areas, blasthole deviation, regulatory impact when blasting at Superfund sites, computer-aided blast design and monitoring, tunneling techniques, shaft excavations, video camera analysis of blasting operations, soil densification, cost optimization, mine blasting accidents, non-electric initiation systems, and delay detonators. Papers have been indexed separately for inclusion on the data base

  10. Database indexing for production MegaBLAST searches.

    Science.gov (United States)

    Morgulis, Aleksandr; Coulouris, George; Raytselis, Yan; Madden, Thomas L; Agarwala, Richa; Schäffer, Alejandro A

    2008-08-15

    The BLAST software package for sequence comparison speeds up homology search by preprocessing a query sequence into a lookup table. Numerous research studies have suggested that preprocessing the database instead would give better performance. However, production usage of sequence comparison methods that preprocess the database has been limited to programs such as BLAT and SSAHA that are designed to find matches when query and database subsequences are highly similar. We developed a new version of the MegaBLAST module of BLAST that does the initial phase of finding short seeds for matches by searching a database index. We also developed a program makembindex that preprocesses the database into a data structure for rapid seed searching. We show that the new 'indexed MegaBLAST' is faster than the 'non-indexed' version for most practical uses. We show that indexed MegaBLAST is faster than miBLAST, another implementation of BLAST nucleotide searching with a preprocessed database, for most of the 200 queries we tested. To deploy indexed MegaBLAST as part of NCBI'sWeb BLAST service, the storage of databases and the queueing mechanism were modified, so that some machines are now dedicated to serving queries for a specific database. The response time for such Web queries is now faster than it was when each computer handled queries for multiple databases. The code for indexed MegaBLAST is part of the blastn program in the NCBI C++ toolkit. The preprocessor program makembindex is also in the toolkit. Indexed MegaBLAST has been used in production on NCBI's Web BLAST service to search one version of the human and mouse genomes since October 2007. The Linux command-line executables for blastn and makembindex, documentation, and some query sets used to carry out the tests described below are available in the directory: ftp://ftp.ncbi.nlm.nih.gov/pub/agarwala/indexed_megablast [corrected] Supplementary data are available at Bioinformatics online.

  11. Gene interactions and genetics of blast resistance and yield

    Indian Academy of Sciences (India)

    Blast disease caused by the pathogen Pyricularia oryzae is a serious threat to rice production. Six generations viz., P1, P2, F1, F2, B1 and B2 of a cross between blast susceptible high-yielding rice cultivar ADT 43 and resistant near isogenic line (NIL) CT13432-3R, carrying four blast resistance genes Pi1, Pi2, Pi33 and Pi54 ...

  12. The Pre-Blast Concept for use on Armour Materials

    Science.gov (United States)

    2016-02-01

    UNCLASSIFIED UNCLASSIFIED The Pre-Blast Concept for use on Armour Materials C. Choi1, C. Peng2 and B. Dixon1 1Land Division Defence...to improve blast resistance Repeated blast test results (up to 7 times) of candidate armour materials showed that the greatest deformation...evidence of cracking in the armour steels and Crack-starter explosion bulge testing of the armour steels at -18 ºC demonstrated that the steels have

  13. Identification and detection of murine leukemia blasts by flow cytometry

    OpenAIRE

    sprotocols

    2015-01-01

    Human leukemia has been determined and classified with the help of flow cytometry for the past two decades. Past attempts to detect leukemia blasts relied on both forward and side scatter (FSC and SSC) based on cell size and granularity. However, this technique failed to show a clean separation of blasts from normal lineage cells. In 1993, Borowitz, et al developed flow cytometric analysis to distinguish human leukemia blasts from other normal lineage cells by using fluorescence-conjugated CD...

  14. Proceedings of the eighteenth annual conference on explosives and blasting technique

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    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

  15. Simulations of the design basis accident at conditions of power increase and the o transient of MSIV at overpressure conditions of the Laguna Verde Power Station

    International Nuclear Information System (INIS)

    Araiza M, E.; Nunez C, A.

    2001-01-01

    This document presents the analysis of the simulation of the loss of coolant accident at uprate power conditions, that is 2027 MWt (105% of the current rated power of 1931MWt). This power was reached allowing an increase in the turbine steam flow rate without changing the steam dome pressure value at its rated conditions (1020 psiaJ. There are also presented the results of the simulation of the main steam isolation va/ve transient at overpressure conditions 1065 psia and 1067 MWt), for Laguna Verde Nuclear Power Station. Both simulations were performed with the best estimate computer code TRA C BF1. The results obtained in the loss of coolant accident show that the emergency core coolant systems can recover the water level in the core before fuel temperature increases excessively, and that the peak pressure reached in the drywell is always below its design pressure. Therefore it is concluded that the integrity of the containment is not challenged during a loss of coolant accident at uprate power conditions.The analysis of the main steam isolation valve transients at overpressure conditions, and the analysis of the particular cases of the failure of one to six safety relief valves to open, show that the vessel peak pressures are below the design pressure and have no significant effect on vessel integrity. (Author)

  16. WU-Blast2 server at the European Bioinformatics Institute

    Science.gov (United States)

    Lopez, Rodrigo; Silventoinen, Ville; Robinson, Stephen; Kibria, Asif; Gish, Warren

    2003-01-01

    Since 1995, the WU-BLAST programs (http://blast.wustl.edu) have provided a fast, flexible and reliable method for similarity searching of biological sequence databases. The software is in use at many locales and web sites. The European Bioinformatics Institute's WU-Blast2 (http://www.ebi.ac.uk/blast2/) server has been providing free access to these search services since 1997 and today supports many features that both enhance the usability and expand on the scope of the software. PMID:12824421

  17. Mechanical study of the Chartreuse Fold-and-Thrust Belt: relationships between fluids overpressure and decollement within the Toarcian source-rock

    Science.gov (United States)

    Berthelon, Josselin; Sassi, William; Burov, Evgueni

    2016-04-01

    Many source-rocks are shale and constitute potential detachment levels in Fold-and-Thrust Belts (FTB): the toarcian Schistes-Cartons in the French Chartreuse FTB for example. Their mechanical properties can change during their burial and thermal maturation, as for example when large amount of hydrocarbon fluids are generated. A structural reconstruction of the Chartreuse FTB geo-history places the Toarcian Formation as the major decollement horizon. In this work, a mechanical analysis integrating the fluids overpressuring development is proposed to discuss on the validity of the structural interpretation. At first, an analogue of the Chartreuse Toarcian Fm, the albanian Posidonia Schist, is documented as it can provide insights on its initial properties and composition of its kerogen content. Laboratory characterisation documents the vertical evolution of the mineralogical, geochemical and mechanical parameters of this potential decollement layer. These physical parameters (i.e. Total Organic Carbon (TOC), porosity/permeability relationship, friction coefficient) are used to address overpressure buildup in the frontal part of the Chartreuse FTB with TEMISFlow Arctem Basin modelling approach (Faille et al, 2014) and the structural emplacement of the Chartreuse thrust units using the FLAMAR thermo-mechanical model (Burov et al, 2014). The hydro-mechanical modeling results highlight the calendar, distribution and magnitude of the overpressure that developed within the source-rock in the footwall of a simple fault-bend fold structure localized in the frontal part of the Chartreuse FTB. Several key geological conditions are required to create an overpressure able to fracture the shale-rocks and induce a significant change in the rheological behaviour: high TOC, low permeability, favourable structural evolution. These models highlight the importance of modeling the impact of a diffuse natural hydraulic fracturing to explain fluids propagation toward the foreland within

  18. A Phased Array Approach to Rock Blasting

    Energy Technology Data Exchange (ETDEWEB)

    Leslie Gertsch; Jason Baird

    2006-07-01

    A series of laboratory-scale simultaneous two-hole shots was performed in a rock simulant (mortar) to record the shock wave interference patterns produced in the material. The purpose of the project as a whole was to evaluate the usefulness of phased array techniques of blast design, using new high-precision delay technology. Despite high-speed photography, however, we were unable to detect the passage of the shock waves through the samples to determine how well they matched the expected interaction geometry. The follow-up mine-scale tests were therefore not conducted. Nevertheless, pattern analysis of the vectors that would be formed by positive interference of the shockwaves from multiple charges in an ideal continuous, homogeneous, isotropic medium indicate the potential for powerful control of blast design, given precise characterization of the target rock mass.

  19. Plastic Media Blasting Data Gathering Study

    Science.gov (United States)

    1986-12-01

    matt, reducing the filtering surface. 25 3) Cartridge Collectors: Cartridge dust collectors consist of a number of nonwoven tubular filters placed...by up to 90 percent. This task gathered data in five areas: chemical stripping, equipment and facilities, economics, safety and health , and surface...analyses conducted for the blast booth at Hill Air Force Base. The Safety section discusses the safety and health risks associated with PMB such as

  20. Blast Performance of Four Armour Materials

    Science.gov (United States)

    2013-08-01

    Charpy V- notch impact toughness results, as well as the highest carbon content of the steels tested . 5. For all steels the greatest deformation...Explosion Bulge Test (EBT). A number of conclusions may be drawn from these investigations and are summarised as follows: All steels tested were...good toughness and greater ductility, but less hardness. Multiple blast testing showed that steel A and steel M possessed the best resistance to

  1. Blast Injuries: What Clinicians Need to Know

    Centers for Disease Control (CDC) Podcasts

    2008-11-05

    In this podcast, Dr. Richard C. Hunt, Director of the CDC’s Division of Injury Response, National Center for Injury Prevention and Control provides a brief overview for health care providers on how to respond and care for persons injured by an explosion or blast event.  Created: 11/5/2008 by National Center for Injury Prevention and Control (NCIPC), Division of Injury Response (DIR).   Date Released: 11/6/2008.

  2. Centrifugal shot blasting. Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-07-01

    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

  3. Advanced MRI in Blast-related TBI

    Science.gov (United States)

    2012-07-01

    this study possible; the staff at the LRMC MRI clinic, including Don Al- brant, Kenny Caywood, Kelly McKay, Tim McKay, Tim Roberts, Kris Robertson...erans with persistent post-concussive symp- toms . Neuroimage 2011;54:Suppl 1:S76- S82. 12. Warden DL, French LM, Shupenko L, et al. Case report of a...Luethcke CA, Bryan CJ, Morrow CE, Isler WC. Comparison of concussive symp- toms , cognitive performance, and psycho- logical symptoms between acute blast

  4. Blast-induced electromagnetic fields in the brain from bone piezoelectricity.

    Science.gov (United States)

    Lee, Ka Yan Karen; Nyein, Michelle K; Moore, David F; Joannopoulos, J D; Socrate, Simona; Imholt, Timothy; Radovitzky, Raul; Johnson, Steven G

    2011-01-01

    In this paper, we show that bone piezoelectricity-a phenomenon in which bone polarizes electrically in response to an applied mechanical stress and produces a short-range electric field-may be a source of intense blast-induced electric fields in the brain, with magnitudes and timescales comparable to fields with known neurological effects. We compute the induced charge density in the skull from stress data on the skull from a finite-element full-head model simulation of a typical IED-scale blast wave incident on an unhelmeted human head as well as a human head protected by a kevlar helmet, and estimate the resulting electric fields in the brain in both cases to be on the order of 10 V/m in millisecond pulses. These fields are more than 10 times stronger than the IEEE safety guidelines for controlled environments (IEEE Standards Coordinating Committee 28, 2002) and comparable in strength and timescale to fields from repetitive Transcranial Magnetic Stimulation (rTMS) that are designed to induce neurological effects (Wagner et al., 2006a). They can be easily measured by RF antennas, and may provide the means to design a diagnostic tool that records a quantitative measure of the head's exposure to blast insult. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

    Directory of Open Access Journals (Sweden)

    Dong Sam Park

    2008-02-01

    Full Text Available For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a preprocess, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels.

  6. D-BLAST OFDM with Channel Estimation

    Directory of Open Access Journals (Sweden)

    Du Jianxuan

    2004-01-01

    Full Text Available Multiple-input and multiple-output (MIMO systems formed by multiple transmit and receive antennas can improve performance and increase capacity of wireless communication systems. Diagonal Bell Laboratories Layered Space-Time (D-BLAST structure offers a low-complexity solution for realizing the attractive capacity of MIMO systems. However, for broadband wireless communications, channel is frequency-selective and orthogonal frequency division multiplexing (OFDM has to be used with MIMO techniques to reduce system complexity. In this paper, we investigate D-BLAST for MIMO-OFDM systems. We develop a layerwise channel estimation algorithm which is robust to channel variation by exploiting the characteristic of the D-BLAST structure. Further improvement is made by subspace tracking to considerably reduce the error floor. Simulation results show that the layerwise estimators require 1 dB less signal-to-noise ratio (SNR than the traditional blockwise estimator for a word error rate (WER of when Doppler frequency is 40 Hz. Among the layerwise estimators, the subspace-tracking estimator provides a 0.8 dB gain for WER with 200 Hz Doppler frequency compared with the DFT-based estimator.

  7. Air-injected slurry blasting tests

    International Nuclear Information System (INIS)

    Wood, C.R.

    1983-01-01

    The Defense Waste Processing Facility (DWPF) will immobilize SRP high-level liquid waste in a borosilicate glass form. The molten waste glass at about 1050 0 C is poured into large (2-ft-dia, 10-ft-long) stainless steel canisters. During this operation the exterior of the canister reaches a temperature of up to 550 0 C and a thin oxide film is formed. This film traps radionuclide particles and must be removed to achieve the decontamination required before the canister leaves the DWPF canyon building. Air-injected frit slurry blasting has been chosen as the DWPF canister decontamination process based on results of tests with radioactively contaminated coupons. A small frit blaster in the Equipment Test Facility (ETF) has been used to optimize this process. Stainless steel coupons were heated at 600 0 C for 1 hour to simulate the canister oxide film. The coupons were weighed and then blasted at different parametric conditions. By weighing the coupons after blasting, the effects produced by each parameter could be compared and optimum parametric values determined

  8. Blast furnace hearth lining: post mortem analysis

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Bruno Vidal de; Vernilli Junior, Fernando, E-mail: bva@usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia; Neves; Elton Silva; Silva, Sidiney Nascimento [Companhia Siderugica Nacional (CSN), Rio de Janeiro, RJ (Brazil)

    2017-05-15

    The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10{sup 6} ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

  9. Multiphase blast interaction between heterogeneous explosives

    Science.gov (United States)

    Ripley, Robert; Ryan, Sydney; Jenkins, Charles M.

    2017-06-01

    Spherical charges loaded with micrometric metal powders feature explosively dispersed particle fields. The interaction phenomena of opposing multiphase flow fields from multiple charges depend on the charge spacing, loading configuration and particle morphology. For identical heterogeneous charges with a separation distance in the near field, the multiphase blast interaction includes particle-particle collision in the shocked air and impinging detonation products between the charges. Experiments recorded using high-speed framing cameras show the blast interaction process and resolve details of the multiphase structures. Hydrocode simulations are conducted using inelastic Lagrangian particle groups with a Direct Simulation Monte Carlo particle collision model. The numerical results distinguish the multiphase interaction layer and gas dynamic boundaries, with an emphasis on the particle laden Mach stem. The experimental results provide data for comparison to the interacting front velocities and Mach stem velocity. Modeling results for twin charges are shown to be different from a single heterogeneous blast reflection due to the stochastic and dissipative particle collisions. Remaining differences between the experimental and numerical results are discussed. The numerical results are further analyzed to assess particle fragmentation and potential for enhanced reaction in the interaction region between heterogeneous charges. DISTRIBUTION A. Approved for public release; distribution is unlimited. 96TW-2017-0079.

  10. Verification of wet blasting decontamination technology

    International Nuclear Information System (INIS)

    Matsubara, Sachito; Murayama, Kazunari; Yoshida, Hirohisa; Igei, Shigemitsu; Izumida, Tatsuo

    2013-01-01

    Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

  11. Blast Wave Mitigation in Granular Materials

    Science.gov (United States)

    Pontalier, Quentin; Lhoumeau, Maxime; Frost, David

    2017-06-01

    A common technique to mitigate the blast wave from a high explosive is to surround the explosive with a layer of inert particles or liquid. In the case of a powder layer in spherical geometry, the spherically expanding shock wave that propagates first within the porous powder bed has a complex structure and induces the formation of force chains through particles in contact, shock propagation in the interstitial gas, and leads to shock compaction and deformation of the particle bed. Overall, the shock accelerates the particles and heats the gas in the pores and the partition of the total energy between kinetic and internal energy is primarily a function of the layer porosity and mass ratio of material to explosive. This energy partition is explored computationally with a multiphase hydrocode as a function of the bed parameters and compared with the case of a homogeneous liquid. The results are compared with experiments which track the strength of the blast wave emerging from the material layer as well as the material velocity using high-speed photography. For a given mass ratio, the strength of the blast wave transmitted into the air and the material velocity are significantly lower for particle beds than liquid layers due to energy dissipation during compaction of the bed.

  12. Numerical Investigation of Structural Response of Corrugated Blast Wall Depending on Blast Load Pulse Shapes

    Directory of Open Access Journals (Sweden)

    Jung Min Sohn

    Full Text Available Abstract Hydrocarbon explosions are one of most hazardous events for workers on offshore platforms. To protect structures against explosion loads, corrugated blast walls are typically installed. However, the profiles of real explosion loads are quite different depending on the congestion and confinement of Topside structures. As the level of congestion and confinement increases, the explosion load increases by up to 8 bar, and the rising time of the load decreases. This study primarily aims to investigate the structural behavior characteristics of corrugated blast walls under different types of explosion loadings. Four loading shapes were applied in the structural response analysis, which utilized a dynamic nonlinear finite element method.

  13. Studies on induction of blast-resistant mutation in rice

    International Nuclear Information System (INIS)

    Tanaka, Sachihiko; Kawai, Takeshi; Yamasaki, Yoshito; Niizeki, Hiroo; Kiyosawa, Shigehisa.

    1980-01-01

    The mutation frequency of blast resistance in rice and that of increased pathogenicity of blast fungi were examined, using the rice variety, Norin 8, which is susceptible to all races of blast fungi in Japan, and a fungus strain, Ina 168, which carries 6 virulent genes, respectively. Four different inoculation methods were employed for screening blast resistant mutants, i.e., spraying spore suspensions in growth chambers, in a greenhouse and in a field nursery, and injecting spore suspensions into newly developed tillers. The number of lesions and their types were used as the criteria of blast resistance. For screening the fungus mutants with increased pathogenicity, the spore suspensions of the fungi to be tested were sprayed on the seedlings of the blast resistant varieties, and when susceptible-type lesions were formed, single spores were isolated from these lesions, and the change in its pathogenicity was confirmed. When seeds were irradiated with gamma ray and treated with chemicals (EMS or EI), the frequency of the mutants with high resistance to blast was 5/4,575 and 4/5,851 respectively, in the M 2 generation. The frequency of dominant blast resistant mutations following gamma-ray irradiation at the pre-embryo stage of growing plants was 3/60,101 in the M 1 generation. When the spore suspensions of blast fungi were treated with X-ray, the frequency of the mutants with increased pathogenicity was about 0.5%. Thus, the mutants highly resistant against blast of rice induced by radiation or chemicals would eventually become susceptible varieties because blast fungus mutants occurred more frequently with increased pathogenicity. (Kaihara, S.)

  14. Influence of Blasted Uranium Ore Heap on Radon Concentration in Confined Workspaces of Shrinkage Mining Stope

    Science.gov (United States)

    Ye, Y. J.; Liang, T.; Ding, D. X.; Lei, B.; Su, H.; Zhang, Y. F.

    2017-07-01

    A calculation model for radon concentration in shrinkage mining stopes under various ventilation conditions was established in this study. The model accounts for the influence of permeability and area of the blasted ore heap, ventilation air quantity, and airflow direction on radon concentration in a confined workspace; these factors work together to allow the engineer to optimize the ventilation design. The feasibility and effectiveness of the model was verified by applying it to mines with elevated radon radiation exposure. The model was found to accurately changes in radon concentration according to the array of influence factors in underground uranium mines.

  15. Glacially-derived overpressure in the northeastern Alaskan subduction zone: combined tomographic and morphometric analysis of shallow sediments on the Yakutat shelf and slope, Gulf of Alaska

    Science.gov (United States)

    Clary, W. A.; Worthington, L. L.; Scuderi, L. A.; Daigle, H.; Swartz, J. M.

    2017-12-01

    The Pamplona zone fold and thrust belt is the offshore expression of convergence and shallow subduction of the Yakutat microplate beneath North America in the northeastern Alaska subduction zone. The combination of convergent tectonics and glaciomarine sedimentary processes create patterns of deformation and deposition resulting in a shallow sedimentary sequence with varying compaction, fluid pressure, and fault activity. We propose that velocity variations observed in our tomographic analysis represent long-lived fluid overpressure due to loading by ice sheets and sediments. Regions with bathymetric and stratigraphic evidence of recent ice sheets and associated sedimentation should be collocated with evidence of overpressure (seismic low velocity zones) in the shallow sediments. Here, we compare a velocity model with shelf seismic stratigraphic facies and modern seafloor morphology. To document glacially derived morphology we use high resolution bathymetry to identify channel and gully networks on the western Yakutat shelf-slope then analyze cross-channel shape indices across the study area. We use channel shape index measurements as a proxy of recent ice-proximal sedimentation based on previously published results that proposed a close correlation. Profiles taken at many locations were fitted with a power function and assigned a shape - U-shape channels likely formed proximal to recent ice advances. Detailed velocity models were created by a combination of streamer tomography and pre-stack depth migration velocities with seismic data including: a 2008 R/V Langseth dataset from the St. Elias Erosion and Tectonics Project (STEEP); and a 2004 high-resolution R/V Ewing dataset. Velocity-porosity-permeability relationships developed using IODP Expedition 341 drilling data inform interpretation and physical properties analyses of the shallow sediments. Initial results from a 35 km profile extending SE seaward of the Bering glacier and subparallel to the Bering trough

  16. Blast injury ear in a low intensity conflict.

    Science.gov (United States)

    Kakkar, A

    2001-07-01

    The Eardrum is the most sensitive organ involved i blast injury and can be ruptured at relatively low pressure differentials. This study presents 200 cases of traumatic perforation among service personnel involved in a low intensity conflict, treated in a forward zonal hospital. Most blast injuries of the tympanic membrane (TM) heal spontaneously with conservative treatment (83%).

