WorldWideScience

Sample records for blast overpressure studies

  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. Experimental Study of the Effect of Water Mist Location On Blast Overpressure Attenuation in A Shock Tube

    Science.gov (United States)

    Mataradze, Edgar; Chikhradze, Nikoloz; Bochorishvili, Nika; Akhvlediani, Irakli; Tatishvili, Dimitri

    2017-12-01

    Explosion protection technologies are based on the formation of a shock wave mitigation barrier between the protection site and the explosion site. Contemporary protective systems use water mist as an extinguishing barrier. To achieve high effectiveness of the protective system, proper selection of water mist characteristics is important. The main factors defining shock wave attenuation in water mist include droplet size distribution, water concentration in the mist, droplet velocity and geometric properties of mist. This paper examines the process of attenuation of shock waves in mist with droplets ranging from 25 to 400 microns under different conditions of water mist location. Experiments were conducted at the Mining Institute with the use of a shock tube to study the processes of explosion suppression by a water mist barrier. The shock tube consists of a blast chamber, a tube, a system for the dosed supply of water, sensors, data recording equipment, and a process control module. Shock wave overpressure reduction coefficient was studied in the shock tube under two different locations of water mist: a) when water mist is created in direct contact with blast chamber and b) the blast chamber and the mist are separated by air space. It is established that in conditions when the air space distance between the blast chamber and the mist is 1 meter, overpressure reduction coefficient is 1.5-1.6 times higher than in conditions when water mist is created in direct contact with blast chamber.

  3. Blast overpressure after tire explosion: a fatal case.

    Science.gov (United States)

    Pomara, Cristoforo; D'Errico, Stefano; Riezzo, Irene; Perilli, Gabriela; Volpe, Umberto; Fineschi, Vittorio

    2013-12-01

    Fatal blast injuries are generally reported in literature as a consequence of the detonation of explosives in war settings. The pattern of lesion depends on the position of the victim in relation to the explosion, on whether the blast tracks through air or water, and whether it happens in the open air or within an enclosed space and the distance from the explosion. Tire explosion-related injuries are rarely reported in literature. This study presents a fatal case of blast overpressure due to the accidental explosion of a truck tire occurring in a tire repair shop. A multidisciplinary approach to the fatality involving forensic pathologists and engineers revealed that the accidental explosion, which caused a series of primary and tertiary blast wave injuries, was due to tire deterioration.

  4. Simulation and Measurements of Small Arms Blast Wave Overpressure in the Process of Designing a Silencer

    Directory of Open Access Journals (Sweden)

    Hristov Nebojša

    2015-02-01

    Full Text Available Simulation and measurements of muzzle blast overpressure and its physical manifestations are studied in this paper. The use of a silencer can have a great influence on the overpressure intensity. A silencer is regarded as an acoustic transducer and a waveguide. Wave equations for an acoustic dotted source of directed effect are used for physical interpretation of overpressure as an acoustic phenomenon. Decomposition approach has proven to be suitable to describe the formation of the output wave of the wave transducer. Electroacoustic analogies are used for simulations. A measurement chain was used to compare the simulation results with the experimental ones.

  5. Blast Overpressure Studies. Nonauditory Damage Risk Assessment for Simulated Muzzle Blast from a l2Omm Ml2l Mortar System

    National Research Council Canada - National Science Library

    Yelverton, John

    1997-01-01

    This study was undertaken to establish the subthreshold, threshold, and suprathresholds for nonauditory injuries in a simulated muzzle blast environment like that produced when firing a 120mm M121 mortar system...

  6. 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.

  7. Control of blast overpressure and vibrations at the Underground Research Laboratory

    International Nuclear Information System (INIS)

    Kuzyk, G.W.; Onagi, D.P.; Mohanty, B.

    1991-01-01

    AECL Research (AECL) has constructed an Underground Research Laboratory (URL) as a facility for research and development in the Canadian Nuclear Fuel Waste Management Program. The objectives of the program are to develop and evaluate the technology to ensure safe, permanent disposal of Canada's nuclear fuel waste. Several multidisciplinary experiments and engineering demonstrations are planned for the URL over the next ten years. In 1989, AECL excavated a test room for the Buffer/Container Experiment at the 240 Level. The blasts were designed to limit vibration and overpressure damage because the excavation was located close to existing furnishings and services that were very susceptible to blast-induced vibration and overpressure. An experimental room, which contained sensitive instrumentation, was located within 30 m of the initial blasts. A concrete floor slab, timber curtains and a bulkhead were installed to protect furnishings and services from fly-rock and overpressure. Five of the initial blasts were monitored. This paper describes the results of the monitoring program and the effectiveness of the blast design, floor slab and timber curtains and bulkhead in reducing blast overpressure and vibrations at the blast site. It is shown that greater than a 20-fold reduction in both blast vibrations and air overpressures can be achieved with specific combinations of blast design, installation of timber curtains and construction of a concrete floor slab

  8. BLEVE overpressure: multi-scale comparison of blast wave modeling

    International Nuclear Information System (INIS)

    Laboureur, D.; Buchlin, J.M.; Rambaud, P.; Heymes, F.; Lapebie, E.

    2014-01-01

    BLEVE overpressure modeling has been already widely studied but only few validations including the scale effect have been made. After a short overview of the main models available in literature, a comparison is done with different scales of measurements, taken from previous studies or coming from experiments performed in the frame of this research project. A discussion on the best model to use in different cases is finally proposed. (authors)

  9. Assessment of the Effectiveness of Combat Eyewear Protection Against Blast Overpressure.

    Science.gov (United States)

    Sundaramurthy, A; Skotak, M; Alay, E; Unnikrishnan, G; Mao, H; Duan, X; Williams, S T; Harding, T H; Chandra, N; Reifman, J

    2018-07-01

    It is unclear whether combat eyewear used by U. S. Service members is protective against blast overpressures (BOPs) caused by explosive devices. Here, we investigated the mechanisms by which BOP bypasses eyewear and increases eye surface pressure. We performed experiments and developed three-dimensional (3D) finite element (FE) models of a head form (HF) equipped with an advanced combat helmet (ACH) and with no eyewear, spectacles, or goggles in a shock tube at three BOPs and five head orientations relative to the blast wave. Overall, we observed good agreement between experimental and computational results, with average discrepancies in impulse and peak-pressure values of less than 15% over 90 comparisons. In the absence of eyewear and depending on the head orientation, we identified three mechanisms that contributed to pressure loading on the eyes. Eyewear was most effective at 0 deg orientation, with pressure attenuation ranging from 50 (spectacles) to 80% (goggles) of the peak pressures observed in the no-eyewear configuration. Spectacles and goggles were considerably less effective when we rotated the HF in the counter-clockwise direction around the superior-inferior axis of the head. Surprisingly, at certain orientations, spectacles yielded higher maximum pressures (80%) and goggles yielded larger impulses (150%) than those observed without eyewear. The findings from this study will aid in the design of eyewear that provides better protection against BOP.

  10. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    Science.gov (United States)

    2015-10-01

    Gould , 1994; Yu et al ., 2004; Montaron et al ., 2006); with males showing...ety, and depression (Gentilini et al ., 1985; Schoenhuber and Gentilini, 1988 ; Ponsford et al ., 1995). Blast induced traumatic brain injury (bTBI...into neuronal circuits (Kempermann, 2002a; Kozorovitskiy and Gould , 2003; Abrous et al ., 2005; Hagg, 2005; Ming and Song, 2005; Zhao et al .,

  11. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    Science.gov (United States)

    2014-11-01

    detail elsewhere.13,41 After silver staining, sections were washed thoroughly in distilled water, mounted on gelatin -coated slides, and counterstained...neuropathological changes resulting from a single BOP exposure are modest and largely consist of limited fiber degeneration that is evident in silver -stained...Walter Reed Army Institute of Research, Silver Spring, MD 20910 Age-dependent variations in the pathophysiology of blast-induced traumatic brain

  12. Nonlinear Analysis of Frame Structures Subjected to Blast Overpressures

    Science.gov (United States)

    1977-05-01

    columns have the same plastic bending capacity., CIMp . 16 •,, vi In most cases, more economical designs of blast-resistant frames are realized when...3 HH+(w-I)L’] ~~~(-IE r3+H((201A)I-~L COMBINED MECHANISM L+2n 2C ccW CP CIMP R n Number of bay* a ,2,3... w =Uniform ___________L ____ equivalent *For

  13. 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.

  14. 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)

  15. 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

  16. 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.

  17. 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.

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

    Science.gov (United States)

    2015-07-01

    et al ., 1973; Saivin and Houin, 1988 ). Similar to its tetracycline analogs, the side...neuroinflammation and elevated CORT levels are known inhibitors of hippocampal de novo neurogen- esis (Cameron and Gould , 1994; Yu et al ., 2004; Montaron et al ...memory problems, increased anxi- ety, and depression (Gentilini et al ., 1985; Schoenhuber and Gentilini, 1988 ; Ponsford et al ., 1995). Blast

  19. 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.

  20. A study on the overpressure estimation of BLEVE

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Tae [Korean Fire Protection Association (Korea); Kim, In Won; Song, Hee Oeul [Department of Chemical Engineering, Konkuk University (Korea)

    2000-03-01

    Explosion quantities and flashing mass resulting from the variation of temperature are calculated by a computer program, BLEVE ESTIMATOR, to carry out the risk assessment of BLEVE. The damages caused by the BLEVE are estimated under the explosion of the simulation condition similar to the Puchun LP gas station accident, and the results are compared with the commercial program SAFER of Dupont Co. Explosion quantities and flashing mass increase exponentially with the increase of explosion temperature. These values for propane are relatively higher than those for n-butane. In conditions of higher vessel temperature, vessel pressure, and liquid ratio of containment, higher overpressures are calculated. 10 refs., 12 figs., 2 tabs.

  1. 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

  2. Assessment of the Effects of Acute and Repeated Exposure to Blast Overpressure in Rodents: Towards a Greater Understanding of Blast and the Potential Ramifications for Injury in Humans Exposed to Blast

    Directory of Open Access Journals (Sweden)

    Stephen Thomas Ahlers

    2012-03-01

    Full Text Available Mild traumatic brain injury (mTBI resulting from exposure to improvised explosive devices (IEDs has fueled a requirement to develop animals models that mirror this condition using exposure to blast overpressure (BOP. En route to developing a model of repeated exposure to BOP we sought to initially characterize the effects of acute BOP exposure in rodents, focusing specifically on the levels of BOP exposure that produced clinical mTBI symptoms. We first measured BOP effects on gross motor function on a balance beam. Separate groups of unanesthetized rats were exposed (in different orientations to 40 kPa, 75 kPa and 120 kPa BOP exposure inside a pneumatically driven shock tube. Results demonstrated that rats exposed to 120 kPa demonstrated transient alterations or loss of consciousness indicated by a transient loss of righting and by increased latencies on the balance beam. The 120 kPa exposure was the threshold for overt pathology for acute BOP exposure with approximately 30% of rats presenting with evidence of subdural hemorrhage and cortical contusions. All animals exposed to 120 kPa BOP manifested evidence of significant pulmonary hemorrhage. Anterograde memory deficits were observed in rats exposed to 75 kPa facing the BOP wave and rats exposed to 120 kPa in the lateral (side orientation. We next assessed repeated exposure to either lateral or frontal 40 kPa BOP in anesthetized rats, once per day for 12 days. Results showed that repeated exposure in the frontal, but not side, orientation to the BOP wave produced a transitory learning deficit on a Morris water maze (MWM task as shown by significantly longer latencies to reach the submerged platform in the second and third blocks of a four block session. Implications of these data are discussed in relation to the manifestation of mTBI in military personnel exposed to IEDs. Finally, we suggest that there are multiple types of brain injury from blast.

  3. A wireless lingual feedback device to reduce overpressures in seated posture: a feasibility study.

    Directory of Open Access Journals (Sweden)

    Olivier Chenu

    2009-10-01

    Full Text Available Pressure sores are localized injuries to the skin and underlying tissues and are mainly resulting from overpressure. Paraplegic peoples are particularly subjects to pressure sores because of long-time seated postures and sensory deprivation at the lower limbs.Here we report outcomes of a feasibility trial involving a biofeedback system aimed at reducing buttock overpressure whilst an individual is seated. The system consists of (1 pressure sensors, (2 a laptop coupling sensors and actuator (3 a wireless Tongue Display Unit (TDU consisting of a circuit embedded in a dental retainer with electrodes put in contact with the tongue. The principle consists in (1 detecting overpressures in people who are seated over long periods of time, (2 estimating a postural change that could reduce these overpressures and (3 communicating this change through directional information transmitted by the TDU.Twenty-four healthy subjects voluntarily participated in this study. Twelve healthy subjects initially formed the experimental group (EG and were seated on a chair with the wireless TDU inside their mouth. They were asked to follow TDU orders that were randomly spread throughout the session. They were evaluated during two experimental sessions during which 20 electro-stimulations were sent. Twelve other subjects, added retrospectively, formed the control group (CG. These subjects participated in one session of the same experiment without any biofeedback.Three dependent variables were computed: (1 the ability of subjects to reach target posture (EG versus CG, (2 high pressure reductions after a biofeedback (EG versus CG and (3 the level of these reductions relative to their initial values (EG only. Results show (1 that EG reached target postures in 90.2% of the trials, against 5,3% in the CG, (2 a significant reduction in overpressures in the EG compared to the CG and (3, for the EG, that the higher the initial pressures were, the more they were decreased

  4. A Wireless Lingual Feedback Device to Reduce Overpressures in Seated Posture: A Feasibility Study

    Science.gov (United States)

    Chenu, Olivier; Vuillerme, Nicolas; Demongeot, Jacques; Payan, Yohan

    2009-01-01

    Background Pressure sores are localized injuries to the skin and underlying tissues and are mainly resulting from overpressure. Paraplegic peoples are particularly subjects to pressure sores because of long-time seated postures and sensory deprivation at the lower limbs. Methodology/Principal Findings Here we report outcomes of a feasibility trial involving a biofeedback system aimed at reducing buttock overpressure whilst an individual is seated. The system consists of (1) pressure sensors, (2) a laptop coupling sensors and actuator (3) a wireless Tongue Display Unit (TDU) consisting of a circuit embedded in a dental retainer with electrodes put in contact with the tongue. The principle consists in (1) detecting overpressures in people who are seated over long periods of time, (2) estimating a postural change that could reduce these overpressures and (3) communicating this change through directional information transmitted by the TDU.Twenty-four healthy subjects voluntarily participated in this study. Twelve healthy subjects initially formed the experimental group (EG) and were seated on a chair with the wireless TDU inside their mouth. They were asked to follow TDU orders that were randomly spread throughout the session. They were evaluated during two experimental sessions during which 20 electro-stimulations were sent. Twelve other subjects, added retrospectively, formed the control group (CG). These subjects participated in one session of the same experiment without any biofeedback.Three dependent variables were computed: (1) the ability of subjects to reach target posture (EG versus CG), (2) high pressure reductions after a biofeedback (EG versus CG) and (3) the level of these reductions relative to their initial values (EG only). Results show (1) that EG reached target postures in 90.2% of the trials, against 5,3% in the CG, (2) a significant reduction in overpressures in the EG compared to the CG and (3), for the EG, that the higher the initial pressures

  5. Blast Overpressure Studies with Animals and Man: Biological Response to Complex Blast Waves

    Science.gov (United States)

    1993-10-31

    in cotton webbing harnesses and suspended vertically from the ceiling at a height of 1.2 m from the floor as measured to their xiphisternums. They...illustrated in Figure 1 or outdoors on a concrete pad. Two to three sheep at a time were placed in cotton webbing harnesses and suspended 1.22-m from the...52.00 48.001 1.06 12.00 44.00 0.27 WIX 40.00 0.00 40. 00 0.0 22.00, 48.001 0.46 0.00 44.00 0.00 2.00 40.00 0.05 0.00 40. 00 0.00 30.00 48.001 0.63 3.00

  6. 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

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-21

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

  9. 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.

  10. Study on the Rationality and Validity of Probit Models of Domino Effect to Chemical Process Equipment caused by Overpressure

    International Nuclear Information System (INIS)

    Sun, Dongliang; Huang, Guangtuan; Jiang, Juncheng; Zhang, Mingguang; Wang, Zhirong

    2013-01-01

    Overpressure is one important cause of domino effect in accidents of chemical process equipments. Some models considering propagation probability and threshold values of the domino effect caused by overpressure have been proposed in previous study. In order to prove the rationality and validity of the models reported in the reference, two boundary values of three damage degrees reported were considered as random variables respectively in the interval [0, 100%]. Based on the overpressure data for damage to the equipment and the damage state, and the calculation method reported in the references, the mean square errors of the four categories of damage probability models of overpressure were calculated with random boundary values, and then a relationship of mean square error vs. the two boundary value was obtained, the minimum of mean square error was obtained, compared with the result of the present work, mean square error decreases by about 3%. Therefore, the error was in the acceptable range of engineering applications, the models reported can be considered reasonable and valid.

  11. Study on the Rationality and Validity of Probit Models of Domino Effect to Chemical Process Equipment caused by Overpressure

    Science.gov (United States)

    Sun, Dongliang; Huang, Guangtuan; Jiang, Juncheng; Zhang, Mingguang; Wang, Zhirong

    2013-04-01

    Overpressure is one important cause of domino effect in accidents of chemical process equipments. Some models considering propagation probability and threshold values of the domino effect caused by overpressure have been proposed in previous study. In order to prove the rationality and validity of the models reported in the reference, two boundary values of three damage degrees reported were considered as random variables respectively in the interval [0, 100%]. Based on the overpressure data for damage to the equipment and the damage state, and the calculation method reported in the references, the mean square errors of the four categories of damage probability models of overpressure were calculated with random boundary values, and then a relationship of mean square error vs. the two boundary value was obtained, the minimum of mean square error was obtained, compared with the result of the present work, mean square error decreases by about 3%. Therefore, the error was in the acceptable range of engineering applications, the models reported can be considered reasonable and valid.

  12. Attenuation of blast pressure behind ballistic protective vests.

    Science.gov (United States)

    Wood, Garrett W; Panzer, Matthew B; Shridharani, Jay K; Matthews, Kyle A; Capehart, Bruce P; Myers, Barry S; Bass, Cameron R

    2013-02-01

    Clinical studies increasingly report brain injury and not pulmonary injury following blast exposures, despite the increased frequency of exposure to explosive devices. The goal of this study was to determine the effect of personal body armour use on the potential for primary blast injury and to determine the risk of brain and pulmonary injury following a blast and its impact on the clinical care of patients with a history of blast exposure. A shock tube was used to generate blast overpressures on soft ballistic protective vests (NIJ Level-2) and hard protective vests (NIJ Level-4) while overpressure was recorded behind the vest. Both types of vest were found to significantly decrease pulmonary injury risk following a blast for a wide range of conditions. At the highest tested blast overpressure, the soft vest decreased the behind armour overpressure by a factor of 14.2, and the hard vest decreased behind armour overpressure by a factor of 56.8. Addition of body armour increased the 50th percentile pulmonary death tolerance of both vests to higher levels than the 50th percentile for brain injury. These results suggest that ballistic protective body armour vests, especially hard body armour plates, provide substantial chest protection in primary blasts and explain the increased frequency of head injuries, without the presence of pulmonary injuries, in protected subjects reporting a history of blast exposure. These results suggest increased clinical suspicion for mild to severe brain injury is warranted in persons wearing body armour exposed to a blast with or without pulmonary injury.

  13. A Study on the Optimization Method of the Main Steam Safety Valve Characteristics for Overpressure Protection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Ryun; Kim, Ung Soo; Pakr, Min Soo; Lee, Gyu Cheon; Kim, Shin Whan [KEPCO EnC Company Inc., Daejeon (Korea, Republic of)

    2015-05-15

    The safety analysis on Loss of Condenser Vacuum (LOCV) event should be performed in accordance with Standard Review Plan (SRP) for pressurized water reactor. SRP is prepared for the guidance of staff reviewers in the office of nuclear reactor regulation in performing safety reviews of applications to operate nuclear power plants. The recent SRP requires that peak pressure in the primary and secondary system be evaluated separately since initial conditions are different for the primary and secondary systems. This paper presents an evaluation of the effect of the MSSVs characteristics with the analysis of LOCV event in order to have the sufficient safety margin of RCS and secondary system. This study has been conducted with the sensitivity analysis on the design parameters of MSSV which are the opening logic, set-point pressure and discharging capacity to the atmosphere. In this work, the effect of optimization method for the MSSV is evaluated from the viewpoints of opening logic change, discharge capacity increase and opening set-point decrease to mitigate the RCS and secondary system peak pressure resulting in additional safety margin. From the results, the optimization method is identified to be effective in reducing system peak pressure, especially for the secondary system. The opening logic which has increased number of MSSVs in the 1''st MSSV bank remarkably decreases the pressure of the secondary system. In the cases of 1/1/3, 2/1/2, the peak pressure of the main steam system is limited to the set-point of the 3''rd bank of MSSVs, and in the case of 3/1/1 it is limited to the set- point of the 2''nd bank of MSSVs. Consequently, the opening logic of the MSSVs is very important parameter to have the safety margin of the secondary system. The capacity and set-point of MSSVs do not involve increasing the peak pressure of RCS. It is recommended that the new design method of MSSVs as shown in this study be adopted to have the sufficient

  14. 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)

  15. Brain injuries from blast.

    Science.gov (United States)

    Bass, Cameron R; Panzer, Matthew B; Rafaels, Karen A; Wood, Garrett; Shridharani, Jay; Capehart, Bruce

    2012-01-01

    Traumatic brain injury (TBI) from blast produces a number of conundrums. This review focuses on five fundamental questions including: (1) What are the physical correlates for blast TBI in humans? (2) Why is there limited evidence of traditional pulmonary injury from blast in current military field epidemiology? (3) What are the primary blast brain injury mechanisms in humans? (4) If TBI can present with clinical symptoms similar to those of Post-Traumatic Stress Disorder (PTSD), how do we clinically differentiate blast TBI from PTSD and other psychiatric conditions? (5) How do we scale experimental animal models to human response? The preponderance of the evidence from a combination of clinical practice and experimental models suggests that blast TBI from direct blast exposure occurs on the modern battlefield. Progress has been made in establishing injury risk functions in terms of blast overpressure time histories, and there is strong experimental evidence in animal models that mild brain injuries occur at blast intensities that are similar to the pulmonary injury threshold. Enhanced thoracic protection from ballistic protective body armor likely plays a role in the occurrence of blast TBI by preventing lung injuries at blast intensities that could cause TBI. Principal areas of uncertainty include the need for a more comprehensive injury assessment for mild blast injuries in humans, an improved understanding of blast TBI pathophysiology of blast TBI in animal models and humans, the relationship between clinical manifestations of PTSD and mild TBI from blunt or blast trauma including possible synergistic effects, and scaling between animals models and human exposure to blasts in wartime and terrorist attacks. Experimental methodologies, including location of the animal model relative to the shock or blast source, should be carefully designed to provide a realistic blast experiment with conditions comparable to blasts on humans. If traditional blast scaling is

  16. A study of sonic boom overpressure trends with respect to weight, altitude, Mach number, and vehicle shaping

    Science.gov (United States)

    Needleman, Kathy E.; Mack, Robert J.

    1990-01-01

    This paper presents and discusses trends in nose shock overpressure generated by two conceptual Mach 2.0 configurations. One configuration was designed for high aerodynamic efficiency, while the other was designed to produce a low boom, shaped-overpressure signature. Aerodynamic lift, sonic boom minimization, and Mach-sliced/area-rule codes were used to analyze and compute the sonic boom characteristics of both configurations with respect to cruise Mach number, weight, and altitude. The influence of these parameters on the overpressure and the overpressure trends are discussed and conclusions are given.

  17. Experimental Study and Engineering Practice of Pressured Water Coupling Blasting

    Directory of Open Access Journals (Sweden)

    J. X. Yang

    2017-01-01

    Full Text Available Overburden strata movement in large space stope is the major reason that induces the appearance of strong mining pressure. Presplitting blasting for hard coal rocks is crucial for the prevention and control of strong pressure in stope. In this study, pressured water coupling blasting technique was proposed. The process and effect of blasting were analyzed by orthogonal test and field practice. Results showed that the presence of pressure-bearing water and explosive cartridges in the drill are the main influence factors of the blasting effect of cement test block. The high load-transmitting performance of pore water and energy accumulation in explosive cartridges were analyzed. Noxious substances produced during the blasting process were properly controlled because of the moistening, cooling, and diluting effect of pore water. Not only the goal of safe and static rock fragmentation by high-explosive detonation but also a combination of superdynamic blast loading and static loading effect of the pressured water was achieved. Then the practice of blasting control of hard coal rocks in Datong coal mine was analyzed to determine reasonable parameters of pressured water coupling blasting. A good presplitting blasting control effect was achieved for the hard coal rocks.

  18. Porcine head response to blast.

    Science.gov (United States)

    Shridharani, Jay K; Wood, Garrett W; Panzer, Matthew B; Capehart, Bruce P; Nyein, Michelle K; Radovitzky, Raul A; Bass, Cameron R 'dale'

    2012-01-01

    Recent studies have shown an increase in the frequency of traumatic brain injuries related to blast exposure. However, the mechanisms that cause blast neurotrauma are unknown. Blast neurotrauma research using computational models has been one method to elucidate that response of the brain in blast, and to identify possible mechanical correlates of injury. However, model validation against experimental data is required to ensure that the model output is representative of in vivo biomechanical response. This study exposes porcine subjects to primary blast overpressures generated using a compressed-gas shock tube. Shock tube blasts were directed to the unprotected head of each animal while the lungs and thorax were protected using ballistic protective vests similar to those employed in theater. The test conditions ranged from 110 to 740 kPa peak incident overpressure with scaled durations from 1.3 to 6.9 ms and correspond approximately with a 50% injury risk for brain bleeding and apnea in a ferret model scaled to porcine exposure. Instrumentation was placed on the porcine head to measure bulk acceleration, pressure at the surface of the head, and pressure inside the cranial cavity. Immediately after the blast, 5 of the 20 animals tested were apneic. Three subjects recovered without intervention within 30 s and the remaining two recovered within 8 min following respiratory assistance and administration of the respiratory stimulant doxapram. Gross examination of the brain revealed no indication of bleeding. Intracranial pressures ranged from 80 to 390 kPa as a result of the blast and were notably lower than the shock tube reflected pressures of 300-2830 kPa, indicating pressure attenuation by the skull up to a factor of 8.4. Peak head accelerations were measured from 385 to 3845 G's and were well correlated with peak incident overpressure (R(2) = 0.90). One SD corridors for the surface pressure, intracranial pressure (ICP), and head acceleration are

  19. Effect of surface conditions on blast wave propagation

    International Nuclear Information System (INIS)

    Song, Seung Ho; Li, Yi Bao; Lee, Chang Hoon; Choi, Jung Il

    2016-01-01

    We performed numerical simulations of blast wave propagations on surfaces by solving axisymmetric two-dimensional Euler equations. Assuming the initial stage of fireball at the breakaway point after an explosion, we investigated the effect of surface conditions considering surface convex or concave elements and thermal conditions on blast wave propagations near the ground surface. Parametric studies were performed by varying the geometrical factors of the surface element as well as thermal layer characteristics. We found that the peak overpressure near the ground zero was increased due to the surface elements, while modulations of the blast wave propagations were limited within a region for the surface elements. Because of the thermal layer, the precursor was formed in the propagations, which led to the attenuation of the peak overpressure on the ground surface

  20. 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

  1. Effect of Surface Blasting on Subway Tunnels- A Parametric Study

    Directory of Open Access Journals (Sweden)

    Hossein Entezari Zarch

    2017-01-01

    Full Text Available During wars and crises, the underground tunnels are used as a safe space. Therefore, the stability and safety of them under a blast is of particular importance. In this paper, the Finite Difference Method has been used to study the influence of the change in geotechnical parameters and depth on surface blasting on subway tunnels. Results showed that increasing the internal friction angle, modulus of elasticity and cohesion of the soil reduced the effects of blast loads on the vertical displacement and bending moment in the center of tunnel crown. Furthermore, the results showed that increasing the depth of the tunnel reduced the effects of blast loading. Comparing all parameters collectively showed that the increase in the modulus of elasticity of the soil and depth of the tunnel is the most effective in reducing the influence of the blast loads on the vertical displacement and bending moment of the tunnel crown, respectively.