  17. Blast injury ear in a low intensity conflict

    OpenAIRE

    Kakkar, Anil

    2001-01-01

    The Eardrum is the most sensitive organ involved i blast injury and can be ruptured at relatively low pressure differentials. This study presents 200 cases of traumatic perforation among service personnel involved in a low intensity conflict, treated in a forward zonal hospital. Most blast injuries of the tympanic membrane (TM) heal spontaneously with conservative treatment (83%).

  18. Single point methods for determining blast wave injury

    NARCIS (Netherlands)

    Teland, J.A.; Doormaal, J.C.A.M. van; Horst, M.J. van der; Svinsas, E.

    2011-01-01

    Models for calculating human injury from a blast wave are examined. The Axelsson BTD model is able to give injury estimates also for complex shock waves, but is difficult to use in practise since it requires input from four pressure sensors on a BTD (Blast Test Device) in the specific location. To

  19. Measurement and Modelling of Blast Movement to Reduce Ore ...

    African Journals Online (AJOL)

    This paper describes the application of the latest measurements and modelling techniques in understanding the blast dynamics and develops site specific solutions to minimise blast induced dilution and ore losses. These solutions are validated at Newmont Ahafo open pit mine through systematic trials and subsequently ...

  20. Blasting Standards for the Ghanaian Mining Industry | Amegbey ...

    African Journals Online (AJOL)

    Ghana is a well known mining nation and hard rock mining has been going on since the 10th century. Mining companies in Ghana are well aware of the regulatory requirements to carry out blasting activities such that neighbouring communities are protected from excessive impact as a result of blast vibrations amongst other ...

  1. Gene interactions and genetics of blast resistance and yield ...

    Indian Academy of Sciences (India)

    2014-08-11

    Aug 11, 2014 ... Keywords. blast; gene action; generation mean analysis; resistance; yield. Journal of Genetics, Vol. 93, No. .... Utilizing the variance of different generations, the variances of A, B, C and D scales were ...... Jia Y. 2003 Marker assisted selection for the control of rice blast disease. Pesticide Outlook 14 ...

  2. Methodology of Testing Shot Blasting Machines in Industrial Conditions

    Directory of Open Access Journals (Sweden)

    R. Wrona

    2012-04-01

    Full Text Available Shot blasting machines are widely used for automated surface treatment and finishing of castings. In shot blasting processes the stream of shots is generated and shaped by blasting turbines, making up a kinetic and dynamic system comprising a separating rotor, an adapting sleeve and a propelling rotor provided with blades. The shot blasting performance- i.e. the quality of shot treated surfaces depends on the actual design and operational parameters of the unit whilst the values of relevant parameters are associated with the geometry of turbine components and the level of its integration with the separator system. The circulation of the blasting medium becomes the integrating factor of the process line, starting from the hopper, through the propeller turbine, casting treatment, separation of contaminated abrasive mixture, to its recycling and reuse.Inferior quality of the abrasive agent (shot and insufficient purity of the abrasive mixture are responsible for low effectiveness of shot blasting. However, most practitioners fail to fully recognise the importance of proper diagnostics of the shot blasting process in industrial conditions. The wearing of major machine components and of the blasting agent and quality of shot treated surfaces are often misinterpreted, hence the need to take into account all factors involved in the process within the frame of a comprehensive methodology.This paper is an attempt to formulate and apply the available testing methods to the engineering practice in industrial conditions.

  3. Delineating rockmass damage zones in blasting from in-field ...

    African Journals Online (AJOL)

    Delineating rockmass damage zones in blasting from in-field seismic velocity and peak particle velocity measurement. ... has been found that the integrity of rockmass is reduced significantly from pre to post blast condition due to disregard paid to the surrounding rockmass. For exercising suitable engineering controls ...

  4. Testing the blast wave model with Swift GRBs

    NARCIS (Netherlands)

    Curran, P.A.; Starling, R.L.C.; van der Horst, A.J.; Wijers, R.A.M.J.

    2009-01-01

    The complex structure of the light curves of Swift Gamma-Ray Bursts (GRBs) has made the identification of breaks, and the interpretation of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to identify breaks, which are possibly hidden, and to constrain the blast

  5. Testing the blast wave model with Swift GRBs

    NARCIS (Netherlands)

    Curran, P.A.; Starling, R.L.C.; van der Horst, A.J.; Wijers, R.A.M.J.; de Pasquale, M.; Page, M.

    2011-01-01

    The complex structure of the light curves of Swift GRBs (e.g. superimposed flares and shallow decay) has made their interpretation and that of the blast wave caused by the burst, more difficult than in the pre-Swift era. We aim to constrain the blast wave parameters: electron energy distribution, p,

  6. Genetic diversity of the blast fungus, Magnaporthe grisea (Hebert ...

    African Journals Online (AJOL)

    The effectiveness of some resistance genes indicated that they could be pyramided to provide durable resistance to blast fungus in Burkina Faso. The study also revealed the possible existence of new pathotypes in Burkina Faso. Fifty-five isolates of the blast fungus, Magnaporthe grisea, collected from the nurseries and rice ...

  7. Dry ice blasting for the conservation cleaning of metals

    NARCIS (Netherlands)

    van der Molen, R.; Joosten, I.; Beentjes, T.; Megens, L.; Mardikian, P.; Chemello, C.; Watters, C.; Hull, P.

    2011-01-01

    This research was carried out to assess the feasibility of dry ice blasting as a replacement for solvent cleaning for the removal of organic layers from metal cultural heritage objects. The effects of dry ice blasting on test samples of aluminium, bronze and weathering steel were studied along with

  8. 30 CFR 75.1310 - Explosives and blasting equipment.

    Science.gov (United States)

    2010-07-01

    ... for use so long as the present approval is maintained. (e) Electric detonators shall be compatible... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives and blasting equipment. 75.1310... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1310...

  9. 30 CFR 75.1316 - Preparation before blasting.

    Science.gov (United States)

    2010-07-01

    ... before blasting. (a)(1) All nonbattery-powered electric equipment, including cables, located within 50... cable or detonator circuitry shall not come in contact with energized electric equipment, including... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Preparation before blasting. 75.1316 Section 75...

  10. Investigation on Blast Resistance of Precast Reinforced Concrete Floor Slab

    Science.gov (United States)

    Bonora, Nicola; Gentile, Domenico; Iannitti, Gianluca; Ruggiero, Andrew; Testa, Gabriel; Bernabei, Manuele; Cassioli, Luigi; Grossi, Silvana

    2017-06-01

    The knowledge of the effective blast resistance of civil infrastructures is a fundamental information for risk assessment and modelling consequences of terrorist attack in high population density urban environment. In this work, blast resistance of precast reinforced concrete floor slab, commonly used for commercial parking, was investigated performing blast tests, detonating bare explosive charge of RDX 80-20 in contact with the slab. The charge mass, and the stand-off distance, was varied in order to generate different damage extents, from visible to fully breached condition. Numerical simulations were performed considering all slab structural elements. Failure model for concrete was calibrated on breach size and shape observed in the experiments. The explosive and blast wave-structure interaction were simulated using arbitrary Lagrangian-Eulerian method (ALE) and particle blast method (PBM) for comparison.

  11. SURFACE PREPARATION OF STEEL SUBSTRATES USING GRIT-BLASTING

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; D. J. Varacalle, Jr.; D. Deason; W. Rhodaberger; E. Sampson

    2005-05-01

    The primary purpose of grit blasting for thermal spray applications is to ensure a strong mechanical bond between the substrate and the coating by the enhanced roughening of the substrate material. This study presents statistically designed experiments that were accomplished to investigate the effect of abrasives on roughness for A36/1020 steel. The experiments were conducted using a Box statistical design of experiment (SDE) approach. Three grit blasting parameters and their effect on the resultant substrate roughness were investigated. These include blast media, blast pressure, and working distance. The substrates were characterized for roughness using surface profilometry. These attributes were correlated with the changes in operating parameters. Twin-Wire Electric Arc (TWEA) coatings of aluminum and zinc/aluminum were deposited on the grit-blasted substrates. These coatings were then tested for bond strength. Bond strength studies were conducted utilizing a portable adhesion tester following ASTM standard D4541.

  12. 30 CFR 56.6404 - Separation of blasting circuits from power source.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of blasting circuits from power... MINES Explosives Electric Blasting § 56.6404 Separation of blasting circuits from power source. (a) Switches used to connect the power source to a blasting circuit shall be locked in the open position except...

  13. 30 CFR 57.6404 - Separation of blasting circuits from power source.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Separation of blasting circuits from power... NONMETAL MINES Explosives Electric Blasting-Surface and Underground § 57.6404 Separation of blasting circuits from power source. (a) Switches used to connect the power source to a blasting circuit shall be...

  14. Proceedings of the seventeenth annual conference on explosives and blasting technique. Volume 2

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Papers from this conference dealt with the following topics: surface and underground mine blasting, ground vibrations and blast effects, design for explosive fracturing of rock, sequential timing for blasting control, design for production optimization, use of blasting for abandoned mine reclamation, chemical explosives, lightning warning systems, magazine security, fire safety, and drilling equipment. Papers have been indexed separately for inclusion on the data base

  15. Survey of rice blast race identity for blast resistance gene identification in the USA and Puerto Rico

    Science.gov (United States)

    Rice blast disease is a significant threat to stable rice production in the USA and worldwide. The major resistance gene (Pi-ta) located within a cluster of resistance genes on rice chromosome 12 has been demonstrated to confer resistance to the rice blast disease. Katy, a rice cultivar released in ...

  16. Value/impact analysis of Generic Issue 94, /open quotes/Additional Low Temperature Overpressure Protection for Light Water Reactors/close quotes/

    International Nuclear Information System (INIS)

    Gore, B.F.; Vo, T.V.; Colburn, A.J.; Eschbach, E.J.; Harris, M.S.

    1988-11-01

    This document presents a value/impact analysis of the expected risk reduction and associated costs for seven regulatory alternatives which have been proposed to resolve the generic issue of low temperature overpressure (LTOP) transients. It also presents an analysis of the reduction of public risk which was accomplished by the 1979 imposition of requirements for LTOP transient protection, when LTOP had previously been designated as a generic issue. The alternatives evaluated were: no action, prohibit operations with the reactor cooling system (RCS) ''water solid'' except when it is depressurized and vented, and require all operating reactors to maintain a bubble of steam or noncondensible gas (N 2 ) in the pressurizer when the RCS is not vented; prohibit operation of the RCS in a water-solid condition when either train of the overpressure mitigation system (OMS) is out of service; prohibit operation with the RCS in a water-solid condition when a high pressure safety injection pump is in service; prohibit restart of a reactor coolant pump when the RCS is in a water-solid condition; require that the pressure setpoint for automatic isolation of the residual heat removal system be raised above the setpoint for residual heat removal safety relief valve opening to maintain this relief path as backup to the OMS; and require the OMS to be safety grade. The risk analysis of each alternative estimated the public risk from the operation of the 63 presently operating pressurized water reactors summed over the period from the present to end of licensing. 20 refs., 7 figs., 45 tabs

  17. Slag wool manufacturing from blast furnace slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Руських

    2016-11-01

    Full Text Available Slag wool is the most expensive and valuable product of blast furnace slag processing. Slag wool is in great demand nowadays. The article highlights the factors influencing the mineral wool quality: chemical composition that determines the acidity of the module, the temperature of the molten slag and the required slag jet thickness consistency. Mineral wool is produced by blowing air or steam into a jet of molten slag. As a result of it the slag crushes into droplets stretching. The resulting wool contains 5% slag and 95% air. The quality of the obtained slag wool depends on the module acidity of the slag. The blast furnace slags of «Ilyich iron and steel works of Mariupol» and «Azovstal iron & steel works» are the main (short slags – they give short fibers. To obtain high-quality long fiber wool it is necessary to add admixtures into basic blast furnace slag to reduce its basicity. As a result of the fuel and energy rising prices and the necessity to reduce the slag wool cost it is necessary to develop a new technology with fiery-liquid slag, with the removal of iron compounds and sulphur from the melts and the introduction of corrective additives to improve the quality of slag wool. Good thermal conductivity (about 0,03 kcal/m∙h∙°C and other indicators (resistance, volume weight make it possible to use the materials from slag wool (pads, rigid and semi-rigid plates as heat and sound insulating materials

  18. BLAST: RESOLVING THE COSMIC SUBMILLIMETER BACKGROUND

    International Nuclear Information System (INIS)

    Marsden, Gaelen; Chapin, Edward L.; Halpern, Mark; Ngo, Henry; Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo; Bock, James J.; Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff; Gundersen, Joshua O.; Hughes, David H.; Magnelli, Benjamin; Netterfield, Calvin B.; Olmi, Luca; Patanchon, Guillaume

    2009-01-01

    The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) has made 1 deg 2 , deep, confusion-limited maps at three different bands, centered on the Great Observatories Origins Deep Survey South Field. By calculating the covariance of these maps with catalogs of 24 μm sources from the Far-Infrared Deep Extragalactic Legacy Survey, we have determined that the total submillimeter intensities are 8.60 ± 0.59, 4.93 ± 0.34, and 2.27 ± 0.20 nW m -2 sr -1 at 250, 350, and 500 μm, respectively. These numbers are more precise than previous estimates of the cosmic infrared background (CIB) and are consistent with 24 μm-selected galaxies generating the full intensity of the CIB. We find that the fraction of the CIB that originates from sources at z ≥ 1.2 increases with wavelength, with 60% from high-redshift sources at 500 μm. At all BLAST wavelengths, the relative intensity of high-z sources is higher for 24 μm-faint sources than that for 24 μm-bright sources. Galaxies identified as active galactic nuclei (AGNs) by their Infrared Array Camera colors are 1.6-2.6 times brighter than the average population at 250-500 μm, consistent with what is found for X-ray-selected AGNs. BzK-selected galaxies are found to be moderately brighter than typical 24 μm-selected galaxies in the BLAST bands. These data provide high-precision constraints for models of the evolution of the number density and intensity of star-forming galaxies at high redshift.

  19. Civilian blast-related burn injuries.

    Science.gov (United States)

    Patel, J N; Tan, A; Dziewulski, P

    2016-03-31

    There is limited English literature describing the experience of a civilian hospital managing blast-related burn injuries. As the largest regional burn unit, we reviewed our cases with the aim of identifying means to improve current management. A 6-year retrospective analysis of all patients coded as sustaining blast-related burns was conducted through the unit's burns database. Medical case notes were reviewed for information on burn demographics, management and outcomes. 42 patients were identified. Male to female ratio was 37:5. Age range was 12-84 years, (mean=33 years). Total body surface area (%TBSA) burn ranged from 0.25% to 60%, (median=1%). The most common burn injury was flame (31/42, 73.8%). Gas explosions were the most common mechanism of injury (19 cases; 45.2%). 7/42 cases (16.7%) had full ATLS management pre-transfer to the burns unit. The Injury Severity Score (ISS) ranged from 0-43 (median=2). 17/42 (40.4%) patients required admission. 37/36 (88.1%) patients were managed conservatively of which 1 patient later required surgery due to deeper burns. 5/42 (11.9%) patients required surgical management at presentation and these were noted to be burns with >15% TBSA requiring resuscitation. One case required emergency escharotomies and finger amputations. All patients survived their burn injuries. Blast-related burn injuries are generally uncommon in the civilian setting. Following proper assessment, most of these cases can be deemed as minor injuries and managed conservatively. Improvement in burns management education and training at local emergency departments would provide efficient patient care and avoid unnecessary referrals to a burns unit.

  20. The nature of white matter abnormalities in blast-related mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Jasmeet P. Hayes

    2015-01-01

    Full Text Available Blast-related traumatic brain injury (TBI has been a common injury among returning troops due to the widespread use of improvised explosive devices in the Iraq and Afghanistan Wars. As most of the TBIs sustained are in the mild range, brain changes may not be detected by standard clinical imaging techniques such as CT. Furthermore, the functional significance of these types of injuries is currently being debated. However, accumulating evidence suggests that diffusion tensor imaging (DTI is sensitive to subtle white matter abnormalities and may be especially useful in detecting mild TBI (mTBI. The primary aim of this study was to use DTI to characterize the nature of white matter abnormalities following blast-related mTBI, and in particular, examine the extent to which mTBI-related white matter abnormalities are region-specific or spatially heterogeneous. In addition, we examined whether mTBI with loss of consciousness (LOC was associated with more extensive white matter abnormality than mTBI without LOC, as well as the potential moderating effect of number of blast exposures. A second aim was to examine the relationship between white matter integrity and neurocognitive function. Finally, a third aim was to examine the contribution of PTSD symptom severity to observed white matter alterations. One hundred fourteen OEF/OIF veterans underwent DTI and neuropsychological examination and were divided into three groups including a control group, blast-related mTBI without LOC (mTBI - LOC group, and blast-related mTBI with LOC (mTBI + LOC group. Hierarchical regression models were used to examine the extent to which mTBI and PTSD predicted white matter abnormalities using two approaches: 1 a region-specific analysis and 2 a measure of spatial heterogeneity. Neurocognitive composite scores were calculated for executive functions, attention, memory, and psychomotor speed. Results showed that blast-related mTBI + LOC was associated with greater odds of

  1. Carbon Tubular Morphologies in Blast Furnace Coke

    Directory of Open Access Journals (Sweden)

    Stanislav S. Gornostayev

    2008-01-01

    Full Text Available The paper reports on the first occurrence of microscale carbon tubular morphologies (CMTs in a blast furnace (BF coke. The CMTs were probably formed as a result of the conversion of solid disordered carbon via liquid phase metal particles involving a gas phase containing a substantial amount of N2 and O2. The presence of CMTs may lie behind the generation of the smallest fraction of fines in BF exhaust dust. If the amount of CMTs present in the BF exhausts gases at any particular metallurgical site proves to be substantial, it could become a subject of environmental concern.

  2. Rock breaking methods to replace blasting

    Science.gov (United States)

    Zhou, Huisheng; Xie, Xinghua; Feng, Yuqing

    2018-03-01

    The method of breaking rock by blasting has a high efficiency and the cost is relatively low, but the associated vibration, flyrock, production of toxic gases since the 1970’s, the Western developed countries began to study the safety of breaking rock. This paper introduces different methods and their progress to safely break rock. Ideally, safe rock breaking would have little vibration, no fly stone, and no toxic gases, which can be widely used in municipal engineering, road excavation, high-risk mining, quarrying and complex environment.

  3. NASA TEERM Project: Corn Based Blast Media

    Science.gov (United States)

    Griffin, Chuck

    2009-01-01

    Coatings removal is a necessary part of the maintenance, repair, and overhaul activities at many NASA centers and contractor support sites. Sensitive substrates, such as composites and thin aluminum alloys require special handling such as the use of chemical stripping, pneumatic hand sanding, or softer blast media. Type V, acrylic based PMB is commonly used to de-coat, strip, or de-paint the delicate substrates of the Solid Rocket Boosters (SRBs) currently used in support of the Shuttle and slated to be used in support of CxP.

  4. Design of blast simulators for nuclear testing

    International Nuclear Information System (INIS)

    Mark, A.; Opalka, K.O.; Kitchens, C.W. Jr.

    1983-01-01

    A quasi-one-dimensional computational technique is used to model the flow of a large, complicated shock tube. The shock tube, or Large Blast Simulator, is used to simulate conventional or nuclear explosions by shaping the pressure history. Results from computations show favorable agreement when compared with data taken in the facility at Gramat, France. Such future shock tubes will include a thermal irradiation capability to better simulate a nuclear event. The computations point to the need for venting of the combustion products since the pressure history will be considerably altered as the shock propagates through these hot gases

  5. Explosive and accessories in rock blasting

    Energy Technology Data Exchange (ETDEWEB)

    Pingua, B.M.P.; Nabiullah, M.; Jagdish, S.; Mishra, G.D.; Singh, T.N. [Central Mining Research Institute, Dhanbad (India)

    1999-02-01

    Chemical explosives are commonly used in the mining industry. Those used in India include nitroglycerine (NG) base, ammonium nitrate fuel oil mixture (ANFO), slurry emulsion and liquid oxygen (LOX). Examples of each type and their general properties are lighted. The electric and non-electric detonating systems used are described. Two Indian companies are producing non-electric in-hole delay system. Raydet (IDL-make) and Excel (ICI-make). Their firing characteristics are listed. Tables are given for burden for different density of rock and explosive strength. Causes of bad blast are itemised. 7 refs., 4 figs., 7 tabs.

  6. Vestibular, balance, microvascular and white matter neuroimaging characteristics of blast injuries and mild traumatic brain injury: Four case reports.

    Science.gov (United States)

    Gattu, Ramtilak; Akin, Faith W; Cacace, Anthony T; Hall, Courtney D; Murnane, Owen D; Haacke, E Mark

    2016-01-01

    Case reports are presented on four Veterans, aged 29-46 years, who complained of chronic dizziness and/or postural instability following blast exposures. Two of the four individuals were diagnosed with mild traumatic brain injury and three of the four were exposed to multiple blasts. Comprehensive vestibular, balance, gait, audiometry and neuroimaging procedures were used to characterize their injuries. Vestibular assessment included videonystagmography, rotary chair and cervical and ocular vestibular evoked myogenic potentials. Balance and gait testing included the sensory organization test, preferred gait speed and the dynamic gait index. Audiometric studies included pure tone audiometry and middle-ear measurements. Neuroimaging procedures included high resolution structural magnetic resonance imaging, susceptibility-weighted imaging and diffusion-tensor imaging. Based on the neuroimaging and vestibular and balance test results, it was found that all individuals had diffuse axonal injuries and all had one or more micro-hemorrhages or vascular anomalies. Three of the four individuals had abnormal vestibular function, all had abnormally slow walking speeds and two had abnormal gait and balance dysfunction. The use of contemporary neuroimaging studies in conjunction with comprehensive vestibular and balance assessment provided a better understanding of the pathophysiology and pathoanatomy of dizziness following blast exposures than standard vestibular and balance testing alone.