  2. Human Injury Criteria for Underwater Blasts.

    Directory of Open Access Journals (Sweden)

    Rachel M Lance

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

  3. Blasting in hot zone - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Nabiullah, B.M.P.; Pingua, J.; Dhar, B.B. [Central Mining Research Institute, Dhanbad (India)

    1997-12-31

    A significant quantity of coking coal reserves in the country are under fire particularly in Jharia coalfield. To control the fire and prevent loss of coal, an opencast mining method is adopted. The main problem with these opencast mines is drilling in hot strata and selection of suitable explosives and blasting in the fire zone. Trial blasts were conducted at two open cast mines. The problem was tackled by quenching the hot blast holes with water. Temperature of blast holes were recorded soon after drilling, after quenching with water and just before charging with explosives. The rise in temperature of charged explosives with time was also recorded until blasting. The thermal behaviour of commercially available explosives (including slurry, emulsion, ANFO and detonating cord) was investigated in laboratory and field simulated conditions. Emulsion, slurry compositions and detonating cord were found safe to use in hot holes up to 120{degree}C for duration of two hours. This paper describes the blasting practices adopted in the fire zones. 4 refs., 6 figs., 8 tabs.

  4. 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

  5. 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

    actual determination of a risk threshold and (2) the article has laid the groundwork for such a determination. These statements misrepresent what...applied as a limit. This is a small point, but one that pervades the article and leads the authors to miss their main finding— namely, that an LAEQ8 of...WESTERN MICHIGAN UNIVERSITY G A FLAMME ASSOCIATE PROFESSOR DEPARTMENT OF SPEECH PATHOLOGY AND AUDIOLOGY 1903 W MICHIGAN AVE

  6. 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.

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

    Science.gov (United States)

    2017-09-01

    acute hemorrhage characterized by partial filling of small groups of alveoli by blood . 240 kPa: Mild multifocal pools of acute hemorrhage which...Neurotrauma, Blast TBI, Primary blast brain injury, Blast overpressure, Blood -brain barrier, Neuroinflammation, Oxidative stress, Neuroproteomics 16...stress, neuroinflammation and BBB damage as a result of blast overpressure in the acute phase (0, 4 and 24 hours post-exposure). Our group

  8. 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 %.

  9. 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

    Righting Reflex of rats following double blast exposure. 0 4 8 12 16 20 R ig ht in g Re fle x (m in ut es ) PLACEBO FISH OIL Total Lived Died...experiments. Funding Support: Geneva Foundation contractor – WRAIR Name: Joseph B. Long, Ph.D. Project Role: Co-Investigator – WRAIR Researcher...Funding Support: Clinical Research Management contractor Name: Andrew B. Batuure Project Role: Technician - WRAIR Researcher Identifier (e.g. ORCID

  10. EXPERIMENTAL STUDY ON THE STABILITY OF SURROUNDING ROCK IN TUNNEL BLASTING CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Hongxian Fu

    2018-04-01

    Full Text Available In this study, criteria and blasting technologies are introduced in order to control the stability of surrounding rock of tunnel built using drill-and-blast safety. The paper is composed of three parts, namely, a blast vibration propagation law in roof surrounding rock in close proximity to tunnel face, two formulae to calculate particle critical vibration velocity of shotcrete and key structural element at the roof of tunnel, and innovative technologies of tunnel blasting. The blast vibration propagation law is the base to control the stability of surrounding rock during tunnel blasting. Based on Morhr-Coulomb criterion and the dynamic analysis, two formulae to calculate the critical particle vibration velocity are proposed. Based on a series of trial blasts using electronic detonators, two innovative blasting technologies are derived. One is the blast holes detonated one by one by using electronic detonator, and another is the blast holes detonated by combining initiation system of electronic detonators and nonel detonators. The use of electronic detonators in tunnel blasting not only leads to a smaller blast vibration but also to a smaller extent of the EDZ (excavation damaged zone.

  11. Experimental study of hydraulic ram effects on a liquid storage tank: Analysis of overpressure and cavitation induced by a high-speed projectile.

    Science.gov (United States)

    Lecysyn, Nicolas; Bony-Dandrieux, Aurélia; Aprin, Laurent; Heymes, Frédéric; Slangen, Pierre; Dusserre, Gilles; Munier, Laurent; Le Gallic, Christian

    2010-06-15

    This work is part of a project for evaluating catastrophic tank failures caused by impacts with a high-speed solid body. Previous studies on shock overpressure and drag events have provided analytical predictions, but they are not sufficient to explain ejection of liquid from the tank. This study focuses on the hydrodynamic behavior of the liquid after collision to explain subsequent ejection of liquid. The study is characterized by use of high-velocity projectiles and analysis of projectile dynamics in terms of energy loss to tank contents. New tests were performed at two projectile velocities (963 and 1255 m s(-1)) and over a range of viscosities (from 1 to 23.66 mPa s) of the target liquid. Based on data obtained from a high-speed video recorder, a phenomenological description is proposed for the evolution of intense pressure waves and cavitation in the target liquids. Copyright 2010 Elsevier B.V. All rights reserved.

  12. 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.

  13. Study of blasting seismic effects of underground powerhouse of pumped storage project in granite condition

    Science.gov (United States)

    Wan, Sheng; Li, Hui

    2018-03-01

    Though the test of blasting vibration, the blasting seismic wave propagation laws in southern granite pumped storage power project are studied. Attenuation coefficient of seismic wave and factors coefficient are acquired by the method of least squares regression analysis according to Sadaovsky empirical formula, and the empirical formula of seismic wave is obtained. This paper mainly discusses on the test of blasting vibration and the procedure of calculation. Our practice might as well serve as a reference for similar projects to come.

  14. Calculating overpressure from BLEVE explosions

    Energy Technology Data Exchange (ETDEWEB)

    Planas-Cuchi, E.; Casal, J. [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Chemical Engineering, Centre for Technological Risk Studies; Salla, J.M. [Universitat Politecnica de Catalunya, Barcelona (Spain). Department of Heat Engines

    2004-11-01

    Although a certain number of authors have analyzed the prediction of boiling liquid expanding vapour explosion (BLEVE) and fireball effects, only very few of them have proposed methodologies for predicting the overpressure from such explosions. In this paper, the methods previously published are discussed and shown to introduce a significant overestimation due to erroneous thermodynamic assumptions - ideal gas behaviour and isentropic vapour expansion - on which they are based (in fact, they give the maximum value of overpressure which can be caused by a BLEVE). A new approach is proposed, based on the - more realistic - assumption of an adiabatic and irreversible expansion process; the real properties of the substance involved in the explosion are used. The two methods are compared through the application to a given case. (author)

  15. Anatomical manifestations of primary blast ocular trauma observed in a postmortem porcine model.

    Science.gov (United States)

    Sherwood, Daniel; Sponsel, William E; Lund, Brian J; Gray, Walt; Watson, Richard; Groth, Sylvia L; Thoe, Kimberly; Glickman, Randolph D; Reilly, Matthew A

    2014-02-24

    We qualitatively describe the anatomic features of primary blast ocular injury observed using a postmortem porcine eye model. Porcine eyes were exposed to various levels of blast energy to determine the optimal conditions for future testing. We studied 53 enucleated porcine eyes: 13 controls and 40 exposed to a range of primary blast energy levels. Eyes were preassessed with B-scan and ultrasound biomicroscopy (UBM) ultrasonography, photographed, mounted in gelatin within acrylic orbits, and monitored with high-speed videography during blast-tube impulse exposure. Postimpact photography, ultrasonography, and histopathology were performed, and ocular damage was assessed. Evidence for primary blast injury was obtained. While some of the same damage was observed in the control eyes, the incidence and severity of this damage in exposed eyes increased with impulse and peak pressure, suggesting that primary blast exacerbated these injuries. Common findings included angle recession, internal scleral delamination, cyclodialysis, peripheral chorioretinal detachments, and radial peripapillary retinal detachments. No full-thickness openings of the eyewall were observed in any of the eyes tested. Scleral damage demonstrated the strongest associative tendency for increasing likelihood of injury with increased overpressure. These data provide evidence that primary blast alone (in the absence of particle impact) can produce clinically relevant ocular damage in a postmortem model. The blast parameters derived from this study are being used currently in an in vivo model. We also propose a new Cumulative Injury Score indicating the clinical relevance of observed injuries.

  16. A study on impulsive sound attenuation for a high-pressure blast flow field

    International Nuclear Information System (INIS)

    Kang, Kuk Jeong; Ko, Sung Ho; Lee, Dong Soo

    2008-01-01

    The present work addresses a numerical study on impulsive sound attenuation for a complex high-pressure blast flow field; these characteristics are generated by a supersonic propellant gas flow through a shock tube into an ambient environment. A numerical solver for analyzing the high pressure blast flow field is developed in this study. From numerical simulations, wave dynamic processes (which include a first precursor shock wave, a second main propellant shock wave, and interactions in the muzzle blasts) are simulated and discussed. The pressure variation of the blast flow field is analyzed to evaluate the effect of a silencer. A live firing test is also performed to evaluate four different silencers. The results of this study will be helpful in understanding blast wave and in designing silencers

  17. A study on impulsive sound attenuation for a high-pressure blast flow field

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kuk Jeong [Agency for Defence Development, Daejeon (Korea, Republic of); Ko, Sung Ho; Lee, Dong Soo [Chungnam National University, Daejeon (Korea, Republic of)

    2008-01-15

    The present work addresses a numerical study on impulsive sound attenuation for a complex high-pressure blast flow field; these characteristics are generated by a supersonic propellant gas flow through a shock tube into an ambient environment. A numerical solver for analyzing the high pressure blast flow field is developed in this study. From numerical simulations, wave dynamic processes (which include a first precursor shock wave, a second main propellant shock wave, and interactions in the muzzle blasts) are simulated and discussed. The pressure variation of the blast flow field is analyzed to evaluate the effect of a silencer. A live firing test is also performed to evaluate four different silencers. The results of this study will be helpful in understanding blast wave and in designing silencers

  18. 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.

  19. Numerical Study on Blast Wave Propagation Driven by Unsteady Ionization Plasma

    International Nuclear Information System (INIS)

    Ogino, Yousuke; Sawada, Keisuke; Ohnishi, Naofumi

    2008-01-01

    Understanding the dynamics of laser-produced plasma is essential for increasing the available thrust and energy conversion efficiency from a pulsed laser to a blast wave in a gas-driven laser-propulsion system. The performance of a gas-driven laser-propulsion system depends heavily on the laser-driven blast wave dynamics as well as on the ionizing and/or recombining plasma state that sustains the blast wave. In this study, we therefore develop a numerical simulation code for a laser-driven blast wave coupled with time-dependent rate equations to explore the formation of unsteady ionizing plasma produced by laser irradiation. We will also examine the various properties of blast waves and unsteady ionizing plasma for different laser input energies

  20. Effect of overpressure on gas hydrate distribution

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, G.; Chapman, W.G.; Hirasaki, G.J. [Rice Univ., Houston, TX (United States). Dept. of Chemical and Biomolecular Engineering; Dickens, G.R.; Dugan, B. [Rice Univ., Houston, TX (United States). Dept. of Earth Sciences

    2008-07-01

    Natural gas hydrate systems can be characterized by high sedimentation rates and/or low permeability sediments, which can lead to pore pressure higher than hydrostatic. This paper discussed a study that examined this effect of overpressure on gas hydrate and free gas distribution in marine sediments. A one-dimensional numerical model that coupled sedimentation, fluid flow, and gas hydrate formation was utilized. In order to quantify the relative importance of sedimentation rates and low permeability sediments, a dimensionless sedimentation-compaction group (scN) was defined, that compared the absolute permeability of the sediments to the sedimentation rate. Higher values of scN mean higher permeability or low sedimentation rate which generally yield hydrostatic pore pressure while lower values of scN normally create pore pressure greater than hydrostatic. The paper discussed non-hydrostatic consolidation in gas hydrate systems, including mass balances; constitutive relationships; normalized variables; and dimensionless groups. A numerical solution to the problem was presented. It was concluded that simulation results demonstrated that decreasing scN not only increased pore pressure above hydrostatic values, but also lowered the lithostatic stress gradient and gas hydrate saturation. This occurred because overpressure resulted in lower effective stress, causing higher porosity and lower bulk density of the sediment. 16 refs., 5 figs., 1 appendix.

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

    Science.gov (United States)

    2017-11-01

    Many TBIs are associated with blast from improvised explosive devices.2–4 Explosions are physical, chemical , or nuclear reactions involving a rapid...ARL-TR-8210 ● NOV 2017 US Army Research Laboratory Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave...Research Laboratory Bioeffects on an In Vitro Model by Small-Scale Explosives and Shock Wave Overpressure Impacts by Nicole E Zander, Thuvan

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

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Keywords: Blast impact, Environment, Prediction, Regulatory threshold. 1 Introduction ... Noise is an environmental nuisance. .... explosion energy released into the ground generates vibration waves within the rock. Several.

  3. 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.

  4. 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

  5. Brain Vulnerability to Repeated Blast Overpressure and Polytrauma

    Science.gov (United States)

    2010-05-28

    devoid of any obvious cell loss or injury when assessed using either Nissl or Fluoro Jade stains , they consistently showed widespread fiber degeneration...injured brain after thionine (l) or silver (r) staining . experimental parameters (e.g. driver volume, tube position, Mylar membrane thickness, and type...5. Thionine- (top) and silver- (bottom) stained brain sections following exposure to 126 kPa airblast at the mouth of the tube. From Long et al

  6. Effect of Stemming to Burden Ratio and Powder Factor on Blast Induced Rock Fragmentation- A Case Study

    Science.gov (United States)

    Prasad, Sandeep; Choudhary, B. S.; Mishra, A. K.

    2017-08-01

    Rock fragmentation size is very important parameters for economical point of view in any surface mining. Rock fragment size direct effects on the costs of drilling, blasting, loading, secondary blasting and crushing. The main purpose of this study is to investigate effect of blast design parameters such as burden, blast hole length, stemming length, and powder factor on rock fragmentation. The fragment sizes (MFS, K50, m), and maximum fragment size (K95, m) of rock were determined by using the computer software. For every blast, after blasting operation, the images of whole muck pile are captured and there images were used for fragmentation analysis by using the Fragalyst software. It was observed that the optimal fragment size (MFS, K50, m and maximum fragment size, K95, m) of rock depends strongly on the blast design parameters and explosive parameters.

  7. Apparatus for reducing shock and overpressure

    Science.gov (United States)

    Walter, C.E.

    1975-01-28

    An apparatus for reducing shock and overpressure is particularly useful in connection with the sequential detonation of a series of nuclear explosives under ground. A coupling and decoupling arrangement between adjacent nuclear explosives in the tubing string utilized to emplace the explosives is able to support lower elements on the string but yields in a manner which absorbs energy when subjected to the shock wave produced upon detonation of one of the explosives. Overpressure is accomodated by an arrangement in the string which provides an additional space into which the pressurized material can expand at a predetermined overpressure. (10 claims)

  8. Experimental Study on the Measurement of Water Bottom Vibration Induced by Underwater Drilling Blasting

    OpenAIRE

    Wenbin, Gu; Jianghai, Chen; Zhenxiong, Wang; Zhihua, Wang; Jianqing, Liu; Ming, Lu

    2015-01-01

    Due to the lack of proper instrumentations and the difficulties in underwater measurements, the studies about water bottom vibration induced by underwater drilling blasting are seldom reported. In order to investigate the propagation and attenuation laws of blasting induced water bottom vibration, a water bottom vibration monitor was developed with consideration of the difficulties in underwater measurements. By means of this equipment, the actual water bottom vibration induced by underwater ...

  9. Novel method to dynamically load cells in 3D-hydrogels culture for blast injury studies

    Science.gov (United States)

    Sory, David R.; Areias, Anabela C.; Overby, Darryl R.; Proud, William G.

    2017-01-01

    For at least a century explosive devices have been one of the most important causes of injuries in military conflicts as well as in terrorist attacks. Although significant experimental and modelling efforts have been focussed on blast injuries at the organ or tissue level, few studies have investigated the mechanisms of blast injuries at the cellular level. This paper introduces an in vitro method compatible with living cells to examine the effects of high stress and short-duration pulses relevant to blast loadings and blunt trauma. The experimental phase involves high strain-rate axial compression of cylindrical specimens within an hermetically sealed chamber made of biocompatible polymer. Numerical simulations were performed in order to verify the experimental loading conditions and to characterize the loading path within the sample. A proof of concept is presented so as to establish a new window to address fundamental questions regarding blast injury at the cellular level.

  10. A Health Hazard Assessment for Blast Overpressure Exposures Subtitle - Biological Response to Blast Overpressure: A Summary of Modeling

    National Research Council Canada - National Science Library

    Stuhmiller, James

    1996-01-01

    .... For the past 15 years, JAYCOR, working together with the Walter Reed Army Institute of Research, has been using modeling, simulation, and data analysis to determine the nature of injury in animal...

  11. Experimental Study of Bilinear Initiating System Based on Hard Rock Pile Blasting

    Directory of Open Access Journals (Sweden)

    Yusong Miao

    2017-01-01

    Full Text Available It is difficult to use industrial explosives to excavate hard rock and achieve suitable blasting effect due to the low energy utilization rate resulting in large rocks and short blasting footage. Thus, improving the utilization ratio of the explosive energy is important. In this study, a novel bilinear initiation system based on hard rock blasting was proposed to improve the blasting effects. Furthermore, on the basis of the detonation wave collision theory, frontal collision, oblique reflection, and Mach reflection during detonation wave propagation were studied. The results show that the maximum detonation pressure at the Mach reflection point where the incident angle is 46.9° is three times larger than the value of the explosive complete detonation. Then, in order to analyze the crack propagation in different initiation forms, a rock fracture test slot was designed, and the results show that bilinear initiating system can change the energy distribution of explosives. Finally, field experiment was implemented at the hard rock pile blasting engineering, and experimental results show that the present system possesses high explosive energy utilization ratio and low rock fragments size. The results of this study can be used to improve the efficiency in hard rock blasting.

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

    Energy Technology Data Exchange (ETDEWEB)

    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 {mu}m 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{sup 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

  13. Overpressurization performance of containment structures

    International Nuclear Information System (INIS)

    Barr, P.; Bleackley, M.; Harrop, L.P.; Hargreaves, J.; Jowett, J.; Phillips, D.W.

    1987-01-01

    The containment building of a PWR is the outermost engineered barrier between the reactor and the environment. The most important element of such a containment system is the pressure boundary structure and its associated seals and penetrations. This containment structure is designed deterministically to withstand a number of loads and load combinations of which the dominant one is generally the internal pressure due to the double-ended guillotine break in one of the primary circuit loops. Typically, the design basis large LOCA produces a peak pressure increase in the region of 0.3 MPa in some 10 seconds and with a duration of up to a few tens of seconds. The assessment of overpressure performance of the containment structure is a key component of the PWR safety case, and is usually carried out by estimating a static factor of safety to some failure limit state. These estimates can be made using simple force-balance calculations or complicated finite element calculations, and both approaches have merit. In this paper we examine these approaches and discuss their value in estimating failure pressures and failure modes for a variety of internal pressurization transients. This discussion covers both general design and risk considerations and is illustrated by numerical examples taken from previous and on-going analysis

  14. 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

  15. Study of Perturbations on High Mach Number Blast Waves in Various Gasses

    Science.gov (United States)

    Edens, A.; Adams, R.; Rambo, P.; Shores, J.; Smith, I.; Atherton, B.; Ditmire, T.

    2006-10-01

    We have performed a series of experiments examining the properties of high Mach number blast waves. Experiments were conducted on the Z-Beamlet^1 laser at Sandia National Laboratories. We created blast waves in the laboratory by using 10 J- 1000 J laser pulses to illuminate millimeter scale solid targets immersed in gas. Our experiments studied the validity of theories forwarded by Vishniac and Ryu^2-4 to explain the dynamics of perturbations on astrophysical blast waves. These experiments consisted of an examination of the evolution of perturbations of known primary mode number induced on the surface of blast waves by means of regularly spaced wire arrays. The temporal evolution of the amplitude of the induced perturbations relative to the mean radius of the blast wave was fit to a power law in time. Measurements were taken for a number of different mode numbers and background gasses and the results show qualitative agreement with previously published theories for the hydrodynamics of thin shell blast wave. The results for perturbations on nitrogen gas have been recently published^5. .^1 P. K. Rambo, I. C. Smith, J. L. Porter, et al., Applied Optics 44, 2421 (2005). ^2 D. Ryu and E. T. Vishniac, Astrophysical Journal 313, 820 (1987). ^3 D. Ryu and E. T. Vishniac, Astrophysical Journal 368, 411 (1991). ^4 E. T. Vishniac, Astrophysical Journal 274, 152 (1983). ^5 A. D. Edens, T. Ditmire, J. F. Hansen, et al., Physical Review Letters 95 (2005).

  16. Experimental studies on intake headloss of a blasted lake tap

    International Nuclear Information System (INIS)

    Yang, James; Billstein, Mats; Engström, Fredrik; Strand, Rikard

    2014-01-01

    In existing reservoirs, construction of an intake is sometimes achieved by so-called lake tapping, a submerged tunnel piercing by blasting out the rock plug at the intake. The blasting process involves phases of rock, water, air and gas released from the explosive charge; the resulting entrance profile often differs from design assumptions. The intake headloss is a factor of concern for power generation. For a vertical intake formed by lake tapping, experiments have been carried out in a 1:30 physical model to examine the effect of entrance shapes on intake headlosses. The purpose is that, if there is potential to reduce the headlosses, the originally blasted intake shape would be modified. In the model, five alternative shapes are evaluated. The test results show that to enlarge the vertical shaft area is the most effective way to reduce the intake headloss; to further blast out a narrow channel upstream does not give much effect. Bearing in mind the risk of free-surface vortex at the intake, the influence of the intake modifications on vortex is also checked

  17. 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.

  18. Development of GP and GEP models to estimate an environmental issue induced by blasting operation.

    Science.gov (United States)

    Faradonbeh, Roohollah Shirani; Hasanipanah, Mahdi; Amnieh, Hassan Bakhshandeh; Armaghani, Danial Jahed; Monjezi, Masoud

    2018-05-21

    Air overpressure (AOp) is one of the most adverse effects induced by blasting in the surface mines and civil projects. So, proper evaluation and estimation of the AOp is important for minimizing the environmental problems resulting from blasting. The main aim of this study is to estimate AOp produced by blasting operation in Miduk copper mine, Iran, developing two artificial intelligence models, i.e., genetic programming (GP) and gene expression programming (GEP). Then, the accuracy of the GP and GEP models has been compared to multiple linear regression (MLR) and three empirical models. For this purpose, 92 blasting events were investigated, and subsequently, the AOp values were carefully measured. Moreover, in each operation, the values of maximum charge per delay and distance from blast points, as two effective parameters on the AOp, were measured. After predicting by the predictive models, their performance prediction was checked in terms of variance account for (VAF), coefficient of determination (CoD), and root mean square error (RMSE). Finally, it was found that the GEP with VAF of 94.12%, CoD of 0.941, and RMSE of 0.06 is a more precise model than other predictive models for the AOp prediction in the Miduk copper mine, and it can be introduced as a new powerful tool for estimating the AOp resulting from blasting.

  19. Study of consumer fireworks post-blast residues by ATR-FTIR.

    Science.gov (United States)

    Martín-Alberca, Carlos; Zapata, Félix; Carrascosa, Héctor; Ortega-Ojeda, Fernando E; García-Ruiz, Carmen

    2016-03-01

    Specific analytical procedures are requested for the forensic analysis of pre- and post-blast consumer firework samples, which present significant challenges. Up to date, vibrational spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) have not been tested for the analysis of post-blast residues in spite of their interesting strengths for the forensic field. Therefore, this work proposes a simple and fast procedure for the sampling and analysis of consumer firework post-blast residues by a portable FTIR instrument with an Attenuated Total Reflection (ATR) accessory. In addition, the post-blast residues spectra of several consumer fireworks were studied in order to achieve the identification of their original chemical compositions. Hence, this work analysed 22 standard reagents usually employed to make consumer fireworks, or because they are related to their combustion products. Then, 5 different consumer fireworks were exploded, and their residues were sampled with dry cotton swabs and directly analysed by ATR-FTIR. In addition, their pre-blast fuses and charges were also analysed in order to stablish a proper comparison. As a result, the identification of the original chemical compositions of the post-blast samples was obtained. Some of the compounds found were potassium chlorate, barium nitrate, potassium nitrate, potassium perchlorate or charcoal. An additional study involving chemometric tools found that the results might greatly depend on the swab head type used for the sampling, and its sampling efficiency. The proposed procedure could be used as a complementary technique for the analysis of consumer fireworks post-blast residues. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Studies on induced resistance to blast in rice

    International Nuclear Information System (INIS)

    Zhang Mingxian

    1985-01-01

    Eleven rice varieties were treated with 60 Co gamma ray, laser and other mutagens. 154 mutants with different characters were developed. 154 mutants and their parents have been inoculated with blast (Piricularia oryzae) races. It was found that the mutants of disease-resistance could be produced. The disease-resistant mutants with various better cheracters were selected. The frequencies of mutation in disease-resistance are different with different parental varieties. After inoculation with 13 blast physiological races, the results showed that the spectrum of resistance of mutants, other characters were changed, when one character was changed. In order to get a veriety with higher yield and disease-resistance, it is important to take account of other economic charaters

  1. 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

  2. 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.

  3. 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.

  4. A Comparative Study of Ground and Underground Vibrations Induced by Bench Blasting

    Directory of Open Access Journals (Sweden)

    Xiuzhi Shi

    2016-01-01

    Full Text Available 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 mine and thus to seek vibration control methods to protect engineering objects at the site. Vibrations arising from measurement devices at surface and in an underground tunnel at the Zijinshan Open-Pit Mine were obtained. Comparative analysis of the peak particle velocities shows that, in the greatest majority of cases, surface values are higher than underground values for the same vibration distance. The transmission laws of surface and underground vibrations were established depending on the type of rock mass, the explosive charge, and the distance. Compared with the Chinese Safety Regulations for Blasting (GB6722-2014, the bench blasting induced vibrations would not currently cause damage to the underground tunnel. According to the maximum allowable peak particle velocities for different objects, the permitted maximum charges per delay are obtained to reduce damage to these objects at different distances.

  5. Experimental Study on the Measurement of Water Bottom Vibration Induced by Underwater Drilling Blasting

    Directory of Open Access Journals (Sweden)

    Gu Wenbin

    2015-01-01

    Full Text Available Due to the lack of proper instrumentations and the difficulties in underwater measurements, the studies about water bottom vibration induced by underwater drilling blasting are seldom reported. In order to investigate the propagation and attenuation laws of blasting induced water bottom vibration, a water bottom vibration monitor was developed with consideration of the difficulties in underwater measurements. By means of this equipment, the actual water bottom vibration induced by underwater drilling blasting was measured in a field experiment. It shows that the water bottom vibration monitor could collect vibration signals quite effectively in underwater environments. The followed signal analysis shows that the characteristics of water bottom vibration and land ground vibration induced by the same underwater drilling blasting are quite different due to the different geological environments. The amplitude and frequency band of water bottom vibration both exceed those of land ground vibration. Water bottom vibration is mainly in low-frequency band that induced by blasting impact directly acts on rock. Besides the low-frequency component, land vibration contains another higher frequency band component that induced by followed water hammer wave acts on bank slope.

  6. 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.

  7. Nineteen-Foot Diameter Explosively Driven Blast Simulator; TOPICAL

    International Nuclear Information System (INIS)

    VIGIL, MANUEL G.

    2001-01-01

    This report describes the 19-foot diameter blast tunnel at Sandia National Laboratories. The blast tunnel configuration consists of a 6 foot diameter by 200 foot long shock tube, a 6 foot diameter to 19 foot diameter conical expansion section that is 40 feet long, and a 19 foot diameter test section that is 65 feet long. Therefore, the total blast tunnel length is 305 feet. The development of this 19-foot diameter blast tunnel is presented. The small scale research test results using 4 inch by 8 inch diameter and 2 foot by 6 foot diameter shock tube facilities are included. Analytically predicted parameters are compared to experimentally measured blast tunnel parameters in this report. The blast tunnel parameters include distance, time, static, overpressure, stagnation pressure, dynamic pressure, reflected pressure, shock Mach number, flow Mach number, shock velocity, flow velocity, impulse, flow duration, etc. Shadowgraphs of the shock wave are included for the three different size blast tunnels

  8. 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.

  9. Rice Blast Control and Polyvarietal Planting in the Philippines: A Study in Genotype by Environment Biogeography

    Directory of Open Access Journals (Sweden)

    Daniel J. Falvo

    2001-06-01

    Full Text Available Current approaches to biogeography are based on organismic biology. Certain biogeographical phenomena, however, cannot be fully understood using organismic approaches to biogeography. I employed an approach based on molecular biology and biochemistry that I call genotype by environment biogeography in order to provide a more complete understanding of why the dispersal of rice blast disease is less efficient in fields planted with mixtures of rice varieties. In a case study of an upland ricefield in the Philippines, I found that planting varietal mixtures results in a form of effective blast control that I call intrafield gene deployment. I suggest that intrafield gene deployment be used to design more effective methods of blast control in intensive rice agriculture.

  10. 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

  11. Experimental Study on Environment Friendly Tap Hole Clay for Blast Furnace

    Science.gov (United States)

    Siva kumar, R.; Mohammed, Raffi; Srinivasa Rao, K.

    2018-03-01

    Blast furnace (BF) is the best possible route of iron production available. Blast furnace is a high pressure vessel where iron ore is melted and liquid iron is produced. The liquid iron is tapped through the hole in Blast Furnace called tap hole. The tapped liquid metal flowing through the tap hole is plugged using a clay called tap hole clay. Tap hole clay (THC) is a unshaped refractory used to plug the tap hole. The tap hole clay extruded through the tap hole using a gun. The tap hole clay is designed to expand and plug the tap hole. The tap hole filled with clay is drilled using drill bit and the hole made through the tap hole to tap the liquid metal accumulated inside the furnace. The number of plugging and drilling varies depending on the volume of the furnace. The tap hole clay need to have certain properties to avoid problems during plugging and drilling. In the present paper tap hole clay properties in industrial use was tested and studied. The problems were identified related to tap hole clay manufacturing. Experiments were conducted in lab scale to solve the identified problems. The present composition was modified with experimental results. The properties of the modified tap hole clay were found suitable and useful for blast furnace operation with lab scale experimental results.

  12. A Feasibility Study for Recycling Used Automotive Oil Filters In A Blast Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Ralph M. Smailer; Gregory L. Dressel; Jennifer Hsu Hill

    2002-01-21

    This feasibility study has indicated that of the approximately 120,000 tons of steel available to be recycled from used oil filters (UOF's), a maximum blast furnace charge of 2% of the burden may be anticipated for short term use of a few months. The oil contained in the most readily processed UOF's being properly hot drained and crushed is approximately 12% to 14% by weight. This oil will be pyrolized at a rate of 98% resulting in additional fuel gas of 68% and a condensable hydrocarbon fraction of 30%, with the remaining 2% resulting as carbon being added into the burden. Based upon the writer's collected information and assessment, there appears to be no operational problems relating to the recycling of UOF's to the blast furnace. One steel plant in the US has been routinely charging UOF's at about 100 tons to 200 tons per month for many years. Extensive analysis and calculations appear to indicate no toxic consideration as a result of the pyrolysis of the small contained oil ( in the 'prepared' UOFs) within the blast furnace. However, a hydrocarbon condensate in the ''gasoline'' fraction will condense in the blast furnace scrubber water and may require additional processing the water treatment system to remove benzene and toluene from the condensate. Used oil filters represent an additional source of high quality iron units that may be effectively added to the charge of a blast furnace for beneficial value to the operator and to the removal of this resource from landfills.

  13. Rising threat of terrorist bomb blasts in Karachi--a 5-year study.

    Science.gov (United States)

    Mirza, Farhat Hussain; Parhyar, Hamid Ali; Tirmizi, Syed Zubair Ahmed

    2013-08-01

    This study aims to determine the frequency of injuries and fatalities associated with terrorist bomb explosions in the city of Karachi from 1 January 2007 to 31 December 2011. Moreover, this study is aimed to determine age and sex vulnerability among the victims of blast explosion. A descriptive cross-sectional study was conducted. The study was carried out at mortuaries and medicolegal sections at Jinnah Postgraduate Medical Center, Civil Hospital and Abbasi-Shaheed Hospital Karachi, the three main hospitals, which cater to all these cases of Karachi. The study included all bomb blast victims examined and autopsied from January 2007 to December 2011 at Jinnah Postgraduate Medical Center, Civil Hospital and Abbassi Shaheed Hospital Karachi. Details of 1142 cases were collected for those medicolegal deaths and injured persons, identified to be the victims of bomb blasts from January 2007 to December 2011. Data were collected on a preformed proforma from the mortuaries and medicolegal sections of these three public sector hospitals. The variables investigated include age, gender, year-wise distribution of the injured and the dead along with the cause of death and body parts injured in survivors. Out of the total 11,109 autopsies during the study period, 249 (2.24%) were carried out on deaths due to bomb blasts. Similarly, 135,065 injury cases were reported during the study period out of which 893 (0.66%) cases were due to bomb blasts. An initial peak in the year 2007, followed by a decline in 2008 and since then a steady rise of bomb blast incidences with casualties and fatalities, has been observed. The highest numbers of injured victims were reported in the year 2010 and fatalities in 2007. Among 1142 cases, 95.18% were male and 4.82% female with a male to female ratio of 19.76:1. Persons of ages between 15 and 45 years were chiefly involved. Shock due to multiple injuries was the leading cause of death, followed by head injury with or without haemorrhage. The

  14. Blast from pressurized carbon dioxide released into a vented atmospheric chamber

    Science.gov (United States)

    Hansen, P. M.; Gaathaug, A. V.; Bjerketvedt, D.; Vaagsaether, K.

    2018-03-01

    This study describes the blast from pressurized carbon dioxide (CO2) released from a high-pressure reservoir into an openly vented atmospheric chamber. Small-scale experiments with pure vapor and liquid/vapor mixtures were conducted and compared with simulations. A motivation was to investigate the effects of vent size and liquid content on the peak overpressure and impulse response in the atmospheric chamber. The comparison of vapor-phase CO2 test results with simulations showed good agreement. This numerical code described single-phase gas dynamics inside a closed chamber, but did not model any phase transitions. Hence, the simulations described a vapor-only test into an unvented chamber. Nevertheless, the simulations reproduced the incident shock wave, the shock reflections, and the jet release inside the atmospheric chamber. The rapid phase transition did not contribute to the initial shock strength in the current test geometry. The evaporation rate was too low to contribute to the measured peak overpressure that was in the range of 15-20 kPa. The simulation results produced a calculated peak overpressure of 12 kPa. The liquid tests showed a significantly higher impulse compared to tests with pure vapor. Reducing the vent opening from 0.1 to 0.01 m2 resulted in a slightly higher impulse calculated at 100 ms. The influence of the vent area on the calculated impulse was significant in the vapor-phase tests, but not so clear in the liquid/vapor mixture tests.

  15. Nankai Stress History and Implications for an Overpressured Decollement

    Science.gov (United States)

    Moran, K.; O'Regan, M.

    2005-12-01

    The Nankai Trough, formed from the subduction of the Shikoku Basin beneath the island arc of southwestern Japan, is a relatively young accretionary complex converging at a rate of ~4 cm/yr [Shipboard Scientific Party, 2001a]. The region was studied during the Deep Sea Drilling Project and on three Ocean Drilling Program (ODP) Legs-131, 190 and 196. Three sites visited during these Legs form a single cross-margin transect (dubbed the Muroto Transect) that traverses the leading edge of the Nankai accretionary prism, from seaward of the deformation front at Site 1173, to close to the deformation front (Site 1174), and landward to the first frontal thrust (Site 808). The decollement, which forms the major boundary between the converging plates, occurs within the Lower Shikoku Basin stratigraphic unit. The ODP sites were drilled and cored to depths below the decollement (Sites 808 and 1174) and the proto-decollement (Site 1173). Here we present consolidation test results [Moran et al., 1993] that are consistent with porosity-depth functions from core and log measurements for the Lower Shikoku Basin sediments, assuming that the decollement is an overpressured seal. At 1173, where a true decollement has not yet formed, moderate fluid overpressures occur that can be fully attributed to high turbiditic sedimentation rates. Forward modeling of this site into the deformation front over a period of ~300 ky shows that the present 1173 porosity-depth function matches the porosity-depth function at 1174. These results suggest that the young decollement on the Muroto Transect at the deformation front and landward is highly overpressured and forms a seal to sediments below that can be classically modeled as a one-dimensional consolidation system.

  16. Rapid release of tissue enzymes into blood after blast exposure: potential use as biological dosimeters.

    Directory of Open Access Journals (Sweden)

    Peethambaran Arun

    Full Text Available Explosive blast results in multiple organ injury and polytrauma, the intensity of which varies with the nature of the exposure, orientation, environment and individual resilience. Blast overpressure alone may not precisely indicate the level of body or brain injury after blast exposure. Assessment of the extent of body injury after blast exposure is important, since polytrauma and systemic factors significantly contribute to blast-induced traumatic brain injury. We evaluated the activity of plasma enzymes including aspartate aminotransferase (AST, alanine aminotransferase (ALT, lactate dehydrogenase (LDH and creatine kinase (CK at different time points after blast exposure using a mouse model of single and repeated blast exposures to assess the severity of injury. Our data show that activities of all the enzymes in the plasma were significantly increased as early as 1 h after blast exposure. The elevated enzyme activity remained up to 6 h in an overpressure dose-dependent manner and returned close to normal levels at 24 h. Head-only blast exposure with body protection showed no increase in the enzyme activities suggesting that brain injury alone does not contribute to the systemic increase. In contrast to plasma increase, AST, ALT and LDH activity in the liver and CK in the skeletal muscle showed drastic decrease at 6 h after blast exposures. Histopathology showed mild necrosis at 6 h and severe necrosis at 24 h after blast exposures in liver and no changes in the skeletal muscle suggesting that the enzyme release from the tissue to plasma is probably triggered by transient cell membrane disruption from shockwave and not due to necrosis. Overpressure dependent transient release of tissue enzymes and elevation in the plasma after blast exposure suggest that elevated enzyme activities in the blood can be potentially used as a biological dosimeter to assess the severity of blast injury.

  17. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    International Nuclear Information System (INIS)

    Wu Jun; Xu Di; Fan Ting-Bo; Zhang Dong

    2014-01-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  18. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    Science.gov (United States)

    Wu, Jun; Fan, Ting-Bo; Xu, Di; Zhang, Dong

    2014-10-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles.

  19. A Numerical Study on the Screening of Blast-Induced Waves for Reducing Ground Vibration

    Science.gov (United States)

    Park, Dohyun; Jeon, Byungkyu; Jeon, Seokwon

    2009-06-01

    Blasting is often a necessary part of mining and construction operations, and is the most cost-effective way to break rock, but blasting generates both noise and ground vibration. In urban areas, noise and vibration have an environmental impact, and cause structural damage to nearby structures. Various wave-screening methods have been used for many years to reduce blast-induced ground vibration. However, these methods have not been quantitatively studied for their reduction effect of ground vibration. The present study focused on the quantitative assessment of the effectiveness in vibration reduction of line-drilling as a screening method using a numerical method. Two numerical methods were used to analyze the reduction effect toward ground vibration, namely, the “distinct element method” and the “non-linear hydrocode.” The distinct element method, by particle flow code in two dimensions (PFC 2D), was used for two-dimensional parametric analyses, and some cases of two-dimensional analyses were analyzed three-dimensionally using AUTODYN 3D, the program of the non-linear hydrocode. To analyze the screening effectiveness of line-drilling, parametric analyses were carried out under various conditions, with the spacing, diameter of drill holes, distance between the blasthole and line-drilling, and the number of rows of drill holes, including their arrangement, used as parameters. The screening effectiveness was assessed via a comparison of the vibration amplitude between cases both with and without screening. Also, the frequency distribution of ground motion of the two cases was investigated through fast Fourier transform (FFT), with the differences also examined. From our study, it was concluded that line-drilling as a screening method of blast-induced waves was considerably effective under certain design conditions. The design details for field application have also been proposed.

  20. Study on blast furnace cooling stave for various refractory linings based on numerical modeling

    International Nuclear Information System (INIS)

    Mohanty, T R; Sahoo, S K; Moharana, M K

    2016-01-01

    Cooling technology for refractory lining of blast furnace is very important for the metallurgical industry, because it can substantially increase output and operation life of furnaces. A three dimensional mathematical model for the temperature field of the blast furnace stave cooler with refractory lining has been developed and analyzed. The temperature and heat dissipated by stave cooler is examined by using the finite element method. The cast steel stave is studied and computational analysis is made to know the effect of the cooling water velocity, temperature, and the lining material on the maximum temperature of the stave hot surface. The refractory lining materials, which are used in this experiment, are high alumina bricks with different stave materials (copper, aluminum and cast iron). The obtained numerical calculations are compared with that obtained from experiments performed at Rourkela Steel Plant, Odisha taking a stave in belly zone having maximum heat load shows very good agreement. (paper)

  1. 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)

  2. Anchorage of TiO2-blasted, HA-coated, and machined implants: an experimental study with rabbits

    DEFF Research Database (Denmark)

    Gotfredsen, K; Wennerberg, A; Johansson, C

    1995-01-01

    The purpose of this study was to evaluate the histometrical and biomechanical anchorage of TiO2-blasted implants and TiO2-blasted implants coated with hydroxyapatite. The control implants were machined. Twenty-six rabbits had a total of 156 implants placed in the proximal part of the tibia. Each...... rabbit had a machined, a TiO2-blasted, and a TiO2-blasted, HA-coated implant placed in each tibia. After a healing period of 3 and 12 weeks, respectively, the implants placed in the right tibia were used for removal torque test, and the implants placed in the left tibia were used for histomorphometrical...

  3. A study in cost analysis of aggregate production as depending on drilling and blasting design

    Science.gov (United States)

    Bilim, Niyazi; Çelik, Arif; Kekeç, Bilgehan

    2017-10-01

    Since aggregate production has vital importance for many engineering projects-such as construction, highway and plant-mixed concrete production-this study was undertaken to determine how the costs for such production are affected by the design of drilling and blasting processes used. Aggregates are used in the production of concrete and asphalt, which are critical resources for the construction sector. The ongoing population increase and the growth of living standards around the world drive the increasing demand for these products. As demand grows, competition has naturally arisen among producers in the industry. Competition in the market has directly affected prices, which leads to the need for new measures and cost analysis on production costs. The cost calculation is one of the most important parameters in mining activities. Aggregate production operations include drilling, blasting, secondary crushing (if necessary), loading, hauling and crushing-screening, and each of these factors affects cost. In this study, drilling and blasting design parameters (such as hole diameter, hole depth, hole distance and burden) were investigated and evaluated for their effect on the total cost of quarrying these products, based on a particular quarry selected for this research. As the result of evaluation, the parameters actually driving costs have been identified, and their effects on the cost have been determined. In addition, some suggestions are presented regarding production design which may lead to avoiding increased production costs.

  4. 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.

  5. Fundamental study on carbon composite iron ore hot briquette used as blast furnace burden

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Man-sheng; Liu, Zheng-gen; Wang, Zhao-cai [Institute of Ferrous Metallurgy, Northeastern University, Shenyang (China); Yagi, Jun-ichiro [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University (Japan)

    2011-05-15

    Carbon composite iron ore hot briquette (CCB) is the product of fine iron ore and fine coal by hot briquetting process, which attracts more and more attention as a new type of ironmaking raw materials aiming to improve the operation efficiency and reduce the coke consumption of blast furnace. This paper is devoted to experimental study on metallurgical properties of CCB and numerical simulation of the BF operation with CCB charging. At first, the metallurgical properties of CCB, including cold crushing strength, RDI, RSI, reducibility, high temperature strength, and softening and dripping are experimentally tested and compared with the common burdens, which revealed that the CCB possesses the required metallurgical properties and is suitable to use as the blast furnace burden. Then, the effects of charging CCB on the dripping properties of comprehensive burdens are elucidated based on the experiments under simulated blast furnace conditions. The results showed that the maximum charging ratio of CCB in the iron burdens is 40%-50% for achieving appropriate dripping properties of the mixed burdens. Finally, a multi-fluid blast furnace model is used to simulate BF operation with CCB charging. According to model simulations, charging CCB will cause the temperature level to decreases in the furnace and the location of the cohesive zone shifts downward. On the other hand, the productivity tends to increase while coke rate and total reducing agent rate decrease, the heat efficiency improves remarkably and the operation performance of BF is effectively enhanced. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. AN EXPERIMENTAL STUDY ON BEHAVIOUR OF RECYCLED AGGREGATE CONCRETE WITH GROUND GRANULATED BLAST FURNACE SLAG FLYASH

    OpenAIRE

    B.Sasikala*, K.Shanthi, B.Jose RavindraRaj

    2017-01-01

    Concrete is the single largest manufactured material in the world . The use of recycled materials in construction is an issue of great importance. Utilization of Recycled Aggregates (RA), Ground Granulated Blast Furnace Slag (GGBFS) and fly ash in concrete addresses this issue. In this project, strength, durability of Recycled Aggregate Concrete (RAC) with GGBFS was studied. M-50 grade concrete with 0.30 w/c ratio and maximum size of 16mm course aggregate was used for this study. Totally 16 m...

  7. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T; Kilpinen, P; Hupa, M [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1997-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  8. Soot formation in a blast furnace - Prediction via a parametric study, using detailed kinetic modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nordstroem, T.; Kilpinen, P.; Hupa, M. [Aabo Akademi, Turku (Finland). Combustion Chemistry Group

    1996-12-31

    The objective of this work has been to investigate the soot formation in a blast furnace fired with heavy fuel oil, using detailed kinetic modelling. This work has been concentrated on parameter studies that could explain under which conditions soot is formed and how that formation could be avoided. The parameters investigated were temperature, pressure, stoichiometric ratio, pyrolysis gas composition and reactor model. The calculations were based on a reaction mechanism that consists of 100 species and 446 reactions including polyaromatic hydrocarbons (PAM) up to 7 aromatic rings SULA 2 Research Programme; 4 refs.

  9. Novel method to dynamically load cells in 3D-gel culture for primary blast injury studies

    Science.gov (United States)

    Sory, David; Cepa-Areias, Anabela; Overby, Darryl; Proud, William; Institute of Shock Physics, Department of Bioengineering; Royal British Legion CentreBlast I Collaboration

    2015-06-01

    For at least a century explosive devices have been reported as one of the most important causes of injuries on battlefield in military conflicts as well as in terrorist attacks. Although significant experimental and modelling efforts have been focussed on blast injury at the organ or tissue level, few studies have investigated the mechanism of blast injury at the cellular level. This paper introduces an in vitro method compatible with living cells to examine the effects of high stress and short-duration pulses similar to those observed in blast waves. The experimental phase involved high strain rate axial compression of biological cylindrical specimens within a hermetically sealed sample holder made of a biocompatible polymer. Numerical simulations were performed in order to characterize the loading path within the sample and assess the loading conditions. A proof of concept is presented so as to establish a new window to address fundamental questions regarding primary blast injury at the cellular level. The Institute of Shock Physics acknowledges the support of AWE, Aldermaston, UK and Imperial College London. The Centre for Blast Injury Studies acknowledges the support of the Royal British Legion and Imperial College London.

  10. Optimization Of Blasting Design Parameters On Open Pit Bench A Case Study Of Nchanga Open Pits

    Directory of Open Access Journals (Sweden)

    Victor Mwango Bowa

    2015-08-01

    Full Text Available Abstract In hard rock mining blasting is the most productive excavation technique applied to fragment insitu rock to the required size for efficient loading and crushing. In order to blast the insitu rock to the desired fragment size blast design parameter such as bench height hole diameter spacing burden hole length bottom charge specific charge and rock factor are considered. The research was carried out as a practical method on Nchanga Open Pits NOP ore Bench to optimize the blasting design parameters that can yield the required fragmentation size thereby reducing the shovel loading times and maximizing efficiency of the subsequent mining unit operations such as hauling and crushing. Fragmentation characteristics such as the mean fragment size were measured by means of a digital measuring tape and predicated using the Kuznetsov equation and rock factor value of ore bench was calculated using Lilly 1986 equations by means of rock characteristics. Traditional blasting design parameters were acquired for NOP and modified using Langerfors and Sharma P.A approaches. Several blast operations were conducted using both traditional and modified blasting design parameters on the same ore bench with the same geological conditions. Loading times of the shovel and fragment sizes were obtained after the blasts from ore bench where both the traditional and modified blasting design parameters were applied. Results show that mean fragment size and loading times were reduced from 51cm and 12minutes to 22cm and 3minutes where traditional and modified blasting design parameters were applied respectively.

  11. 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.

  12. Behaviour of concrete containment under over-pressure conditions

    International Nuclear Information System (INIS)

    Atchison, R.J.; Asmis, G.J.K.; Campbell, F.R.

    1979-01-01

    The Atomic Energy Control Board of Canada initiated June, 1975, a major study of the behaviour of concrete containment under over-pressure conditions. Although extensive theoretical and experimental work has been carried out for thick-walled Prestressed Concrete Reactor Vessels (PCRV's), there is a want of information on the non-linear response of thin-walled structures typical of the CANDU, 600 MW(e) cylindrical/spherical, post-tensioned containment shells. The purpose of this paper is to provide an overview of the total program, to present the reasons behind the research contract, and the specification and implementation of the work. The results of the theoretical and experimental work and their implications with respect to Canadian Concrete Containment practice are discussed. This study is unique, and, as far as is known, has no world-wide precedence. (orig.)

  13. 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.

  14. Groundwater Chemistry and Overpressure Evidences in Cerro Prieto Geothermal Field

    Directory of Open Access Journals (Sweden)

    Ivan Morales-Arredondo

    2017-01-01

    Full Text Available In order to understand the geological and hydrogeological processes influencing the hydrogeochemical behavior of the Cerro Prieto Geothermal Field (CP aquifer, Mexico, a characterization of the water samples collected from geothermal wells was carried out. Different hydrochemical diagrams were used to evaluate brine evolution of the aquifer. To determine pressure conditions at depth, a calculation was performed using hydrostatic and lithostatic properties from CP, considering geological characteristics of the study area, and theoretical information about some basin environments. Groundwater shows hydrogeochemical and geological evidences of the diagenetic evolution that indicate overpressure conditions. Some physical, chemical, textural, and mineralogical properties reported in the lithological column from CP are explained understanding the evolutionary process of the sedimentary material that composes the aquifer.

  15. Experimental investigation of blast mitigation and particle-blast interaction during the explosive dispersal of particles and liquids

    Science.gov (United States)

    Pontalier, Q.; Loiseau, J.; Goroshin, S.; Frost, D. L.

    2018-04-01

    The attenuation of a blast wave from a high-explosive charge surrounded by a layer of inert material is investigated experimentally in a spherical geometry for a wide range of materials. The blast wave pressure is inferred from extracting the blast wave velocity with high-speed video as well as direct measurements with pressure transducers. The mitigant consists of either a packed bed of particles, a particle bed saturated with water, or a homogeneous liquid. The reduction in peak blast wave overpressure is primarily dependent on the mitigant to explosive mass ratio, M/C, with the mitigant material properties playing a secondary role. Relative peak pressure mitigation reduces with distance and for low values of M/C (pressure levels in the mid-to-far field. Solid particles are more effective at mitigating the blast overpressure than liquids, particularly in the near field and at low values of M/C, suggesting that the energy dissipation during compaction, deformation, and fracture of the powders plays an important role. The difference in scaled arrival time of the blast and material fronts increases with M/C and scaled distance, with solid particles giving the largest separation between the blast wave and cloud of particles. Surrounding a high-explosive charge with a layer of particles reduces the positive-phase blast impulse, whereas a liquid layer has no influence on the impulse in the far field. Taking the total impulse due to the blast wave and material impact into account implies that the damage to a nearby structure may actually be augmented for a range of distances. These results should be taken into consideration in the design of explosive mitigant systems.

  16. ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

    International Nuclear Information System (INIS)

    Emsley, S.; Olsson, Olle; Stenberg, L.; Alheid, H.J.; Falls, S.

    1997-12-01

    The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations

  17. ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

    Energy Technology Data Exchange (ETDEWEB)

    Emsley, S [Golder Associates, Maidenhead (United Kingdom); Olsson, Olle; Stenberg, L [Swedish Nuclear Fuel and Waste Co., Figeholm (Sweden); Alheid, H J [Federal Inst. for Geosciences and Natural Resources, Hannover (Germany); Falls, S [Queens Univ., Kingston, ON (Canada)

    1997-12-01

    The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations 68 refs, 92 figs, 31 tabs

  18. Histomorphometric and removal torque analysis for TiO2-blasted titanium implants. An experimental study on dogs

    DEFF Research Database (Denmark)

    Gotfredsen, K; Nimb, L; Hjörting-Hansen, E

    1992-01-01

    The aim of the present study was to compare the anchorage of TiO2-blasted screw and cylindrical implants with conventionally used machine-produced screw and cylindrical implants inserted immediately in extraction sockets on dogs. 6 adult mongrel dogs had 3rd and 4th mandibular premolars extracted...... bilaterally and 24 commercial pure titanium implants were placed immediately in extraction sockets and covered with mucoperiosteum. Each dog had inserted 4 implants: 1 screw implant and 1 cylindrical implant blasted with titanium-dioxide-particles; 1 screw implant and 1 cylindrical implant with machine...

  19. 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

  20. 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.

    2018-05-01

    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

  1. Blast characteristics of firework mixture, 'Raiyaku'. Raiyaku no bakufuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Iida, M.; Nakayama, Y.; Matsunaga, T.; Tanaka, K.; Yoshida, M.; Kakudate, Y.; Usuba, S.; Fujiwara, S. (National Chemical Lab. for Industry, Tsukuba (Japan))

    1991-10-31

    Raiyaku, as a type of raw material for explosive, are very dangerous , has high explosive power but there are difficulties in dretermining blast characteristics in terms of TNT equivalence. This study was made using raiyaku, firework mixture of 70 wt % potassium perchlorate, 15 wt % aluminium powder and 15 wt % titanium Powder. Blast characteristics of the raiyaku were studied exploding 1 Kg of the mixture in the sky and 30 Kg and 50 Kg in the surface at range in scaled distance from 1 to 15 m/kg{sup (1/3)} using piezoelectric gauges and lead-Plate blastmeters. As blast characteristics, equivalence was determined on the basis of measured Peak overpressures. Scaled distances when ploted against TNT equivalence, it has been cleared that TNT equivalence was 52.2 % on average with standard error of 8.4 %. Further it was clear that with the increase of equivalent distance TNT equivalence has increased from about 40 % to 60 %. 10 refs., 4 figs., 3 tabs.

  2. 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

  3. Insulation vacuum and beam vacuum overpressure release

    CERN Document Server

    Parma, V

    2009-01-01

    There is evidence that the incident of 19th September caused a high pressure build-up inside the cryostat insulation vacuum which the existing overpressure devices could not contain. As a result, high longitudinal forces acting on the insulation vacuum barriers developed and broke the floor and the floor fixations of the SSS with vacuum barriers. The consequent large longitudinal displacements of the SSS damaged chains of adjacent dipole cryo-magnets. Estimates of the helium mass flow and the pressure build- up experienced in the incident are presented together with the pressure build-up for an even more hazardous event, the Maximum Credible Incident (MCI). The strategy of limiting the maximum pressure by the installation of addition pressure relieve devices is presented and discussed. Both beam vacuum lines were ruptured during the incident in sector 3-4 giving rise to both mechanical damage and pollution of the system. The sequence, causes and effects of this damage will be briefly reviewed. We will then an...