  7. Determination of Destress Blasting Effectiveness Using Seismic Source Parameters

    Science.gov (United States)

    Wojtecki, Łukasz; Mendecki, Maciej J.; Zuberek, Wacaław M.

    2017-12-01

    Underground mining of coal seams in the Upper Silesian Coal Basin is currently performed under difficult geological and mining conditions. The mining depth, dislocations (faults and folds) and mining remnants are responsible for rockburst hazard in the highest degree. This hazard can be minimized by using active rockburst prevention, where destress blastings play an important role. Destress blastings in coal seams aim to destress the local stress concentrations. These blastings are usually performed from the longwall face to decrease the stress level ahead of the longwall. An accurate estimation of active rockburst prevention effectiveness is important during mining under disadvantageous geological and mining conditions, which affect the risk of rockburst. Seismic source parameters characterize the focus of tremor, which may be useful in estimating the destress blasting effects. Investigated destress blastings were performed in coal seam no. 507 during its longwall mining in one of the coal mines in the Upper Silesian Coal Basin under difficult geological and mining conditions. The seismic source parameters of the provoked tremors were calculated. The presented preliminary investigations enable a rapid estimation of the destress blasting effectiveness using seismic source parameters, but further analysis in other geological and mining conditions with other blasting parameters is required.

  8. Discrimination of Earthquake and Blast Seismicity in Western Alberta

    Science.gov (United States)

    Spriggs, N.; Law, A.; Yenier, E.; Reynen, A.; Baturan, D.

    2015-12-01

    Recorded seismicity in western Alberta is caused by natural and induced earthquakes or blast events from mining and quarry operations. Accurate discrimination of earthquakes from blast events is crucial for evaluating recent seismicity with respect to the historical catalog and for assessing seismic hazards associated with naturally occurring or induced seismicity. In general, blast events are discriminated from earthquakes based on their proximity to active mines and quarries in addition to day-of-week and time-of-day timing patterns. In some parts of western Alberta, however, seismicity originates in regions with active mines, historical earthquake seismicity, and hydraulic fracturing operations. Based on timing patterns or event locations alone, natural or induced seismicity may be misidentified as mining activity. Several studies report that relative differences in Fourier or response spectra can be used to discriminate blast and earthquake events. Other studies report that the relative timing and amplitude of seismic phases may provide useful metrics for classifying blast events. Here we propose an alternative method that accounts for both differences in phase spectra and phase timing and amplitude. In particular, we evaluate the normalized time integral for characteristic functions of particle motion from confirmed blast and earthquake events recorded by regional Alberta seismic networks. We then use these time-integral profiles to re-classify events that are initially categorized as suspected blasts based on timing pattern and event location indicators.

  9. Compressive strength after blast of sandwich composite materials.

    Science.gov (United States)

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

    2014-05-13

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

  10. An intervention for noise control of blast furnace in steel industry.

    Science.gov (United States)

    Golmohammadi, Rostam; Giahi, Omid; Aliabadi, Mohsen; Darvishi, Ebrahim

    2014-01-01

    Noise pollution is currently a major health risk factor for workers in industries. The aim of this study was to investigate noise pollution and implement a control intervention plan for blast furnace in a steel industry. The measurement of sound pressure level (SPL) along with frequency analysis was done with the sound-level-meter Cell-450. Personal noise exposure was performed using dosimeter TES-1345 calibrated with CEL-282. Before planning noise controls, acoustic insulation properties of the furnace control unit and workers' rest room were assessed. Control room and workers' rest room were redesigned in order to improve acoustical condition. The SPL before intervention around the Blast Furnace was 90.3 dB (L) and its dominant frequency was 4000 Hz. Besides, noise transmission loss of the control and rest rooms were 10.3 dB and 4.2 dB, respectively. After intervention, noise reduction rates in the control and rest rooms were 27.4 dB and 27.7 dB, respectively. The workers' noise dose before and after the intervention was 240% and less than 100%, respectively. Improvement the workroom acoustic conditions through noise insulation can be considered effective method for preventing workers exposure to harmful noise.

  11. Protecting the lower extremity against a/p blast mines

    CSIR Research Space (South Africa)

    van Dyk, T

    2006-09-01

    Full Text Available protection concept Result: Chaos and arguments Slide 4 © CSIR 2006 www.csir.co.za A/P Blast Mines Effects Slide 5 © CSIR 2006 www.csir.co.za Basic Principles Shock Effect Slide 6 © CSIR 2006... the Lower Extremity against a/p Blast Mines J T van Dyk DEFENCE, PEACE, SAFETY AND SECURITY LANDWARDS SCIENCES COMPETENCY AREA Slide 2 © CSIR 2006 www.csir.co.za Contents • R&D overview • Effect of a/p blast mines • Basic...

  12. The tank's dynamic response under nuclear explosion blast wave

    International Nuclear Information System (INIS)

    Xu Mei; Wang Lianghou; Li Xiaotian; Yu Suyuan; Zhang Zhengming; Wan Li

    2005-01-01

    To weapons and equipment, blast wave is the primary destructive factor. In this paper, taken the real model-59 tank as an example, we try to transform the damage estimation problem into computing a fluid structure interaction problem with finite element method. The response of tank under nuclear explosion blast wave is computed with the general-coupling algorithm. Also, the dynamical interaction of blast wave and tank is reflected in real time. The deformation of each part of the tank is worked out and the result corresponds to the real-measured data. (authors)

  13. Lateral blasts at Mount St. Helens and hazard zonation

    Science.gov (United States)

    Crandell, D.R.; Hoblitt, R.P.

    1986-01-01

    Lateral blasts at andesitic and dacitic volcanoes can produce a variety of direct hazards, including ballistic projectiles which can be thrown to distances of at least 10 km and pyroclastic density flows which can travel at high speed to distances of more than 30 km. Indirect effect that may accompany such explosions include wind-borne ash, pyroclastic flows formed by the remobilization of rock debris thrown onto sloping ground, and lahars. Two lateral blasts occurred at a lava dome on the north flank of Mount St. Helens about 1200 years ago; the more energetic of these threw rock debris northeastward across a sector of about 30?? to a distance of at least 10 km. The ballistic debris fell onto an area estimated to be 50 km2, and wind-transported ash and lapilli derived from the lateral-blast cloud fell on an additional lobate area of at least 200 km2. In contrast, the vastly larger lateral blast of May 18, 1980, created a devastating pyroclastic density flow that covered a sector of as much as 180??, reached a maximum distance of 28 km, and within a few minutes directly affected an area of about 550 km2. The May 18 lateral blast resulted from the sudden, landslide-induced depressurization of a dacite cryptodome and the hydrothermal system that surrounded it within the volcano. We propose that lateral-blast hazard assessments for lava domes include an adjoining hazard zone with a radius of at least 10 km. Although a lateral blast can occur on any side of a dome, the sector directly affected by any one blast probably will be less than 180??. Nevertheless, a circular hazard zone centered on the dome is suggested because of the difficulty of predicting the direction of a lateral blast. For the purpose of long-term land-use planning, a hazard assessment for lateral blasts caused by explosions of magma bodies or pressurized hydrothermal systems within a symmetrical volcano could designate a circular potential hazard area with a radius of 35 km centered on the volcano

  14. Relativistic blast waves in two dimensions. I - The adiabatic case

    Science.gov (United States)

    Shapiro, P. R.

    1979-01-01

    Approximate solutions are presented for the dynamical evolution of strong adiabatic relativistic blast waves which result from a point explosion in an ambient gas in which the density varies both with distance from the explosion center and with polar angle in axisymmetry. Solutions are analytical or quasi-analytical for the extreme relativistic case and numerical for the arbitrarily relativistic case. Some general properties of nonplanar relativistic shocks are also discussed, including the incoherence of spherical ultrarelativistic blast-wave fronts on angular scales greater than the reciprocal of the shock Lorentz factor, as well as the conditions for producing blast-wave acceleration.

  15. Biomarkers of Blast-Induced Neurotrauma: Profiling Molecular and Cellular Mechanisms of Blast Brain Injury

    Science.gov (United States)

    2009-06-01

    common locations are the corticome- dullary (gray matter-white matter) junction (particularly in the frontal and temporal areas), the internal capsule ...Vascular responses and dysregulation of cell adhesion molecules as bridges connecting vascular-endothelial- neural tissue disturbances, including but not...3371–3376. Lew, H.L. (2005). Rehabilitation needs of an increasing popula- tion of patients: Traumatic brain injury, polytrauma, and blast-related

  16. Environmental problems associated with blasting in mines: public apprehensions of damage due to blast vibrations - case studies

    Energy Technology Data Exchange (ETDEWEB)

    Padhi, S.N. [DGMS, Bhubaneswar (India)

    1994-12-31

    Blast vibrations may be felt in intensities as small as 1/100 of that required to cause any damage to structures. Therefore, the public response and thus complaints regarding damages are often imaginary. The paper deals with three case studies, involving alleged damage from blasting in surface and underground coal mines where public litigations and agitations resulted due to such apprehensions. The paper is written in simple technical language as the situations warranted that the blast vibration studies should be understood by the general public. 7 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bajpayee, T.S.; Rehak, T.R.; Mowrey, G.L.; Ingram, D.K. [NIOSH, Pittsburgh, PA (USA). Pittsburgh Research Lab.

    2004-07-01

    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. During the 21-year period from 1978 to 1998, the mean yearly explosive-related injuries (fatal and nonfatal) for surface coal mines was 8.86 (95% CI: 6.38-11.33), and for surface metal/nonmetal mines 10.76 (95% CI: 8.39-13.14). Flyrock and lack of blast area security accounted for 68.2% of these injuries. Case studies indicate that the causative factors for fatal injuries are primarily personal and task-related and to some extent environmental. A reduction in the annual injuries in surface coal mines was observed during the 10-year period of 1989-1998 (5.80 (95% CI: 2.71-8.89)) compared to the previous 10-year period of 1979-1988 (10.90 (95% CI: 7.77-14.14)). However, such reduction was not noticed in the metal/nometal sector (i.e., 9.30 (95% CI: 6.84-11.76) for the period 1989-1998 compared with 11.00 (95% CI: 7.11-14.89) for the period 1979-1988). Discussion of case studies during safety meetings will help to mitigate fatal injuries and derive important payoffs in terms of lower risks and costs of injuries.

  18. An Operational Model for the Prediction of Jet Blast

    Science.gov (United States)

    2012-01-09

    This paper presents an operational model for the prediction of jet blast. The model was : developed based upon three modules including a jet exhaust model, jet centerline decay : model and aircraft motion model. The final analysis was compared with d...

  19. Damage to underground coal mines caused by surface blasting

    International Nuclear Information System (INIS)

    Fourie, A.B.; Green, R.W.

    1993-01-01

    An investigation of the potential damage to underground coal workings as a result of surface blasting at an opencast coal mine is described. Seismometers were installed in a worked out area of an underground mine, in the eastern Transvaal region of South Africa, and the vibration caused by nearby surface blasting recorded. These measurements were used to derive peak particle velocities. These velocities were correlated with observed damage underground in order to establish the allowable combination of the two blasting parameters of charge mass per relay, and blast-to-gage point distance. An upper limit of 110mm/sec peak particle velocity was found to be sufficient to ensure that the damage to the particular workings under consideration was minimal. It was further found that a cube-root scaling law provided a better fit to the field data than the common square-root law. 11 refs., 6 figs., 5 tabs

  20. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING

    Science.gov (United States)

    This evaluation addressed product quality, waste reduction/pollution prevention and economics in replacing chemical solvent strippers with a bicarbonate of soda blasting technology for removal of paint from aircraft wheels. The evaluation was conducted in the Paint Stripping Sho...

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

    Energy Technology Data Exchange (ETDEWEB)

    Dale Karr; Marc Perlin; Benjamin Langhorst; Henry Chu

    2009-10-01

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

  2. Spreading of sediment due to underwater blasting and dredging

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard; Bach, Lis; Bollwerk, Sandra

    2015-01-01

    leads to a wider spreading of the organic part of the sediment. Almost all material less than 2 μm, including surficial clay minerals and much organic material, was transported away from the construction site and its vicinity, which could imply mobilization and export of pollutants. Environmental...... impacts of suspended sediment from underwater blasting, which could include coverage of the benthos or increased turbidity, can be managed by timing the blast favourably relative to currents, waves and stratification. It is argued that the environmental impact of blasting can be minimized by decreasing...... out in connection with the construction of a new quay at the existing harbour of Sisimiut, Greenland. Subsequent to the largest of a series of underwater blasts, the distribution of suspended sediment in the water column at and around the construction site was observed using a CTD (Conductivity...

  3. Seismic stations with GSM telemetry for registration of quarry blasts

    Czech Academy of Sciences Publication Activity Database

    Brož, Milan; Číž, Radim; Málek, Jiří; Žanda, Libor

    2000-01-01

    Roč. 2000, 16 (118) (2000), s. 25-32 ISSN 1211-1910 Institutional research plan: CEZ:AV0Z3046908 Keywords : blasting * seismic station * GSM mobile modem Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  4. Seismic safety in conducting large-scale blasts

    Science.gov (United States)

    Mashukov, I. V.; Chaplygin, V. V.; Domanov, V. P.; Semin, A. A.; Klimkin, M. A.

    2017-09-01

    In mining enterprises to prepare hard rocks for excavation a drilling and blasting method is used. With the approach of mining operations to settlements the negative effect of large-scale blasts increases. To assess the level of seismic impact of large-scale blasts the scientific staff of Siberian State Industrial University carried out expertise for coal mines and iron ore enterprises. Determination of the magnitude of surface seismic vibrations caused by mass explosions was performed using seismic receivers, an analog-digital converter with recording on a laptop. The registration results of surface seismic vibrations during production of more than 280 large-scale blasts at 17 mining enterprises in 22 settlements are presented. The maximum velocity values of the Earth’s surface vibrations are determined. The safety evaluation of seismic effect was carried out according to the permissible value of vibration velocity. For cases with exceedance of permissible values recommendations were developed to reduce the level of seismic impact.

  5. Ductile shear zones can induce hydraulically over-pressured fractures in deep hot-dry rock reservoirs: a new target for geothermal exploration?

    Science.gov (United States)

    Schrank, C. E.; Karrech, A.; Regenauer-Lieb, K.

    2014-12-01

    It is notoriously difficult to create and maintain permeability in deep hot-dry rock (HDR) geothermal reservoirs with engineering strategies. However, we predict that long-lived, slowly deforming HDR reservoirs likely contain hydraulically conductive, over-pressured fracture systems, provided that (a) the underlying lower crust and/or mantle are not entirely depleted of fluids and (b) the fracture system has not been drained into highly permeable overlying rocks. Such fracture systems could be targeted for the extraction of geothermal energy. Our prediction hinges on the notion that polycrystalline creep through matter transfer by a liquid phase (dissolution-precipitation creep) is a widespread mechanism for extracting fluids from the lower crust and mantle. Such processes - where creep cavities form during the slow, high-temperature deformation of crystalline solids, e.g., ceramics, metals, and rocks - entail the formation of (intergranular) fluid-assisted creep fractures. They constitute micron-scale voids formed along grain boundaries due to incompatibilities arising from diffusion or dislocation creep. Field and laboratory evidence suggest that the process leading to creep fractures may generate a dynamic permeability in the ductile crust, thus extracting fluids from this domain. We employed an elasto-visco-plastic material model that simulates creep fractures with continuum damage mechanics to model the slow contraction of high-heat-producing granites overlain by sedimentary rocks in 2D. The models suggest that deformation always leads to the initiation of a horizontal creep-damage front in the lower crust. This front propagates upwards towards the brittle-ductile transition (BDT) during protracted deformation where it collapses into highly damaged brittle-ductile shear zones. If the BDT is sufficiently shallow or finite strain sufficiently large, these shear zones trigger brittle faults emerging from their tips, which connect to the sub-horizontal damage

  6. Blast Load Simulator Experiments for Computational Model Validation Report 3

    Science.gov (United States)

    2017-07-01

    establish confidence in the simulation results specific to their intended use. One method for providing experimental data for computational model...walls, to higher blast pressures required to evaluate the performance of protective construction methods . Figure 1. ERDC Blast Load Simulator (BLS... Instrumentation included 3 pressure gauges mounted on the steel calibration plate, 2 pressure gauges mounted in the wall of the BLS, and 25 pressure gauges

  7. Test methods for protective footwear against AP mine blast

    OpenAIRE

    Cronin, D.S.; Williams, K.; Bass, C.R.; Magnan, P.; Dosquet, F.; Bergeron, D.M.; Bree, J.L.M.J. van

    2003-01-01

    The testing and development of protective footwear for anti-personnel landmine blast threats is of great importance to civilian and military deminers, and peacekeepers. This study will review the wide range of test methods that have been developed by NATO countries to test footwear against the effects of anti-personnel blast mines. Experimental testing requires the definition of a threat and a means of assessing the expected trauma to the human leg. The latter is accomplished with various phy...

  8. Study of wet blasting of components in nuclear power stations

    International Nuclear Information System (INIS)

    Hall, J.

    1999-12-01

    This report looks at the method of wet blasting radioactive components in nuclear power stations. The wet blaster uses pearl shaped glass beads with the dimensions of 150-250 μm mixed with water as blasting media. The improved design, providing outer operator's positions with proper radiation protection and more efficient blasting equipment has resulted in a lesser dose taken by the operators. The main reason to decontaminate components in nuclear power plants is to enable service on these components. On components like valves, pump shafts, pipes etc. oxides form and bind radiation. These components are normally situated at some distance from the reactor core and will mainly suffer from radiation from so called activation products. When a component is to be decontaminated it can be decontaminated to a radioactive level where it will be declassified. This report has found levels ranging from 150-1000 Bq/kg allowing declassification of radioactive materials. This difference is found between different countries and different organisations. The report also looks at the levels of waste generated using wet blasting. This is done by tracking the contamination to determine where it collects. It is either collected in the water treatment plant or collected in the blasting media. At Barsebaeck the waste levels, from de-contaminating nearly 800 components in one year, results in a waste volume of about 0,250 m 3 . This waste consists of low and medium level waste and will cost about 3 600 EURO to store. The conclusions of the report are that wet blasting is an indispensable way to treat contaminated components in modern nuclear power plants. The wet blasting equipment can be improved by using a robot enabling the operators to remotely treat components from the outer operator's positions. There they will benefit from better radiation protection thus further reduce their taken dose. The wet blasting equipment could also be used to better control the levels of radioactivity on

  9. A New Middle Path Approach For Alignements In Blast

    OpenAIRE

    Garg, Deepak; Saxena, S C; Bhardwaj, L M

    2012-01-01

    This paper deals with a new middle path approach developed for reducing alignment calculations in BLAST algorithm. This is a new step which is introduced in BLAST algorithm in between the ungapped and gapped alignments. This step of middle path approach between the ungapped and gapped alignments reduces the number of sequences going for gapped alignment. This results in the improvement in speed for alignment up to 30 percent.

  10. Pellet reduction properties under different blast furnace operating conditions

    OpenAIRE

    Leimalm, Ulrika

    2006-01-01

    One of the aims of modern blast furnace (BF) ironmaking is to reduce coke consumption. One way is to increase the injection of reduction agents, such as pulverized coal. An increase in pulverized coal injection rate (PCR) will affect the blast furnace process and the conditions for iron oxide reduction. Changes in PCR influence the composition of the ascending gases and the in-furnace temperature isotherms. The performed tests involve full-scale, pilot and laboratory investigations. Raw mater...

  11. Remote operated vehicle with carbon dioxide blasting (ROVCO2)

    International Nuclear Information System (INIS)

    Resnick, A.M.

    1995-01-01

    The Remote Operated Vehicle with Carbon Dioxide Blasting (ROVCO 2 ), as shown in a front view, is a six-wheeled remote land vehicle used to decontaminate concrete floors. The remote vehicle has a high pressure Cryogenesis blasting subsystem, Oceaneering Technologies (OTECH) developed a CO 2 xY Orthogonal Translational End Effector (COYOTEE) subsystem, and a vacuum/filtration and containment subsystem. Figure 2 shows a block diagram with the various subsystems labeled

  12. PaperBLAST: Text Mining Papers for Information about Homologs.

    Science.gov (United States)

    Price, Morgan N; Arkin, Adam P

    2017-01-01

    Large-scale genome sequencing has identified millions of protein-coding genes whose function is unknown. Many of these proteins are similar to characterized proteins from other organisms, but much of this information is missing from annotation databases and is hidden in the scientific literature. To make this information accessible, PaperBLAST uses EuropePMC to search the full text of scientific articles for references to genes. PaperBLAST also takes advantage of curated resources (Swiss-Prot, GeneRIF, and EcoCyc) that link protein sequences to scientific articles. PaperBLAST's database includes over 700,000 scientific articles that mention over 400,000 different proteins. Given a protein of interest, PaperBLAST quickly finds similar proteins that are discussed in the literature and presents snippets of text from relevant articles or from the curators. PaperBLAST is available at http://papers.genomics.lbl.gov/. IMPORTANCE With the recent explosion of genome sequencing data, there are now millions of uncharacterized proteins. If a scientist becomes interested in one of these proteins, it can be very difficult to find information as to its likely function. Often a protein whose sequence is similar, and which is likely to have a similar function, has been studied already, but this information is not available in any database. To help find articles about similar proteins, PaperBLAST searches the full text of scientific articles for protein identifiers or gene identifiers, and it links these articles to protein sequences. Then, given a protein of interest, it can quickly find similar proteins in its database by using standard software (BLAST), and it can show snippets of text from relevant papers. We hope that PaperBLAST will make it easier for biologists to predict proteins' functions.