  4. Blast management

    OpenAIRE

    Shouraki, Mohammad Kargar; Naserkheil, Ali Asghar

    2011-01-01

    Blast Management (BM) is composed of the combination of human resources management (HRM) principles and concepts and various methods of quality management (QM) with a financial approach. BM is made up of three aspects: hard, soft and concept and BLAST means an explosive shift in organization's mindset and thought and rapid action against it. The first aspect, hard, includes a set of managerial toots and philosophies to improve the quality and productivity with a financial approach.

  5. Experimental and Theoretical Study on Influence of Different Charging Structures on Blasting Vibration Energy

    Directory of Open Access Journals (Sweden)

    Wenbin Gu

    2015-01-01

    Full Text Available As an important parameter in blasting design, charging structure directly influences blasting effect. Due to complex conditions of this blasting and excavating engineering in Jiangsu, China, the authors carried out comparative researches with coupling structure, air-decoupling structure, and water-decoupling structure. After collecting, comparing, and analyzing produced signals on blasting vibration, the authors summarized that when proportional distances are the same, water-decoupling structure can reduce instantaneous energy of blasting vibration more effectively with more average rock fragmentation and less harm of dust. From the perspective of impedance matching, the present paper analyzed influence of charging structure on blasting vibration energy, demonstrating that impedance matching relationship between explosive and rock changes because of different charging structures. Through deducing relationship equation that meets the impedance matching of explosive and rock under different charging structures, the research concludes that when blasting rocks with high impedance, explosive with high impedance can better transmits blasting energy. Besides, when employing decoupling charging, there exists a reasonable decoupling coefficient helping realize impedance matching of explosive and rock.

  6. Experimental investigation of blast mitigation and particle-blast interaction during the explosive dispersal of particles and liquids

    Science.gov (United States)

    Pontalier, Q.; Loiseau, J.; Goroshin, S.; Frost, D. L.

    2018-05-01

    The attenuation of a blast wave from a high-explosive charge surrounded by a layer of inert material is investigated experimentally in a spherical geometry for a wide range of materials. The blast wave pressure is inferred from extracting the blast wave velocity with high-speed video as well as direct measurements with pressure transducers. The mitigant consists of either a packed bed of particles, a particle bed saturated with water, or a homogeneous liquid. The reduction in peak blast wave overpressure is primarily dependent on the mitigant to explosive mass ratio, M/ C, with the mitigant material properties playing a secondary role. Relative peak pressure mitigation reduces with distance and for low values of M/ C (compaction, deformation, and fracture of the powders plays an important role. The difference in scaled arrival time of the blast and material fronts increases with M/ C and scaled distance, with solid particles giving the largest separation between the blast wave and cloud of particles. Surrounding a high-explosive charge with a layer of particles reduces the positive-phase blast impulse, whereas a liquid layer has no influence on the impulse in the far field. Taking the total impulse due to the blast wave and material impact into account implies that the damage to a nearby structure may actually be augmented for a range of distances. These results should be taken into consideration in the design of explosive mitigant systems.

  7. Traumatic brain injury produced by exposure to blasts, a critical problem in current wars: biomarkers, clinical studies, and animal models

    Science.gov (United States)

    Dixon, C. Edward

    2011-06-01

    Traumatic brain injury (TBI) resulting from exposure to blast energy released by Improvised Explosive Devices (IEDs) has been recognized as the "signature injury" of Operation Iraqi Freedom and Operation Enduring Freedom. Repeated exposure to mild blasts may produce subtle deficits that are difficult to detect and quantify. Several techniques have been used to detect subtle brain dysfunction including neuropsychological assessments, computerized function testing and neuroimaging. Another approach is based on measurement of biologic substances (e.g. proteins) that are released into the body after a TBI. Recent studies measuring biomarkers in CSF and serum from patients with severe TBI have demonstrated the diagnostic, prognostic, and monitoring potential. Advancement of the field will require 1) biochemical mining for new biomarker candidates, 2) clinical validation of utility, 3) technical advances for more sensitive, portable detectors, 4) novel statistical approach to evaluate multiple biomarkers, and 5) commercialization. Animal models have been developed to simulate elements of blast-relevant TBI including gas-driven shock tubes to generate pressure waves similar to those produced by explosives. These models can reproduce hallmark clinical neuropathological responses such as neuronal degeneration and inflammation, as well as behavioral impairments. An important application of these models is to screen novel therapies and conduct proteomic, genomic, and lipodomic studies to mine for new biomarker candidates specific to blast relevant TBI.

  8. Blast response of curved carbon/epoxy composite panels: Experimental study and finite-element analysis

    International Nuclear Information System (INIS)

    Phadnis, V A; Roy, A; Silberschmidt, V V; Kumar, P; Shukla, A

    2013-01-01

    Experimental and numerical studies were conducted to understand the effect of plate curvature on blast response of carbon/epoxy composite panels. A shock-tube system was utilized to impart controlled shock loading to quasi-isotropic composite panels with differing range of radii of curvatures. A 3D Digital Image Correlation (DIC) technique coupled with high-speed photography was used to obtain out-of-plane deflection and velocity, as well as in-plane strain on the back face of the panels. Macroscopic post-mortem analysis was performed to compare yielding and deformation in these panels. A dynamic computational simulation that integrates fluid-structure interaction was conducted to evaluate the panel response in general purpose finite-element software ABAQUS/Explicit. The obtained numerical results were compared to the experimental data and showed a good correlation

  9. 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.

  10. Studies to overcome the manufacturing problems in blast furnace tap hole clay of Integrated Steel Plants: Experimental approach

    Science.gov (United States)

    Siva kumar, R.; Mohammed, Raffi; Srinivasa Rao, K.

    2018-03-01

    Integrated Steel Plants commonly uses Blast Furnace route for iron production which accounts for over 60 % of the world iron output. Blast Furnace runs for ten to twenty years without repairing hearth walls and Tap Hole (TH). Tap hole is an outlet for hot metal produced in a Blast Furnace and run from the shell of the furnace into the interior allowing access to the molten material. Tapping is the term used for drilling a hole through the tap hole which allows the molten iron and slag to flow out. In Iron making process, removal of liquid iron from furnace and sending it for steel making is known as cast house practice. For tapping liquid iron and operating the tap hole requires a special type of clay. Tap hole clay (THC) used to stop the flow of liquid iron and slag from the blast furnace. Present work deals with the study on manufacturing of THC at Visakhapatnam Steel Plant and problems related to manufacturing. Experiments were conducted to solve the identified problems and results are furnished in detail. The findings can improve the manufacturing process and improve the productivity of tap hole clay.

  11. Analysis of selected Halden overpressure tests using the FALCON code

    Energy Technology Data Exchange (ETDEWEB)

    Khvostov, G., E-mail: grigori.khvostov@psi.ch [Paul Scherrer Institut, CH 5232 Villigen PSI (Switzerland); Wiesenack, W. [Institute for Energy Technology – OECD Halden Reactor Project, P.O. Box 173, N-1751 Halden (Norway)

    2016-12-15

    Highlights: • We analyse four Halden overpressure tests. • We determine a critical overpressure value for lift-off in a BWR fuel sample. • We show the role of bonding in over-pressurized rod behaviour. • We analytically quantify the degree of bonding via its impact on cladding elongation. • We hypothesize on an effect of circumferential cracks on thermal fuel response to overpressure. • We estimate a thermal effect of circumferential cracks based on interpretation of the data. - Abstract: Four Halden overpressure (lift-off) tests using samples with uranium dioxide fuel pre-irradiated in power reactors to a burnup of 60 MWd/kgU are analyzed. The FALCON code coupled to a mechanistic model, GRSW-A for fission gas release and gaseous-bubble swelling is used for the calculation. The advanced version of the FALCON code is shown to be applicable to best-estimate predictive analysis of overpressure tests using rods without, or weak pellet-cladding bonding, as well as scoping analysis of tests with fuels where stronger pellet-cladding bonding occurs. Significant effects of bonding and fuel cracking/relocation on the thermal and mechanical behaviour of highly over-pressurized rods are shown. The effect of bonding is particularly pronounced in the tests with the PWR samples. The present findings are basically consistent with an earlier analysis based on a direct interpretation of the experimental data. Additionally, in this paper, the specific effects are quantified based on the comparison of the data with the results of calculation. It is concluded that the identified effects are largely beyond the current traditional fuel-rod licensing analysis methods.

  12. Mucosal wave characteristics in three voice modes (fry, hiss & overpressure) produced by a female speaker: a preliminary study using stroboscopy, HSDI and analyzed by kymography, P-FFT & Nyquist plots

    Science.gov (United States)

    Izdebski, Krzysztof; Ward, Ronald R.; Yan, Yuling

    2012-02-01

    HSDI provides a whole new way to investigate visually intra-laryngeal behavior and posturing during phonation by providing detailed real-time information about laryngeal biomechanics that include observations about mucosal wave, wave motion directionality, glottic area wave form, asymmetry of vibrations within and across vocal folds and contact area of the glottis including posterior commissure closure. These observations are fundamental to our understanding and modeling of both normal and disordered phonation. In this preliminary report we focus on direct HSDI in vivo observations of not only the glottic region, but also on the entire supraglottic laryngeal posturing during fry, breathy/hiss and over-pressured phonation modes produced in a non-pathological settings. Analysis included spatio-temporal vibration patterns of vocal folds, multi-line kymograms, spectral PFFT analysis, and Nyquist spatio-temporal plots. The presented examples reveal that supraglottic contraction assists in prolonged closed phase of the vibratory cycle, and that prolonged closed phase is longest in fry and overpressure and shortest albeit complex in hiss. Hiss also allows for vocal fold vibration despite glottis separation. These findings need to be compared to pathologic phonation representing the three voice modes to derive at better differential diagnosis.

  13. Sub-lethal Ocular Trauma (SLOT): Establishing a Standardized Blast Threshold to Facilitate Diagnostic, Early Treatment, and Recovery Studies for Blast Injuries to the Eye and Optic Nerve

    Science.gov (United States)

    2013-09-01

    doors. Center: damage to the sensor mounts. Right: Damage to the blast curtain . Figure 6. US Army Institute of Surgical Research shock...for 5 min. The stained slides were placed on filter paper and air -dried for 5 min. Prior to starting the MALDI analysis, the sections were...internal scleral delaminations. Development of a rigorous experimental methodology and use of pre-blast ultrasound screening gave confidence that the

  14. Computational Fluid Dynamics Application to Gun Muzzle Blast - A Validation Case Study

    National Research Council Canada - National Science Library

    Cler, Daniel

    2003-01-01

    ...) simulations of these flow-fields a viable alternative. Techniques and specialized CFD codes are being developed in order to properly model the unsteady, very high-pressure flows of gun muzzle blast...

  15. Rock fragmentation control in opencast blasting

    Directory of Open Access Journals (Sweden)

    P.K. Singh

    2016-04-01

    Full Text Available The blasting operation plays a pivotal role in the overall economics of opencast mines. The blasting sub-system affects all the other associated sub-systems, i.e. loading, transport, crushing and milling operations. Fragmentation control through effective blast design and its effect on productivity are the challenging tasks for practicing blasting engineer due to inadequate knowledge of actual explosive energy released in the borehole, varying initiation practice in blast design and its effect on explosive energy release characteristic. This paper describes the result of a systematic study on the impact of blast design parameters on rock fragmentation at three mines in India. The mines use draglines and shovel–dumper combination for removal of overburden. Despite its pivotal role in controlling the overall economics of a mining operation, the expected blasting performance is often judged almost exclusively on the basis of poorly defined parameters such as powder factor and is often qualitative which results in very subjective assessment of blasting performance. Such an approach is very poor substitutes for accurate assessment of explosive and blasting performance. Ninety one blasts were conducted with varying blast designs and charging patterns, and their impacts on the rock fragmentation were documented. A high-speed camera was deployed to record the detonation sequences of the blasts. The efficiency of the loading machines was also correlated with the mean fragment size obtained from the fragmentation analyses.

  16. 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.)

  17. Over-pressure in road tankers; Ueberdrucksicherung an Tankfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Frobese, Dirk-Hans; Pape, Harald [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2011-08-15

    This work was aimed at determining possible causes of overpressure damages on road tankers. In cooperation with the manufacturers of road tankers, the equipment of road tankers usually used today was, therefore, discussed and possible error sources determined. In measurements performed at two filling stations, real pressure, temperature and volume flow ratios for the loading of a road tanker were recorded. Parallel to it, tests in a cold chamber were carried out to determine the possibility and the general conditions of an icing of the tilting valve and the flame arrester. With these results, scenarios have been worked out which can explain known overpressure damaging events. On the basis of a risk assessment, measures are described how such overpressure damages on road tankers can in future be avoided. (orig.)

  18. 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.

  19. 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.

  20. Probabalistic analysis of the protection of a PWR against overpressure

    International Nuclear Information System (INIS)

    Coudert, C.; Amesz, J.; Volta, G.

    1977-03-01

    The problem of assessing the probability distribution of accidental transients in a nuclear plant is dealt with. The presented method consists of a combined probabilistic-deterministic approach. This approach is probabilistic in the sense that for each combination of system states a probability figure is determined by means of a fault-free analysis. It is deterministic in the sense that the corresponding sequence (e.g. magnitude of over-pressure) for each combination of states is computed by deterministic codes. An example is given in which the overpressure distribution of a pressurized water reactor is estimated

  1. 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.

  2. The development of shock wave overpressure driven by channel expansion of high current impulse discharge arc

    Science.gov (United States)

    Xiong, Jia-ming; Li, Lee; Dai, Hong-yu; Wu, Hai-bo; Peng, Ming-yang; Lin, Fu-chang

    2018-03-01

    During the formation of a high current impulse discharge arc, objects near the discharge arc will be strongly impacted. In this paper, a high power, high current gas switch is used as the site of the impulse discharge arc. The explosion wave theory and the arc channel energy balance equation are introduced to analyze the development of the shock wave overpressure driven by the high current impulse discharge arc, and the demarcation point of the arc channel is given, from which the energy of the arc channel is no longer converted into shock waves. Through the analysis and calculation, it is found that the magnitude of the shock wave overpressure caused by impulse discharge arc expansion is closely related to the arc current rising rate. The arc shock wave overpressure will undergo a slow decay process and then decay rapidly. The study of this paper will perform the function of deepening the understanding of the physical nature of the impulse arc discharge, which can be used to explain the damage effect of the high current impulse discharge arc.

  3. Contribution of the study of thermal interaction: modelling of a thermal blast in a multi-phase medium

    International Nuclear Information System (INIS)

    Scott, Edouard

    1978-01-01

    This research thesis aims at being a contribution to the safety of nuclear facilities by reporting the study of the interaction between nuclear fuel and coolant in simplified conditions. It focuses on the thermal aspect of this interaction between a very hot body and an easily vaporized cold body, which could produce a blast. Thus, this author addresses the field of existence of a thermal blast, and reports the development of a hydrodynamic model which takes the heterogeneous nature of the interacting medium into account, in order to precisely describe the conditions of fuel fragmentation. This model includes the propagation of a shock in a mixture, and the calculation of a multi-phase flow in the reaction zone, and proposes criteria for a self-sustained shock wave propagation in the reactive medium. Results are compared with those obtained with the Bankoff model [fr

  4. Profiles of referrals to a psychiatric service: a descriptive study of survivors of the Nairobi US Embassy terrorist bomb blast.

    Science.gov (United States)

    Ndetei, D M; Omar, A; Mutiso, V N; Ongecha, F A; Kokonya, D A

    2009-11-01

    To document the socio-demographic characteristics and psychiatric profiles of the survivors of the Nairobi United States Embassy terrorist bomb blast referred to a psychiatric and psychotherapy (counselling) service. This was a descriptive cross-sectional study. Clinical interviews and structured questionnaires for post-traumatic stress disorder (PTSD) and stress were administered. Survivors of the bomb blast referred to a psychiatric and psychotherapy service one year or more after the bombing were included in the study. These survivors had been treated using psychopharmacotherapy and individualised (not group) therapy/counselling. Eighty-three consecutive referrals to a psychiatric service participated in this study. There were more males and the sample was generally well educated. The referrals made contact with the referring agency for a number of reasons including seeking psychological, financial and medical assistance. All the patients reported varying degrees of psychiatric symptoms and functional impairment on various aspects of social occupational functioning. High scores for PTSD and other related stress were recorded one or more years after the bombing. Although the survivors indicated that initial counselling following the blast had helped them, they still scored high on PTSD suggesting that clinically, the initial counselling had little, if any impact on the development of PTSD. There is need for a holistic approach to the management of psychotrauma in individuals.

  5. Study of the reduction mechanism of ironsands with addition of blast furnace bag dust

    Science.gov (United States)

    Xing, Xiangdong; Chen, Yunfei; Liu, Yiran

    2018-02-01

    To improve the reduction properties of ironsands carbon-containing briquettes, the behavior of ironsand during reduction by the addition of blast furnace bag dust (BFBD) is studied using a high temperature resistance furnace, X-ray diffraction (XRD) analysis and scanning electron microscopy. Additionally, the reduction mechanism is discussed in this study. The results showed that the reduction level and compressive strength of ironsand carbon-containing briquettes could be promoted by increasing the proportion of BFBD. When the addition rate of BFBD was 31.25%, the metallization rate and compressive strength increased from 82.1% and 21.5 N/a to 91.4% and 172.5 N/a, respectively. Metallic iron reduced from BFBD particles favored the carbon gasification reaction, which enhanced the internal CO concentration, and then promoted the FeTiO3 reduction to Fe in ironsand. Meanwhile, a large amount of the liquid phase generated during the reduction process also favored Fe2+ diffusion, spread of iron joined crystals and the growth of crystals, which resulted in the improvement of the compressive strength of the ironsand carbon-containing briquettes.

  6. CFD study of ejector flow behavior in a blast furnace gas galvanizing plant

    Science.gov (United States)

    Besagni, Giorgio; Mereu, Riccardo; Inzoli, Fabio

    2015-02-01

    In recent years, there has been a growing interest toward Blast Furnace Gas (BFG) as a low-grade energy source for industrial furnaces. This paper considers the revamping of a galvanic plant furnace converted to BFG from natural gas. In the design of the new system, the ejector on the exhaust line is a critical component. This paper studies the flow behavior of the ejector using a Computational Fluid Dynamics (CFD) analysis. The CFD model is based on a 3D representation of the ejector, using air and exhaust gases as working fluids. This paper is divided in three parts. In the first part, the galvanic plant used as case study is presented and discussed, in the second part the CFD approach is outlined, and in the third part the CFD approach is validated using experimental data and the numerical results are presented and discussed. Different Reynolds-Averaged Navier-Stokes (RANS) turbulence models ( k-ω SST and k-ɛ Realizable) are evaluated in terms of convergence capability and accuracy in predicting the pressure drop along the ejector. Suggestions for future optimization of the system are also provided.

  7. 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

  8. The BLAST experiment

    NARCIS (Netherlands)

    Hasell, D.; Botto, T.; van den Brand, J.F.J.

    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.

  9. 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

  10. Numerical study of laser-induced blast wave coupled with unsteady ionization processes

    International Nuclear Information System (INIS)

    Ogino, Y; Ohnishi, N; Sawada, K

    2008-01-01

    We present the results of the numerical simulation of laser-induced blast wave coupled with rate equations to clarify the unsteady property of ionization processes during pulse heating. From comparison with quasi-steady computations, the plasma region expands more widely, which is sustained by the inverse-bremsstrahlung since an ionization equilibrium does not establish at the front of the plasma region. The delayed relaxation leads to the rapid expansion of the driving plasma and enhances the energy conversion efficiency from a pulse heating laser to the blast wave

  11. The role of salt tectonics and overburden in the generation of overpressure in the Dutch North Sea area

    NARCIS (Netherlands)

    Nelskamp, S.; Verweij, J.M.; Witmans, N.

    2012-01-01

    In this paper we study the effects of timing of salt movement and mechanical compaction on the generation of overpressures in Mesozoic rocks. To that end we apply 2D basin modelling on two N-S trending cross sections in the Dutch Central Graben and Terschelling Basin, respectively. Several

  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. Plasma Discharge Initiation of Explosives in Rock Blasting Application: A Case Study

    International Nuclear Information System (INIS)

    Chae, Jae-Ou; Jeong, Young-Jun; Shmelev, V M; Denicaev, A A; Poutchkov, V M; Ravi, V

    2006-01-01

    A plasma discharge initiation system for the explosive volumetric combustion charge was designed, investigated and developed for practical application. Laboratory scale experiments were carried out before conducting the large scale field tests. The resultant explosions gave rise to less noise, insignificant seismic vibrations and good specific explosive consumption for rock blasting. Importantly, the technique was found to be safe and environmentally friendly

  14. Study on Collapse Mechanism of Steel Frame Structure under High Temperature and Blast Loading

    Science.gov (United States)

    Baoxin, Qi; Yan, Shi; Bi, Jialiang

    2018-03-01

    Numerical simulation analysis for collapsing process and mechanism of steel frame structures under the combined effects of fire and explosion is performed in this paper. First of all, a new steel constitutive model considering fire (high temperature softening effect) and blast (strain rate effect) is established. On the basis of the traditional Johnson-Cook model and the Perzyna model, the relationship between strain and scaled distance as well as the EOUROCODE3 standard heating curve taking into account the temperature effect parameters is introduced, and a modified Johnson-Cook constitutive model is established. Then, the influence of considering the scaled distance is introduced in order to more effectively describe the destruction and collapse phenomena of steel frame structures. Some conclusions are obtained based on the numerical analysis that the destruction will be serious and even progressively collapse with decreasing of the temperature of the steel column for the same scaled distance under the combined effects of fire and blast; the damage will be serious with decreasing of the scaled distance of the steel column under the same temperature under the combined effects of fire and blast; in the case of the combined effects of fire and blast happening in the side-spans, the partial progressive collapse occurs as the scaled distance is less than or equal to 1.28; six kinds of damages which are no damage, minor damage, moderate damage, severe damage, critical collapse, and progressive collapse.

  15. Studies to identify genes and their expression for resistance to blast ...

    African Journals Online (AJOL)

    aps

    2013-06-26

    Jun 26, 2013 ... Rice (Oryza sativa L.) is the staple food for more than half of the world population of Asia. Also, the genetic and functional syntenies observed among cereal crops over ..... action for the leaf rust of wheat. Sandhu et al. (2003) suggested a polygenic control for blast resistance. Naqvi and Chattoo (1996) also ...

  16. Methodology study for documentation and 3D modelling of blast induced fractures

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Mats (Swebrec - Swedish Blasting Research Centre, Luleaa (Sweden)); Markstroem, Ingemar; Pettersson, Anders (Golder Associates (Sweden))

    2008-05-15

    The purpose of this activity as part of the Zuse project was to test whether it is possible to produce a 3D model of blast induced fractures around a tunnel and also to find a methodology suitable for large scale studies. The purpose of the studies is to increase the understanding of the excavation damage zone (EDZ) and the possibility of an existing continuous EDZ along the tunnel. For the investigation, an old test area in the Q tunnel at the Aespoe Hard Rock Laboratory was selected, where slabs were excavated in 2003 to investigate the fracture pattern around the contour holes of a blasted tunnel. The rock walls of the excavated niche were studied and documented in the tunnel, while the excavated rock slabs were documented above ground. The work flow included photo documentation of both sides. The photos taken in the tunnel had to be rectified and then the fractures were vectorized automatically in a vectorization program, generating AutoCad DWG-files as output. The vectorized fractures were then moved to MicroStation/RVS where they were interpreted and connected into continuous line strings. The digitized slab and rock sides were then moved to the correct position in 3D space. Finally, a 3D model was made in RVS where the fracture traces were connected into undulating fracture planes in 3D. The conclusion is that it is possible to build a 3D model; the model is presented in Chapter 3.5. However, the age and condition of the slabs may have influenced the quality of the model in this study. The quality of a model that can be built in a future investigation, should be much better if the surveys are adapted to the investigation at hand and the slabs and rock sides are fresh and in better condition. The validity of a model depends on the density of the investigation data. There is also always a risk of over interpretation; the wish to identify a fracture from one section to the next can lead to an interpretation of the fractures as more persistent than they actually

  17. Methodology study for documentation and 3D modelling of blast induced fractures

    International Nuclear Information System (INIS)

    Olsson, Mats; Markstroem, Ingemar; Pettersson, Anders

    2008-05-01

    The purpose of this activity as part of the Zuse project was to test whether it is possible to produce a 3D model of blast induced fractures around a tunnel and also to find a methodology suitable for large scale studies. The purpose of the studies is to increase the understanding of the excavation damage zone (EDZ) and the possibility of an existing continuous EDZ along the tunnel. For the investigation, an old test area in the Q tunnel at the Aespoe Hard Rock Laboratory was selected, where slabs were excavated in 2003 to investigate the fracture pattern around the contour holes of a blasted tunnel. The rock walls of the excavated niche were studied and documented in the tunnel, while the excavated rock slabs were documented above ground. The work flow included photo documentation of both sides. The photos taken in the tunnel had to be rectified and then the fractures were vectorized automatically in a vectorization program, generating AutoCad DWG-files as output. The vectorized fractures were then moved to MicroStation/RVS where they were interpreted and connected into continuous line strings. The digitized slab and rock sides were then moved to the correct position in 3D space. Finally, a 3D model was made in RVS where the fracture traces were connected into undulating fracture planes in 3D. The conclusion is that it is possible to build a 3D model; the model is presented in Chapter 3.5. However, the age and condition of the slabs may have influenced the quality of the model in this study. The quality of a model that can be built in a future investigation, should be much better if the surveys are adapted to the investigation at hand and the slabs and rock sides are fresh and in better condition. The validity of a model depends on the density of the investigation data. There is also always a risk of over interpretation; the wish to identify a fracture from one section to the next can lead to an interpretation of the fractures as more persistent than they actually

  18. Investigation of the Propagation Characteristics of Underwater Shock Waves in Underwater Drilling Blasting

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2018-01-01

    Full Text Available During the first-stage project of the main channel of Ningbo-Zhoushan Port’s Shipu Harbor, underwater shock waves were monitored. By analyzing a typical measured pressure time history curve, the characteristics of underwater shock waves in an engineering context were obtained. We obtained a traditional exponential attenuation formula for underwater shock waves based on the measured data, simplified the model of underwater drilling blasting based on engineering practice, deduced a revised formula for underwater shock wave peak overpressure on the basis of dimensional analysis, established a linear fitting model, and obtained the undetermined coefficients of the revised formula using a linear regression analysis. In addition, the accuracies of the two formulas used to predict underwater shock wave peak overpressure and the significance order of influence and influence mechanism of factors included in the revised formula on the underwater shock wave peak overpressure were discussed.

  19. 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

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

    Science.gov (United States)

    2014-11-01

    previously used such procedures to evaluate the effects of drugs , toxins and ischemic injury (Genovese et al., 1988, 1992, 1993, 2006). Moreover, TBI, from...Lee JLC, Dickinson A, Everitt BJ (2005) Conditioned suppression and freezing as measures of aversive Pavlovian conditioning: effects of discreet...freezing and instrumental suppression in Pavlovian fear conditioning. Behav Brain Res 211:111–117. McDannald MA, Galarce EM (2011) Measuring Pavlovian

  1. Thermodynamically consistent model of brittle oil shales under overpressure

    Science.gov (United States)

    Izvekov, Oleg

    2016-04-01

    The concept of dual porosity is a common way for simulation of oil shale production. In the frame of this concept the porous fractured media is considered as superposition of two permeable continua with mass exchange. As a rule the concept doesn't take into account such as the well-known phenomenon as slip along natural fractures, overpressure in low permeability matrix and so on. Overpressure can lead to development of secondary fractures in low permeability matrix in the process of drilling and pressure reduction during production. In this work a new thermodynamically consistent model which generalizes the model of dual porosity is proposed. Particularities of the model are as follows. The set of natural fractures is considered as permeable continuum. Damage mechanics is applied to simulation of secondary fractures development in low permeability matrix. Slip along natural fractures is simulated in the frame of plasticity theory with Drucker-Prager criterion.

  2. The influence of para-seismic vibrations, induced by blasting works, on structures: a Case Study

    Science.gov (United States)

    Andrusikiewicz, Wacław

    2018-04-01

    Underground mining operations are often associated with the necessity to use explosives. Several hundreds of kilograms of explosives, subdivided into small charges suitable for a specific mining job, are used each time in a blasting operation. In many cases, mining engineers carry out remote central blasting works, which means that all the charges placed at faces are initiated from one control point (usually, a control room in the mine) at the same time. Such coordinated explosions generate para-seismic movements whose consequences can be felt on land surface, with subsequent effects identified in buildings and structures. This paper discusses briefly selected standards applicable to the harmful para-seismic impacts. The author presents the results of the research conducted with the intention to identify harmful effects of the basting works carried out in the "Kłodawa" Salt Mine.

  3. Neuronal DNA Methylation Profiling of Blast-Related Traumatic Brain Injury.

    Science.gov (United States)

    Haghighi, Fatemeh; Ge, Yongchao; Chen, Sean; Xin, Yurong; Umali, Michelle U; De Gasperi, Rita; Gama Sosa, Miguel A; Ahlers, Stephen T; Elder, Gregory A

    2015-08-15

    Long-term molecular changes in the brain resulting from blast exposure may be mediated by epigenetic changes, such as deoxyribonucleic acid (DNA) methylation, that regulate gene expression. Aberrant regulation of gene expression is associated with behavioral abnormalities, where DNA methylation bridges environmental signals to sustained changes in gene expression. We assessed DNA methylation changes in the brains of rats exposed to three 74.5 kPa blast overpressure events, conditions that have been associated with long-term anxiogenic manifestations weeks or months following the initial exposures. Rat frontal cortex eight months post-exposure was used for cell sorting of whole brain tissue into neurons and glia. We interrogated DNA methylation profiles in these cells using Expanded Reduced Representation Bisulfite Sequencing. We obtained data for millions of cytosines, showing distinct methylation profiles for neurons and glia and an increase in global methylation in neuronal versus glial cells (pDNA methylation perturbations in blast overpressure-exposed animals, compared with sham blast controls, within 458 and 379 genes in neurons and glia, respectively. Differentially methylated neuronal genes showed enrichment in cell death and survival and nervous system development and function, including genes involved in transforming growth factor β and nitric oxide signaling. Functional validation via gene expression analysis of 30 differentially methylated neuronal and glial genes showed a 1.2 fold change in gene expression of the serotonin N-acetyltransferase gene (Aanat) in blast animals (pDNA methylation induced in response to multiple blast overpressure exposures. In particular, increased methylation and decreased gene expression were observed in the Aanat gene, which is involved in converting serotonin to the circadian hormone melatonin and is implicated in sleep disturbance and depression associated with traumatic brain injury.

  4. 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.

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

    Science.gov (United States)

    Nance, Donald K.; Liever, Peter A.

    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 (SMAT), conducted at Marshall Space Flight Center (MSFC). 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.

  6. Mechanical behaviour of alkali-activated blast furnace slag-activated metakaolin blended pastes. Statistical study

    Directory of Open Access Journals (Sweden)

    Higuera, I.

    2012-06-01

    Full Text Available The study and development of alternative, more ecoefficient binders than portland cement are attracting a good deal of scientific and technological interest. Binders obtained from the chemical interaction between calcium silico-aluminous materials and highly alkaline solutions are one of several types of such possible cements. The present paper discusses the mechanical behaviour and mineralogical composition of blended pastes made from NaOH-activated vitreous blast furnace slag and metakaolin. The aim of the study was to determine how parameters such as the slag/metakaolin ratio, activating solution concentration and curing temperature affect strength development in these binders. A statistical study was conducted to establish the impact of each variable and model strength behaviour in these alkaline cements. The conclusion drawn is that activator concentration and the slag/metakaolin ratio are both determinant parameters.

    El estudio y desarrollo de cementos alternativos y más eco-eficientes que el cemento Portland es un tema de gran impacto a nivel científico y tecnológico. Entre esos posibles cementos se encuentran los cementos alcalinos que son materiales conglomerantes obtenidos por la interacción química de materiales silico-aluminosos cálcicos y disoluciones fuertemente alcalinas. En el presente trabajo se estudia el comportamiento mecánico y la composición mineralógica de mezclas de escoria vítrea de horno alto y metacaolín activadas alcalinamente con disoluciones de NaOH. El objetivo de este estudio es conocer cómo afectan parámetros tales como la relación escoria/metacaolín, la concentración de la disolución activadora y la temperatura de curado, al desarrollo resistente de las mezclas. A través del estudio estadístico realizado se ha podido establecer la influencia de cada variable y modelizar el comportamiento resistente de estos cementos alcalinos. Se concluye que la concentración del activador y la relaci

  7. 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.

  8. Machine learning techniques in disease forecasting: a case study on rice blast prediction

    Directory of Open Access Journals (Sweden)

    Kapoor Amar S

    2006-11-01

    Full Text Available Abstract Background Diverse modeling approaches viz. neural networks and multiple regression have been followed to date for disease prediction in plant populations. However, due to their inability to predict value of unknown data points and longer training times, there is need for exploiting new prediction softwares for better understanding of plant-pathogen-environment relationships. Further, there is no online tool available which can help the plant researchers or farmers in timely application of control measures. This paper introduces a new prediction approach based on support vector machines for developing weather-based prediction models of plant diseases. Results Six significant weather variables were selected as predictor variables. Two series of models (cross-location and cross-year were developed and validated using a five-fold cross validation procedure. For cross-year models, the conventional multiple regression (REG approach achieved an average correlation coefficient (r of 0.50, which increased to 0.60 and percent mean absolute error (%MAE decreased from 65.42 to 52.24 when back-propagation neural network (BPNN was used. With generalized regression neural network (GRNN, the r increased to 0.70 and %MAE also improved to 46.30, which further increased to r = 0.77 and %MAE = 36.66 when support vector machine (SVM based method was used. Similarly, cross-location validation achieved r = 0.48, 0.56 and 0.66 using REG, BPNN and GRNN respectively, with their corresponding %MAE as 77.54, 66.11 and 58.26. The SVM-based method outperformed all the three approaches by further increasing r to 0.74 with improvement in %MAE to 44.12. Overall, this SVM-based prediction approach will open new vistas in the area of forecasting plant diseases of various crops. Conclusion Our case study demonstrated that SVM is better than existing machine learning techniques and conventional REG approaches in forecasting plant diseases. In this direction, we have also

  9. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B.; Brown, C. G.; May, M. J.; Compton, S.; Walton, O. R.; Shingleton, N.; Kane, J. O.; Holtmeier, G.; Loey, H.; Mirkarimi, P. B.; Dunlop, W. H. [Lawrence Livermore National Laboratory, P.O. Box 808, L-481, Livermore, California 94550 (United States); Guyton, R. L.; Huffman, E. [National Securities Technologies, Vasco Rd., Livermore, California 94551 (United States)

    2014-09-15

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

  11. 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.

  12. 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

  13. Relationship between changes in the cochlear blood flow and disorder of hearing function induced by blast injury in guinea pigs.

    Science.gov (United States)

    Chen, Wei; Wang, Jianmin; Chen, Jing; Chen, Jichuan; Chen, Zhiqiang

    2013-01-01

    The auditory system is the most susceptible to damages from blast waves. Blast injuries always lead to varying degrees of hearing impairment. Although a disorder of the cochlear blood flow (CoBF) has been considered to be related to many pathological processes of the auditory system and to contribute to various types of hearing loss, changes in the CoBF induced by blast waves and the relationship between such changes and hearing impairment are undefined. To observe the changes in the cochlear microcirculation after exposure to an explosion blast, investigate the relationship between changes in the CoBF and hearing impairment and subsequently explore the mechanism responsible for the changes in the CoBF, we detected the perfusion of the cochlear microcirculation and hearing threshold shift after exposure to an explosion blast. Then, an N-nitro-L-arginine-methyl ester (L-NAME, NO synthase inhibitor) solution and artificial perilymph were applied to the round window (RW) of the cochlea before the blast exposure, followed by an evaluation of the CoBF and hearing function. The results indicated that the changes in the CoBF were correlated to the strength of the blast wave. The cochlear blood flow significantly increased when the peak value of the blast overpressure was greater than approximately 45 kPa, and there was no significant change in the cochlear blood flow when the peak value of the blast overpressure was less than approximately 35 kPa. Following local administration of the NO synthase inhibitor L-NAME, the increase in the CoBF induced by the blast was inhibited, and this reduction was significantly associated with the hearing threshold.

  14. Study on properties of mortar using silica fume and ground blast furnace slag. Silica fume oyobi koro slag funmatsu wo mochiita mortar no tokusei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Shiiba, H; Honda, S; Araki, A [Fukuoka University, Fukuoka (Japan). Faculty of Engineering

    1992-09-01

    The effect of silica fume and ground blast furnace slag in concrete on the content of superplasticizer, and dynamic properties of hardened mortar with such admixtures were studied experimentally. Although the dependence of a flow value on the superplasticizer was dominated by kinds of superplasticizers, blast furnace slag enhanced the flow value resulting in a high fluidity. Adsorption of superplasticizers onto admixtures was dependent on kinds of superplasticizers, and adsorption onto blast furnace slag was 1.3-2 times that onto normal Portland cement (NPC). The compressive strength of mortar increased by mixing admixtures, while the bending strength was enhanced only by mixing silica fume. Mixing mortar was lower in dynamic elastic modulus than NPC mortar at the same compressive strength, and the velocity of supersonic wave in mortar was scarcely affected by mixing. 11 refs., 14 figs., 3 tabs.

  15. Study on the early warning mechanism for the security of blast furnace hearths

    Science.gov (United States)

    Zhao, Hong-bo; Huo, Shou-feng; Cheng, Shu-sen

    2013-04-01

    The campaign life of blast furnace (BF) hearths has become the limiting factor for safety and high efficiency production of modern BFs. However, the early warning mechanism of hearth security has not been clear. In this article, based on heat transfer calculations, heat flux and erosion monitoring, the features of heat flux and erosion were analyzed and compared among different types of hearths. The primary detecting elements, mathematical models, evaluating standards, and warning methods were discussed. A novel early warning mechanism with the three-level quantificational standards was proposed for BF hearth security.

  16. 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

  17. 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.

  18. STUDY ON THE BLASTING SEISMIC DAMAGE CONTROL TECHNOLOGY FOR SMALL SPACING SOFT ROCK TUNNEL

    Directory of Open Access Journals (Sweden)

    Yang Chengzhong

    2017-07-01

    Full Text Available With a lot construction of transportation infrastructure in Chinese mountainous area, because of its unique advantages such as less land occupation, beautiful appearance and convenient route planning, small spacing tunnels are widely used. The shallow buried tunnel with small spacing, the blasting excavation will lead to tunnel surrounding rock especially in the middle rock wall damage and reduce the self-bearing capacity of surrounding rock. Through detecting and analyzing by the geological radar of the excavated red layer soft rock tunnel surrounding rock found that the middle rock wall loose circle thickness of the tunnel reaches to 1.8 m, the vault and sidewall loose circle thickness is about 1.2 m. Through selection of rational strengthening measures and blasting design scheme to improve drilling parameters and methods, as far as possible to protect the integrity and self-bearing capacity of the surrounding rock, the deformation and vibration of the tunnel would be controlled in reasonable limits and ensure the safety of tunnel construction.

  19. Spark gap overpressures in the transfer capacitor device

    International Nuclear Information System (INIS)

    Burkhardt, L.C.; Dike, R.S.

    1977-01-01

    A designer of spark gaps is often faced with two gas pressure problems, one static and one dynamic. The former is easy to obtain data on which to base intelligent design specifications; about the latter, less is known. It is the total internal pressure environment we have attempted to measure, in an un-time-resolved way, in order to give the designer some rationale in designing gaps of this category. We measure overpressures of approximately 400 PSI in a 13 cubic inch gap passing currents of approximately 200 kA

  20. 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.

  1. Calculation of driling and blasting parameters in blasting performance

    OpenAIRE

    Dambov, Risto; Karanakova Stefanovska, Radmila; Dambov, Ilija

    2015-01-01

    In all mining technology drilling and blasting parameters and works are one of the main production processes at each mine. The parameters of drilling and blasting and explosives consumption per ton of blasting mass are define economic indicators of any blasting no matter for what purpose and where mining is performed. The calculation of rock blasting should always have in mind that the methodology of calculation of all drilling and blasting parameters in blasting performance are performed for...

  2. Investigations of Tissue-Level Mechanisms of Primary Blast Injury Through Modeling, Simulation, Neuroimaging and Neuropathological Studies

    Science.gov (United States)

    2012-07-10

    2007;25(1):97-98. [19] Stewart C. Blast Injuries. Colorado Springs: USAF Academy Hospital; 2006. 88 p. [20] Cernak I, Wang Z, Jiang J, Bian X, Savic J...Wang Z, Jiang J, Bian X, Savic J. Ultrastructural and Functional Characteristics of Blast Injury- Induced Neurotrauma. Journal of Trauma: Injury

  3. Approximating a free-field blast environment in the test section of an explosively driven conical shock tube

    Science.gov (United States)

    Stewart, J. B.

    2018-02-01

    This paper presents experimental data on incident overpressures and the corresponding impulses obtained in the test section of an explosively driven 10° (full angle) conical shock tube. Due to the shock tube's steel walls approximating the boundary conditions seen by a spherical sector cut out of a detonating sphere of energetic material, a 5.3-g pentolite shock tube driver charge produces peak overpressures corresponding to a free-field detonation from an 816-g sphere of pentolite. The four test section geometries investigated in this paper (open air, cylindrical, 10° inscribed square frustum, and 10° circumscribed square frustum) provide a variety of different time histories for the incident overpressures and impulses, with a circumscribed square frustum yielding the best approximation of the estimated blast environment that would have been produced by a free-field detonation.

  4. Pressure Sores Prevention for Paraplegic People: Effects of Visual, Auditory and Tactile Supplementations on Overpressures Distribution in Seated Posture

    Directory of Open Access Journals (Sweden)

    Olivier Chenu

    2012-01-01

    Full Text Available This paper presents a study on the usage of different informative modalities as biofeedbacks of a perceptual supplementation device aiming at reducing overpressure at the buttock area. Visual, audio and lingual electrotactile modalities are analysed and compared with a non-biofeedback session. In conclusion, sensory modalities have a positive and equal effect, but they are not equally judged in terms of comfort and disturbance with some other activities.

  5. Acoustic investigation of the aperture dynamics of an elastic membrane closing an overpressurized cylindrical cavity

    Science.gov (United States)

    Sánchez, Claudia; Vidal, Valérie; Melo, Francisco

    2015-08-01

    We report an experimental study of the acoustic signal produced by the rupture of an elastic membrane that initially closes a cylindrical overpressurized cavity. This configuration has been recently used as an experimental model system for the investigation of the acoustic emission from the bursting of elongated gas bubbles rising in a conduit. Here, we investigate the effect of the membrane rupture dynamics on the acoustic signal produced by the pressure release by changing the initial tension of the membrane. The initial overpressure in the cavity is fixed at a value such that the system remains in the linear acoustic regime. For large initial membrane deformation, the rupture time τ rup is small compared to the wave propagation time in the cavity and the pressure wave inside the conduit can be fully captured by the linear theory. For low membrane tension, a hole is pierced in the membrane but its rupture does not occur. For intermediate deformation, finally, the rupture progresses in two steps: first the membrane opens slowly; then, after reaching a critical size, the rupture accelerates. A transversal wave is excited along the membrane surface. The characteristic signature of each opening dynamics on the acoustic emission is described.

  6. RELAP5 Low Temperature Overpressurization Analysis for NPP Krsko

    International Nuclear Information System (INIS)

    Basic, I.; Krajnc, B.; Bajs, T.

    2000-01-01

    NEK has expressed interest in the acceptability of removing the autoclosure interlock (ACI) on the Residual Heat Removal System (RHRS) suction/isolation valves. This interest is in response to growing concerns about the loss of residual heat removal capability during cold shutdown and refueling operations. This article describes effort done to justify removal of the ACI in the light of low temperature overpressure protection of Reactor Coolant System (RCS) and RHRS and interfacing system LOCA potential. The intent of this article is to review the NEK RHRS relief valves sizing design basis and verify if the relief valves provide RHRS overpressure protection for the events possible at cold shutdown. Inadvertent isolation of RHRS during hot and cold shutdown (with reactor coolant system closed and temperatures below 177o Code 4 and5) presents one of the major safety concerns in this mode of operation. Detailed RELAP5 model of NPP Kriko following steam generator (SG) replacement and core uprate has been used in the frame of this analysis verification of RHRS relief valves sizing. The following limiting cases for cold shutdown with RCS solid conditions have been analyzed: - ransients that affect the system input/output mass balance, - ransients that affect the heat input/removal balance. (author)

  7. Computational Study of Thrust Generation from Laser-Driven Blast Wave

    International Nuclear Information System (INIS)

    Ohnishi, Naofumi; Ogino, Yousuke

    2008-01-01

    We have performed axisymmetric simulations in order to investigate the thrust generation resulting from the interference between the projectile and the blast wave produced by a pulsed laser. The results obtained by our numerical code well agree for the pressure history and the momentum coupling coefficient with the experimental data. In such analysis, it is found that the approximate impulse estimated only by the pressure history at the projectile base is difficult to predict the actual one. Since the shock wave rapidly attenuates in low fill pressure, and the interaction with the projectile almost finishes in the shroud, a high momentum coupling coefficient can be achieved unlike the case of high fill pressure in which the projectile experiences the subsequent negative thrust

  8. Otologic consequences of blast exposure: a Finnish case study of a shopping mall bomb explosion.

    Science.gov (United States)

    Mrena, Roderik; Pääkkönen, Rauno; Bäck, Leif; Pirvola, Ulla; Ylikoski, Jukka

    2004-10-01

    On 11 October, 2002, in the Myyrmanni shopping mall, Vantaa city, Finland, an explosion by a suicide bomber killed 7 people and injured at least 160,44 of whom had ear trauma. We investigated the acute and subacute otologic consequences of the explosion. Otologic examination of the 29 patients treated for ear trauma at the ENT clinic of the University Hospital of Helsinki was performed during the first month after the explosion, and a questionnaire was completed regarding subjective aural symptoms. Symptoms occurring directly after the explosion and for up to 1 month afterwards were assessed. Of the 29 patients, 66% had tinnitus as the initial symptom, 55% hearing loss, 41% pain in the ears and 28% sound distortion. Tinnitus and hearing loss in combination were experienced by 12 patients (41%). Eight patients who had been situated<10 m from the center of the explosion had a rupture of the tympanic membrane. This supported the initial evaluation by the authorities that the bomb had consisted of approximately 3 kg ammonium nitrate, equivalent to approximately 0.5 kg of trinitrotoluene. It was estimated that some kind of ear injury was likely for individuals situated<70 m from the center of the explosion. People often think that tinnitus and hearing impairment are naturally occurring phenomena after blast exposure, and if their symptoms resolve they do not seek medical advice. However, some of them may have substantial hearing impairment, particularly at high frequencies. Otologic consultation, or at least an audiometric screening test to exclude hearing impairment, should be performed regardless of symptoms, on the basis of exposure data only. Some symptoms, such as tinnitus and hearing loss, may be permanent consequences of a blast injury and their effect on quality of life may be substantial.

  9. Primary blast survival and injury risk assessment for repeated blast exposures.

    Science.gov (United States)

    Panzer, Matthew B; Bass, Cameron R Dale; Rafaels, Karin A; Shridharani, Jay; Capehart, Bruce P

    2012-02-01

    The widespread use of explosives by modern insurgents and terrorists has increased the potential frequency of blast exposure in soldiers and civilians. This growing threat highlights the importance of understanding and evaluating blast injury risk and the increase of injury risk from exposure to repeated blast effects. Data from more than 3,250 large animal experiments were collected from studies focusing on the effects of blast exposure. The current study uses 2,349 experiments from the data collection for analysis of the primary blast injury and survival risk for both long- and short-duration blasts, including the effects from repeated exposures. A piecewise linear logistic regression was performed on the data to develop survival and injury risk assessment curves. New injury risk assessment curves uniting long- and short-duration blasts were developed for incident and reflected pressure measures and were used to evaluate the risk of injury based on blast over pressure, positive-phase duration, and the number of repeated exposures. The risk assessments were derived for three levels of injury severity: nonauditory, pulmonary, and fatality. The analysis showed a marked initial decrease in injury tolerance with each subsequent blast exposure. This effect decreases with increasing number of blast exposures. The new injury risk functions showed good agreement with the existing experimental data and provided a simplified model for primary blast injury risk. This model can be used to predict blast injury or fatality risk for single exposure and repeated exposure cases and has application in modern combat scenarios or in setting occupational health limits. .Copyright © 2012 by Lippincott Williams & Wilkins

  10. CFD Assessment of Forward Booster Separation Motor Ignition Overpressure on ET XT 718 Ice/Frost Ramp

    Science.gov (United States)

    Tejnil, Edward; Rogers, Stuart E.

    2012-01-01

    Computational fluid dynamics assessment of the forward booster separation motor ignition over-pressure was performed on the space shuttle external tank X(sub T) 718 ice/frost ramp using the flow solver OVERFLOW. The main objective of this study was the investigation of the over-pressure during solid rocket booster separation and its affect on the local pressure and air-load environments. Delta pressure and plume impingement were investigated as a possible contributing factor to the cause of the debris loss on shuttle missions STS-125 and STS-127. A simplified computational model of the Space Shuttle Launch Vehicle was developed consisting of just the external tank and the solid rocket boosters with separation motor nozzles and plumes. The simplified model was validated by comparison to full fidelity computational model of the Space Shuttle without the separation motors. Quasi steady-state plume solutions were used to calibrate the thrust of the separation motors. Time-accurate simulations of the firing of the booster-separation motors were performed. Parametric studies of the time-step size and the number of sub-iterations were used to find the best converged solution. The computed solutions were compared to previous OVERFLOW steady-state runs of the separation motors with reaction control system jets and to ground test data. The results indicated that delta pressure from the overpressure was small and within design limits, and thus was unlikely to have contributed to the foam losses.

  11. Study on the detonation properties of explosives in bore hole and precise controlled blasting; Happa konai no bakuyaku no bakugosei to seimitsu seigyo happa ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-08

    In order to perform efficient and safe controlled blasting, attaining sufficient detonation from explosive is important. Therefore, a mechanism of detonation in a bore hole was studied. Two detonation phenomenon measuring methods were established: one is a continuous detonation speed measuring method by using a resistance wire probe, and another is a detonation mark observing and evaluating method using aluminum and metallic lead plates. Assuming delay blastings in multiple bore holes used practically, discussions were given on detonation phenomena of explosives under pressurized condition. Under dynamic pressure condition, size of the pressurization and delay time of the detonations affected largely the detonation. Discussions were given on blasting effect and safety according to difference in forward initiation and reverse initiation. The reverse initiation method was verified to have excellent blasting effect, maintain good face conditions, and assure safety against inflammable gases. A precision initiation method was developed, which can control the initiation time of a detonator more precisely. The initiation accuracy is more than 1000 times greater than the ordinary instantaneously detonating electric detonator. The precision control of the initiation time proved to develop greater crack propagation. Vibration and stone scattering were also controlled. This paper also describes application of the method to a rock elastic wave exploration technique. 136 refs., 99 figs., 13 tabs.

  12. 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.

  13. FY 2000 Study report. Feasibility study on model project for effective utilization of sensible heat of off gas from hot stoves at blast furnaces in India; 2000 nendo Indo ni okeru koro netsufuro hai gas kennetsu yuko riyo model jigyo jisshi kanosei chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The feasibility study was conducted on a model project in India for the energy saving effect and reduction of the greenhouse gas emissions by introducing blast furnace hot stove waste heat recovery systems in steelworks. The blast furnaces studied are Blast Furnace G at Jamshedpur Steelworks of TISCO, the largest private steel maker in India, and No.7 Blast Furnace at Bhilai Steelworks of state-operated Steel Authority of India Ltd. (SAIL). The study results indicate that the annual energy-saving effects of 8,255 and 8,190 tons as heavy oil, and annual CO2 emission reduction of 25,543 and 25,342 tons are expected in the TISCO and SAIL blast furnaces, respectively, in the case of increasing blast temperature and reducing blast furnace fuel coke (increased iron production possible). The model project is applicable to both blast furnaces. There are a total of 46 blast furnaces in India in which the heat recovery systems can be introduced. The nation-wide annual energy saving and CO2 abatement would reach 126,202 tons as heavy oil and 390,501 tons, when all of these blast furnaces could be provided with the heat recovery systems. (NEDO)

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. Behavior of coke in large blast furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, N

    1978-01-01

    Three blast furnaces were quenched in operation and the contents were examined; the temperature distribution was also measured, using Tempil pellets. The furnaces examined included a low productivity one, which was examined to see what was wrong. Changes in the quality of coke as it descends in the furnace, and coke behavior in the raceway and hearth are reported. The functions required of coke, and the effects of poor coke quality, are explained, together with the coke quality required in large blast furnaces. A theoretical study of the role of coke in large blast furnaces is included.

  19. Blast induces oxidative stress, inflammation, neuronal loss and subsequent short-term memory impairment in rats.

    Science.gov (United States)

    Cho, H J; Sajja, V S S S; Vandevord, P J; Lee, Y W

    2013-12-03

    Molecular and cellular mechanisms of brain injury after exposure to blast overpressure (BOP) are not clearly known. The present study hypothesizes that pro-oxidative and pro-inflammatory pathways in the brain may be responsible for neuronal loss and behavioral deficits following BOP exposure. Male Sprague-Dawley rats were anesthetized and exposed to calibrated BOP of 129.23±3.01kPa while controls received only anesthesia. In situ dihydroethidium fluorescence staining revealed that BOP significantly increased the production of reactive oxygen species in the brain. In addition, real-time reverse transcriptase-polymerase chain reaction, immunofluorescence staining and enzyme-linked immunosorbent assay demonstrated a significant up-regulation of mRNA and protein expressions of pro-inflammatory mediators, such as interferon-γ and monocyte chemoattractant protein-1, in brains collected from BOP-exposed animals compared with the controls. Furthermore, immunoreactivity of neuronal nuclei in brains indicated that fewer neurons were present following BOP exposure. Moreover, novel object recognition paradigm showed a significant impairment in the short-term memory at 2weeks following BOP exposure. These results suggest that pro-oxidative and pro-inflammatory environments in the brain could play a potential role in BOP-induced neuronal loss and behavioral deficits. It may provide a foundation for defining a molecular and cellular basis of the pathophysiology of blast-induced neurotrauma (BINT). It will also contribute to the development of new therapeutic approaches selectively targeting these pathways, which have great potential in the diagnosis and therapy of BINT. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface

    DEFF Research Database (Denmark)

    Gotfredsen, K; Karlsson, U

    2001-01-01

    PURPOSE: The aim of the present study was to evaluate whether there was a difference between machined and TiO(2)-blasted implants regarding survival rate and marginal bone loss during a 5-year observation period. MATERIALS AND METHODS: A total of 133 implants (Astra Tech Dental Implants; Astra Tech...... AB, Mölndal, Sweden) were placed in 50 patients at 6 centers in 4 Scandinavian countries. Forty-eight implants were installed in the maxilla and 85 implants in the mandible. A randomization and a stratification were done, so that each fixed partial prosthesis was supported by at least 1 machined...... and 1 TiO(2)-blasted implant. The implant-supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow...

  1. 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.