  13. Power Tillers for Demining: Blast Test

    Directory of Open Access Journals (Sweden)

    Emanuela Elisa Cepolina

    2007-06-01

    Full Text Available Power tillers are very simple and versatile machines with large scale diffusion in developing countries, where they are commonly used both for agriculture and for transportation purposes. A new integrated participatory approach that makes use of and improves local end-users knowledge has been used to design a new robotic system for humanitarian demining applications in Sri Lanka, using power tiller as core module. A demining machine composed by a tractor unit, a ground processing tool and a vegetation cutting tool is here presented together with results obtained from the first blast test on the preliminary version of tractor unit armouring. Different breakable connections between wheels and axle have been designed to cause physical detachment and interrupt the transmission of the shock wave released by the explosion of a mine under one wheel. Effects of explosions on different types of wheels and on the chassis have been recorded and commented.

  14. Power Tillers for Demining: Blast Test

    Directory of Open Access Journals (Sweden)

    Emanuela Elisa Cepolina

    2008-11-01

    Full Text Available Power tillers are very simple and versatile machines with large scale diffusion in developing countries, where they are commonly used both for agriculture and for transportation purposes. A new integrated participatory approach that makes use of and improves local end-users knowledge has been used to design a new robotic system for humanitarian demining applications in Sri Lanka, using power tiller as core module. A demining machine composed by a tractor unit, a ground processing tool and a vegetation cutting tool is here presented together with results obtained from the first blast test on the preliminary version of tractor unit armouring. Different breakable connections between wheels and axle have been designed to cause physical detachment and interrupt the transmission of the shock wave released by the explosion of a mine under one wheel. Effects of explosions on different types of wheels and on the chassis have been recorded and commented.

  15. Blast Testing and Modelling of Composite Structures

    DEFF Research Database (Denmark)

    Giversen, Søren

    The motivation for this work is based on a desire for finding light weight alternatives to high strength steel as the material to use for armouring in military vehicles. With the use of high strength steel, an increase in the level of armouring has a significant impact on the vehicle weight......-up proved functional and provided consistent data of the panel response. The tests reviled that the sandwich panels did not provide a decrease in panel deflection compared with the monolithic laminates, which was expected due to their higher flexural rigidity. This was found to be because membrane effects...... a pressure distribution on a selected surfaces and has been based on experimental pressure measurement data, and (ii) with a designed 3 step numerical load model, where the blast pressure and FSI (Fluid Structure Interaction) between the pressure wave and modelled panel is modelled numerically. The tested...

  16. Blasting detonators incorporating semiconductor bridge technology

    Energy Technology Data Exchange (ETDEWEB)

    Bickes, R.W. Jr.

    1994-05-01

    The enormity of the coal mine and extraction industries in Russia and the obvious need in both Russia and the US for cost savings and enhanced safety in those industries suggests that joint studies and research would be of mutual benefit. The author suggests that mine sites and well platforms in Russia offer an excellent opportunity for the testing of Sandia`s precise time-delay semiconductor bridge detonators, with the potential for commercialization of the detonators for Russian and other world markets by both US and Russian companies. Sandia`s semiconductor bridge is generating interest among the blasting, mining and perforation industries. The semiconductor bridge is approximately 100 microns long, 380 microns wide and 2 microns thick. The input energy required for semiconductor bridge ignition is one-tenth the energy required for conventional bridgewire devices. Because semiconductor bridge processing is compatible with other microcircuit processing, timing and logic circuits can be incorporated onto the chip with the bridge. These circuits can provide for the precise timing demanded for cast effecting blasting. Indeed tests by Martin Marietta and computer studies by Sandia have shown that such precise timing provides for more uniform rock fragmentation, less fly rock, reduce4d ground shock, fewer ground contaminants and less dust. Cost studies have revealed that the use of precisely timed semiconductor bridges can provide a savings of $200,000 per site per year. In addition to Russia`s vast mineral resources, the Russian Mining Institute outside Moscow has had significant programs in rock fragmentation for many years. He anticipated that collaborative studies by the Institute and Sandia`s modellers would be a valuable resource for field studies.

  17. Development of Lead Free Energy Absorber for Space Shuttle Blast Container

    Science.gov (United States)

    Balles, Donald; Ingram, Thomas; Novak, Howard; Schricker, Albert

    1999-01-01

    The Space Shuttle is connected to the mobile launch platform (MLP) by four aft skirt hold down studs on each solid rocket booster (SRB). Prior to lift-off, the frangible nuts inside the aft skirt blast containers are severed into two nut halves by two pyrotechnic booster cartridges. This action releases the Space Shuttle and allows the hold down studs to eject through the aft skirt bore and then down into the MLP. USBI has been tasked to upgrade the blast container for two specific reasons: (1) To eliminate lead for environmental concerns, and (2) To reduce the chance of nut recontact with the holddown stud. Nut recontact with the stud has been identified as a likely contributor to stud hang-ups. This upgrade will replace the lead liner with a unique open cell aluminum foam material, that has commercial and military uses. The aluminum foam used as an energy absorber is a proven design in many other aerospace/defense applications. Additional benefits of using the open cell, energy absorbent aluminum foam in place of the solid lead liner are: (1) Lead handling / exposure and possible contamination, along with hazardous waste disposal, will be eliminated; (2) Approximately 200 lbs. weight savings will be contributed to each Space Shuttle flight by using aluminum foam instead of lead; (3) The new aluminum liner is designed to catch all shrapnel from frangible nuts, thus virtually eliminating chance of debris exiting the HDP and causing potential damage to the vehicle; (4) Using the lighter aluminum liner instead of lead, allows for easier assembly and disassembly of blast container elements, which also improves safety, operator handling, and the efficiency of operations.

  18. prfectBLAST: a platform-independent portable front end for the command terminal BLAST+ stand-alone suite.

    Science.gov (United States)

    Santiago-Sotelo, Perfecto; Ramirez-Prado, Jorge Humberto

    2012-11-01

    prfectBLAST is a multiplatform graphical user interface (GUI) for the stand-alone BLAST+ suite of applications. It allows researchers to do nucleotide or amino acid sequence similarity searches against public (or user-customized) databases that are locally stored. It does not require any dependencies or installation and can be used from a portable flash drive. prfectBLAST is implemented in Java version 6 (SUN) and runs on all platforms that support Java and for which National Center for Biotechnology Information has made available stand-alone BLAST executables, including MS Windows, Mac OS X, and Linux. It is free and open source software, made available under the GNU General Public License version 3 (GPLv3) and can be downloaded at www.cicy.mx/sitios/jramirez or http://code.google.com/p/prfectblast/.

  19. H-BLAST: a fast protein sequence alignment toolkit on heterogeneous computers with GPUs.

    Science.gov (United States)

    Ye, Weicai; Chen, Ying; Zhang, Yongdong; Xu, Yuesheng

    2017-04-15

    The sequence alignment is a fundamental problem in bioinformatics. BLAST is a routinely used tool for this purpose with over 118 000 citations in the past two decades. As the size of bio-sequence databases grows exponentially, the computational speed of alignment softwares must be improved. We develop the heterogeneous BLAST (H-BLAST), a fast parallel search tool for a heterogeneous computer that couples CPUs and GPUs, to accelerate BLASTX and BLASTP-basic tools of NCBI-BLAST. H-BLAST employs a locally decoupled seed-extension algorithm for better performance on GPUs, and offers a performance tuning mechanism for better efficiency among various CPUs and GPUs combinations. H-BLAST produces identical alignment results as NCBI-BLAST and its computational speed is much faster than that of NCBI-BLAST. Speedups achieved by H-BLAST over sequential NCBI-BLASTP (resp. NCBI-BLASTX) range mostly from 4 to 10 (resp. 5 to 7.2). With 2 CPU threads and 2 GPUs, H-BLAST can be faster than 16-threaded NCBI-BLASTX. Furthermore, H-BLAST is 1.5-4 times faster than GPU-BLAST. https://github.com/Yeyke/H-BLAST.git. yux06@syr.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  20. Pressure differences between over-pressured sands and bounding shales of the Eugene island 330 field (offshore Louisiana, USA) with implications for fluid flow induced by sediment loading

    Energy Technology Data Exchange (ETDEWEB)

    Stump, B.B.; Flemings, P.B. [Pennsylvania Univ., Philadelphia, PA (United States); Finkbeiner, Th.; Zoback, M.D. [Stanford Univ., Dept. of Geophysics, CA (United States)

    1999-04-01

    We document pressure differences between adjacent sands and shales in geopressured Plio-Pleistocene strata of offshore Louisiana and we quantify a sediment loading model that describes the origin of these differences. The JD sand is in moderate geo-pressure (P{sub f}/{sigma}{sub 1} = 0.6) and has a lower pressure than its bounding shale. The L1 sand is severely over-pressured (P{sub f}/{sigma}{sub 1} = 0.9) and has a pressure greater than its bounding shale. Shales which are adjacent to the JD and L1 sands have pressures (derived from a porosity-effective stress relationship) which follow a litho-static gradient. We interpret this behaviour to result from rapid, spatially varying loading of permeable sand bodies by relatively impermeable shales. Under these conditions. pore pressures at the peak of structure can significantly exceed the pore pressure of bounding shales. The L1 sand records this behaviour. In contrast, the low relative pressures in the JD sand may record dissipation of pressure by fluid migration along permeable pathways. The sediment loading model predicts along-stratal flow within sands and cross-stratal flow at structural highs. In a companion paper. FINKBEINER et al. (this volume) describe how sediment loading and the buoyant effect of hydrocarbons combine to drive sand pressures toward the minimum principal stress of bounding cap rocks, resulting in fluid migration. (author)

  1. Full-scale testing of leakage of blast waves inside a partially vented room exposed to external air blast loading

    Science.gov (United States)

    Codina, R.; Ambrosini, D.

    2018-03-01

    For the last few decades, the effects of blast loading on structures have been studied by many researchers around the world. Explosions can be caused by events such as industrial accidents, military conflicts or terrorist attacks. Urban centers have been prone to various threats including car bombs, suicide attacks, and improvised explosive devices. Partially vented constructions subjected to external blast loading represent an important topic in protective engineering. The assessment of blast survivability inside structures and the development of design provisions with respect to internal elements require the study of the propagation and leakage of blast waves inside buildings. In this paper, full-scale tests are performed to study the effects of the leakage of blast waves inside a partially vented room that is subjected to different external blast loadings. The results obtained may be useful for proving the validity of different methods of calculation, both empirical and numerical. Moreover, the experimental results are compared with those computed using the empirical curves of the US Defense report/manual UFC 3-340. Finally, results of the dynamic response of the front masonry wall are presented in terms of accelerations and an iso-damage diagram.

  2. Partitioning of a scaled shallow-buried near-field blast load

    CSIR Research Space (South Africa)

    Reinecke, J

    2015-07-01

    Full Text Available Buried blast threats have been used for many years in both conventional and unconventional warfare. They are cheap, easily hidden, remain viable for extremely long periods after deployment and are effective, focusing the resulting blast products...

  3. Investigation of accretion formation in a blast furnace shaft

    Energy Technology Data Exchange (ETDEWEB)

    Klima, R.; Hoefer, O.; Chiarotti, U.; Fredman, T.; Hillmann, C.; Raipala, K.; Eriksson, J. (eds.) [BFI Duesseldorf (Germany)

    2005-07-01

    Accretions in the bosh, belly and shaft have a significant influence on blast furnace performance and on the service life of the refractory lining and the cooling system. To analyse the mechanisms of formation and dislodging of accretions, investigations were carried out at four different blast furnaces. Three blast furnaces were equipped with additional measurements to investigate the accretion formation process and to provide information for the development of accretion estimation models. Installation activities included thermocouples, heat-flux meters, staves with instrumentation for heat-flux measurement and a small horizontal lance. The distribution of accretions in the shaft was documented. Samples were taken out of accretions during blast furnace stoppages. Their acquisition was simplified with newly developed sampling devices. The samples were analysed to determine chemical and mineralogical properties and thermal conductivity. Samples were mainly made up of reduced iron or of coke and sinter structures glued together by zinc or alkali compounds. Together with a newly developed offline model for the simulation of accretion formation, different parameters influencing the formation process were identified. The main parameters are: burden material composition, blast furnace operating conditions; and the cooling system. Countermeasures to prevent excessive accretion growth were determined. They offer a better operational control of accretions. Different models to identify accretion formation were developed and an overview was presented. Different models were necessary to distinguish between the various measurement, cooling-system and blast-furnace setups. Most of the models are already implemented and in operational use. For some of them application at other blast furnaces was already realised or is possible. 9 refs., 18 figs., 20 tab.

  4. Evaluating the Effectiveness of Various Blast Loading Descriptors as Occupant Injury Predictors for Underbody Blast Events

    Science.gov (United States)

    2014-01-09

    t:N , CFC # Pulse type Dec. g ion ms al ms m/s Sp. Pwr Eff. G G- ava @2ms @Oms @15ms 1000 @3ms @7ms @7ms @30ms @Oms 1 Triangular 44 40 2 8.6 376 27 22...Power, Blast, ROM, reduced order models, MADYMO, occupant, injury, pulse , loading, descriptor, calculator 16. SECURITY CLASSIFICATION OF: 17... pulse and occupant injury It has been shown before that there is no single input parameter which can be used to effectively assess occupant injury

  5. ORGANISATIONAL-TECHNOLOGICAL CHARACTERISTICS OF BLASTING WORKS ON THE GRIČ TUNNEL

    OpenAIRE

    Zvonimir Deković; Zvonimir Ester; Mario Dobrilović

    2005-01-01

    The paper describes organisational-technological characteristics of blasting works during the excavation of the Grič Tunnel. The significance of blasting works during the excavation of the tunnel is shown through adjustment of blasting parameters taking into consideration the dynamics of the works, cost-effectiveness and influence of geological circumstances. Successfulness of blasting directly influences the subsequent tunnel excavation cycle both in terms of duration as well as eventually i...

  6. Primary blast-induced traumatic brain injury: lessons from lithotripsy

    Science.gov (United States)

    Nakagawa, A.; Ohtani, K.; Armonda, R.; Tomita, H.; Sakuma, A.; Mugikura, S.; Takayama, K.; Kushimoto, S.; Tominaga, T.

    2017-11-01

    Traumatic injury caused by explosive or blast events is traditionally divided into four mechanisms: primary, secondary, tertiary, and quaternary blast injury. The mechanisms of blast-induced traumatic brain injury (bTBI) are biomechanically distinct and can be modeled in both in vivo and in vitro systems. The primary bTBI injury mechanism is associated with the response of brain tissue to the initial blast wave. Among the four mechanisms of bTBI, there is a remarkable lack of information regarding the mechanism of primary bTBI. On the other hand, 30 years of research on the medical application of shock waves (SWs) has given us insight into the mechanisms of tissue and cellular damage in bTBI, including both air-mediated and underwater SW sources. From a basic physics perspective, the typical blast wave consists of a lead SW followed by shock-accelerated flow. The resultant tissue injury includes several features observed in primary bTBI, such as hemorrhage, edema, pseudo-aneurysm formation, vasoconstriction, and induction of apoptosis. These are well-described pathological findings within the SW literature. Acoustic impedance mismatch, penetration of tissue by shock/bubble interaction, geometry of the skull, shear stress, tensile stress, and subsequent cavitation formation are all important factors in determining the extent of SW-induced tissue and cellular injury. In addition, neuropsychiatric aspects of blast events need to be taken into account, as evidenced by reports of comorbidity and of some similar symptoms between physical injury resulting in bTBI and the psychiatric sequelae of post-traumatic stress. Research into blast injury biophysics is important to elucidate specific pathophysiologic mechanisms of blast injury, which enable accurate differential diagnosis, as well as development of effective treatments. Herein we describe the requirements for an adequate experimental setup when investigating blast-induced tissue and cellular injury; review SW physics

  7. Controlled blasting and its implications for the NNWSI project exploratory shaft

    International Nuclear Information System (INIS)

    Van Eeckhout, E.M.

    1987-09-01

    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

  8. 29 CFR 1926.904 - Storage of explosives and blasting agents.

    Science.gov (United States)

    2010-07-01

    ..., electric blasting caps, detonating primers, and primed cartridges shall not be stored in the same magazine... feet of explosives and detonator storage magazine. (d) No explosives or blasting agents shall be... 29 Labor 8 2010-07-01 2010-07-01 false Storage of explosives and blasting agents. 1926.904 Section...

  9. Modelling of turbulent combustion in the blast furnace raceway

    Energy Technology Data Exchange (ETDEWEB)

    Karvinen, R.; Maekiranta, R. [Tampere Univ. (Finland). Energy and Process Engineering

    1996-12-31

    The phenomena concerning coke-gas -suspension and simultaneous combustion of solid coke particles and residual fuel oil in a blast furnace raceway are modelled. The flow field of suspension is predicted by using the two fluid model, which is based on the Eulerian method, in the Phoenics code. The standard k-e -model of turbulence is used. Pyrolysis of oil droplets is calculated with the own coded subroutine, which is based on the Lagrangian approach. Gas phase reaction rate is assumed to be controlled by chemical kinetics. Radiative heat transfer is calculated by using the six-flux method. Heterogenous surface reactions are used for the coke particles. Calculations without coke combustion show that due to a poor mixing in the hot blast, pyrolysis gases of residual fuel oil have not time enough to react with oxygen. It is obvious that if combustion of coke particles is taken into account, the oxygen content in the blast decreases to such a level, that unburnt pyrolysis gases can flow out of the raceway causing problems. The distribution of coke void fraction has been succeeded to predict in the raceway domain. Coke particles fall from the upper part of the raceway to the hot blast forming locally high concentrations, which affect very strongly the oxygen distribution of the hot blast. (orig.) SULA 2 Research Programme; 10 refs.

  10. Controlled Blasting for Deconstruction of a Railway Bridge Near Sahibganj

    Science.gov (United States)

    Mandal, S. K.; Ghosh, A. K.; Oraon, S.

    2018-02-01

    Some of the Indian Railway bridges require reconstruction for electrification and expansion of railway tracks. Dismantling of bridge within time schedule in densely populated area requires controlled and pre-planned blasting methodology for safe pulling down of the structure and quick removal of blasted debris for fast restoration of tracks and smooth plying of trains. The three arched railway bridge (Bridge No. 61) located between Sahibganj and Karamtola cases one such example where the bridge was dismantled and the track was restored within 4 h of blasting, though the stipulated block period for demolition and restoration of tracks was 6 h. The 25.48 m long three-arched bridge was drilled and blasted with 225 number of blastholes (32 mm diameter) and 100 kg explosive (25 mm diameter). Length of blastholes varied between 0.5 and 1.8 m with blast geometry of 0.3-0.35 m burden and 0.33 m spacing. This paper deals with the conceptual and theoretical model developed for identification of the key locations for drilling and implementation of the same. It also discusses about the precautionary measures and the drilling pattern adopted for quick demolition and speedy restoration of tracks.

  11. TREATMENT OF LOW-BLAST COUNT AML USING HYPOMETHYLATING AGENTS

    Directory of Open Access Journals (Sweden)

    Eleonora De Bellis

    2017-07-01

    Full Text Available In 2002, the WHO classification reduced the proportion of blasts in the bone marrow (BM necessary for the diagnosis of acute myeloid leukemia (AML from 30% to 20%, eliminating the RAEB-t subtype of myelodysplastic syndromes (MDS. However, this AML subtype, defined as low-blast count AML (LBC-AML, with 20-30% BM-blasts is characterized by peculiar features, as increased frequency in elderly individuals and after cytotoxic treatment for a different primary disease (therapy-related, poor-risk cytogenetics, lower white blood cell counts, and less frequent mutations of NPM1 and FLT3 genes. The clinical course of this entity is often similar to MDS with 10-19% BM-blasts. The hypomethylating agents azacitidine and decitabine have been shown to induce responses and prolong survival both in MDS and LBC-AML.  The role of these agents has been also demonstrated in AML with >30% BM-blasts, particularly in patients with poor-risk cytogenetics and in AML with myelodysplasia related changes. Most recent studies are evaluating strategies to improve outcome, including combinations of hypomethylating agents with immune-response checkpoint inhibitors, which have a role in cancer immune surveillance. Efforts are also ongoing to identify mutations which may predict response and survival in these patients.

  12. Diagrammatic scale for the assessment of blast on wheat spikes

    Directory of Open Access Journals (Sweden)

    João Leodato Nunes Maciel

    2013-09-01

    Full Text Available The correct quantification of blast caused by the fungus Magnaporthe oryzae on wheat (Triticum aestivum spikes is an important component to understand the development of this disease aimed at its control. Visual quantification based on a diagrammatic scale can be a practical and efficient strategy that has already proven to be useful against several plant pathosystems, including diseases affecting wheat spikes like glume blotch and fusarium head blight. Spikes showing different disease severity values were collected from a wheat field with the aim of elaborating a diagrammatic scale to quantify blast severity on wheat spikes. The spikes were photographed and blast severity was determined by using resources of the software ImageJ. A diagrammatic scale was developed with the following disease severity values: 3.7, 7.5, 21.4, 30.5, 43.8, 57.3, 68.1, 86.0, and 100.0%. An asymptomatic spike was added to the scale. Scale validation was performed by eight people who estimated blast severity by using digitalized images of 40 wheat spikes. The precision and the accuracy of the evaluations varied according to the rater (0.82blast on wheat spikes.