  2. Feasibility and economic analysis of solid desiccant wheel used for dehumidification and preheating in blast furnace: A case study of steel plant, Nanjing, China

    International Nuclear Information System (INIS)

    Guan, Yipeng; Zhang, Yufeng; Sheng, Ying; Kong, Xiangrui; Du, Song

    2015-01-01

    To overcome the shortcomings of huge energy consumption from conventional dehumidification using lithium bromide adsorption refrigerating (LBARD) system, a novel desiccant wheel dehumidification and preheating (DWDP) system using two-stage desiccant wheel for blast furnace is brought forward. The DWDP system was designed for dehumidification and preheating in blast furnace of steel plant. It takes waste heat in the slag flushing water as desiccant regeneration and preheating energy. To validate the feasibility of the new DWDP system, experimental studies were conducted based on a steel plant in Nanjing, China. The experiment was designed to use DWDP system in humid outdoor climates e.g. summer seasons. The experimental results indicate that the moisture removal capacity of DWDP system can reach 8.7 g/kg which will lead to the improvement of steel production by 0.9% and the coal is saved of about 2100 tons per year. With the DWDP system, the energy consumed by cooling tower of slag flushing water can decrease 7.3%. All of these energy saved equates to 10.3 million CNY annually. A comparison of initial investment and operating cost between DWDP system and LBRAD system was then carried out. The results show that the initial investment and operating cost of DWDP system is 37% and 57% of present LBARD system, and the payback period is shortened 66%. - Highlights: • A novel two-stage desiccant wheel dehumidification system for blast furnace is proposed. • Average moisture removal of 8.7 g/kg is achieved and dehumidification efficiency is 47%. • Outlet humidity ratio is less than 10 g/kg that satisfies the requirement of blast air. • Waste heat in slag flushing water is utilized and 61.4 million kJ is saved annually. • The investment and operating cost is 37% and 57% of former dehumidification system

  3. 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

    Distribution Interview diagnosis of mTBI after blast Page 12 of 30 low certainty using 90% or higher confidence as the anchor for high certainty...n = 32), ankle (n = 19), and hip (n = 16) regions. Full results of each of the preliminary hierarchical linear regressions are presented in Table 2

  4. Heart Failure Therapeutics on the Basis of a Biased Ligand of the Angiotensin-2 Type 1 Receptor Rationale and Design of the BLAST-AHF Study (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure)

    NARCIS (Netherlands)

    Felker, G. Michael; Butler, Javed; Collins, Sean P.; Cotter, Gad; Davison, Beth A.; Ezekowitz, Justin A.; Filippatos, Gerasimos; Levy, Phillip D.; Metra, Marco; Ponikowski, Piotr; Soergel, David G.; Teerlink, John R.; Violin, Jonathan D.; Voors, Adriaan A.; Pang, Peter S.

    The BLAST-AHF (Biased Ligand of the Angiotensin Receptor Study in Acute Heart Failure) study is designed to test the efficacy and safety of TRV027, a novel biased ligand of the angiotensin-2 type 1 receptor, in patients with acute heart failure (AHF). AHF remains a major public health problem, and

  5. Influence of Basalt Mesh Induced Increase of Heterogeneity of Cement Composites with Dispersed Fibers on Its Resistance under Near-Field Blast

    Science.gov (United States)

    Zíma, J.; Foglar, M.

    2017-09-01

    This paper describes the influence of multiple basalt meshes in the cement composite specimens on the damage induced by near-field blast. Experimental measurements performed in the Boletice military area in 2014 and 2015 are evaluated by numerical simulations. The evaluation of the results is mainly focused on the stress propagation in the cement composite with dispersed fibers, the propagation of the overpressure caused by the blast and velocity of the ejected parts from the specimen. The influence of the presence and position of the basalt meshes in the specimen on its damage induced by delamination is also examined.

  6. Water-Depth-Based Prediction Formula for the Blasting Vibration Velocity of Lighthouse Caused by Underwater Drilling Blasting

    OpenAIRE

    Gu, Wenbin; Wang, Zhenxiong; Liu, Jianqing; Xu, Jinglin; Liu, Xin; Cao, Tao

    2017-01-01

    Lighthouses are the most important hydraulic structures that should be protected during underwater drilling blasting. Thus, the effect of blasting vibration on lighthouse should be studied. On the basis of the dimensional analysis, we deduced a revised formula for water depth based on Sodev’s empirical formula and established the linear fitting model. During the underwater reef project in the main channel of Shipu Harbor in the Ningbo–Zhoushan Port, the blasting vibration data of the lighthou...

  7. Water-Depth-Based Prediction Formula for the Blasting Vibration Velocity of Lighthouse Caused by Underwater Drilling Blasting

    Directory of Open Access Journals (Sweden)

    Wenbin Gu

    2017-01-01

    Full Text Available Lighthouses are the most important hydraulic structures that should be protected during underwater drilling blasting. Thus, the effect of blasting vibration on lighthouse should be studied. On the basis of the dimensional analysis, we deduced a revised formula for water depth based on Sodev’s empirical formula and established the linear fitting model. During the underwater reef project in the main channel of Shipu Harbor in the Ningbo–Zhoushan Port, the blasting vibration data of the lighthouse near the underwater blasting area were monitored. The undetermined coefficient, resolvable coefficient, and F value of the two formulas were then obtained. The comparison of the data obtained from the two formulas showed that they can effectively predict the blasting vibration on the lighthouse. The correction formula that considers water depth can obviously reduce prediction errors and accurately predict blasting vibration.

  8. 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.

  9. Assessment of Blasting Operations Effects During Highway Tunnel Construction

    Directory of Open Access Journals (Sweden)

    Valašková Veronika

    2015-12-01

    Full Text Available Blasting operations are one of the fundamental parts of daily civil engineering. Drilling and blasting still remain the only possible ways of tunnelling in very adverse geological conditions. However, this method is a source of various disadvantages, the main one being tremors propagating through the geological environment which not only affect buildings, but also disturb the comfort of living in the vicinity of the source. Designing this procedure is mostly done using standardized empirical relations. This article shows the possibility of using a FEM technique in predicting blast effects. This approach is demonstrated in a simple case study on the impact of blasting operations on steel pipes.

  10. 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.

  11. Sub-lethal Ocular Trauma (SLOT): Establishing a Standardized Blast Threshold to Facilitate Diagnostic, Early Treatment, and Recovery Studies for Blast Injuries to the Eye and Optic Nerve

    Science.gov (United States)

    2015-11-01

    and LS-DYNA. One of the invaluable lessons learned in previous blunt impact studies was that numerical simulations have the potential to identify...forming a Friedlander- style shock wave before reaching the eye specimen (Figure 2). The peak pressure of the shock wave is controlled by the number of...this proinflammatory cytokine prompted a significant analgesic effect by measuring the hind paw tactile allogynia from 1 to 4 h after injection (Chen

  12. Review of SKB's ZEDEX Report - A study of the zone of excavation disturbance for blasted and bored tunnels - SKB ICR 96-03, Vol. 1-3

    International Nuclear Information System (INIS)

    Palmqvist, K.

    1997-11-01

    We have reviewed and evaluated the contents of the ZEDEX report. The review has been focussed on investigation methods, results and interpretations. The conclusions of the review are that the ZEDEX was successful in some aspects. However, the study has not met with the objective of understanding the excavation disturbed zone (EDZ). A lot of questions remain to be answered as regards the origin, character and extent of the EDZ. Investigation of the hydraulic properties of the EDZ was not included as a major aim in the ZEDEX study and only some supporting studies were conducted. We find it regrettable that priority was not given to these aspects, since improved knowledge in this field is considered important with respect to the performance and safety of the repository. The review has identified a number of shortages in the expected outcome and objectives set up for the ZEDEX experiment that more or less have influenced the results of the study. Several problems of interpretation were introduced directly as a result of the unsatisfactory performance of the drill and blast drift. It would have been valuable if cautious blasting had been applied. A number of recommendations for future studies are made

  13. Studies on the mechanism for in-place leaching of fragmented uranium ore by blasting

    International Nuclear Information System (INIS)

    Wu Hengshan; Wang Changhan

    2001-01-01

    The report is based on the locale test studies at No.745 Mine and Baifang Copper (Uranium) Mine. According to hydrokinetics of porous medium. The character of mining methods of in-place leaching of fragmented uranium are, the best application conditions, in-place leaching theory, the fittest composite of fragments of crashing uranium ore, the lowest velocity of flow in solution liquid, the reasonable parameter of stop structure, the technology of leaching, meaning, the equation of solution liquid, the name of solution mining and its classification are studied. Especially some creation in the theory of leaching in mud ore and the technology of strengthened leaching are given. It would be helpful to the design and production

  14. 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.

  15. Liquid flow in the hearth of the blast furnace

    International Nuclear Information System (INIS)

    Gauje, P.; Nicolle, R.; Steiler, J.M.; Venturini, M.J.; Libralesso, J.M.

    1992-01-01

    The hearth of a blast furnace is poorly known. Our approach to characterize the hearth involves classical methods of chemical engineering, assessing the flow conditions by means of radioactive tracer techniques. The most important feature of this study is to combine measurements on industrial blast furnaces, experiments on a small scale model and flow model. calculations. 8 refs., 16 figs

  16. 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.

  17. A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

    Science.gov (United States)

    Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

    2015-11-01

    White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages.

  18. 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.

  19. 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)

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. Study of mass attenuation coefficients and effective atomic numbers of bismuth-ground granulated blast furnace slag concretes

    International Nuclear Information System (INIS)

    Kumar, Sandeep; Singh, Sukhpal

    2016-01-01

    Five samples of Bismuth-Ground granulated blast furnace slag (Bi-GGBFS) concretes were prepared using composition (0.6 cement + x Bi_2O_3 + (0.4-x) GGBFS, x = 0.05, 0.10, 0.15, 0.20 and 0.25) by keeping constant water (W) cement (C) ratio. Mass attenuation coefficients (μ_m) of these prepared samples were calculated using a computer program winXCOM at different gamma ray energies, whereas effective atomic numbers (Z_e_f_f) is calculated using mathematical formulas. The radiation shielding properties of Bi-GGBFS concrete has been compared with standard radiation shielding concretes.

  5. 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.

  6. 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.

  7. Prediction of sonic boom from experimental near-field overpressure data. Volume 2: Data base construction

    Science.gov (United States)

    Glatt, C. R.; Reiners, S. J.; Hague, D. S.

    1975-01-01

    A computerized method for storing, updating and augmenting experimentally determined overpressure signatures has been developed. A data base of pressure signatures for a shuttle type vehicle has been stored. The data base has been used for the prediction of sonic boom with the program described in Volume I.

  8. 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.

  9. Mortality study of Canadian military personnel exposed to radiation: atomic test blasts and Chalk River nuclear reactor clean-ups, 1950's

    International Nuclear Information System (INIS)

    Raman, S.; Dulberg, C.S.; Spasoff, R.A.

    1984-08-01

    This report describes a historical cohort study of the group of Canadian military personnel exposed to radiation in the 1950s at atomic bomb test blasts in the U.S. and Australia, and at clean-up operations at the Chalk River Nuclear Laboratories. Overall and cause-specific mortality in the exposed group was compared to that of the control cohort of unexposed military personnel, matched on age, service, rank and trade. Analyses indicated no elevation in the exposed cohort, in overall or cause-specific mortality due to diseases associated with radiation. Since this study was restricted to an investigation of mortality, we must stress that we cannot generalize these results or conclusions to current morbidity experienced by the exposed cohort

  10. A pilot plant study for CO{sub 2} capture by aqueous ammonia applied to blast furnace gas in iron and steel making process

    Energy Technology Data Exchange (ETDEWEB)

    Young Kim, J.; Han, K.; Dong Chun, H. [CO2 Project, Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of)

    2009-07-01

    This presentation reported on a study in which carbon dioxide (CO{sub 2}) was captured from a demonstration iron and steel plant using low concentration aqueous ammonia as the absorbent chemical. The pilot plant was designed to process 50 Nm{sup 3}/h of blast furnace gas (BFG). The feed gas contained more than 20 per cent CO{sub 2} at 35 to 60 degrees C. Test runs revealed that the absorption efficiency of CO{sub 2} exceeded 80 per cent with a CO{sub 2} purity of more than 90 per cent in the product stream. The process parameters are currently being studied along with the various salts needed to prevent salt precipitation. It was determined that the use of waste heat recovery technology in the iron and steel-making process can render ammonia-based CO{sub 2} capture technology more economically feasible for the reduction of CO{sub 2}.

  11. Studies on the corrosion resistance of reinforced steel in concrete with ground granulated blast-furnace slag--An overview.

    Science.gov (United States)

    Song, Ha-Won; Saraswathy, Velu

    2006-11-16

    The partial replacement of clinker, the main constituent of ordinary Portland cement by pozzolanic or latent hydraulic industrial by-products such as ground granulated blast furnace slag (GGBFS), effectively lowers the cost of cement by saving energy in the production process. It also reduces CO2 emissions from the cement plant and offers a low priced solution to the environmental problem of depositing industrial wastes. The utilization of GGBFS as partial replacement of Portland cement takes advantage of economic, technical and environmental benefits of this material. Recently offshore, coastal and marine concrete structures were constructed using GGBFS concrete because high volume of GGBFS can contribute to the reduction of chloride ingress. In this paper, the influence of using GGBFS in reinforced concrete structures from the durability aspects such as chloride ingress and corrosion resistance, long term durability, microstructure and porosity of GGBFS concrete has been reviewed and discussed.

  12. A theoretical study using the multiphase numerical simulation technique for effective use of H2 as blast furnaces fuel

    Directory of Open Access Journals (Sweden)

    Jose Adilson de Castro

    2017-07-01

    Full Text Available We present a numerical simulation procedure for analyzing hydrogen, oxygen and carbon dioxide gases injections mixed with pulverized coals within the tuyeres of blast furnaces. Effective use of H2 rich gas is highly attractive into the steelmaking blast furnace, considering the possibility of increasing the productivity and decreasing the specific emissions of carbon dioxide becoming the process less intensive in carbon utilization. However, the mixed gas and coal injection is a complex technology since significant changes on the inner temperature and gas flow patterns are expected, beyond to their effects on the chemical reactions and heat exchanges. Focusing on the evaluation of inner furnace status under such complex operation a comprehensive mathematical model has been developed using the multi interaction multiple phase theory. The BF, considered as a multiphase reactor, treats the lump solids (sinter, small coke, pellets, granular coke and iron ores, gas, liquids metal and slag and pulverized coal phases. The governing conservation equations are formulated for momentum, mass, chemical species and energy and simultaneously discretized using the numerical method of finite volumes. We verified the model with a reference operational condition using pulverized coal of 215 kg per ton of hot metal (kg thm−1. Thus, combined injections of varying concentrations of gaseous fuels with H2, O2 and CO2 are simulated with 220 kg thm−1 and 250 kg thm−1 coals injection. Theoretical analysis showed that stable operations conditions could be achieved with productivity increase of 60%. Finally, we demonstrated that the net carbon utilization per ton of hot metal decreased 12%.

  13. Impact of Drill and Blast Excavation on Repository Performance Confirmation

    International Nuclear Information System (INIS)

    Keller, R.; Francis, N.; Houseworth, J.; Kramer, N.

    2000-01-01

    There has been considerable work accomplished internationally examining the effects of drill and blast excavation on rock masses surrounding emplacement openings of proposed nuclear waste repositories. However, there has been limited discussion tying the previous work to performance confirmation models such as those proposed for Yucca Mountain, Nevada. This paper addresses a possible approach to joining the available information on drill and blast excavation and performance confirmation. The method for coupling rock damage data from drill and blast models to performance assessment models for fracture flow requires a correlation representing the functional relationship between the peak particle velocity (PPV) vibration levels and the potential properties that govern water flow rates in the host rock. Fracture aperture and frequency are the rock properties which may be most influenced by drill and blast induced vibration. If it can be shown (using an appropriate blasting model simulation) that the effect of blasting is far removed from the waste package in an emplacement drift, then disturbance to the host rock induced in the process of drill and blast excavation may be reasonably ignored in performance assessment calculations. This paper proposes that the CANMET (Canada Center for Mineral and Energy Technology) Criterion, based on properties that determine rock strength, may be used to define a minimum PPV. This PPV can be used to delineate the extent of blast induced damage. Initial applications have demonstrated that blasting models can successfully be coupled with this criterion to predict blast damage surrounding underground openings. The Exploratory Studies Facility at Yucca Mountain has used a blasting model to generate meaningful estimates of near-field vibration levels and damage envelopes correlating to data collected from pre-existing studies conducted. Further work is underway to expand this application over a statistical distribution of geologic

  14. Controlled blasting experiments in a small drift at the CANMET experimental mine

    Energy Technology Data Exchange (ETDEWEB)

    Lizotte, Y.C.

    1994-03-01

    Experiments on controlled blasting conducted at the CANMET Experimental Mine to develop suitable controlled blasting techniques for small development headings are described. The methods selected for study must maintain the drill-blast-muck cycle achieved each work shift. The experiments also examine blast damage mechanisms to formulate criteria for dilution minimization with blast designs in stopes. The drift faces are 2.4 m square, with 34 to 43 holes drilled 2.4 m deep. Cartridged water gels, emulsions, and semi-gelatin dynamite were used in the cuts and as primers, ANFO as the main explosive, and semi- gelatin dynamite in 19 mm diameter cartridges was used in perimeter holes. The results of the first set of experiments show the efficiency of controlled blasting techniques to reduce blast damage. 60 refs., 71 figs., 9 tabs.

  15. 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.

  16. 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.

  17. Fracture assessment of the Oskarshamn 1 reactor pressure vessel under cold over-pressurization

    Energy Technology Data Exchange (ETDEWEB)

    Sattari-Far, I. [DNV Technical Consulting AB, Stockholm (Sweden)

    2001-03-01

    The major motivation of this study was to develop a methodology for fracture assessment of surface defects in the 01 reactor pressure vessel under cold loading scenarios, particularly the cold over-pressurization event. According to a previous study, the FENIX project, the cold over-pressurization of the O1 reactor is a limiting loading case, as the ductile/brittle transition temperature (RT{sub NDT}) of certain welds in the O1 beltline region may be over 100 deg C at the-end-of-life condition. The FENIX project gave values of the acceptable and critical crack depth to be equal to the thickness of the cladding layer (about 6 mm) under this load case using the ASME K{sub Ic} reference curve methodology. This study is aimed to develop a methodology to give a more precise fracture assessment of the O1 reactor under cold loading scenarios. Some of the main objectives of this study have been as below: To prepare a material which can simulate the mechanical properties and RT{sub NDT} of the O1 reactor at the end-of-life conditions. To conduct a fracture mechanics test program to cover the essential influencing factors, such as crack geometry (shallow and deep cracks) and loading condition (uniaxial and biaxial) on the cleavage fracture toughness. To perform fracture mechanics analyses to identify a suitable methodology for assessment of the experimental results. To study the responses of engineering fracture assessment methods to the experimental results from the clad specimens. To propose a fracture assessment procedure for determination of the acceptable and critical flaw sizes in the 01 reactor under the cold loading events. A test program consisted of experiments on standard SEN(B) specimens and clad beams, containing surface cracks was conducted during the course of this project. A total of nine clad beams and clad cruciform specimens were tested under uniaxial and biaxial loading. The test material is reactor steel of type A 508 Grade B, which is specially heat

  18. Fracture assessment of the Oskarshamn 1 reactor pressure vessel under cold over-pressurization

    International Nuclear Information System (INIS)

    Sattari-Far, I.

    2001-03-01

    The major motivation of this study was to develop a methodology for fracture assessment of surface defects in the 01 reactor pressure vessel under cold loading scenarios, particularly the cold over-pressurization event. According to a previous study, the FENIX project, the cold over-pressurization of the O1 reactor is a limiting loading case, as the ductile/brittle transition temperature (RT NDT ) of certain welds in the O1 beltline region may be over 100 deg C at the-end-of-life condition. The FENIX project gave values of the acceptable and critical crack depth to be equal to the thickness of the cladding layer (about 6 mm) under this load case using the ASME K Ic reference curve methodology. This study is aimed to develop a methodology to give a more precise fracture assessment of the O1 reactor under cold loading scenarios. Some of the main objectives of this study have been as below: To prepare a material which can simulate the mechanical properties and RT NDT of the O1 reactor at the end-of-life conditions. To conduct a fracture mechanics test program to cover the essential influencing factors, such as crack geometry (shallow and deep cracks) and loading condition (uniaxial and biaxial) on the cleavage fracture toughness. To perform fracture mechanics analyses to identify a suitable methodology for assessment of the experimental results. To study the responses of engineering fracture assessment methods to the experimental results from the clad specimens. To propose a fracture assessment procedure for determination of the acceptable and critical flaw sizes in the 01 reactor under the cold loading events. A test program consisted of experiments on standard SEN(B) specimens and clad beams, containing surface cracks was conducted during the course of this project. A total of nine clad beams and clad cruciform specimens were tested under uniaxial and biaxial loading. The test material is reactor steel of type A 508 Grade B, which is specially heat-treated to

  19. Fiscal 1999 technical survey report. Model project implementation feasibility study in India on effective utilization of blast furnace gas pressure energy; 1999 nendo Indo ni okeru koro gas atsuryoku energy yuko riyo model jigyo jisshi kanosei chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    From the viewpoint of energy utilization stated above, blast furnace top pressure recovery turbine (TRT) unit installability was studied at Bhilai Steel Works of Steel Authority of India, Ltd., Bokaro Steel Works of Steel Authority of India, Ltd., and Visakhapatnum Steel Works of Rashtriya Ispat Nigem. The energy consumption rate at an Indian steelmaking plant is 8Gcal/t-steel, which is larger than 5-6Gcal/t-steel of Japan and therefore needs improvement. Out of the blast furnaces in India, 26 are larger than 1,000m{sup 3}, and two of them are provided with a TRT device of now-defunct Soviet Union manufacture. The blast furnaces were examined for pressure at the top, amount of gas at the top, amount of dust, and safeness in operation. The No. 2 blast furnace of the Borkaro plant was selected for the project, and studies were made for a wet type TRT device. Improvements to be achieved by TRT device installation were calculated to be a TRT output of 5,900kW, power output of 49,100MWh/year, saved crude oil amount of 12,990toe/year, and CO2 reduction of 40,200 tons-CO2/year. (NEDO)

  20. The Influence of Allocation on the Carbon Footprint of Electricity Production from Waste Gas, a Case Study for Blast Furnace Gas

    Directory of Open Access Journals (Sweden)

    Joeri Van Mierlo

    2013-03-01

    Full Text Available Producing electricity from waste gas is an after treatment for waste gas while recovering the energy content. This paper addresses the methodology to calculate the effect that waste gas energy recovery has on lowering the impact of climate change. Greenhouse gases are emitted while burning the waste gas. However, a thorough study should include the production of the feedstock as well as the production of the infrastructure. A framework is developed to calculate the environmental impact of electricity production from waste gas with a life cycle approach. The present paper has a twofold purpose: to assess the climate change impact of generating electricity with blast furnace gas (BFG as a waste gas from the steel industry; and to establish a sensitivity assessment of the environmental implications of different allocation rules.

  1. Spectrum of abdominal organ injury in a primary blast type

    Directory of Open Access Journals (Sweden)

    Amin Abid

    2009-12-01

    Full Text Available Abstract Introduction Abdominal organ injury in a primary blast type is always challenging for diagnosis. Air containing abdominal viscera is most vulnerable to effects of primary blast injury. In any patient exposed to a primary blast wave who presents with an acute abdomen, an abdominal organ injury is to be kept in a clinical suspicion. Aim Study various abdominal organ injuries occurring in a primary type of blast injury. Material and methods: All those who had exploratory laparotomy for abdominal organ injuries after a primary blast injury for a period of 10 years from January 1998 - January 2008 were included in this retrospective study. Results Total 154 patients had laparotomy for abdominal organ injuries with a primary blast type of injury. Small intestine was damaged in 48 patients (31.1% followed by spleen in 22.7% cases. 54 patients (35.06% had more than one organ injured. Liver laceration was present in 30 patients (19.48%. Multiple small gut perforations were present in 37 patients (77.08%. Negative laparotomy was found in 5 patients (3.24% whereas 3 (1.94% had re-exploration. Mortality was present in 6 patients (3.89%. Conclusions Primary blast injury causes varied abdominal organ injuries. Single or multiple organ damage can be there. Small intestine is commonest viscera injured. Laparotomy gives final diagnosis.

  2. Blasting agent package

    Energy Technology Data Exchange (ETDEWEB)

    Fox, R.

    1971-03-17

    A protected preassembled package for blasting agents susceptible to desensitization by water consists of, in combination: (1) an inner rigid and self-supporting tube, the upper end of which is suited to be connected, or attached, to the discharge end of a loading hose for a blasting agent and the lower end of which is open; and (2) a flexible tubular liner made of water-resistant film, having a diameter greater than that of the inner tube and a length at least equal to the desired depth of its insertion into the borehole, the liner being sleeved over the length of the inner tube, the upper end of the liner being attached to the inner tube and the lower end of the liner being closed so as to prevent substantial discharge of the explosive mixture therefrom when the latter is pumped into it. (24 claims)

  3. 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.

  4. Blasting technology advances

    Energy Technology Data Exchange (ETDEWEB)

    1990-04-01

    Nitroglycerine explosives are increasingly giving way to emulsions and low cost Anfo compositions, the latter sometimes incorporating emulsion in order to improve water resistance and performance. The aim is to produce an explosive which is extremely efficient, relatively safe and can be tailored to meet user requirements. Discussion is presented of emulsion delivery systems, initiation systems, electronic detonators, computer blast modelling, directional explosives, underground automation, and the development of Soviet explosives. 3 refs., 4 figs.

  5. Evaluation of blast-induced vibration effects on structures 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Rim; Jeon, Gyu Shick; Lee, Dae Soo; Joo, Kwang Ho; Lee, Woong Keon [Korea Electrotechnology Research Inst., Changwon (Korea, Republic of); Ryu, Chang Ha; Chung, So Keul; Lee, Kyung Won; Shin, Hee Soon; Chun, Sun Woo; Park, Yeon Jun; Synn, Joong Ho; Choi, Byung Hee [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-31

    Due to the difficulties of obtaining construction site for new plants, following ones are inevitably being built in the site adjacent to existing power plants. Therefore considerable thought has been recently given to the dynamic loading generated by blasting works near the plants to maintain the safety of structures and facilities in power plants. Our own standard for safety level of blast vibration is not prepared yet, and foreign standards have been generally employed without theoretical and experimental verification. Safety-related structures of power plants and facilities have to be protected against the effects of possible hazards due to blast vibration. Earthquakes have been considered a major dynamic design loading as a requirement of plant design, but the effects of blast-induced vibration are not. In order to ensure the safety, rational safe criterion should be established and blast design should be satisfy it, which requires the development of a model for prediction of vibration level through more systematic measurement and analysis. The main objectives of the study are : to provide background data for establishing the rational safe vibration limits, to develop models for prediction of blast vibration level, to establish safe blast design criterion, and to accumulate techniques for field measurements, data acquisition and analysis (author). 80 refs., 347 figs.

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

    CSIR Research Space (South Africa)

    van Dyk, T

    2006-09-01

    Full Text Available 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... explosive principles – Shock effect (brisance) – Blast effect • Test methods • Protection concepts • Test results Slide 3 © CSIR 2006 www.csir.co.za Goals: Compare LEAP study results with field injuries Investigate energy...

  7. 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.

  8. Evaluation of Grade 120 Granulated Ground blast Furnace Slag.

    Science.gov (United States)

    1999-06-01

    This study evaluates Grade 120 Granulated Ground Blast Furnace Slag (GGBFS) and its effect on the properties of hydraulic cement concretes used in structural and pavement construction. Several mix designs, structural and pavement, were used for this ...

  9. Analysis of over-pressure mechanisms in the Uinta Basin, Utah

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, B.; Bredehoeft, J. [Geological Survey, Menlo Park, CA (United States)

    1995-03-01

    Extremely high pore fluid pressures exist in the area of the Altamount/Bluebell oil field in the Uinta basin, Utah. We discuss two possible mechanisms for the cause of these over-pressures in this paper: (1) compaction disequilibrium, and (2) conversion of kerogen to liquid hydrocarbon (oil). Compaction disequilibrium occurs during periods of rapid sedimentation. If the permeability of deeply buried strata is low, then connate water within the rock matrix does not escape rapidly enough as compaction occurs; as sedimentary deposition continues, high pore fluid pressures develop. Conversion of solid kerogen to a liquid generates both a liquid and additional pore space for the liquid to occupy. If the volume of the liquid generated is just sufficient to fill the pore space generated, then there will be no accompanying effect on the pore pressure. If the liquid is less dense than the solid it replaces, then there is more liquid than pore space created; pore pressure will increase, causing flow away from the area of the reaction. Pore pressure is a sensitive measure of the balance between hydrocarbon generation and expulsion from the source into adjacent strata. If high pore pressures exist only where source rocks are thought to be generating oil, then kerogen conversion is a likely over-pressure mechanism. However, if over-pressures are found in low-permeability strata regardless of source rock proximity, then sedimentary compaction is probably a more dominant mechanism.

  10. Oil injection into the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Dongsheng Liao; Mannila, P.; Haerkki, J.

    1997-12-31

    Fuel injection techniques have been extensively used in the commercial blast furnaces, a number of publications concerning the fuels injection have been reported. This present report only summarizes the study achievements of oil injection due to the research need the of authors, it includes the following parts: First, the background and the reasons reducing coke rate of oil injection are analyzed. Reducing coke rate and decreasing the ironmaking costs are the main deriving forces, the contents of C, H and ash are direct reasons reducing coke rate. It was also found that oil injection had great effects on the state of blast furnace, it made operation stable, center gas flow develop fully, pressure drop increase, descent speed of burden materials decrease and generation of thermal stagnation phenomena, the quality of iron was improved. Based on these effects, as an ideal mean, oil injection was often used to adjust the state of blast furnace. Secondly, combustion behavior of oil in the raceway and tuyere are discussed. The distribution of gas content was greatly changed, the location of CO, H{sub 2} generation was near the tuyere; the temperature peak shifts from near the raceway boundary to the tuyere. Oxygen concentration and blast velocity were two important factors, it was found that increasing excess oxygen ratio 0.9 to 1.3, the combustion time of oil decreases 0.5 msec, an increase of the blast velocity results in increasing the flame length. In addition, the nozzle position and oil rate had large effects on the combustion of oil. Based on these results, the limit of oil injection is also discussed, soot formation is the main reason limiting to further increase oil injection rate, it was viewed that there were three types of soot which were generated under blast furnace operating conditions. The reason generating soot is the incomplete conversion of the fuel. Finally, three methods improving combustion of oil in the raceway are given: Improvement of oil

  11. Numerical simulation of muzzle blast

    NARCIS (Netherlands)

    Tyler-Street, M.

    2014-01-01

    Structural design methods for naval ships include environmental, operational and military load cases. One of the operational loads acting on a typical naval vessel is the muzzle blast from a gun. Simulating the muzzle blast load acting on a ship structure with CFD and ALE methods leads to large

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

    Science.gov (United States)

    Cevizci, Halim

    2014-10-01

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

  13. Development and Application of Blast Casting Technique in Large-Scale Surface Mines: A Case Study of Heidaigou Surface Coal Mine in China

    Directory of Open Access Journals (Sweden)

    Li Ma

    2016-01-01

    Full Text Available Blast casting is a high-efficiency technique applied in surface mines for overburden removal and results in stripping cost savings. According to ballistic theory and center-of-mass frame basic movement principles, key factors influencing blast casting effect were analyzed, which include bench height and mining panel width, inclined angle of blast holes, explosive unit consumption (EUC, delay-time interval, presplitting, and blast hole pattern parameters. An intelligent design software was developed for obtaining better breaking and casting effect, and the error rates predicted with actual result can be controlled with 10%. Blast casting technique was successfully applied in Heidaigou Surface Coal Mine (HSCM with more than 34% of material casted into the inner dump. A ramp ditch was set within the middle inner dump for coal transportation. The procedure of stripping and excavating was implemented separately and alternately in the two sections around the middle ramp ditch. An unconstrained-nonlinear model was deduced for optimizing the shift distance of the middle ramp. The calculation results show that optimum shift distance of HSCM is 480 m, and the middle ditch should be shifted after 6 blast casting mining panels being stripped.

  14. Early clearance of peripheral blasts measured by flow cytometry during the first week of AML induction therapy as a new independent prognostic factor: a GOELAMS study.

    Science.gov (United States)

    Lacombe, F; Arnoulet, C; Maynadié, M; Lippert, E; Luquet, I; Pigneux, A; Vey, N; Casasnovas, O; Witz, F; Béné, M C

    2009-02-01

    An early appreciation of treatment efficacy could be very useful in acute myeloblastic leukemia (AML), and a prognostic value has been suggested for the morphological assessment of decrease in blasts during induction therapy. More sensitive, multiparametric flow cytometry (FCM) can detect far lower blast counts, allowing for a precise and reliable calculation of blast cell decrease rate (BDR). Such a multiparametric FCM four-colours/single-tube protocol, combining CD11b, CD45-ECD and CD16-PC5, was applied to peripheral blood samples from 130 AML patients, collected daily during induction chemotherapy. Normalized blast cell percentages were used to calculate the relevant decrease slopes. Slope thresholds (-15), or the time required to reach 90% depletion of the peripheral blast load (5 days), was strongly associated with the achievement of complete remission (P<0.0001). Log-rank test and Cox model showed that they also carried high statistical significance (P<0.0001) for disease-free survival. The prognostic value of cytogenetic features, confirmed in this series, was refined by BDR, which allowed to discriminate between good- and poor-risk patients among those with intermediate or normal karyotypes. This simple FCM protocol allows for an accurate prognostic sequential approach adapted to the determination of decrease in peripheral blast cells during induction chemotherapy.

  15. 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.

  16. NCBI BLAST+ integrated into Galaxy.

    Science.gov (United States)

    Cock, Peter J A; Chilton, John M; Grüning, Björn; Johnson, James E; Soranzo, Nicola

    2015-01-01

    The NCBI BLAST suite has become ubiquitous in modern molecular biology and is used for small tasks such as checking capillary sequencing results of single PCR products, genome annotation or even larger scale pan-genome analyses. For early adopters of the Galaxy web-based biomedical data analysis platform, integrating BLAST into Galaxy was a natural step for sequence comparison workflows. The command line NCBI BLAST+ tool suite was wrapped for use within Galaxy. Appropriate datatypes were defined as needed. The integration of the BLAST+ tool suite into Galaxy has the goal of making common BLAST tasks easy and advanced tasks possible. This project is an informal international collaborative effort, and is deployed and used on Galaxy servers worldwide. Several examples of applications are described here.

  17. 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.

  18. 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.

  19. Flow of supersonic jets across flat plates: Implications for ground-level flow from volcanic blasts

    Science.gov (United States)

    Orescanin, Mara M.; Prisco, David; Austin, Joanna M.; Kieffer, Susan W.

    2014-04-01

    We report on laboratory experiments examining the interaction of a jet from an overpressurized reservoir with a canonical ground surface to simulate lateral blasts at volcanoes such as the 1980 blast at Mount St. Helens. These benchmark experiments test the application of supersonic jet models to simulate the flow of volcanic jets over a lateral topography. The internal shock structure of the free jet is modified such that the Mach disk shock is elevated above the surface. In elevation view, the width of the shock is reduced in comparison with a free jet, while in map view the dimensions are comparable. The distance of the Mach disk shock from the vent is in good agreement with free jet data and can be predicted with existing theory. The internal shock structures can interact with and penetrate the boundary layer. In the shock-boundary layer interaction, an oblique shock foot is present in the schlieren images and a distinctive ground signature is evident in surface measurements. The location of the oblique shock foot and the surface demarcation are closely correlated with the Mach disk shock location during reservoir depletion, and therefore, estimates of a ground signature in a zone devastated by a blast can be based on the calculated shock location from free jet theory. These experiments, combined with scaling arguments, suggest that the imprint of the Mach disk shock on the ground should be within the range of 4-9 km at Mount St. Helens depending on assumed reservoir pressure and vent dimensions.

  20. Blast from the past

    Science.gov (United States)

    Carlowicz, Michael

    1996-02-01

    Forget dynamite or hydraulic and mechanical drills. Industrial and federal researchers have started boring holes with rocket fuel. In a cooperative arrangement between Sandia National Laboratory, Global Environmental Solutions, and Universal Tech Corp., scientists and engineers extracted fuel from 200 rocket motors and used it as a mining explosive. In a demonstration completed last fall, researchers used 4950 kg of solid rocket propellant to move more than 22,500 metric tons of rock from the Lone Star Quarry in Prairie, Oklahoma. They found that the fuel improved blast energy and detonation velocity over traditional explosives, and it required fewer drill holes.

  1. Trouble shooting problem blasts

    Energy Technology Data Exchange (ETDEWEB)

    Konya, K.D. [Society of Explosive Engineers, Montville, OH (United States)

    1996-02-01

    There have been many occurrences of water-gel or emulsion explosives or heavy Anfo`s (ammonium nitrate and fuel oil) either not detonating in some blast holes in surface coal mining operations, or producing yellow or reddish-brown fumes upon reaction. The explosives rely on entrapped gas to detonate properly. It is important to control the size of the bubble and the dispersion of gas bubbles throughout the explosive. The article discusses and compares the use of microspheres and of gassing agents for detonation control.

  2. Dismounted Complex Blast Injury.

    Science.gov (United States)

    Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R

    2012-01-01

    The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.

  3. 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

  4. Control technology for crystalline silica exposures in construction: wet abrasive blasting.

    Science.gov (United States)

    Golla, Vijay; Heitbrink, William

    2004-03-01

    This study was designed to document the effect that wet abrasive blasting has on reducing worker exposure to crystalline silica, which has been associated with silicosis and premature death. In this study, worker exposure to respirable crystalline silica was monitored during wet abrasive blasting on the exterior walls of a parking garage to remove surface concrete and expose the underlying aggregate. In this process a wet sand mix comprised of 80% dry sand and 20% water was used. Sampling and analysis revealed that the geometric mean respirable quartz concentration was 0.2 mg/m(3) for workers conducting abrasive blasting and 0.06 mg/m(3) for helpers. When abrasive blasting was conducted in areas that apparently had reduced natural ventilation, dust exposures appeared to increase. When compared with other published data, this case study suggests that wet abrasive blasting causes less exposure to crystalline silica than dry abrasive blasting.

  5. The use of computer blast simulations to improve blast quality

    International Nuclear Information System (INIS)

    Favreau, R.F.; Kuzyk, G.W.; Babulic, P.J.; Tienkamp, N.J.

    1989-01-01

    Atomic Energy of Canada Limited is constructing an Underground Research Laboratory (URL) as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in crystalline rock formations. Careful blasting methods have been used to minimize damage to the excavation surfaces. Good wall quality is desirable in any excavation. In excavations required for nuclear waste disposal, the objective will be to minimize blast-induced fractures which may complicate the sealing requirements necessary to control subsequent movement of groundwater around a sealed disposal vault. The construction of the URL has provided an opportunity for the development of controlled blasting methods, especially for drilling accuracy and optimization of explosive loads in the perimeter and cushion holes. The work has been assisted by the use of blast simulations with the mathematical model Blaspa. This paper reviews the results of a recent project to develop a controlled method of full-face blasting, and compares the observed field results with the results of a blast simulator called Blaspa. Good agreement is found between the two, and the Blaspa results indicate quantitatively how the blasting may induce damage in the final excavation surface. In particular, the rock in the final wall may be stressed more severely by the cushion holes than by the perimeter holes. Bootleg of the rock between the perimeter and cushion rows occurs when the burst-out velocity imparted to it by the explosive loads in the perimeter holes is inadequate. In practice, these findings indicate that quantitative rock stress and rock burst-out velocity criteria can be established to minimize wall damage and bootleg. Thus, blast simulations become an efficient way to design controlled blasting and to optimize quality of the excavation surface

  6. 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.

  7. Centrifugal shot blast system

    International Nuclear Information System (INIS)

    1998-02-01

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

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

    African Journals Online (AJOL)

    Michael O. Mensah

    2015-12-02

    Dec 2, 2015 ... Case Study* ... using the proposed blast parameters increased by 14.3 to 50.0% for ore zones and 12.5 ... of gold, compels technologists in the industry to .... 127. Bench Height (H), m. 4. 4. 4.5. 4.5. 4.5. 4.5. Sub-drill (U), m. 0.5.

  9. 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.

  10. 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.

  11. Analysis of effect of aluminized canfo on fragmentation and economics of quarry blast

    International Nuclear Information System (INIS)

    Shoukat, M.R.; Akram, M.

    2016-01-01

    Reducing the explosive cost for drilling and blasting operations conducted at limestone quarries is a major concern for every mine operator. In Pakistan, to reduce explosive cost, Calcium Ammonium Nitrate with Fuel Oil (CANFO) is commonly used in explosive column charge in place of Ammonium nitrate fuel oil (ANFO). However, fragmentation of the blast has to be compromised over cost reduction. Hence it is desired to enhance the performance of CANFO. In this study, Aluminum (AL) is added into Calcium Ammonium Nitrate (CAN) to analyze its effect on fragmentation and economics of blast at a limestone quarry. Experimental shots were held using rectangular drilling pattern (current practice), using CANFO and ALCANFO in separate shots, while all other blast design factors were kept constant. Post blast analysis for all shots was done in terms of fragmentation and cost. The shots using ALCANFO proved to be better fragmentation wise, and also assured a saving of 1.6% in drilling and blasting costs. (author)

  12. 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.

  13. Hydrogen gettering the overpressure gas from highly radioactive liquids

    International Nuclear Information System (INIS)

    Riley, D.L.; Schicker, J.R.

    1996-04-01

    Remediation of current inventories of high-activity radioactive liquid waste (HALW) requires transportation of Type-B quantities of radioactive material, possibly up to several hundred liters. However, the only currently certified packaging is limited to quantities of 50 ml (0.01 gal) quantities of Type-B radioactive liquid. Efforts are under way to recertify the existing packaging to allow the shipment of up to 4 L (1.1 gal) of Type-B quantities of HALW, but significantly larger packaging could be needed in the future. Scoping studies and preliminary designs have identified the feasibility of retrofitting an insert into existing casks, allowing the transport of up to 380 L (100 gal) of HALW. However, the insert design and ultimate certification strategy depend heavily on the gas-generating attributes of the HALW. A non-vented containment vessel filled with HALW, in the absence of any gas-mitigation technologies, poses a deflagration threat and, therefore, gas generation, specifically hydrogen generation, must be reliably controlled during all phases of transportation. Two techniques are available to mitigate hydrogen accumulation: recombiners and getters. Getters have an advantage over recombiners in that oxides are not required to react with the hydrogen. A test plan was developed to evaluate three forms of getter material in the presence of both simulated HALW and the gases that are produced by the HALW. These tests demonstrated that getters can react with hydrogen in the presence of simulated waste and in the presence of several other gases generated by the HALW, such as nitrogen, ammonia, nitrous oxide, and carbon monoxide. Although the use of such a gettering system has been shown to be technically feasible, only a preliminary design for its use has been completed. No further development is planned until the requirement for bulk transport of Type-B quantities of HALW is more thoroughly defined

  14. Interim Tests of the Effects of Long Duration Blast-Type FLows on Fires in Urban Interiors and Contents of Emergency Operating Centers (EOC)

    Science.gov (United States)

    1976-01-01

    orifices A,f and A„ respectively) were conducted, all at a (.ornpression chamber overpressure of about 2 psi. During the current testing program, an...actually reflect a pressure decrease with time derived from the modified exponencial relationship given in Eq. 2-14. Blast Flow vs. LDFF Flow Through...indicating the presence of strong eddies and counter currents . »"JCüat^Liöt -r*"- aK.m.ju.J’ aBBtflbsSii ^’ :•.. ’ ä l 1 2 \\ 2 Lzi .3

  15. 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.

  16. 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

  17. An improved probit method for assessment of domino effect to chemical process equipment caused by overpressure.

    Science.gov (United States)

    Mingguang, Zhang; Juncheng, Jiang

    2008-10-30

    Overpressure is one important cause of domino effect in accidents of chemical process equipments. Damage probability and relative threshold value are two necessary parameters in QRA of this phenomenon. Some simple models had been proposed based on scarce data or oversimplified assumption. Hence, more data about damage to chemical process equipments were gathered and analyzed, a quantitative relationship between damage probability and damage degrees of equipment was built, and reliable probit models were developed associated to specific category of chemical process equipments. Finally, the improvements of present models were evidenced through comparison with other models in literatures, taking into account such parameters: consistency between models and data, depth of quantitativeness in QRA.

  18. Assessment of Blasting Performance Using Electronic Vis-à-Vis Shock Tube Detonators in Strong Garnet Biotite Sillimanite Gneiss Formations

    Science.gov (United States)

    Sharma, Suresh Kumar; Rai, Piyush

    2016-04-01

    This paper presents a comparative investigation of the shock tube and electronic detonating systems practised in bench blasting. The blast trials were conducted on overburden rocks of Garnet Biotite Sillimanite Gneiss formations in one of the largest metalliferous mine of India. The study revealed that the choice of detonating system was crucial in deciding the fragment size and its distribution within the blasted muck-piles. The fragment size and its distribution affected the digging rate of excavators. Also, the shape of the blasted muck-pile was found to be related to the degree of fragmentation. From the present work, it may be inferred that in electronic detonation system, timely release of explosive energy resulted in better overall blasting performance. Hence, the precision in delay time must be considered in designing blast rounds in such overburden rock formations. State-of-art image analysis, GPS based muck-pile profile plotting techniques were rigorously used in the investigation. The study revealed that a mean fragment size (K50) value for shock tube detonated blasts (0.55-0.59 m) was higher than that of electronically detonated blasts (0.43-0.45 m). The digging rate of designated shovels (34 m3) with electronically detonated blasts was consistently more than 5000 t/h, which was almost 13 % higher in comparison to shock tube detonated blasts. Furthermore, favourable muck-pile shapes were witnessed in electronically detonated blasts from the observations made on the dozer performance.

  19. Comparison of under-pressure and over-pressure pulse tests conducted in low-permeability basalt horizons at the Hanford Site, Washington State

    International Nuclear Information System (INIS)

    Thorne, P.D.; Spane, F.A. Jr.

    1984-10-01

    Over-pressure pulse tests (pressurized slug tests have been widely used by others for hydraulic characterization of low-permeability ( -8 m/sec) rock formations. Recent field studies of low-permeability basalt horizons at the Hanford Site, Washington, indicate that the under-pressure pulse technique is also a viable test method for hydraulic characterization studies. For over-pressure pulse tests, fluid within the test system is rapidly pressurized and the associated pressure decay is monitored as compressed fluid within the test system expands and flows into the test formation. Under-pressure pulse tests are conducted in a similar manner by abruptly decreasing the pressure of fluid within the test system, and monitoring the associated increase in pressure as fluid flows from the formation into the test system. Both pulse test methods have been used in conjunction with other types of tests to determine the hydraulic properties of selected low-permeability basalt horizons at Hanford test sites. Results from both pulse test methods generally provide comparable estimates of hydraulic properties and are in good agreement with those from other tests

  20. Activity of Bruton's tyrosine-kinase inhibitor ibrutinib in patients with CD117-positive acute myeloid leukaemia: a mechanistic study using patient-derived blast cells.

    Science.gov (United States)

    Rushworth, Stuart A; Pillinger, Genevra; Abdul-Aziz, Amina; Piddock, Rachel; Shafat, Manar S; Murray, Megan Y; Zaitseva, Lyubov; Lawes, Matthew J; MacEwan, David J; Bowles, Kristian M

    2015-05-01

    Roughly 80% of patients with acute myeloid leukaemia have high activity of Bruton's tyrosine-kinase (BTK) in their blast cells compared with normal haemopoietic cells, rendering the cells sensitive to the oral BTK inhibitor ibrutinib in vitro. We aimed to develop the biological understanding of the BTK pathway in acute myeloid leukaemia to identify clinically relevant diagnostic information that might define a subset of patients that should respond to ibrutinib treatment. We obtained acute myeloid leukaemia blast cells from unselected patients attending our UK hospital between Feb 19, 2010, and Jan 20, 2014. We isolated primary acute myeloid leukaemia blast cells from heparinised blood and human peripheral blood mononuclear cells to establish the activity of BTK in response to CD117 activation. Furthermore, we investigated the effects of ibrutinib on CD117-induced BTK activation, downstream signalling, adhesion to primary bone-marrow mesenchymal stromal cells, and proliferation of primary acute myeloid leukaemia blast cells. We used the Mann-Whitney U test to compare results between groups. We obtained acute myeloid leukaemia blast cells from 29 patients. Ibrutinib significantly inhibited CD117-mediated proliferation of primary acute myeloid leukaemia blast cells (p=0·028). CD117 activation increased BTK activity by inducing phosphorylated BTK in patients with CD117-positive acute myeloid leukaemia. Furthermore, ibrutinib inhibited CD117-induced activity of BTK and downstream kinases at a concentration of 100 nM or more. CD117-mediated adhesion of CD117-expressing blast cells to bone-marrow stromal cells was significantly inhibited by Ibrutinib at 500 nM (p=0·028) INTERPRETATION: As first-in-man clinical trials of ibrutinib in patients with acute myeloid leukaemia commence, the data suggest not all patients will respond. Our findings show that BTK has specific pro-tumoural biological actions downstream of surface CD117 activation, which are inhibited by ibrutinib

  1. 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.

  2. Influence of overpressure on formation velocity evaluation of Neogene strata from the eastern Bengal Basin, Bangladesh

    Science.gov (United States)

    Zahid, Khandaker M.; Uddin, Ashraf

    2005-06-01

    Interpretation of sonic log data of anticlinal structures from eastern Bangladesh reveals significant variations of acoustic velocity of subsurface strata. The amount of variation in velocity is 32% from Miocene to Pliocene stratigraphic units in Titas and Bakhrabad structure, whereas 21% in Rashidpur structure. Velocity fluctuations are influenced by the presence of gas-bearing horizons, with velocities of gas-producing strata 3-7% lower than laterally equivalent strata at similar depth. Average velocities of Miocene Boka Bil and Bhuban formations are, respectively, 2630 and 3480 m/s at Titas structure; 2820 and 3750 m/s at Bakhrabad; and 3430 and 3843 m/s at the Rashidpur structure. From the overall velocity-depth distribution for a common depth range of 915-3000 m, the Titas, Bakhrabad and Rashidpur structures show a gradual increase in velocity with depth. In contrast, the Sitakund anticline in SE Bangladesh reveals a decrease in velocity with depth from 3000 to 4000 m, probably due to the presence of overpressured mudrocks of the Bhuban Formation. Tectonic compression, associated with the Indo-Burmese plate convergence likely contributed the most toward formation of subsurface overpressure in the Sitakund structure situated in the Chittagong-Tripura Fold Belt of the eastern Bengal basin, Bangladesh.

  3. 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

  4. 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

  5. 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)

  6. Blast furnace hearth lining: post mortem analysis

    International Nuclear Information System (INIS)

    Almeida, Bruno Vidal de; Vernilli Junior, Fernando

    2017-01-01

    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"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)

  7. The Blast Fungus Decoded: Genomes in Flux

    Directory of Open Access Journals (Sweden)

    Thorsten Langner

    2018-04-01

    Full Text Available Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae, which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name, M. oryzae is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018, https://doi.org/10.1128/mBio.01219-17 reports the most extensive population genomic analysis of the blast fungus thus far. M. oryzae consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining M. oryzae as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases.

  8. The Blast Fungus Decoded: Genomes in Flux.

    Science.gov (United States)

    Langner, Thorsten; Białas, Aleksandra; Kamoun, Sophien

    2018-04-17

    Plant disease outbreaks caused by fungi are a chronic threat to global food security. A prime case is blast disease, which is caused by the ascomycete fungus Magnaporthe oryzae (syn. Pyricularia oryzae ), which is infamous as the most destructive disease of the staple crop rice. However, despite its Linnaean binomial name, M. oryzae is a multihost pathogen that infects more than 50 species of grasses. A timely study by P. Gladieux and colleagues (mBio 9:e01219-17, 2018, https://doi.org/10.1128/mBio.01219-17) reports the most extensive population genomic analysis of the blast fungus thus far. M. oryzae consists of an assemblage of differentiated lineages that tend to be associated with particular host genera. Nonetheless, there is clear evidence of gene flow between lineages consistent with maintaining M. oryzae as a single species. Here, we discuss these findings with an emphasis on the ecologic and genetic mechanisms underpinning gene flow. This work also bears practical implications for diagnostics, surveillance, and management of blast diseases. Copyright © 2018 Langner et al.

  9. Probabilistic fracture mechanics analysis of boiling water reactor vessel for cool-down and low temperature over-pressurization transients

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Soon; Choi, Young Hwan; Jhung, Myung Jo [Safety Research Division, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-04-15

    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.

  10. Possible mechanism of horizontal overpressure generation of the Khibiny, Lovozero, and Kovdor ore clusters on the Kola Peninsula

    Science.gov (United States)

    Rebetsky, Yu. L.; Sim, L. A.; Kozyrev, A. A.

    2017-07-01

    The paper discusses questions related to the generation of increasing crustal horizontal compressive stresses compared to the idea of the standard gravitational state at the elastic stage or even from the prevalence of horizontal compression over vertical stress equal to the lithostatic pressure. We consider a variant of superfluous horizontal compression related to internal lithospheric processes occurrin in the crust of orogens, shields, and plates. The vertical ascending movements caused by these motions at the sole of the crust or the lithosphere pertain to these and the concomitant exogenic processes giving rise to denudation and, in particular, to erosion of the surfaces of forming rises. The residual stresses of the gravitational stressed state at the upper crust of the Kola Peninsula have been estimated for the first time. These calculations are based on the volume of sediments that have been deposited in Arctic seas beginning from the Mesozoic. The data speak to the possible level of residual horizontal compressive stresses up to 90 MPa in near-surface crustal units. This estimate is consistent with the results of in situ measurements that have been carried out at the Mining Institute of the Kola Science Center, Russian Academy of Sciences (RAS), for over 40 years. It is possible to forecast the horizontal stress gradient based on depth using our concept on the genesis of horizontal overpressure, and this forecasting is important for studying the formation of endogenic deposits.

  11. 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

  12. The use of computer blast simulations to improve blast quality

    International Nuclear Information System (INIS)

    Favreau, R.F.; Kuzzyk, G.W.; Babulic, P.J.; Morin, R.A.; Tienkamp, N.J.

    1987-01-01

    An underground research laboratory (URL) has been constructed as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal in deep crystalline rock formations. Careful blasting methods have been used to minimize damage to the excavation surfaces. This paper reviews the results of the program to develop controlled blasting for the full-face method, comparing the field observed results achieved with the simulated theoretical results. The simulated results indicate how the blasting may damage the excavation surface. Results suggest that the rock around the final wall is stressed more severely by the cushion holes than by the perimeter holes and that bootleg of the rock between the perimeter and cushion rows occurs when the burst-out velocity imparted to it by the explosive loads in the perimeter holes is inadequate

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Acid etching and plasma sterilization fail to improve osseointegration of grit blasted titanium implants

    DEFF Research Database (Denmark)

    Mortensen, Mikkel Saksø; Jakobsen, Stig Storgaard; Saksø, Henrik

    2012-01-01

    Interaction between implant surface and surrounding bone influences implant fixation. We attempted to improve the bone-implant interaction by 1) adding surface micro scale topography by acid etching, and 2) removing surface-adherent pro-inflammatory agents by plasma cleaning. Implant fixation...... was evaluated by implant osseointegration and biomechanical fixation.The study consisted of two paired animal sub-studies where 10 skeletally mature Labrador dogs were used. Grit blasted titanium alloy implants were inserted press fit in each proximal tibia. In the first study grit blasted implants were...... compared with acid etched grit blasted implants. In the second study grit blasted implants were compared with acid etched grit blasted implants that were further treated with plasma sterilization. Implant performance was evaluated by histomorphometrical investigation (tissue-to-implant contact, peri-implant...