  13. Blasting vibrations control: The shortcomings of traditional methods

    Energy Technology Data Exchange (ETDEWEB)

    Vuillaume, P.M.; Kiszlo, M. [Institut National de l`Environnement Industriel et des Risques, Verneuil en Halatte (France); Bernard, T. [Compagnie Nouvelle de Scientifiques, Nice (France)

    1996-12-31

    In the context of its studies for the French ministry of the environment and for the French national coal board, INERIS (the French institute for the industrial environment and hazards, formerly CERCHAR) has made a complete critical survey of the methods generally used to reduce the levels of blasting vibrations. It is generally acknowledged that the main parameter to control vibrations is the so-called instantaneous charge, or charge per delay. This should be reduced as much as possible in order to diminish vibration levels. On account of this, the use of a new generation of blasting devices, such as non-electric detonators or electronic sequential timers has been developed since the seventies. INERIS has collected data from about 900 blasts in 2 quarries and 3 open pit mines. These data include input parameters such as borehole diameter, burden, spacing, charge per hole, charge per delay, total fired charge, etc ... They also include output measurements, such as vibration peak particle velocities, and main frequencies. These data have been analyzed with the help of multi variable statistical tools. Blasting tests were undertaken to evaluate new methods of vibrations control, such as the superposition of vibration signals. These methods appear to be accurate in many critical cases, but certainly would be highly improved with a better accuracy of firing delays. The development of electronic detonators seems to be the way of the future for a better blasting control.

  14. Impact of complex blast waves on the human head: a computational study.

    Science.gov (United States)

    Tan, Long Bin; Chew, Fatt Siong; Tse, Kwong Ming; Chye Tan, Vincent Beng; Lee, Heow Pueh

    2014-12-01

    Head injuries due to complex blasts are not well examined because of limited published articles on the subject. Previous studies have analyzed head injuries due to impact from a single planar blast wave. Complex or concomitant blasts refer to impacts usually caused by more than a single blast source, whereby the blast waves may impact the head simultaneously or consecutively, depending on the locations and distances of the blast sources from the subject, their blast intensities, the sequence of detonations, as well as the effect of blast wave reflections from rigid walls. It is expected that such scenarios will result in more serious head injuries as compared to impact from a single blast wave due to the larger effective duration of the blast. In this paper, the utilization of a head-helmet model for blast impact analyses in Abaqus(TM) (Dassault Systemes, Singapore) is demonstrated. The model is validated against studies published in the literature. Results show that the skull is capable of transmitting the blast impact to cause high intracranial pressures (ICPs). In addition, the pressure wave from a frontal blast may enter through the sides of the helmet and wrap around the head to result in a second impact at the rear. This study recommended better protection at the sides and rear of the helmet through the use of foam pads so as to reduce wave entry into the helmet. The consecutive frontal blasts scenario resulted in higher ICPs compared with impact from a single frontal blast. This implied that blast impingement from an immediate subsequent pressure wave would increase severity of brain injury. For the unhelmeted head case, a peak ICP of 330 kPa is registered at the parietal lobe which exceeds the 235 kPa threshold for serious head injuries. The concurrent front and side blasts scenario yielded lower ICPs and skull stresses than the consecutive frontal blasts case. It is also revealed that the additional side blast would only significantly affect ICPs at

  15. 77 FR 49277 - Takes of Marine Mammals During Specified Activities; Confined Blasting Operations by the U.S...

    Science.gov (United States)

    2012-08-15

    ... effects that confined blasting can have on marine animals near the blast (Keevin et al., 1999). The visual... Atmospheric Administration Takes of Marine Mammals During Specified Activities; Confined Blasting Operations... Marine Mammals During Specified Activities; Confined Blasting Operations by the U.S. Army Corps of...

  16. Amelioration of acute sequelae of blast induced mild traumatic brain injury by N-acetyl cysteine: a double-blind, placebo controlled study.

    Directory of Open Access Journals (Sweden)

    Michael E Hoffer

    Full Text Available BACKGROUND: Mild traumatic brain injury (mTBI secondary to blast exposure is the most common battlefield injury in Southwest Asia. There has been little prospective work in the combat setting to test the efficacy of new countermeasures. The goal of this study was to compare the efficacy of N-acetyl cysteine (NAC versus placebo on the symptoms associated with blast exposure mTBI in a combat setting. METHODS: This study was a randomized double blind, placebo-controlled study that was conducted on active duty service members at a forward deployed field hospital in Iraq. All symptomatic U.S. service members who were exposed to significant ordnance blast and who met the criteria for mTBI were offered participation in the study and 81 individuals agreed to participate. Individuals underwent a baseline evaluation and then were randomly assigned to receive either N-acetyl cysteine (NAC or placebo for seven days. Each subject was re-evaluated at 3 and 7 days. Outcome measures were the presence of the following sequelae of mTBI: dizziness, hearing loss, headache, memory loss, sleep disturbances, and neurocognitive dysfunction. The resolution of these symptoms seven days after the blast exposure was the main outcome measure in this study. Logistic regression on the outcome of 'no day 7 symptoms' indicated that NAC treatment was significantly better than placebo (OR = 3.6, p = 0.006. Secondary analysis revealed subjects receiving NAC within 24 hours of blast had an 86% chance of symptom resolution with no reported side effects versus 42% for those seen early who received placebo. CONCLUSION: This study, conducted in an active theatre of war, demonstrates that NAC, a safe pharmaceutical countermeasure, has beneficial effects on the severity and resolution of sequelae of blast induced mTBI. This is the first demonstration of an effective short term countermeasure for mTBI. Further work on long term outcomes and the potential use of NAC in civilian m

  17. Superficial characterization of titanium league when submitted to abrasive blasting

    International Nuclear Information System (INIS)

    Suzuki, L.Y.; Leite, I.V.; Szesz, E.M.; Siqueira, C.J.M.

    2010-01-01

    Commercially pure titanium and some of its alloys exhibit a good biocompatibility. These characteristics are frequently used in the manufacture of orthopedic and dental implants. It is possible to modify its surface making it the bioactive using various methods, such as deposition of hydroxyapatite by plasma spray and increasing the roughness of the surface by abrasive blasting. This work is to modify the surface of titanium alloy Ti6Al4V ELI (ASTM F136: 02a) for abrasive blasting and study the morphology, crystallographic phases and the mechanical characteristics of the surface obtained. For such purpose, SEM images, diffraction of X-rays and tests of risk produced by nanoindenter. The sandblasting was done using alumina powder and blasting time of 6s. The morphology of the surfaces of Ti6Al4V ELI changed after sandblasting with increased roughness. It is possible to conclude that after sandblasting the titanium surface do not have a ductile behavior. (author)

  18. Thermal valorisation of automobile shredder residue: injection in blast furnace.

    Science.gov (United States)

    Mirabile, Daphne; Pistelli, Maria Ilaria; Marchesini, Marina; Falciani, Roberta; Chiappelli, Lisa

    2002-01-01

    Wastes with residual heating value, according to the trend of the world legislation, could be thermally reused. The present study is conducted to verify the possibility of thermal valorisation of a waste, denominated fluff, by injection in blast furnace. The fluff, arising from the automobile shredder operations, is a waste characterised by a high organic matrix and is potentially dangerous due to the heavy metals, oils filter and halogenated plastics content. The first step of the work is the chemical, physical and toxicological characterisation of this material. Then the fluff injection in a blast furnace tuyere is theoretically analysed with a mathematical model. Finally, experimental trials are conducted in a pilot plant, simulating the most important part of the blast furnace: the raceway, in order to analyse process and industrial aspects. In view of an industrial application a first economical evaluation is carried out on the basis of model and experimental results.

  19. Strain Rate Effects in CFRP Used For Blast Mitigation

    Directory of Open Access Journals (Sweden)

    Sarah. L. Orton

    2014-04-01

    Full Text Available The purpose of this research is to gain a better understanding of strain rate effects in carbon fiber reinforced polymer (CFRP laminates exposed to blast loading. The use of CFRP offers an attractive option for mitigating structures exposed to blasts. However, the effect of high strain rates in CFRP composites commonly used in the civil industry is unknown. This research conducted tensile tests of 21 CFRP coupons using a hydraulically powered dynamic loader. The strain rates ranged from 0.0015 s−1 to 7.86 s−1 and are representative of strain rates that CFRP may see in a blast when used to strengthen reinforced concrete structures. The results of the testing showed no increase in the tensile strength or stiffness of the CFRP at the higher strain rates. In addition, the results showed significant scatter in the tensile strengths possibly due to the rate of loading or manufacture of the coupon.

  20. Radiometric report for a blast furnace tracing with radioactive isotopes

    International Nuclear Information System (INIS)

    Tanase, G.; Tanase, M.

    1995-01-01

    One of the methods to monitor refractory wall of blast furnace is its tracing with radioactive isotopes. The tracer isotope can be detected by two ways: the external dosimetric measurement at the armour of the blast furnace and/or the radiometric measurement of the iron sample charge by charge. Any change in radiometric situation of tracer radioisotope is recorded in a radiometric report. This paper presents an original concept of radiometric report based upon PARADOX and CORELDRAW soft kits. Their advantage are: quick and easy changes, easy recording of current radioactivity of tracer isotope, short history of changes, visual mapping of the tracer isotope and others. In this way we monitored 6 blast furnaces and more than 180 radioactive sources

  1. Blast venting through blanket material in the HYLIFE ICF reactor

    International Nuclear Information System (INIS)

    Liu, J.C.; Peterson, P.F.; Schrock, V.E.

    1992-01-01

    This work presents a numerical study of blast venting through various blanket configurations in the HYLIFE ICF reactor design. The study uses TSUNAMI -- a multi-dimensional, high-resolution, shock capturing code -- to predict the momentum exchange and gas dynamics for blast venting in complex geometries. In addition, the study presents conservative predictions of wall loading by gas shock and impulse delivered to the protective liquid blanket. Configurations used in the study include both 2700 MJ and 350 MJ fusion yields per pulse for 5 meter and 3 meter radius reactor chambers. For the former, an annular jet array is used for the blanket geometry, while in the latter, both annular jet array as well as slab geometries are used. Results of the study indicate that blast venting and wall loading may be manageable in the HYLIFE-II design by a judicious choice of blanket configuration

  2. Exposure to impulse noise at an explosives company: a case study.

    Science.gov (United States)

    Kulik, Aleksandra; Malinowska-Borowska, Jolanta

    2018-02-15

    Impulse noise encountered in workplaces is a threat to hearing. The aim of this study was to assess the occupational exposure to impulse noise produced by detonation of dynamite on the premises of an explosives company. Test points were located on the blast test area (inside and outside the bunker) and in work buildings across the site. Noise propagation measurement was performed during 130 blast tests at nine measurement points. At every point, at least 10 separate measurements of A-weighted equivalent sound pressure level (L A eq ), maximum A-weighted sound pressure level (L A max ) and C-weighted peak sound pressure level (L C peak ) were made. Noise recorded in the blast test area exceeded occupational exposure limits (OELs). Noise levels measured in buildings did not exceed OELs. Results of the survey showed that for 62% of respondents, impulse noise causes difficulties in performing work. The most commonly reported symptoms include headaches, nervousness and irritability.

  3. PaperBLAST: Text Mining Papers for Information about Homologs

    International Nuclear Information System (INIS)

    Price, Morgan N.; Arkin, Adam P.

    2017-01-01

    Large-scale genome sequencing has identified millions of protein-coding genes whose function is unknown. Many of these proteins are similar to characterized proteins from other organisms, but much of this information is missing from annotation databases and is hidden in the scientific literature. To make this information accessible, PaperBLAST uses EuropePMC to search the full text of scientific articles for references to genes. PaperBLAST also takes advantage of curated resources (Swiss-Prot, GeneRIF, and EcoCyc) that link protein sequences to scientific articles. PaperBLAST’s database includes over 700,000 scientific articles that mention over 400,000 different proteins. Given a protein of interest, PaperBLAST quickly finds similar proteins that are discussed in the literature and presents snippets of text from relevant articles or from the curators. With the recent explosion of genome sequencing data, there are now millions of uncharacterized proteins. If a scientist becomes interested in one of these proteins, it can be very difficult to find information as to its likely function. Often a protein whose sequence is similar, and which is likely to have a similar function, has been studied already, but this information is not available in any database. To help find articles about similar proteins, PaperBLAST searches the full text of scientific articles for protein identifiers or gene identifiers, and it links these articles to protein sequences. Then, given a protein of interest, it can quickly find similar proteins in its database by using standard software (BLAST), and it can show snippets of text from relevant papers. We hope that PaperBLAST will make it easier for biologists to predict proteins’ functions.

  4. Blast-induced damage:a summary of SveBeFo investigations

    OpenAIRE

    Saiang, David

    2008-01-01

    This report presents a summary of the blast damage investigation carried out by SveBeFo (Swedish Rock Engineering Research) during the period 1991 to 2003 at various hard rock sites in Sweden. The objective of this report is to present a synopsis of the important factors that influence the development and extent of the blast-induced damage zone, nature and characteristics of blast-induced fractures, and a summary of the blast-damage thickness with reference to the existing perimeter blasting ...

  5. ORGANISATIONAL-TECHNOLOGICAL CHARACTERISTICS OF BLASTING WORKS ON THE GRIČ TUNNEL

    Directory of Open Access Journals (Sweden)

    Zvonimir Deković

    2005-12-01

    Full Text Available The paper describes organisational-technological characteristics of blasting works during the excavation of the Grič Tunnel. The significance of blasting works during the excavation of the tunnel is shown through adjustment of blasting parameters taking into consideration the dynamics of the works, cost-effectiveness and influence of geological circumstances. Successfulness of blasting directly influences the subsequent tunnel excavation cycle both in terms of duration as well as eventually in terms of influence on the entire tunnel investment. Comparison of changes of basic blasting parameters during tunnel excavation ensured optimal excavation progress with minimal price per meter of tunnel progress.

  6. Windows .NET Network Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST

    Directory of Open Access Journals (Sweden)

    Oliver Melvin J

    2005-04-01

    Full Text Available Abstract Background BLAST is one of the most common and useful tools for Genetic Research. This paper describes a software application we have termed Windows .NET Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST, which enhances the BLAST utility by improving usability, fault recovery, and scalability in a Windows desktop environment. Our goal was to develop an easy to use, fault tolerant, high-throughput BLAST solution that incorporates a comprehensive BLAST result viewer with curation and annotation functionality. Results W.ND-BLAST is a comprehensive Windows-based software toolkit that targets researchers, including those with minimal computer skills, and provides the ability increase the performance of BLAST by distributing BLAST queries to any number of Windows based machines across local area networks (LAN. W.ND-BLAST provides intuitive Graphic User Interfaces (GUI for BLAST database creation, BLAST execution, BLAST output evaluation and BLAST result exportation. This software also provides several layers of fault tolerance and fault recovery to prevent loss of data if nodes or master machines fail. This paper lays out the functionality of W.ND-BLAST. W.ND-BLAST displays close to 100% performance efficiency when distributing tasks to 12 remote computers of the same performance class. A high throughput BLAST job which took 662.68 minutes (11 hours on one average machine was completed in 44.97 minutes when distributed to 17 nodes, which included lower performance class machines. Finally, there is a comprehensive high-throughput BLAST Output Viewer (BOV and Annotation Engine components, which provides comprehensive exportation of BLAST hits to text files, annotated fasta files, tables, or association files. Conclusion W.ND-BLAST provides an interactive tool that allows scientists to easily utilizing their available computing resources for high throughput and comprehensive sequence analyses. The install package for W.ND-BLAST is

  7. CFD‐DEM modelling of blast furnace tapping

    OpenAIRE

    Vango, Mathias; Pirker, Stefan; Lichtenegger, Thomas

    2017-01-01

    The campaign length of a blast furnace is limited by the hearth inner lining lifetime. In order to maximize the campaign length and ensure a good draining of hot metal and slag, a good understanding of the flow in the hearth is essential. Challenges in modelling the flow involve several continuous phases (hot metal, slag and hot blast) as well as the presence of the deadman, a dense bed of coke particles. The shape and position of the deadman depend on the weight of the burden column above an...

  8. Blasting preparation for selective mining of complex structured ore deposition

    Science.gov (United States)

    Marinin, M. A.; Dolzhikov, V. V.

    2017-10-01

    Technological features of ore mining in the open pit development for processing of complex structured ore deposit of steeply falling occurrence have been considered. The technological schemes of ore bodies mining under different conditions of occurrence, consistency and capacity have been considered and offered in the paper. These technologies permit to reduce losses and dilution, but to increase the completeness and quality of mined ore. A method of subsequent selective excavation of ore bodies has been proposed. The method is based on the complex use of buffer-blasting technology for the muck mass and the principle of trim blasting at ore-rock junctions.

  9. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  10. Blast Mitigation by Water Mist, (3) Mitigation of Confined and Unconfined Blasts

    Science.gov (United States)

    2006-07-14

    Mitigation of blasts in chemical processing plants, including the fireworks and propellant industries, has also received considerable attention due to the...15.8982 02 => 15.9465 H20(l) + 21.1976 C02 + 10.3008 N2 + 2963.12 kcal 1 kg of HTA -3 contains: 0.29 kg (1.2768 gm-mol) TNT (C7H5N306) 0.22 kg (8.15419 gm...mol) Aluminum (Al) 0.49 kg (1.65429 gm-mol) HMX (C4H8N808) 1 kg HTA -3 => 9.80916 H20(l) + 4.46881 C(s) + 11.086 CO + 8.53235 N2 + 8.15419 Al(s

  11. Effect of sheath material and reaction overpressure on Ag protrusions into the TiO2 insulation coating of Bi-2212 round wire

    Science.gov (United States)

    Hossain, I.; Jiang, J.; Matras, M.; Trociewitz, U. P.; Lu, J.; Kametani, F.; Larbalestier, D.; Hellstrom, E.

    2017-12-01

    In order to develop a high current density in coils, Bi-2212 wires must be electrically discrete in tight winding packs. It is vital to use an insulating layer that is thin, fulfils the dielectric requirements, and can survive the heat treatment whose maximum temperature reaches 890 °C in oxygen. A thin (20-30 µm) ceramic coating could be better as the insulating layer compared to alumino-silicate braided fiber insulation, which is about 150 μm thick and reacts with the Ag sheathed Bi-2212 wire during heat treatment. At present, TiO2 seems to be the most viable ceramic material for such a thin insulation because it is chemically compatible with Ag and Bi-2212 and its sintering temperature is lower than the maximum temperature used for the Bi-2212 heat treatment. However, recent tests of a large Bi-2212 coil insulated only with TiO2 showed severe electrical shorting between the wires after over pressure heat treatment (OPHT). The origin of the shorting was frequent silver protrusions into the porous TiO2 layer that electrically connected adjacent Bi-2212 wires. To understand the mechanism of this unexpected behaviour, we investigated the effect of sheath material and hydrostatic pressure on Ag protrusions. We found that Ag protrusions occur only when TiO2-insulated Ag-0.2%Mg sheathed wire (Ag(Mg) wire) undergoes OPHT at 50 bar. No Ag protrusions were observed when the TiO2-insulated Ag(Mg) wire was processed at 1 bar. The TiO2-insulated wires sheathed with pure Ag that underwent 50 bar OPHT were also free from Ag protrusions. A key finding is that the Ag protrusions from the Ag(Mg) sheath actually contain no MgO, suggesting that local depletion of MgO facilitates local, heterogeneous deformation of the sheath under hydrostatic overpressure. Our study also suggests that predensifying the Ag(Mg) wire before insulating it with TiO2 and doing the final OPHT can potentially limit Ag protrusions.

  12. Pyramiding of blast and bacterial leaf blight resistance genes into ...

    African Journals Online (AJOL)

    Blast caused by the fungus Magnaporthe oryzae (Hebert) Barr. and bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) are two major diseases of rice (Oryza sativa). The use of varietal resistance is the most appropriate strategy for controlling the diseases, and molecular assisted selection can ...

  13. A numerical technique to design blast noise mitigation measures

    NARCIS (Netherlands)

    Berg, F. van den; Eerden, F.J.M. van der

    2007-01-01

    Large weapons, such as armor, artillery or demolitions, create a high-energy blast wave. It has a low frequency content, typically between 15 and 125 Hz, and can propagate over large distances. As a result it is a relative important cause for annoyance. Mitigation measures need to be close to the

  14. Effect of blasting on the strength of a rock mass

    Energy Technology Data Exchange (ETDEWEB)

    Muller, L.

    1964-01-01

    Although the fact that blasting concussions tend to loosen a rock mass has always been known, the enormous reduction in strength associated with such loosening is not generally recognized. Recent investigations of the effect of blasting on a rock mass have shown that even slight loosening may markedly reduce the strength. This factor introduces a new slant on modern blasting methods, some of which will have to be considered more critically. The sensitivity of the mass to impacts depends on stress concentrations at the end of joints (Kerbspannungen) and on tensile stresses developed in the immediate vicinity of a joint, even in regions where the field stresses are not tensile. Thus, the sensitivity depends on the shape and orientation of the joints and particularly on the degree of separation of the individual joint families. The orientation of the joint families to the strains produced by blasting is just as important as the reduction in overall strength arising from the drop in friction due to the effects of the ''knocking out'' process (Foppl) on the joint body complex. Concussions may critically increase the degree of separation of the joint network thus reducing the tensile and shear strengths of the rock mass. (19 refs.)

  15. Off-center blast in a shocked medium

    Science.gov (United States)

    Duncan-Miller, G. C.; Stone, W. D.

    2017-11-01

    When multiple blasts occur at different times, the situation arises in which a blast wave is propagating into a medium that has already been shocked. Determining the evolution in the shape of the second shock is not trivial, as it is propagating into air that is not only non-uniform, but also non-stationary. To accomplish this task, we employ the method of Kompaneets to determine the shape of a shock in a non-uniform media. We also draw from the work of Korycansky (Astrophys J 398:184-189. https://doi.org/10.1086/171847, 1992) on an off-center explosion in a medium with radially varying density. Extending this to treat non-stationary flow, and making use of approximations to the Sedov solution for the point blast problem, we are able to determine an analytic expression for the evolving shape of the second shock. In particular, we consider the case of a shock in air at standard ambient temperature and pressure, with the second shock occurring shortly after the original blast wave reaches it, as in a sympathetic detonation.

  16. Off-center blast in a shocked medium

    International Nuclear Information System (INIS)

    Duncan-Miller, G. C.; Stone, W. D.

    2017-01-01

    When multiple blasts occur at different times, the situation arises in which a blast wave is propagating into a medium that has already been shocked. Determining the evolution in the shape of the second shock is not trivial, as it is propagating into air that is not only non-uniform, but also non-stationary. To accomplish this task, we employ the method of Kompaneets to determine the shape of a shock in a non-uniform media. We also draw from the work of Korycansky (Astrophys J 398:184–189, 1992) on an off-center explosion in a medium with radially varying density. Extending this to treat non-stationary flow, and making use of approximations to the Sedov solution for the point blast problem, we are able to determine an analytic expression for the evolving shape of the second shock. In particular, we consider the case of a shock in air at standard ambient temperature and pressure, with the second shock occurring shortly after the original blast wave reaches it, as in a sympathetic detonation.

  17. Multiple blast-hole stresses and measured fragmentation

    Science.gov (United States)

    Dowding, Charles H.; Aimone, Catherine T.

    1985-01-01

    A wave superposition code was developed to calculate stresses explosivley induced by long, multiple blast holes within a three dimensional rock mass. Computed stresses were found to correlate with measured fragmentation from fourteen cases in coal cyclotherm geology when actual, rather than planned, initiation times were modelled.

  18. Studying and improving blast furnace cast iron quality

    Directory of Open Access Journals (Sweden)

    Т. К. Balgabekov

    2014-10-01

    Full Text Available In the article there are presented the results of studies to improve the quality of blast furnace cast iron. It was established that using fire clay suspension for increasing the mould covering heat conductivity improves significantly pig iron salable condition and filtration refining method decreases iron contamination by nonmetallic inclusions by 50 – 70 %.

  19. Blast wave injury prediction models for complex scenarios

    NARCIS (Netherlands)

    Teland, J.A.; Doormaal, J.C.A.M. van

    2012-01-01

    Blast waves from explosions can cause lethal injuries to humans. Development of injury criteria has been ongoing for many years, but with the main focus on free field conditions. However, with terrorist actions as a new threat, explosions in urban areas have become of much more interest. Urban areas

  20. Understanding yield reduction in rice due to leaf blast

    NARCIS (Netherlands)

    Bastiaans, L.

    1993-01-01

    The study described in this thesis focuses on a quantitative understanding of the effect of leaf blast on growth and production of a rice crop, based on insight in the physiological processes underlying damage. For this purpose, experimental research was conducted at two levels of

  1. A Mathematical Model for the Comparative Study of the Blast ...

    African Journals Online (AJOL)

    This paper presents a mathematical model of the study of the blast response of aluminium and steel panels. These panels are deemed sufficient to provided protective barrier against explosions, especially from terrorists. With the maximum deflection being the damage criteria used, the behaviour of both panel is studied.

  2. Injection of heavy fuel oil into the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Paloposki, T. [Helsinki Univ. of Technology, Otaniemi (Finland); Hakala, J.; Mannila, P.; Laukkanen, J. [Oulu Univ. (Finland)

    1996-12-31

    This study deals with the injection and combustion of heavy fuel oil in blast furnaces. The injection of the oil was studied experimentally in a small-scale test rig. The combustion of the oil was analysed with a commercial computer program for flow and combustion simulations. Results from computer simulations show that the combustion of the oil can be improved by decreasing the size of the oil drops and by enhancing the mixing between the oil drops and the hot blast. The devolatilization rate of the oil mainly depends on the size of the oil drops. The combustion rate of the volatiles mainly depends on the effectiveness of turbulent mixing with combustion air. Methods to decrease the size of the oil drops were sought in the experimental part of the study. Experimental results show that the size of the oil drops increases with increasing mass flow rate of the oil and decreases with increasing velocity of the hot blast. Methods to improve the mixing between the oil drops and the hot blast are suggested but have not yet been experimentally tested. (author) (4 refs.)

  3. Effect of casing yield stress on bomb blast impulse

    Directory of Open Access Journals (Sweden)

    Hutchinson M.D.

    2012-08-01

    Full Text Available An equation to predict blast effects from cased charges was first proposed by U. Fano in 1944 and revised by E.M. Fisher in 1953 [1]. Fisher’s revision provides much better matches to available blast impulse data, but still requires empirical parameter adjustments. A new derivation [2], based on the work of R.W. Gurney [3] and G.I. Taylor [4], has resulted in an equation which nearly matches experimental data. This new analytical model is also capable of being extended, through the incorporation of additional physics, such as the effects of early case fracture, finite casing thickness, casing metal strain energy dissipation, explosive gas escape through casing fractures and the comparative dynamics of blast wave and metal fragment impacts. This paper will focus on the choice of relevant case fracture strain criterion, as it will be shown that this allows the explicit inclusion of the dynamic properties of the explosive and casing metal. It will include a review and critique of the most significant earlier work on this topic, contained in a paper by Hoggatt and Recht [5]. Using this extended analytical model, good matches can readily be made to available free-field blast impulse data, without any empirical adjustments being needed. Further work will be required to apply this model to aluminised and other highly oxygen-deficient explosives.

  4. Recent development in blast performance of fiber-reinforced concrete

    Science.gov (United States)

    Hajek, R.; Foglar, M.; Kohoutkova, A.

    2017-09-01

    The paper presents an overview of the recent development in blast performance of fiber reinforced concrete. The paper builds on more than ten years’ history of the research in this field by the team of the Department of Concrete and Masonry Structures of the Faculty of Civil Engineering of the Czech Technical University in Prague.

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

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Sarah Jill

    2003-06-01

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

  6. Chloride ingress of carbonated blast furnace slag cement mortars

    NARCIS (Netherlands)

    Holthuizen, P.E.; Çopuroglu, O.; Polder, R.B.

    2017-01-01

    In the Netherlands civil engineering structures, such as overpasses, bridges and tunnels are generally built using blast furnace slag cement (BFSC, CEM III/B) concrete, because of its high resistance against chloride penetration. Although the Dutch experience regarding durability performance of BFSC

  7. Determination and expression of genes for resistance to blast ...

    African Journals Online (AJOL)

    Determination and expression of genes for resistance to blast (Magnaporthe oryza) in Basmati and non-Basmati indica rices (Oryza sativa L.) Naveen Kumar, D Singh, S Gupta, A Sirohi, B Ramesh, Preeti Sirohi, Parul Sirohi, Atar Singh, N Kumar, A Kumar, Rajendra Kumar, R Kumar, J Singh, P. Kumar, P. Chauhan, ...

  8. foreign body in scrotum following a boat engine blast accident

    African Journals Online (AJOL)

    David Ofori-Adjei

    1Urology Unit, 37 Military Hospital, P.O. Box KB 282, Korle-Bu, Accra, Ghana, 2Department of Surgery,. University of Ghana Medical School, PO Box 4236 ... evacuation limits complications. Keywords: Blast Injury, Scrotal ... emergency of the 37 Military Hospital for further care. Patient complained of a headache but had no ...

  9. Blasted copper slag as fine aggregate in Portland cement concrete.

    Science.gov (United States)

    Dos Anjos, M A G; Sales, A T C; Andrade, N

    2017-07-01

    The present work focuses on assessing the viability of applying blasted copper slag, produced during abrasive blasting, as fine aggregate for Portland cement concrete manufacturing, resulting in an alternative and safe disposal method. Leaching assays showed no toxicity for this material. Concrete mixtures were produced, with high aggregate replacement ratios, varying from 0% to 100%. Axial compressive strength, diametrical compressive strength, elastic modulus, physical indexes and durability were evaluated. Assays showed a significant improvement in workability, with the increase in substitution of fine aggregate. With 80% of replacement, the concrete presented lower levels of water absorption capacity. Axial compressive strength and diametrical compressive strength decreased, with the increase of residue replacement content. The greatest reductions of compressive strength were found when the replacement was over 40%. For tensile strength by diametrical compression, the greatest reduction occurred for the concrete with 80% of replacement. After the accelerated aging, results of mechanic properties showed a small reduction of the concrete with blasted copper slag performance, when compared with the reference mixture. Results indicated that the blasted copper slag is a technically viable material for application as fine aggregate for concrete mixtures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Gene interactions and genetics of blast resistance and yield ...

    Indian Academy of Sciences (India)

    2016-08-26

    Oryza sativa L.) ... four blast resistance genes Pi1, Pi2, Pi33 and Pi54 in combination were used to study the nature and magnitude of gene action for disease resistance and yield attributes. ... Please take note of this change.

  11. Development of a Strategy for Simulating Blast-Vehicle Interactions

    Science.gov (United States)

    2010-09-01

    TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES 140 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified...soil model for simulating stress wave propagation due to blast loading. International Journal fro Numerical and Analytical Methods in Geomechanics , 28

  12. A research on ceramsite obtained from blast furnace slag and ...

    African Journals Online (AJOL)

    In order to solve disposal problem of solid waste, blast furnace slag (BFS) and sewage sludge (SS) were tested as components for producing ceramsite. This study investigated the feasibility of that at different preheating and sintering temperature and duration and different mass ratios (BFS: SS: clay). The results show that ...

  13. Foreign body in scrotum following a boat engine blast accident ...

    African Journals Online (AJOL)

    Male genital injuries, demand prompt management to prevent long-term sexual and psychological damage. Injuries to the scrotum and contents may produce impaired fertility.We report our experience in diagnosing and managing a case of a foreign body in the scrotum following a boat engine blast accident. This case ...

  14. Development of Experimental Tissue Models for Blast Injury

    Science.gov (United States)

    Butler, Benjamin; Bo, Chiara; Williams, Alun; Jardine, Andy; Brown, Katherine

    2013-06-01

    There is a pressing need to better understand the relationship between the intensity of a blast wave and the clinical consequences for victims of an explosion. In order to quantitatively study how these factors correlate with one another, blast injury tissue models are being developed. Sections of larynx, trachea and pulmonary tissue were excised from a recently sacrificed pig and maintained on ice prior to testing. The samples were subjected to strain rates of between 0.001 s-1 and 1000 s-1 in the laboratory by using a Split Hopkinson Pressure Bar and quasi-static testing apparatus. During high strain rate testing, samples were housed in a polycarbonate chamber which permitted experimentation on tissue held in fluid. Data were analysed using 1, 2 and 3 wave analysis software in Matlab to yield information about the material properties of both undamaged and damaged tissues. In addition, macroscopic changes in tissue organization were also visualized using histopathological techniques. This work is being extended to cellular and animal models to derive more detailed information about the underlying molecular changes relating to blast-induced damage and repair. The Royal British Legion Centre for Blast Injury Studies.

  15. Columbia River Channel Improvement Project Rock Removal Blasting: Monitoring Plan

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Thomas J.; Johnson, Gary E.

    2010-01-29

    This document provides a monitoring plan to evaluate take as outlined in the National Marine Fisheries Service 2002 Biological Opinion for underwater blasting to remove rock from the navigation channel for the Columbia River Channel Improvement Project. The plan was prepared by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers (USACE), Portland District.

  16. Finite Element Analysis for CFST Columns under Blast Loading

    Directory of Open Access Journals (Sweden)

    Peyman Beiranvand

    2017-10-01

    Full Text Available The columns of frame structures are the key load-bearing components and the exterior columns are susceptible to attack in terrorist blasts. When subjected to blast loads, the columns would suffer a loss of bearing capacity to a certain extent due to the damage imparted which may lead to their collapse and even cause the progressive collapse of the whole structure . The concrete-filled steel columns have been extensively used in the world due to the existence of all suitable characteristics of concrete and steel, more ductility, increasing concrete confinement using the steel wall, the large energy-absorption capacity and the appropriate fire behavior. In the present study, the concrete-filled steel square columns have been simulated under the influence of the blast load using the ABAQUS software. These responses have been compared for scaled distances based on the distance to the source and the weight of the explosive material. As a result, it can be seen that although concrete deformation has been restricted using the steel tube, the inner layer of concrete has been seriously damaged and the column displacement has been decreased by increasing the scaled distance. We also concluded that the concrete-filled steel columns have the high ductility and the blast resistance.

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

    Science.gov (United States)

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

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

  18. Granulated blast furnace slag – A boon for foundry industry

    African Journals Online (AJOL)

    In the present investigation efforts have been put together to employ Granulated Blast furnace (GBF) slag as mould material for replacement of existing silica sand either full or partial in foundry industry. Nishiyama procedure was assumed for appraising the same. The process factors reflected on for this were the % of ...

  19. On dimensionless loading parameters for close-in blasts

    Directory of Open Access Journals (Sweden)

    K Micallef

    2016-10-01

    Full Text Available Close-range blasts pose a threat through severe damage to structures and injury or death. In this work, the spatial and temporal descriptions of a localised blast load are presented using 6 non-dimensional parameters. These are found to be solely functions of the charge stand-off distance to diameter ratio for a cylindrically-shaped charge. Numerical simulations of a localised blast are performed using AUTODYN, where the pressure variation on a rigid barrier for various charge stand-off/diameter combinations is obtained. The least-square regression is then utilised to obtain the relationship between stand-off/diameter ratio and dimensionless loading parameters. The relevant expressions and dimensionless charts are presented. The proposed equations are verified by comparing experimental data with numerical results obtained by finite element analysis (FEA of blast loaded steel plates (using the user-defined subroutine VDLOAD implemented in the FEA package ABAQUS/Explicit. Excellent correlation of the measured permanent displacement with numerically predicted results is obtained.

  20. DNA marker characterization for allele mining of blast and bacterial ...

    African Journals Online (AJOL)

    admiistrator

    2013-05-01

    May 1, 2013 ... Marker assisted selection of bacterial blight resistance genes in rice. Biochem Genet. 39 (7): 261-278. Du PV, Loan, LC, Sang ND (2007). Blast research in Mekong river delta of Vietnam. In: JIRCAS (Japan International Research Center for Agricultural Sciences, Tsukuba, Japan) working report No. 53,.

  1. Test methods for protective footwear against AP mine blast

    NARCIS (Netherlands)

    Cronin, D.S.; Williams, K.; Bass, C.R.; Magnan, P.; Dosquet, F.; Bergeron, D.M.; Bree, J.L.M.J. van

    2003-01-01

    The testing and development of protective footwear for anti-personnel landmine blast threats is of great importance to civilian and military deminers, and peacekeepers. This study will review the wide range of test methods that have been developed by NATO countries to test footwear against the

  2. The Effect of Light Casings on the Blast Parameters from a Spherical Charge of RDX/TNT 60/40

    National Research Council Canada - National Science Library

    Bishop, Valerie J; James, D. J

    1968-01-01

    .... High speed cine films were taken of the fireball growth. Peak overpressure and impulse enhancement over the values from an uncased RDX/TNT charge were obtained only from the thickest lead casing...

  3. Acceleration-based methodology to assess the blast mitigation performance of explosive ordnance disposal helmets

    Science.gov (United States)

    Dionne, J. P.; Levine, J.; Makris, A.

    2018-01-01

    To design the next generation of blast mitigation helmets that offer increasing levels of protection against explosive devices, manufacturers must be able to rely on appropriate test methodologies and human surrogates that will differentiate the performance level of various helmet solutions and ensure user safety. Ideally, such test methodologies and associated injury thresholds should be based on widely accepted injury criteria relevant within the context of blast. Unfortunately, even though significant research has taken place over the last decade in the area of blast neurotrauma, there currently exists no agreement in terms of injury mechanisms for blast-induced traumatic brain injury. In absence of such widely accepted test methods and injury criteria, the current study presents a specific blast test methodology focusing on explosive ordnance disposal protective equipment, involving the readily available Hybrid III mannequin, initially developed for the automotive industry. The unlikely applicability of the associated brain injury criteria (based on both linear and rotational head acceleration) is discussed in the context of blast. Test results encompassing a large number of blast configurations and personal protective equipment are presented, emphasizing the possibility to develop useful correlations between blast parameters, such as the scaled distance, and mannequin engineering measurements (head acceleration). Suggestions are put forward for a practical standardized blast testing methodology taking into account limitations in the applicability of acceleration-based injury criteria as well as the inherent variability in blast testing results.

  4. Monte Carlo simulation as a tool to predict blasting fragmentation based on the Kuz Ram model

    Science.gov (United States)

    Morin, Mario A.; Ficarazzo, Francesco

    2006-04-01

    Rock fragmentation is considered the most important aspect of production blasting because of its direct effects on the costs of drilling and blasting and on the economics of the subsequent operations of loading, hauling and crushing. Over the past three decades, significant progress has been made in the development of new technologies for blasting applications. These technologies include increasingly sophisticated computer models for blast design and blast performance prediction. Rock fragmentation depends on many variables such as rock mass properties, site geology, in situ fracturing and blasting parameters and as such has no complete theoretical solution for its prediction. However, empirical models for the estimation of size distribution of rock fragments have been developed. In this study, a blast fragmentation Monte Carlo-based simulator, based on the Kuz-Ram fragmentation model, has been developed to predict the entire fragmentation size distribution, taking into account intact and joints rock properties, the type and properties of explosives and the drilling pattern. Results produced by this simulator were quite favorable when compared with real fragmentation data obtained from a blast quarry. It is anticipated that the use of Monte Carlo simulation will increase our understanding of the effects of rock mass and explosive properties on the rock fragmentation by blasting, as well as increase our confidence in these empirical models. This understanding will translate into improvements in blasting operations, its corresponding costs and the overall economics of open pit mines and rock quarries.

  5. BlastR—fast and accurate database searches for non-coding RNAs

    Science.gov (United States)

    Bussotti, Giovanni; Raineri, Emanuele; Erb, Ionas; Zytnicki, Matthias; Wilm, Andreas; Beaudoing, Emmanuel; Bucher, Philipp; Notredame, Cedric

    2011-01-01

    We present and validate BlastR, a method for efficiently and accurately searching non-coding RNAs. Our approach relies on the comparison of di-nucleotides using BlosumR, a new log-odd substitution matrix. In order to use BlosumR for comparison, we recoded RNA sequences into protein-like sequences. We then showed that BlosumR can be used along with the BlastP algorithm in order to search non-coding RNA sequences. Using Rfam as a gold standard, we benchmarked this approach and show BlastR to be more sensitive than BlastN. We also show that BlastR is both faster and more sensitive than BlastP used with a single nucleotide log-odd substitution matrix. BlastR, when used in combination with WU-BlastP, is about 5% more accurate than WU-BlastN and about 50 times slower. The approach shown here is equally effective when combined with the NCBI-Blast package. The software is an open source freeware available from www.tcoffee.org/blastr.html. PMID:21624887

  6. Study of the action of blast deck charge in rocky soils

    Directory of Open Access Journals (Sweden)

    Boiko V.V.

    2017-04-01

    Full Text Available Blasting (B in the industry, including the mining extraction of minerals, are carried out mostly with the use of blasthole charges that systematically distributed on the block that is undermined, by individual groups. The latter are blasted according to the scheme of short-delay firing (SDF through the intervals that are accepted not less than 20 Ms. Thus, the seismic effect of group charge explosion, consisting of individual blasthole charges and that actually is a group located charge determined by the formula of concentrated charge. Blast deck charges are effectively used in the driving of the trenches in the mining, formation of screens and cracks near the security objects. Only this method of performing blasting allows to define seismic effect in the transition from one diameter of a charge to another, as well as to determine the actual number of detonated charges in one group, which may differ from the calculated in drilling and blasting project. The work analyzes the physical essence of processes happened while blasting of blast deck charges. The effect of the orientation of the seismic action of blasting of blast deck charges towards the allocation line of charges is investigated. The results of generalized dependence of the speed of the displacement of the ground by the blast parameters and epicentral distance are obtained. We demonstrate with specific examples that blast deck charges that blasting simultaneously make a major chain of the career massive explosions at mining. Keywords: seismic fluctuations; the number of charges; the interaction of charges; the distance between the charges; the coefficients of the seismicity and the attenuation of the intensity of the waves; the unit charge; blast deck and blasthole charges; phase shifting; effective charge.

  7. Cosmic Blasts Much More Common, Astronomers Discover

    Science.gov (United States)

    2006-08-01

    A cosmic explosion seen last February may have been the "tip of an iceberg," showing that powerful, distant gamma ray bursts are outnumbered ten-to-one by less-energetic cousins, according to an international team of astronomers. The VLA The Very Large Array CREDIT: NRAO/AUI/NSF (Click on image for VLA gallery) A study of the explosion with X-ray and radio telescopes showed that it is "100 times less energetic than gamma ray bursts seen in the distant universe. We were able to see it because it's relatively nearby," said Alicia Soderberg, of Caltech, leader of the research team. The scientists reported their findings in the August 31 issue of the journal Nature. The explosion is called an X-ray flash, and was detected by the Swift satellite on February 18. The astronomers subsequently studied the object using the National Science Foundation's Very Large Array (VLA) radio telescope, NASA's Chandra X-ray Observatory, and the Ryle radio telescope in the UK. "This object tells us that there probably is a rich diversity of cosmic explosions in our local Universe that we only now are starting to detect. These explosions aren't playing by the rules that we thought we understood," said Dale Frail of the National Radio Astronomy Observatory. The February blast seems to fill a gap between ordinary supernova explosions, which leave behind a dense neutron star, and gamma ray bursts, which leave behind a black hole, a concentration of mass so dense that not even light can escape it. Some X-ray flashes, the new research suggests, leave behind a magnetar, a neutron star with a magnetic field 100-1000 times stronger than that of an ordinary neutron star. "This explosion occurred in a galaxy about 470 million light-years away. If it had been at the distances of gamma ray bursts, as much as billions of light-years away, we would not have been able to see it," Frail said. "We think that the principal difference between gamma ray bursts and X-ray flashes and ordinary supernova

  8. Wound Ballistics Modeling for Blast Loading Blunt Force Impact and Projectile Penetration.

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Light body armor development for the warfighter is based on trial-and-error testing of prototype designs against ballistic projectiles. Torso armor testing against blast is nonexistent but necessary to protect the heart and lungs. In tests against ballistic projectiles, protective apparel is placed over ballistic clay and the projectiles are fired into the armor/clay target. The clay represents the human torso and its behind-armor, permanent deflection is the principal metric used to assess armor protection. Although this approach provides relative merit assessment of protection, it does not examine the behind-armor blunt trauma to crucial torso organs. We propose a modeling and simulation (M&S) capability for wound injury scenarios to the head, neck, and torso of the warfighter. We will use this toolset to investigate the consequences of, and mitigation against, blast exposure, blunt force impact, and ballistic projectile penetration leading to damage of critical organs comprising the central nervous, cardiovascular, and respiratory systems. We will leverage Sandia codes and our M&S expertise on traumatic brain injury to develop virtual anatomical models of the head, neck, and torso and the simulation methodology to capture the physics of wound mechanics. Specifically, we will investigate virtual wound injuries to the head, neck, and torso without and with protective armor to demonstrate the advantages of performing injury simulations for the development of body armor. The proposed toolset constitutes a significant advance over current methods by providing a virtual simulation capability to investigate wound injury and optimize armor design without the need for extensive field testing.

  9. Surface impurity removal from DIII-D graphite tiles by boron carbide grit blasting

    International Nuclear Information System (INIS)

    Lee, R.L.; Hollerbach, M.A.; Holtrop, K.L.; Kellman, A.G.; Taylor, P.L.; West, W.P.

    1993-11-01

    During the latter half of 1992, the DIII-D tokamak at General Atomics (GA) underwent several modifications of its interior. One of the major tasks involved the removal of accumulated metallic impurities from the surface of the graphite tiles used to line the plasma facing surfaces inside of the tokamak. Approximately 1500 graphite tiles and 100 boron nitride tiles from the tokamak were cleaned to remove the metallic impurities. The cleaning process consisted of several steps: the removed graphite tiles were permanently marked, surface blasted using boron carbide (B 4 C) grit media (approximately 37 μm. diam.), ultrasonically cleaned in ethanol to remove loose dust, and outgassed at 1000 degrees C. Tests were done using, graphite samples and different grit blaster settings to determine the optimum propellant and abrasive media pressures to remove a graphite layer approximately 40-50 μm deep and yet produce a reasonably smooth finish. EDX measurements revealed that the blasting technique reduced the surface Ni, Cr, and Fe impurity levels to those of virgin graphite. In addition to the surface impurity removal, tritium monitoring was performed throughout the cleaning process. A bubbler system was set up to monitor the tritium level in the exhaust gas from the grit blaster unit. Surface wipes were also performed on over 10% of the tiles. Typical surface tritium concentrations of the tiles were reduced from about 500 dpm/100 cm 2 to less than 80 dpm/100 cm 2 following the cleaning. This tile conditioning, and the installation of additional graphite tiles to cover a high fraction of the metallic plasma facing surfaces, has substantially reduced metallic impurities in the plasma discharges which has allowed rapid recovery from a seven-month machine opening and regimes of enhanced plasma energy confinement to be more readily obtained. Safety issues concerning blaster operator exposure to carcinogenic metals and radioactive tritium will also be addressed

  10. Study of high Mach number laser driven blast waves in gases

    International Nuclear Information System (INIS)

    Edens, A. D.; Adams, R. G.; Rambo, P.; Ruggles, L.; Smith, I. C.; Porter, J. L.; Ditmire, T.

    2010-01-01

    A series of experiments were performed examining the evolution of blast waves produced by laser irradiation of a target immersed in gas. Blast waves were produced by illumination of wires by 1 kJ, 1 ns laser pulses from the Z-Beamlet laser at Sandia National Laboratories. The blast waves were imaged by probe laser pulses at various times to examine the trajectory, radiative precursor, and induced perturbations on the blast wave front. Well defined perturbations were induced on the blast wave front with arrays of wires placed in the gas and the results of the experiments are compared to the theoretical predictions for the Vishniac overstability. It is found that the experimental results are in general agreement with these theoretical predictions on thin blast wave shells and are in quantitative agreement in the simplest case.

  11. Structural Response to Blast Loading: The Effects of Corrosion on Reinforced Concrete Structures

    Directory of Open Access Journals (Sweden)

    Hakan Yalciner

    2014-01-01

    Full Text Available Structural blast design has become a necessary part of the design with increasing terrorist attacks. Terrorist attacks are not the one to make the structures important against blast loading where other explosions such as high gas explosions also take an important place in structural safety. The main objective of this study was to verify the structural performance levels under the impact of different blast loading scenarios. The blast loads were represented by using triangular pulse for single degree of freedom system. The effect of blast load on both corroded and uncorroded reinforced concrete buildings was examined for different explosion distances. Modified plastic hinge properties were used to ensure the effects of corrosion. The results indicated that explosion distance and concrete strength were key parameters to define the performance of the structures against blast loading.

  12. Blast-Resistant Improvement of Sandwich Armor Structure with Aluminum Foam Composite

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2013-01-01

    Full Text Available Sandwich armor structures with aluminum foam can be utilized to protect a military vehicle from harmful blast load such as a landmine explosion. In this paper, a system-level dynamic finite element model is developed to simulate the blast event and to evaluate the blast-resistant performance of the sandwich armor structure. It is found that a sandwich armor structure with only aluminum foam is capable of mitigating crew injuries under a moderate blast load. However, a severe blast load causes force enhancement and results in much worse crew injury. An isolating layer between the aluminum foam and the vehicle floor is introduced to remediate this drawback. The results show that the blast-resistant capability of the innovative sandwich armor structure with the isolating layer increases remarkably.

  13. Minimization of Blast furnace Fuel Rate by Optimizing Burden and Gas Distribution

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Chenn Zhou

    2012-08-15

    The goal of the research is to improve the competitive edge of steel mills by using the advanced CFD technology to optimize the gas and burden distributions inside a blast furnace for achieving the best gas utilization. A state-of-the-art 3-D CFD model has been developed for simulating the gas distribution inside a blast furnace at given burden conditions, burden distribution and blast parameters. The comprehensive 3-D CFD model has been validated by plant measurement data from an actual blast furnace. Validation of the sub-models is also achieved. The user friendly software package named Blast Furnace Shaft Simulator (BFSS) has been developed to simulate the blast furnace shaft process. The research has significant benefits to the steel industry with high productivity, low energy consumption, and improved environment.

  14. BlaSTorage: a fast package to parse, manage and store BLAST results.

    Science.gov (United States)

    Orsini, Massimiliano; Carcangiu, Simone

    2013-01-30

    Large-scale sequence studies requiring BLAST-based analysis produce huge amounts of data to be parsed. BLAST parsers are available, but they are often missing some important features, such as keeping all information from the raw BLAST output, allowing direct access to single results, and performing logical operations over them. We implemented BlaSTorage, a Python package that parses multi BLAST results and returns them in a purpose-built object-database format. Unlike other BLAST parsers, BlaSTorage retains and stores all parts of BLAST results, including alignments, without loss of information; a complete API allows access to all the data components. BlaSTorage shows comparable speed of more basic parser written in compiled languages as C++ and can be easily integrated into web applications or software pipelines.

  15. BlaSTorage: a fast package to parse, manage and store BLAST results

    Directory of Open Access Journals (Sweden)

    Orsini Massimiliano

    2013-01-01

    Full Text Available Abstract Background Large-scale sequence studies requiring BLAST-based analysis produce huge amounts of data to be parsed. BLAST parsers are available, but they are often missing some important features, such as keeping all information from the raw BLAST output, allowing direct access to single results, and performing logical operations over them. Findings We implemented BlaSTorage, a Python package that parses multi BLAST results and returns them in a purpose-built object-database format. Unlike other BLAST parsers, BlaSTorage retains and stores all parts of BLAST results, including alignments, without loss of information; a complete API allows access to all the data components. Conclusions BlaSTorage shows comparable speed of more basic parser written in compiled languages as C++ and can be easily integrated into web applications or software pipelines.

  16. Optimization long hole blast fragmentation techniques and detonating circuit underground uranium mine stope

    International Nuclear Information System (INIS)

    Li Qin; Yang Lizhi; Song Lixia; Qin De'en; Xue Yongshe; Wang Zhipeng

    2012-01-01

    Aim at high rate of large blast fragmentation, a big difficulty in long hole drilling and blasting underground uranium mine stope, it is pointed out at the same time of taking integrated technical management measures, the key is to optimize the drilling and blasting parameters and insure safety the act of one that primes, adopt 'minimum burden' blasting technique, renew the stope fragmentation process, and use new process of hole bottom indirect initiation fragmentation; optimize the detonating circuit and use safe, reliable and economically rational duplex non-electric detonating circuit. The production practice shows that under the guarantee of strictly controlled construction quality, the application of optimized blast fragmentation technique has enhanced the reliability of safety detonation and preferably solved the problem of high rate of large blast fragments. (authors)

  17. WImpiBLAST: web interface for mpiBLAST to help biologists perform large-scale annotation using high performance computing.

    Directory of Open Access Journals (Sweden)

    Parichit Sharma

    Full Text Available The function of a newly sequenced gene can be discovered by determining its sequence homology with known proteins. BLAST is the most extensively used sequence analysis program for sequence similarity search in large databases of sequences. With the advent of next generation sequencing technologies it has now become possible to study genes and their expression at a genome-wide scale through RNA-seq and metagenome sequencing experiments. Functional annotation of all the genes is done by sequence similarity search against multiple protein databases. This annotation task is computationally very intensive and can take days to obtain complete results. The program mpiBLAST, an open-source parallelization of BLAST that achieves superlinear speedup, can be used to accelerate large-scale annotation by using supercomputers and high performance computing (HPC clusters. Although many parallel bioinformatics applications using the Message Passing Interface (MPI are available in the public domain, researchers are reluctant to use them due to lack of expertise in the Linux command line and relevant programming experience. With these limitations, it becomes difficult for biologists to use mpiBLAST for accelerating annotation. No web interface is available in the open-source domain for mpiBLAST. We have developed WImpiBLAST, a user-friendly open-source web interface for parallel BLAST searches. It is implemented in Struts 1.3 using a Java backbone and runs atop the open-source Apache Tomcat Server. WImpiBLAST supports script creation and job submission features and also provides a robust job management interface for system administrators. It combines script creation and modification features with job monitoring and management through the Torque resource manager on a Linux-based HPC cluster. Use case information highlights the acceleration of annotation analysis achieved by using WImpiBLAST. Here, we describe the WImpiBLAST web interface features and architecture

  18. WImpiBLAST: web interface for mpiBLAST to help biologists perform large-scale annotation using high performance computing.

    Science.gov (United States)

    Sharma, Parichit; Mantri, Shrikant S

    2014-01-01

    The function of a newly sequenced gene can be discovered by determining its sequence homology with known proteins. BLAST is the most extensively used sequence analysis program for sequence similarity search in large databases of sequences. With the advent of next generation sequencing technologies it has now become possible to study genes and their expression at a genome-wide scale through RNA-seq and metagenome sequencing experiments. Functional annotation of all the genes is done by sequence similarity search against multiple protein databases. This annotation task is computationally very intensive and can take days to obtain complete results. The program mpiBLAST, an open-source parallelization of BLAST that achieves superlinear speedup, can be used to accelerate large-scale annotation by using supercomputers and high performance computing (HPC) clusters. Although many parallel bioinformatics applications using the Message Passing Interface (MPI) are available in the public domain, researchers are reluctant to use them due to lack of expertise in the Linux command line and relevant programming experience. With these limitations, it becomes difficult for biologists to use mpiBLAST for accelerating annotation. No web interface is available in the open-source domain for mpiBLAST. We have developed WImpiBLAST, a user-friendly open-source web interface for parallel BLAST searches. It is implemented in Struts 1.3 using a Java backbone and runs atop the open-source Apache Tomcat Server. WImpiBLAST supports script creation and job submission features and also provides a robust job management interface for system administrators. It combines script creation and modification features with job monitoring and management through the Torque resource manager on a Linux-based HPC cluster. Use case information highlights the acceleration of annotation analysis achieved by using WImpiBLAST. Here, we describe the WImpiBLAST web interface features and architecture, explain design

  19. High-speed photography of microscale blast wave phenomena

    Science.gov (United States)

    Dewey, John M.; Kleine, Harald

    2005-03-01

    High-speed photography has been a primary tool for the study of blast wave phenomena, dating from the work of Toepler, even before the invention of the camera! High-speed photography was used extensively for the study of blast waves produced by nuclear explosions for which, because of the large scale, cameras running at a few hundred frames per second were adequate to obtain sharp images of the supersonic shock fronts. For the study of the blast waves produced by smaller explosive sources, ever-increasing framing rates were required. As a rough guide, for every three orders of magnitude decrease in charge size a ten-fold increase of framing rate was needed. This severely limited the use of photography for the study of blast waves from laboratory-scale charges. There are many techniques for taking single photographs of explosive phenomena, but the strongly time-dependent development of a blast wave, requires the ability to record a high-speed sequence of photographs of a single event. At ICHSPP25, Kondo et al of Shimadzu Corporation demonstrated a 1 M fps video camera that provides a sequence of up to 100 high-resolution frames. This was subsequently used at the Shock Wave Research Center of Tohoku University to record the blast waves generated by an extensive series of silver azide charges ranging in size from 10 to 0.5mg. The resulting images were measured to provide radius-time histories of the primary and secondary shocks. These were analyzed with techniques similar to those used for the study of explosions from charges with masses ranging from 500 kg to 5 kt. The analyses showed the cube-root scaling laws to be valid for the very small charges, and provided a detailed record of the peak hydrostatic pressure as a function of radius for a unit charge of silver azide, over a wide range of scaled distances. The pressure-radius variation was compared to that from a unit charge of TNT and this permitted a detailed determination of the TNT equivalence of silver azide

  20. A Comparative Study of Ground and Underground Vibrations Induced by Bench Blasting

    OpenAIRE

    Xiuzhi Shi; Xianyang Qiu; Jian Zhou; Dan Huang; Xin Chen; Yonggang Gou

    2016-01-01

    Ground vibrations originating from bench blasting may cause damage to slopes, structures, and underground workings in close proximity to an operating open-pit mine. It is important to monitor and predict ground vibration levels induced by blasting and to take measures to reduce their hazardous effects. The aims of this paper are to determine the weaker protection objects by comparatively studying bench blasting induced vibrations obtained at surface and in an underground tunnel in an open-pit...

  1. Blasting Impact by the Construction of an Underground Research Tunnel in KAERI

    International Nuclear Information System (INIS)

    Kwon, S.; Cho, W. J.

    2005-12-01

    The underground research tunnel, which is under construction in KAERI for the validation of HLW disposal system, is excavated by drill and blasting method using high-explosives. In order not to disturb the operation at the research facilities such as HANARO reactor, it is critical to develop a blasting design , which will not influence on the facilities, even though several tens of explosives are detonated almost simultaneously. To develop a reasonable blasting design, a test blasting at the site should be performed. A preliminary analysis for predicting the expected vibration and noise by the blasting for the construction of the underground research tunnel was performed using a typical empirical equation. From the study, a blasting design could be developed not to influence on the major research facilities in KAERI. For the validation of the blasting design, a test blasting was carried out at the site and the parameters of vibration equation could be determined using the measured data during the test blasting. Using the equation, it was possible to predict the vibration at different locations at KAERI and to conclude that the blasting design would meet the design criteria at the major facilities in KAERI. The study would verify the applicability of blasting method for the construction of a research tunnel in a rock mass and that would help the design and construction of large scale underground research laboratory, which might be carried out in the future. It is also meaningful to accumulate technical experience for enhancing the reliability and effectiveness of the design and construction of the HLW disposal repository, which will be constructed in deep underground by drill and blasting technique

  2. SITUATIONAL CONTROL OF HOT BLAST STOVES GROUP BASED ON DECISION TREE

    Directory of Open Access Journals (Sweden)

    E. I. Kobysh

    2016-09-01

    Full Text Available In this paper was developed the control system of group of hot blast stoves, which operates on the basis of the packing heating control subsystem and subsystem of forecasting of modes duration in the hot blast stoves APCS of iron smelting in a blast furnace. With the use of multi-criteria optimization methods, implemented the adjustment of control system conduct, which takes into account the current production situation that has arisen in the course of the heating packing of each hot blast stove group. Developed a situation recognition algorithm and the choice of scenarios of control based on a decision tree.

  3. The effect of blast furnace coke quality on the possibility of its use

    Directory of Open Access Journals (Sweden)

    A. Konstanciak

    2013-04-01

    Full Text Available In the paper behavior of the blast-furnace coke in the high temperature was presented. Comparative analysis of the chemical composition of the blast-furnace coke and the heat treatment of it were done. Coefficients M10 and M40 with the thermo-abrasiveness for chosen cokes were compared. The influence of ash content of the coke on the blast-furnace bed permeability was defined. Usefulness of the coke to blast-furnace process was also defined.

  4. Reduction of optically observed artillery blast wave trajectories using low dimensionality models

    Science.gov (United States)

    Steward, Bryan J.; Gross, Kevin C.; Perram, Glen P.

    2011-05-01

    Muzzle blast trajectories from firings of a 152 mm caliber gun howitzer were obtained with high-speed optical imagers and used to assess the fidelity with which low dimensionality models can be used for data reduction. Characteristic flow regions were defined for the blast waves. The near-field region was estimated to extend to 0.98 - 1.25 meters from the muzzle and the far-field region was estimated to begin at 2.61 - 3.31 meters. Blast wave geometries and radial trajectories were collected in the near through far-fields with visible imagers operating at 1,600 Hz. Beyond the near-field the blast waves exhibited a near-spherical geometry in which the major axis of the blast lay along the axis of the gun barrel and measured within 95% of the minor axis. Several blast wave propagation models were applied to the mid and far-field data to determine their ability to reduce the blast wave trajectories to fewer parameters while retaining the ability to distinguish amongst three munitions configurations. A total of 147 firings were observed and used to assess within-configuration variability relative to separation between configurations. Results show that all models perform well, and drag and point blast model parameters additionally provide insight into phenomenology of the blast.

  5. Computational modeling of blast induced whole-body injury: a review.

    Science.gov (United States)

    Chanda, Arnab; Callaway, Christian

    2018-02-01

    Blast injuries affect millions of lives across the globe due to its traumatic after effects on the brain and the whole body. To date, military grade armour materials are designed to mitigate ballistic and shrapnel attacks but are less effective in resisting blast impacts. In order to improve blast absorption characteristics of armours, the first key step is thoroughly understands the effects of blasts on the human body itself. In the last decade, a plethora of experimental and computational work has been carried out to investigate the mechanics and pathophysiology of Traumatic Brain Injury (TBI). However, very few attempts have been made so far to study the effect of blasts on the various other parts of the body such as the sensory organs (eyes and ears), nervous system, thorax, extremities, internal organs (such as the lungs) and the skeletal system. While an experimental evaluation of blast effects on such physiological systems is difficult, developing finite element (FE) models could allow the recreation of realistic blast scenarios on full scale human models and simulate the effects. The current article reviews the state-of-the-art in computational research in blast induced whole-body injury modelling, which would not only help in identifying the areas in which further research is required, but would also be indispensable for understanding body location specific armour design criteria for improved blast injury mitigation.

  6. Technology Demonstration of Wet Abrasive Blasting for Removal of Lead- and Asbestos-Containing Paint

    National Research Council Canada - National Science Library

    Race, Timothy

    2003-01-01

    ...). This technology demonstration showed that wet blasting using an engineered abrasive can safely and effectively remove lead- and asbestos-containing paint from exterior concrete masonry unit walls...

  7. Investigating the risk of lightning's pressure blast wave

    Directory of Open Access Journals (Sweden)

    Ryan Blumenthal�

    2015-03-01

    Full Text Available We investigated the pathology of human trauma associated with lightning's pressure blast wave. Within what range is a human at risk and what are the risks? Two theories for the trauma currently exist: the flash moisture vaporisation theory and the sixth mechanism theory. We performed a simple proof-of-concept experiment in a high-voltage laboratory to determine which theory makes for better predictions. The experiment confirmed the existence of a non-discriminant pressure blast wave around a spark in air. The lightning data were compared with the known medical data. Findings may now help explain some of the more curious lightning injury patterns seen on lightning-strike victims.

  8. Perspectives on waste minimization with CO2 blasting

    International Nuclear Information System (INIS)

    Krueger, B.E.

    1992-01-01

    Blast-cleaning with dry ice pellets is a technology that has broad applicability for industrial cleaning, surface preparation and decontamination. Alpheus Cleaning Technologies Corp. has pioneered commercial use of this technology with a patented system originally developed by Lockheed Corp. When the dry ice pellets strike the target surface a dual-action cleaning takes place, disappear instantly upon impact, practically eliminating disposal costs. The process is completely dry and can be used on electrical equipment safely. Since there is no grit entrapment or sedimentation residue, in-place cleaning of complex machinery is made possible. Limitations of CO 2 , blasting are that it is a line-of-sight process, it is quite noisy, and the cost of a system exceeds $100,000. Nevertheless, users find they save a great deal of money in pre-cleaning and post-cleaning cost reduction, and the substantial benefits outweigh the other considerations

  9. ACUTE LYMPHOBLASTIC LEUKEMIA WITHOUT CIRCULATING BLASTS PRESENTING AS SEVERE HYPERCALCEMIA

    Directory of Open Access Journals (Sweden)

    Z. Oloomi

    2007-05-01

    Full Text Available Hypercalcemia complicating malignancy is a rare complication in pediatric age group. In this article, we present a case with acute lymphoblastic leukemia presenting as severe hypercalcemia. A 10 years old girl presented with an acute onset of fever, nausea, vomiting, loss of weight, costovertebral pain and frequency. She was admitted with a presumptive diagnosis of acute pyelonephritis. Her examination showed mild hepatosplenomegaly. In laboratory studies she had sever hypercalcemia. Despite the absence of circulating blast, bone marrow aspiration was diagnostic of acute lymphoblastic leukemia. The hypercalcemia was initially treated with intravenous hydration and furosemide but the serum calcium levels normalized only after the beginning of specific chemotherapy. Hypercalcemia represents an emergency in children, and acute leukemia must be considered in differential diagnosis even when there are no circulating blasts.

  10. Numerical dynamic analysis of stiffened plates under blast loading

    Directory of Open Access Journals (Sweden)

    H.R. Tavakoli

    Full Text Available Using the general purpose finite element package Abaqus, an investigation has been carried out to examine the dynamic response of steel stiffened plates subjected to uniform blast loading. The main objective of this study is to determine the dynamic response of the stiffened plates considering the effect of stiffener configurations. Several parameters, such as boundary conditions, mesh dependency and strain rate, have been considered in this study. Special emphasis is focused on the evaluation of midpoint displacements and energy of models. The modeling techniques were described in details. The numerical results provide better insight into the effect of stiffener configurations on the nonlinear dynamic response of the stiffened plates subjected to uniform blast loading.

  11. Radio controlled detonators and sequential real time blast applications

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, T.; Laboz, J.M. [Delta Caps International, Nice (France)

    1995-12-31

    Among the numerous technical evolutions in the blasting environment the authors are going to describe below the concept of electronic detonator sequenced by radio waves, and also its numerous applications. Three major technologies are used in the initiation environment: fused-initiated detonators; electric detonators; and non-electric detonators. The last two technologies were made available under multiple variants. Two major innovations are going to substantially change the way traditional detonators operate: pyrotechnic delays are replaced by electronic delays (greater accuracy); and triggering orders, passing through a cable, is now replaced by radio-waves transmission (possibility to do real time delay pattern). Such a new product provided all the features offered by current detonators, but also allows mastering specific cases that were difficult to control with the current technology, such as: vibration control; underground blast; and building demolition.

  12. [Blasting damage in manmade disasters and terrorist attacks].

    Science.gov (United States)

    Shapovalov, V M; Samokhvalov, I M

    2012-01-01

    In the present case of explosive injuries in peacetime, when suddenly there are usually accidental or intentional explosions methane in mines, tanks with gas or explosives, fuel tanks or gas content, gas tanks, gas pipelines, product pipelines, as well as the explosion of military ordnance--grenades, mines, fuses, shells, and accidentally found child or maliciously used by terrorists. Collected statistical data on manmade disasters in coal mines and explosive injuries in terrorist attacks, the physical parameters of which were able to identify only approximately and type of damage incurred,mostly multiple and combinative combined and presented significant challenges in health care. The reasons and circumstances of the explosion in peacetime, gave a detailed description of the damaging factors, mechanisms, and characteristics arise from injuries suffered in the blast injuries. We describe the pathogenesis of blast injury, basic and clinical manifestations of lesions in the explosions.

  13. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    OpenAIRE

    Ashish Kumar Pathak; Dr. V. Pandey

    2014-01-01

    Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS) and this material is ob...

  14. Controlled drill ampersand blast excavation at AECL's Underground Research Laboratory

    International Nuclear Information System (INIS)

    Kuzyk, G.W.; Onagi, D.P.; Thompson, P.M.

    1996-01-01

    A controlled drill and blast method has been developed and used to excavate the Underground Research Laboratory, a geotechnical facility constructed by Atomic Energy of Canada Limited (AECL) in crystalline rock. It has been demonstrated that the method can effectively reduce the excavation disturbed zone (EDZ) and is suitable for the construction of a used fuel disposal vault in the plutonic rock of the Canadian Shield

  15. Genetic Networks Activated by Blast Injury to the Eye

    Science.gov (United States)

    2018-03-01

    RNA binding protein with multiple splicing) as well as Calb2 (Calbindin 2) and Chrna6 (Cholinergic receptor nicotinic alpha 6). These two networks are...R., O’Neill, H. C., Wageman, C. R., Patzlaff, N. E., et al. (2012). alpha6∗ nicotinic acetylcholine receptor expression and function in a visual...visual function after ocular blast injury can be reduced through immediate-early administration of non-steroidal anti-inflammatory drugs (NSAIDs) such as

  16. Gene pyramiding enhances durable blast disease resistance in rice

    OpenAIRE

    Fukuoka, Shuichi; Saka, Norikuni; Mizukami, Yuko; Koga, Hironori; Yamanouchi, Utako; Yoshioka, Yosuke; Hayashi, Nagao; Ebana, Kaworu; Mizobuchi, Ritsuko; Yano, Masahiro

    2015-01-01

    Effective control of blast, a devastating fungal disease of rice, would increase and stabilize worldwide food production. Resistance mediated by quantitative trait loci (QTLs), which usually have smaller individual effects than R-genes but confer broad-spectrum or non-race-specific resistance, is a promising alternative to less durable race-specific resistance for crop improvement, yet evidence that validates the impact of QTL combinations (pyramids) on the durability of plant disease resista...

  17. Blast Load Simulator Experiments for Computational Model Validation: Report 1

    Science.gov (United States)

    2016-08-01

    to 2 psi) related to failures of conventional annealed glass and hollow concrete masonry unit walls. It can also simulate higher blast pressures for...Army, Air Force, Navy , and De- fense Special Weapons Agency 1998, Hyde 2003) calculations were con- ducted to produce a waveform that matched both peak...the structures located downstream of the cascade section of the BLS. ERDC/GSL TR-16-27 26 References Department of the Army, Air Force, Navy

  18. Blast furnace coke substitutes from Victorian brown coal

    OpenAIRE

    Mollah, Mamun

    2017-01-01

    Iron is usually produced from its ores using coke in a blast furnace (BF). Coke, a hard and macroporous carbon material, is produced from special coals (coking coals) and acts as fuel, smelting agent, and the permeable support for the charge to the BF. No material can completely replace coke in a BF. Coking coals are becoming harder (and more expensive) to obtain. Victorian brown coal (VBC) is accessible, cheap, with low mineral concentrations, which is favourable for iron production in a BF....

  19. Experimental and Numerical Investigations into Polymeric Coatings for Blast Protection

    Science.gov (United States)

    2011-09-01

    reinforced concrete masonry walls. Subsequent research led to a total of twenty-one off- the-shelf prospective polymers being evaluated to determine the...materials such as fibre reinforced composites which delaminate and break up under such large deformations. A circular area of each of the coated...mechanisms of polymer- reinforced concrete masonry walls subjected to blast. Journal of Structural Engineering 131 (8), pp 1194- 1205 4. Whitlock, C

  20. Summary of IVO participation in Paks blast test analysis

    International Nuclear Information System (INIS)

    Varpasuo, P.

    2001-01-01

    The paper deals with the numerical simulation of the triple blast test performed at Paks NPP. A detailed background analysis was carried out to complete the geological and geotechnical properties and, consequently, special frequency dependent soil stiffnesses have been evaluated. The structural model (3D) allowed a very refined result presentation in terms of profiles of displacements and forces at different elevations, for direct comparison with the experimental output. (author)

  1. The concept of explosives malfunctioning in rock blasting

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Q. [Canada Centre for Mineral and Energy Technology, Val d`Or, Quebec (Canada)

    1994-12-31

    The problem of cross-hole explosive malfunctioning in rock blasting (including sympathetic detonation, desensitization and cut-offs) is a function of delay and spacing in a blast which should be designed to avoid such occurrences. On a delay-spacing chart, the phenomenon of explosive malfunctioning is explained by dividing the chart into different regions, while the shape and size of each region could vary from one explosive to the other. Over seventy blasts have been carried out at the CANMET Experimental Mine to identify the malfunctioning characteristics of specific emulsion, water-gel and dynamite explosives. In each experiment, two parallel blastholes, 32 mm in diameter and 1.7 m deep, were drilled downwards in an underground drift. Full coupling was achieved by tamping the explosives in the wet holes. The receptor hole is initiated with a delay following the donor hole in order to observe the timing effect on the explosives being shocked. High frequency vibration monitoring was used to identify the detonation or failure of the receptor hole. The VOD measurement was used for donor holes but not for the receptor holes because of the cut-off at the collar as a result of donor hole cratering, which was further confirmed with high speed video recording. The spacing is varied to modify the shock pressure the receptor charges are subjected to. Results are presented for the three explosives tested.

  2. Shock initiated reactions of reactive multi-phase blast explosives

    Science.gov (United States)

    Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

    2017-01-01

    This paper describes a new class of non-ideal explosive compositions made of perfluoropolyether (PFPE), nanoaluminum, and a micron-size, high mass density, reactive metal. Unlike high explosives, these compositions release energy via a fast self-oxidized combustion wave rather than a true self-sustaining detonation. Their reaction rates are shock dependent and they can be overdriven to change their energy release rate. These compositions are fuel rich and have an extended aerobic energy release phase. The term "reactive multiphase blast" refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts energy and momentum [1]; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. Tantalum-based RMBX formulations were tested in two spherical core-shell configurations - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

  3. Modelling blast induced damage from a fully coupled explosive charge

    Science.gov (United States)

    Onederra, Italo A.; Furtney, Jason K.; Sellers, Ewan; Iverson, Stephen

    2015-01-01

    This paper presents one of the latest developments in the blasting engineering modelling field—the Hybrid Stress Blasting Model (HSBM). HSBM includes a rock breakage engine to model detonation, wave propagation, rock fragmentation, and muck pile formation. Results from two controlled blasting experiments were used to evaluate the code’s ability to predict the extent of damage. Results indicate that the code is capable of adequately predicting both the extent and shape of the damage zone associated with the influence of point-of-initiation and free-face boundary conditions. Radial fractures extending towards a free face are apparent in the modelling output and matched those mapped after the experiment. In the stage 2 validation experiment, the maximum extent of visible damage was of the order of 1.45 m for the fully coupled 38-mm emulsion charge. Peak radial velocities were predicted within a relative difference of only 1.59% at the nearest history point at 0.3 m from the explosive charge. Discrepancies were larger further away from the charge, with relative differences of −22.4% and −42.9% at distances of 0.46 m and 0.61 m, respectively, meaning that the model overestimated particle velocities at these distances. This attenuation deficiency in the modelling produced an overestimation of the damage zone at the corner of the block due to excessive stress reflections. The extent of visible damage in the immediate vicinity of the blasthole adequately matched the measurements. PMID:26412978

  4. [Gunshot or blast injuries of the hand. Principles of treatment].

    Science.gov (United States)

    Kollig, E; Franke, A

    2012-07-01

    Gunshot injuries to the hand are rare in Central Europe. As a result of their special trauma morphology they are a serious threat to the functional integrity of the hand and often lead to a loss of function which can be associated with a permanent unfitness to work or disability. Blast injuries to the hand are more common in this part of the world and are usually caused by the inappropriate use of fireworks. This trauma entity is associated with a number of special kinetic features and effects which have therapeutic consequences and should therefore be discussed separately. As a result of the low incidence of these specific types of injuries in times of peace, experience-based expertise is unlikely to be available. The management of gunshot injuries to the hand is a particular challenge to hand surgeons who must have specialist knowledge and skills in order to achieve an optimum outcome. This applies even more so to the treatment of blast injuries to the hand which are associated with far more complex injury patterns. As a rule blast injuries are associated with a high risk of complications and require a rapid assessment and rigorous management of all damaged structures similar to approaches used for infections of the hand. Illustrated by several cases which have been treated at our institution the basic aspects of the development and morphology of these injuries are discussed as well as different treatment options, algorithms and possible treatment outcomes.

  5. Blast impact behaviour of concrete with different fibre reinforcement

    Directory of Open Access Journals (Sweden)

    Drdlová Martina

    2015-01-01

    Full Text Available The paper summarizes the results of the development of special concrete intended for the explosion resistance applications, with the emphasis on minimal secondary fragments formation at the explosion. The fine-grained concrete matrix has been reinforced by various types of short dispersed fibers (metallic, mineral and polymer of different sizes and by their combination and the effect of the fibre reinforcement on the physico-mechanical properties and blast resistance was observed. The concrete prism specimens have been subjected to the determination of mechanical parameters (compressive and flexural strength at quasi-static load. The blast tests were conducted on the slab specimens prepared from selected mixtures. The material characteristics and explosion test data have been used for numerical investigation, which defined the optimal wall composition and dimensions of the concrete element which should resist the explosion defined by type, size, weight and placement of the blast. In the next step the test elements resistance was verified by real explosion test.

  6. BLAST in Gid (BiG): A Grid-Enabled Software Architecture and Implementation of Parallel and Sequential BLAST

    International Nuclear Information System (INIS)

    Aparicio, G.; Blanquer, I.; Hernandez, V.; Segrelles, D.

    2007-01-01

    The integration of High-performance computing tools is a key issue in biomedical research. Many computer-based applications have been migrated to High-Performance computers to deal with their computing and storage needs such as BLAST. However, the use of clusters and computing farm presents problems in scalability. The use of a higher layer of parallelism that splits the task into highly independent long jobs that can be executed in parallel can improve the performance maintaining the efficiency. Grid technologies combined with parallel computing resources are an important enabling technology. This work presents a software architecture for executing BLAST in a International Grid Infrastructure that guarantees security, scalability and fault tolerance. The software architecture is modular an adaptable to many other high-throughput applications, both inside the field of bio computing and outside. (Author)

  7. Blasting Damage Predictions by Numerical Modeling in Siahbishe Pumped Storage Powerhouse

    Science.gov (United States)

    Eslami, Majid; Goshtasbi, Kamran

    2017-04-01

    One of the popular methods of underground and surface excavations is the use of blasting. Throughout this method of excavation, the loading resulted from blasting can be affected by different geo-mechanical and structural parameters of rock mass. Several factors affect turbulence in underground structures some of which are explosion, vibration, and stress impulses caused by the neighbouring blasting products. In investigating the blasting mechanism one should address the processes which expand with time and cause seismic events. To protect the adjoining structures against any probable deconstruction or damage, it is very important to model the blasting process prior to any actual operation. Efforts have been taken in the present study to demonstrate the potentiality of numerical methods in predicting the specified parameters in order to prevent any probable destruction. For this purpose the blasting process was modeled, according to its natural implementation, in one of the tunnels of Siahbishe dam by the 3DEC and AUTODYN 3D codes. 3DEC was used for modeling the blasting environment as well as the blast holes and AUTODYN 3D for modeling the explosion process in the blast hole. In this process the output of AUTODYN 3D, which is a result of modeling the blast hole and is in the form of stress waves, is entered into 3DEC. For analyzing the amount of destruction made by the blasting operation, the key parameter of Peak Particle Velocity was used. In the end, the numerical modeling results have been compared with the data recorded by the seismographs planted through the tunnel. As the results indicated 3DEC and AUTODYN 3D proved appropriate for analyzing such an issue. Therefore, by means of these two softwares one can analyze explosion processes prior to their implementation and make close estimation of the damage resulting from these processes.

  8. Analysis and Numerical Simulation on the Reduction Effect of Stress Waves Caused by Water Jet Slotting Near Blasting Source

    OpenAIRE

    Su, Dengfeng; Kang, Yong; Li, Dongyang; Wang, Xiaochuan; Yan, Fuwen

    2016-01-01

    As one of the most serious “side effects” of blast excavation, blast-induced vibration must be controlled for existing buildings and human beings. This paper proposes a method for blast-induced vibration reduction with water jet assistance according to the cutting characters of low-noised, environment-friendly water jet. The mechanism of vibration-isolation with water jet assistance was analyzed, and the stress wave energy attenuation models were established based on blasting theory and stres...

  9. 75 FR 23589 - Safety Zones; Blasting Operations and Movement of Explosives, St. Marys River, Sault Sainte Marie...

    Science.gov (United States)

    2010-05-04

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zones; Blasting Operations and Movement of... ensure the safety of the maritime community during blasting and dredging operations. DATES: Effective... action is needed to ensure the public's safety during blasting and dredging operations. Delaying the...

  10. 76 FR 71517 - Takes of Marine Mammals During Specified Activities; Blasting Operations by the U.S. Army Corps...

    Science.gov (United States)

    2011-11-18

    ... shall determine the thickness of stemming using blasting industry conventional stemming calculations... marine animals near the blast (Keevin et al., 1999). The visual evidence from a typical confined blast is..., including inshore waters of the bays, sounds, and estuaries. Except for animals residing within the Southern...

  11. Genetic improvement of resistance to blast and bacterial blight of the ...

    African Journals Online (AJOL)

    Rice blast caused by the fungus Magnaporthe grisea and bacterial blight (BB) caused by Xanthomonas oryzae pv. Oryzae (Xoo) are two major rice diseases in the world. An elite, early maturing maintainer line of hybrid rice, Rongfeng B hybrid rice is susceptible to both blast and BB. For improving its diseases resistance, ...

  12. Induced mutation for disease resistance in rice with special reference to blast, bacterial blight and tungro

    International Nuclear Information System (INIS)

    Mathur, S.C.

    1983-01-01

    Rice varieties Ratna, Pusa 2-21, Vijaya and Pankaj have been treated with gamma rays, EMS or sodium azide to improve their resistance against blast, bacterial leaf blight or tungro virus. For blast and tungro, mutants with improved resistance were selected. Variation in reaction to bacterial leaf blight has been used in crossbreeding to accumulate genes for resistance. (author)

  13. New Marker Development for the Rice Blast Resistance Gene Pi-km

    Science.gov (United States)

    The blast resistance (R) gene Pi-km protects rice against specific races of the fungal pathogen Magnaporthe oryzae. The use of blast R genes remains the most cost-effective method of disease control. To facilitate the breeding process, we developed a Pi-km specific molecular marker. For this purp...

  14. Simulation for the powder movement and accumulation in the lower part of blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Takashi [Mineral Resources Research Center, Nippon Steel Technoresearch, Futtsu-shi Chiba (Japan)

    1997-12-31

    The behavior of unburnt char and coke powder in the blast furnace becomes material for discussion with the increase in injection rate of pulverized coal into the blast furnace. An analysis was made as to the simulation of powder accumulation at the deadman and dripping zone of blast furnace by using a powder/gas two-phases flow experimental data. When an excessive powder has penetrated at a low gas velocity, it brings an increment in holdup and the controlling factors are powder/gas ratio and gas velocity. An empirical formula used for estimating the powder hold-up in the blast furnace internal conditions has proposed based on similarity. The controlling {pi} numbers are Floude number, powder/gas ratio and particle diameter ratio of powder/lump. This empirical formular was connected with Blast Furnace Total Model `BRIGHT` for the simulation of powder amount distribution in the lower part of blast furnace. When Powder diameter Dk exceeds 100 {mu} and gas velocity becomes lower than 0.7m/s at PC1OOkg/T, the powder tends to accumulate in the deadman. These results was available for the decision of optimum blast conditions and optimum powder diameter in the high amount of pulverized coal injection to the blast furnace. (author) 10 refs.

  15. GPS network observation of traveling ionospheric disturbances following the Chelyabinsk meteorite blast

    Directory of Open Access Journals (Sweden)

    F. Ding

    2016-11-01

    Full Text Available We use the Global Positioning System (GPS network in northwest China and central Asia to monitor traveling ionospheric disturbances (TIDs, which were possibly excited by the large meteorite blast over Chelyabinsk, Russia, on 15 February 2013. Two TIDs were observed. The first TID was observed 13 min after the blast within a range of 270–600 km from the blast site. It propagated radially from the blast site with a mean velocity and period of 369 m s−1 and 12 min, respectively. The second TID was found in northwest China, 1.5 h after the time of the blast, at  ∼  2500–3100 km from the blast site. This latter TID propagated southeastward with a velocity and period of 410 m s−1 and 23 min, respectively. Severe dissipation of the perturbation total electronic content (TEC amplitude was observed. Any TIDs propagating in a global range was not found after the meteorite blast. Features of TIDs were compared with those excited by early nuclear explosion tests. It is inferred from our analysis that the energy release of the Chelyabinsk meteorite blast may not be large enough to excite such ionospheric disturbances in a global range as some nuclear explosions did.

  16. Development of a shot-blasting robot for removal of the wall concrete surface

    International Nuclear Information System (INIS)

    Tokioka, Seigo; Inagaki, Hiroichi; Sakai, Sachio; Kasahara, Ichirou; Ishigami, Shinya

    1991-01-01

    This paper reports research and development of a shot-blasting robot, for which the following targets are set up and their performances confirmed through basic experiments: (1) Uniform removal of concrete surface by an impeller type shot-blasting system. (2) Recycling of projecting material (steel shot). (3) Separation of removal material. And on the basis of these, its application to decontamination of nuclear power facilities is projected. The following three problems were focused on and the results of study are reported as follows: Step 1 : As part of a mechanical basic test, a manual type shot-blasting unit was mounted on a test device which may move freely on the concrete, and its data concerning finishing performance was obtained. Step 2 : On the basis of the results of the mechanization basic test, remote controlling of the shot blasting unit and its mounting on the suction type self-climbing carriage were studied first, secondly data of shot-blasting, operation and control method was gathered to develop a shot-blasting robot. Step 3 : A shot-blasting test was conducted for confirming climbing and shot-blasting performances. (author)

  17. Physics of shock tube simulated IED blast for mTBI research

    NARCIS (Netherlands)

    Mediavilla Varas, J.; Philippens, M.M.G.M.; Meijer, S.R.

    2010-01-01

    The objective of this research is to understand the blast propagation into the human skull and brain causing mTBI and use this knowledge for enabling design of effective protection measures against them. A shock tube including sensor system was optimized to simulate realistic IED blast profiles

  18. Blasting chamber of the mine water stained; Voladuras de avance en labores subterraneas

    Energy Technology Data Exchange (ETDEWEB)

    Domingo Perlado, J. F.

    2012-11-01

    In this paper, the main parameters that lay out a developed blast in underground mining are studied. Such parameters affect the geometry of the draft scheme so as to get a regular cut with a minimum consumption of explosive in order to reduce the vibrations caused by blasting. (Author)

  19. Blasting forward in underground work; Voladuras de camara de la mina de Aguas Tenidas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Maneiro, C. H.; Maqueda Jimenez, S.; Pazos Perez, L.; Carnero Ortiz, F.

    2012-11-01

    This paper explains the drilling and blasting techniques of stopes in Aguas Tenidas Mine (Huelva, Spain), including slot raises and slots. Highights are: application of electronic detonators and a 30'' hole in slot raise blasts, ANFO uphole chrging of 89 mm holes and high productive fan drillin, in order to maintain stoping production of 150.000 t/month. (Author)

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

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and... connecting wires are connected up. (b) When detonators or explosives are brought into an air lock, no...