  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. 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

  20. 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...

  1. Blasting Damage Predictions by Numerical Modeling in Siahbishe Pumped Storage Powerhouse

    Science.gov (United States)

    Eslami, Majid; Goshtasbi, Kamran

    2018-04-01

    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.

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

    Science.gov (United States)

    2015-08-14

    Regulation, Chapter IX. For Unclassified/Limited Distribution Documents: Destroy by any method that prevents disclosure of contents or reconstruction of...OVERPRESSURE WOUNDS AND INJURIES IMPACT STATIC TESTS PADS(CUSHIONS) TEST AND EVALUATION TRAUMA ...simplified version of the Facial and Ocular Countermeasure for Safety (FOCUS) headform. The FOCUS headform is commercially available through Humanetics

  3. 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)

  4. 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

    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......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...... with known density and yield stress when for instance deformed under water or subjected to a forced air pressure....

  5. Liquefied extinguishing agent discharge to an overpressure-sensitive enclosed volume

    Directory of Open Access Journals (Sweden)

    Hurda Lukáš

    2018-01-01

    Full Text Available The throttling of liquefied substances from high pressure vessels to an enclosed volume starting at atmospheric pressure is described in order to determine thermodynamic state of the extinguished room gaseous contents. Time dependent, 0D mathematical model is implemented describing the state inside the agent container, the isenthalpic throttling in the distribution system, agent vaporization and mixing with air. The agent is modelled as real gas. Other influences on the process including the heat transfer from selected solid parts inside the room and the gas mixture leakage out of the room are taken into account. Main outcome is an MS Excel tool for integrated fire extinguishers design optimization. The optimization balances the two contradictory requirements: Agent volumetric concentration to sustain the fire extinguishing capabilities and tolerable room overpressure. Agent fill weight and discharge time are being adjusted. The discharge time is controlled by the distribution piping and spray nozzles design. System operation is checked concerning various initial and boundary conditions.

  6. Atmospheric particulate emissions from dry abrasive blasting using coal slag

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskar Kura; Kalpalatha Kambham; Sivaramakrishnan Sangameswaran; Sandhya Potana [University of New Orleans, New Orleans, LA (United States). Department of Civil and Environmental Engineering

    2006-08-15

    Coal slag is one of the widely used abrasives in dry abrasive blasting. Atmospheric emissions from this process include particulate matter (PM) and heavy metals, such as chromium, lead, manganese, nickel. Quantities and characteristics of PM emissions depend on abrasive characteristics and process parameters. Emission factors are key inputs to estimate emissions. Experiments were conducted to study the effect of blast pressure, abrasive feed rate, and initial surface contamination on total PM (TPM) emission factors for coal slag. Rusted and painted mild steel surfaces were used as base plates. Blasting was carried out in an enclosed chamber, and PM was collected from an exhaust duct using U.S. Environment Protection Agency source sampling methods for stationary sources. Results showed that there is significant effect of blast pressure, feed rate, and surface contamination on TPM emissions. Mathematical equations were developed to estimate emission factors in terms of mass of emissions per unit mass of abrasive used, as well as mass of emissions per unit of surface area cleaned. These equations will help industries in estimating PM emissions based on blast pressure and abrasive feed rate. In addition, emissions can be reduced by choosing optimum operating conditions. 40 refs., 5 figs., 2 tabs.

  7. 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.

  8. 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)

  9. 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.

  10. Water in the blast hole

    Energy Technology Data Exchange (ETDEWEB)

    Pilshaw, S.R. [Pilshaw Associates, KS (United States)

    1995-10-01

    Water in the blast area is a considerable problem in US opencast coal mining. While gelatin dynamite was reasonably water resistant, Anfo is not. All potential solutions to this problem: the use of Anfo and emulsion (Heavy Anfo), pumping, draining, and the use of water bags, involve considerable extra cost. With small amounts of water an alternative solution has been formulated: the use of a self inflating gas bag to exclude water, and loading the Anfo from the water line up to the stemming level of the blasthole. Quite substantial water columns may be sealed off in this manner, with little or no deleterious effect on blast effects.

  11. 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

  12. 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

  13. A new method for calculating gas content of coal reservoirs with consideration of a micro-pore overpressure environment

    Directory of Open Access Journals (Sweden)

    Jinxing Song

    2017-05-01

    Full Text Available When the gas content of a coal reservoir is calculated, the reservoir pressure measured by well logging and well testing is generally used for inversion calculation instead of gas pressure. However, the calculation result is not accurate because the reservoir pressure is not equal to the gas pressure in overpressure environments. In this paper, coal samples of different ranks in Shanxi and Henan are collected for testing the capillary pressure of coal pores. Based on the formation process of CBM reservoirs and the hydrocarbon generation and expulsion history of coal beds, the forming mechanisms of micro-pore overpressure environments in coal reservoirs were analyzed. Accordingly, a new method for calculating the gas content of coal reservoirs with consideration of a micro-pore overpressure environment was developed. And it was used to calculate the gas content of No. 1 coal bed of the 2nd member of Lower Permian Shanxi Fm in the Zhongmacun Coal Mine in Jiaozuo, Henan. It is indicated that during the formation and evolution of coals, some solid organic matters were converted into gas and water, and gas–water contact is surely formed in pores. In the end, capillary pressure is generated, so the gas pressure in micro-pores is much higher than the hydrostatic column pressure, which results in a micro-pore overpressure environment. Under such an environment, gas pressure is higher than reservoir pressure, so the gas content of coal reservoirs calculated previously based on the conventional reservoir pressure evaluation are usually underestimated. It is also found that the micro-pore overpressure environment exerts a dominating effect on the CBM content calculation of 3–100 nm pores, especially that of 3–10 nm pores, but a little effect on that of pores >100 nm. In conclusion, this new method clarifies the pressure environment of CBM gas reservoirs, thereby ensuring the calculation accuracy of gas content of coal reservoirs.

  14. X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements

    International Nuclear Information System (INIS)

    Camarini, G.; Djanikian, J.G.

    1994-01-01

    This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95 0 C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab

  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. 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.

  17. Production of blast furnace coke from soft brown coal

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, G.; Wundes, H.; Schkommodau, F.; Zinke, H.-G. (VEB Gaskombinat Schwarze Pumpe (German Democratic Republic))

    1988-01-01

    Reviews experimental production and utilization of high quality brown coal coke in the GDR during 1985 and 1986. The technology of briquetting and coking brown coal dust is described; the superior parameters of produced coke quality are listed in comparison to those of regular industrial coke made from brown and black coal. Dust emission from high quality brown coal coke was suppressed by coke surface treatment with dispersion foam. About 4,200 t of this coke were employed in black coal coke substitution tests in a blast furnace. Substitution rate was 11%, blast furnace operation was positive, a substitution factor of 0.7 t black coal coke per 1 t of brown coal coke was calculated. Technology development of high quality brown coal coke production is regarded as complete; blast furnace coke utilization, however, requires further study. 8 refs.

  18. 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)

  19. NOBLAST and JAMBLAST: New Options for BLAST and a Java Application Manager for BLAST results.

    Science.gov (United States)

    Lagnel, Jacques; Tsigenopoulos, Costas S; Iliopoulos, Ioannis

    2009-03-15

    NOBLAST (New Options for BLAST) is an open source program that provides a new user-friendly tabular output format for various NCBI BLAST programs (Blastn, Blastp, Blastx, Tblastn, Tblastx, Mega BLAST and Psi BLAST) without any use of a parser and provides E-value correction in case of use of segmented BLAST database. JAMBLAST using the NOBLAST output allows the user to manage, view and filter the BLAST hits using a number of selection criteria. A distribution package of NOBLAST and JAMBLAST including detailed installation procedure is freely available from http://sourceforge.net/projects/JAMBLAST/ and http://sourceforge.net/projects/NOBLAST. Supplementary data are available at Bioinformatics online.

  20. Review of SKB`s ZEDEX Report - A study of the zone of excavation disturbance for blasted and bored tunnels - SKB ICR 96-03, Vol. 1-3

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, K [Berggeologiska Undersoekningar AB, Goeteborg (Sweden)

    1997-11-01

    We have reviewed and evaluated the contents of the ZEDEX report. The review has been focussed on investigation methods, results and interpretations. The conclusions of the review are that the ZEDEX was successful in some aspects. However, the study has not met with the objective of understanding the excavation disturbed zone (EDZ). A lot of questions remain to be answered as regards the origin, character and extent of the EDZ. Investigation of the hydraulic properties of the EDZ was not included as a major aim in the ZEDEX study and only some supporting studies were conducted. We find it regrettable that priority was not given to these aspects, since improved knowledge in this field is considered important with respect to the performance and safety of the repository. The review has identified a number of shortages in the expected outcome and objectives set up for the ZEDEX experiment that more or less have influenced the results of the study. Several problems of interpretation were introduced directly as a result of the unsatisfactory performance of the drill and blast drift. It would have been valuable if cautious blasting had been applied. A number of recommendations for future studies are made.

  1. 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

  2. Development of an Anatomically Accurate Finite Element Human Ocular Globe Model for Blast-Related Fluid-Structure Interaction Studies

    Science.gov (United States)

    2017-02-01

    nucleus green ) is attached to the shell of the eye via the zonule fibers (orange) and the ciliary body (pink). The zonule fibers are approximated in our...as shown in the literature.13,24 (a and b) A study conducted by Norman et al.24 with images from normal human subjects sectioned into 15 equal...Fig. 13 Scleral thickness variation procedure in the model: a) scleral thickness variation contours with thickness values noted from Norman et al

  3. Optimizing cast blasting efficiency using ANFO with liners

    Energy Technology Data Exchange (ETDEWEB)

    Madsen, A.

    2007-01-15

    As part of a five research project funded by the National Science Foundation, Peabody Energy studied three experimental cast blasts conducted at the North Antelope Rochelle mine site on July 24,28 and 31 2005. The initial purpose of this research project was to determine the influence that blast initiation sequence have on: NOx production; Face Displacement; Highwall damage; Explosive performance; Vibration emissions; Displacement; Surface swell; and Cast benefit. Two new discoveries on velocity of detonation (VoD) and pressure of detonation (PoD) were made as a result of this research project. Furthermore, a relationship between surface swell velocity and face velocity was also noted. 7 figs., 3 tabs.

  4. 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.

  5. Prevention of Blast-Related Injuries

    Science.gov (United States)

    2013-07-01

    influence of cerebrospinal fluid (CSF) on the shock wave response 3. Development of the geometric model for the head of a 23 55-kg Yucatan pig 4...of Tissue-Tek® optimum cutting compound and 20% sucrose (w/v) and frozen in a stream of liquid nitrogen (Saljo et al, 2008). The frozen blocks will...review of current models of the pig head under air blast loading 2. Development of a 2-D pig head FE model to study the influence of cerebrospinal fluid

  6. Prediction of vibration level in tunnel blasting; Tonneru kusshin happa ni yotte reiki sareru shindo no reberu yosoku ho

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, A. [Kumamoto Industries Univ, Kumamoto (Japan); Yamamoto, M. [Asahi Chemical Industry Co. Ltd., Tokyo (Japan); Inaba, C. [Nishimatsu Construction Co. Ltd., Kanagawa (Japan); Kaneko, K. [Hokkaido Univ (Japan)

    1997-08-01

    For avoiding the generation of public hazard due to ground vibration causes by blasting in tunneling, it is important to devise a blasting method for ensuring the level of the ground vibration caused thereby under a limit, and an exact predication of ground vibration before blasting is desirable. In this study, the characteristics of the ground vibration caused by tunnel blasting are analyzed, and a summary of amplitude spectra calculating method is described. A theoretical analysis method for predicting the vibration level is proposed based on spectrum-multiplicative method. Vibration caused by multistage blasting in tunneling is most strong and deemed as important. When observing the process of elastic wave motion caused by multistage blasting being measured, the process can be divided into three element processes in frequency area as vibration source spectrum, transmission attenuation spectrum and frequency response function vibrating test, and, with the multiplication of them, the amplitude spectra at an observation portion can be estimated. 12 refs., 12 figs.

  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. Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae) Alleviation in the United States.

    Science.gov (United States)

    Nalley, Lawton; Tsiboe, Francis; Durand-Morat, Alvaro; Shew, Aaron; Thoma, Greg

    2016-01-01

    Rice blast (Magnaporthe oryzae) is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA) show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion) impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in production.

  9. Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae Alleviation in the United States.

    Directory of Open Access Journals (Sweden)

    Lawton Nalley

    Full Text Available Rice blast (Magnaporthe oryzae is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in

  10. 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.

  11. 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

  12. Using a gel/plastic surrogate to study the biomechanical response of the head under air shock loading: a combined experimental and numerical investigation.

    Science.gov (United States)

    Zhu, Feng; Wagner, Christina; Dal Cengio Leonardi, Alessandra; Jin, Xin; Vandevord, Pamela; Chou, Clifford; Yang, King H; King, Albert I

    2012-03-01

    A combined experimental and numerical study was conducted to determine a method to elucidate the biomechanical response of a head surrogate physical model under air shock loading. In the physical experiments, a gel-filled egg-shaped skull/brain surrogate was exposed to blast overpressure in a shock tube environment, and static pressures within the shock tube and the surrogate were recorded throughout the event. A numerical model of the shock tube was developed using the Eulerian approach and validated against experimental data. An arbitrary Lagrangian-Eulerian (ALE) fluid-structure coupling algorithm was then utilized to simulate the interaction of the shock wave and the head surrogate. After model validation, a comprehensive series of parametric studies was carried out on the egg-shaped surrogate FE model to assess the effect of several key factors, such as the elastic modulus of the shell, bulk modulus of the core, head orientation, and internal sensor location, on pressure and strain responses. Results indicate that increasing the elastic modulus of the shell within the range simulated in this study led to considerable rise of the overpressures. Varying the bulk modulus of the core from 0.5 to 2.0 GPa, the overpressure had an increase of 7.2%. The curvature of the surface facing the shock wave significantly affected both the peak positive and negative pressures. Simulations of the head surrogate with the blunt end facing the advancing shock front had a higher pressure compared to the simulations with the pointed end facing the shock front. The influence of an opening (possibly mimicking anatomical apertures) on the peak pressures was evaluated using a surrogate head with a hole on the shell of the blunt end. It was revealed that the presence of the opening had little influence on the positive pressures but could affect the negative pressure evidently.

  13. 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

  14. Allo-SCT for  Philadelphia-negative myeloproliferative neoplasms in blast phase: a study from the Societe Française de Greffe de Moelle et de Therapie Cellulaire (SFGM-TC).

    Science.gov (United States)

    Cahu, X; Chevallier, P; Clavert, A; Suarez, F; Michallet, M; Vincent, L; Vigouroux, S; Blaise, D; Mariette, C; Bilger, K; Robin, M; Yakoub-Agha, I; Peffault de Latour, R; Mohty, M

    2014-06-01

    Progression of Philadelphia-negative myeloproliferative (MPN) or myelodysplastic/myeloproliferative neoplasms (MDS/MPN) to acute myeloid leukemia (AML) is an adverse event in the course of the disease. Although allogeneic hematopoietic SCT (allo-SCT) is considered as the only curative therapy, few data exist on the outcome of patients with Philadelphia-negative MPN or MDS/MPN in blast phase who received an allo-SCT. Sixty patients were included in this retrospective study. AML was secondary to an MPN in 43 cases, whereas AML evolved from an MDS/MPN in 17 cases. Patients received allo-SCT in CR or advanced disease in 26 cases and 34 cases, respectively. With a median follow-up of 31 months (range, 25-44), OS and leukemia-free survival (LFS) were, respectively, 18% and 9% at 3 years. CR at transplant was associated with an improved LFS in univariate and multivariate analysis. The 3-year LFS was 18% for patients undergoing allo-SCT in CR versus 3% in advanced disease (P=0.008). Absence of thrombosis and an intermediate or favorable AML karyotype were associated with an improved outcome for patients who received allo-SCT in CR. New strategies are needed to improve the outcome of patients with MPN-MDS/MPN in blast phase.

  15. Introgression of Blast Resistance Genes (Putative Pi-b and Pi-kh) into Elite Rice Cultivar MR219 through Marker-Assisted Selection

    Science.gov (United States)

    Tanweer, Fatah A.; Rafii, Mohd Y.; Sijam, Kamaruzaman; Rahim, Harun A.; Ahmed, Fahim; Ashkani, Sadegh; Latif, Mohammad A.

    2015-01-01

    Blast is the most common biotic stress leading to the reduction of rice yield in many rice-growing areas of the world, including Malaysia. Improvement of blast resistance of rice varieties cultivated in blast endemic areas is one of the most important objectives of rice breeding programs. In this study, the marker-assisted backcrossing strategy was applied to improve the blast resistance of the most popular Malaysian rice variety MR219 by introgressing blast resistance genes from the Pongsu Seribu 2 variety. Two blast resistance genes, Pi-b and Pi-kh, were pyramided into MR219. Foreground selection coupled with stringent phenotypic selection identified 15 plants homozygous for the Pi-b and Pi-kh genes, and background selection revealed more than 95% genome recovery of MR219 in advanced blast resistant lines. Phenotypic screening against blast disease indicated that advanced homozygous blast resistant lines were strongly resistant against pathotype P7.2 in the blast disease endemic areas. The morphological, yield, grain quality, and yield-contributing characteristics were significantly similar to those of MR219. The newly developed blast resistant improved lines will retain the high adoptability of MR219 by farmers. The present results will also play an important role in sustaining the rice production of Malaysia. PMID:26734013

  16. 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

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

    African Journals Online (AJOL)

    Case Study: Accidental hand grenade blast injuries in the Transkei region of South Africa. 348. Vol 51 No 4. SA Fam ... There is some evidence that a substantial number of small arms and hand grenades ... Unfortunately, the safety device was ...

  18. Blast-Induced Acceleration in a Shock Tube: Distinguishing Primary and Tertiary Blast Injury

    Science.gov (United States)

    2016-10-01

    injury conditions (blast and acceleration vs acceleration alone) undergo neurobehavioral and histopathological assessments to comprehensively... reversal . To facilitate mid-air blasts, a release mechanism was devised. Balls were attached to the bail of the mechanism. The blast wave would cause

  19. 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

  20. Blast Testing Issues and TBI; Experimental Models that Lead to Wrong Conclusions

    Directory of Open Access Journals (Sweden)

    Charles E. Needham

    2015-04-01

    Full Text Available Over the past several years we have noticed an increase in the number of blast injury studies published in peer-reviewed biomedical journals that have utilized improperly conceived experiments. Data from these studies will lead to false conclusions and more confusion than advancement in the understanding of blast injury, particularly blast neurotrauma. Computational methods to properly characterize the blast environment have been available for decades. These methods, combined with a basic understanding of blast wave phenomena enable researchers to extract useful information from well documented experiments. This basic understanding must include the differences and interrelationships of static pressure, dynamic pressure, reflected pressure, and total or stagnation pressure in transient shockwave flows, how they relate to loading of objects, and how they are properly measured. However, it is critical that the research community effectively overcomes the confusion that has been compounded by a misunderstanding of the differences between the loading produced by a free field explosive blast and loading produced by a conventional shock tube. The principles of blast scaling have been well established for decades and when properly applied will do much to repair these problems.This paper provides guidance regarding proper experimental methods and offers insights into the implications of improperly designed and executed tests. Through application of computational methods, useful data can be extracted from well documented historical tests, and future work can be conducted in a way to maximize the effectiveness and use of valuable biological test data.

  1. 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.)

  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)

    1997-12-31

    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. A phase I study of low-pressure hyperbaric oxygen therapy for blast-induced post-concussion syndrome and post-traumatic stress disorder.

    Science.gov (United States)

    Harch, Paul G; Andrews, Susan R; Fogarty, Edward F; Amen, Daniel; Pezzullo, John C; Lucarini, Juliette; Aubrey, Claire; Taylor, Derek V; Staab, Paul K; Van Meter, Keith W

    2012-01-01

    This is a preliminary report on the safety and efficacy of 1.5 ATA hyperbaric oxygen therapy (HBOT) in military subjects with chronic blast-induced mild to moderate traumatic brain injury (TBI)/post-concussion syndrome (PCS) and post-traumatic stress disorder (PTSD). Sixteen military subjects received 40 1.5 ATA/60 min HBOT sessions in 30 days. Symptoms, physical and neurological exams, SPECT brain imaging, and neuropsychological and psychological testing were completed before and within 1 week after treatment. Subjects experienced reversible middle ear barotrauma (5), transient deterioration in symptoms (4), and reversible bronchospasm (1); one subject withdrew. Post-treatment testing demonstrated significant improvement in: symptoms, neurological exam, full-scale IQ (+14.8 points; pSPECT coefficient of variation in all white matter and some gray matter ROIs after the first HBOT, and in half of white matter ROIs after 40 HBOT sessions, and SPECT statistical parametric mapping analysis (diffuse improvements in regional cerebral blood flow after 1 and 40 HBOT sessions). Forty 1.5 ATA HBOT sessions in 1 month was safe in a military cohort with chronic blast-induced PCS and PTSD. Significant improvements occurred in symptoms, abnormal physical exam findings, cognitive testing, and quality-of-life measurements, with concomitant significant improvements in SPECT.

  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. 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.

  6. Interspecies Scaling in Blast Neurotrauma

    Science.gov (United States)

    2015-08-27

    and services to assist recovery . Santa Monica, CA: Rand Corporation. Taylor, PA and Ford, CC. 2009. "Simulation of Blast-Induced Early-Time...reducing this burden, to Washington Headquarters Services , Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite... Warden 2006). As of 2008 it was estimated that approximately 19% or 320,000 OIF/OEF veterans had sustained a TBI (Tanielian et al. 2008). In 2011 a

  7. 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

    acid ( DHA ; 22:6ω-3) Eicosapentaenoic acid (EPA; 20:5ω-3) Lipoxin A4 Resolvin E1 Protectin DX Resolvin D1 LOX LOX LOX Structures and Endogenous Source...1 AD_________________ Award Number: W81XWH-12-2-0082 TITLE: Evaluation of Novel Polyunsaturated Fatty Acid Derived Lipid...Evaluation of Novel Polyunsaturated Fatty Acid Derived Lipid Mediators 5a. CONTRACT NUMBER of Inflammation to Ameliorate the Deleterious Effects of

  8. 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.

  9. Water in blast holes can improve blasting efficiency and cut costs

    Energy Technology Data Exchange (ETDEWEB)

    O' Regan, G.

    1983-08-01

    Water in blast holes has been a traditional problem faced by blasting engineers and foremen in surface mining. Presently accepted techniques for blasting in water-filled holes include the use of more expensive water-gel explosives which are denser than water, dewatering of holes by pumping, and blowing out the water with a small charge before loading the main ANFO charge column. These methods involve considerable expense and delay to the normal charge-loading procedure. The author describes a method of using the water in blast holes to improve blasting efficiency and reduce the consumption of explosive.

  10. Comparative genomics and association mapping approaches for blast resistant genes in finger millet using SSRs.

    Directory of Open Access Journals (Sweden)

    B Kalyana Babu

    Full Text Available The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R² of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R². The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R². Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars.

  11. Comparative genomics and association mapping approaches for blast resistant genes in finger millet using SSRs.

    Science.gov (United States)

    Babu, B Kalyana; Dinesh, Pandey; Agrawal, Pawan K; Sood, S; Chandrashekara, C; Bhatt, Jagadish C; Kumar, Anil

    2014-01-01

    The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R²) of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R². The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R². Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars.

  12. The fate of injectant coal in blast furnaces: The origin of extractable materials of high molecular mass in blast furnace carryover dusts

    Energy Technology Data Exchange (ETDEWEB)

    Dong, S.N.; Wu, L.; Paterson, N.; Herod, A.A.; Dugwell, D.R.; Kandiyoti, R. [University of London Imperial College of Science & Technology, London (United Kingdom). Dept. of Chemical Engineering

    2005-07-01

    The aim of the work was to investigate the fate of injectant coal in blast furnaces and the origin of extractable materials in blast furnace carryover dusts. Two sets of samples including injectant coal and the corresponding carryover dusts from a full sized blast furnace and a pilot scale rig have been examined. The samples were extracted using 1-methyl-2-pyrrolidinone (NMP) solvent and the extracts studied by size exclusion chromatography (SEC). The blast furnace carryover dust extracts contained high molecular weight carbonaceous material, of apparent mass corresponding to 10{sup 7}-10{sup 8} u, by polystyrene calibration. In contrast, the feed coke and char prepared in a wire mesh reactor under high temperature conditions did not give any extractable material. Meanwhile, controlled combustion experiments in a high-pressure wire mesh reactor suggest that the extent of combustion of injectant coal in the blast furnace tuyeres and raceways is limited by time of exposure and very low oxygen concentration. It is thus likely that the extractable, soot-like material in the blast furnace dust originated in tars is released by the injectant coal. Our results suggest that the unburned tars were thermally altered during the upward path within the furnace, giving rise to the formation of heavy molecular weight (soot-like) materials.

  13. Acute myeloid leukemia associated with t(10;17)(p13-15;q12-21) and phagocytic activity by leukemic blasts: a clinical study and review of the literature.

    Science.gov (United States)

    Oh, Seung Hwan; Park, Tae Sung; Cho, Sun Young; Kim, Min Jin; Huh, Jungwon; Kim, Bomi; Song, Sae Am; Lee, Ja Young; Jun, Kyung Ran; Shin, Jeong Hwan; Kim, Hye Ran; Lee, Jeong Nyeo

    2010-10-01

    Translocation (10;17)(p13-15;q12-21) in acute leukemia is rarely reported in the literature. Here, we present both a novel t(10;17) case study and a review of relevant literature on t(10;17) in acute leukemia (10 cases). In summary, we came to the following preliminary conclusions: t(10;17) is associated with poorly differentiated acute leukemia subtype [90%; eight cases of acute myeloid leukemia (AML M0, M1) and one case of acute undifferentiated leukemia], phagocytic activity by blasts occurs (30%), and the survival time was short in three of the seven t(10;17) cases for whom follow-up data were available (median, 8 months). More clinical studies concerning the prognosis, treatment response, and survival of patients with t(10;17) are necessary. 2010 Elsevier Inc. All rights reserved.

  14. 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.

  15. Blast resistance behaviour of steel frame structrures

    NARCIS (Netherlands)

    Mediavilla Varas, J.; Soetens, F.

    2010-01-01

    The effect of a blast explosion on a typical steel frame building is investigated by means of computer simulations. The simulations help to identify possible hot spots that may lead to local or global failure. Since the blast energy is transferred to the structure by means of the façade, it is

  16. Blast resistance behaviour of steel frame structures

    NARCIS (Netherlands)

    Varas, J.M.; Soetens, F.

    2010-01-01

    The effect of a blast explosion on a typical steel frame building is investigated by means of computer simulations. The simulations help to identify possible hot spots that may lead to local or global failure. The blast energy is transferred to the structure by means of the façade. In particular

  17. 30 CFR 56.6312 - Secondary blasting.

    Science.gov (United States)

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Explosives Use § 56.6312 Secondary blasting. Secondary blasts fired at the same time in the same work area shall be initiated from...

  18. 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.

  19. Blasting methods for heterogeneous rocks in hillside open-pit mines with high and steep slopes

    Science.gov (United States)

    Chen, Y. J.; Chang, Z. G.; Chao, X. H.; Zhao, J. F.

    2017-06-01

    In the arid desert areas in Xinjiang, most limestone quarries are hillside open-pit mines (OPMs) where the limestone is hard, heterogeneous, and fractured, and can be easily broken into large blocks by blasting. This study tried to find effective technical methods for blasting heterogeneous rocks in such quarries based on an investigation into existing problems encountered in actual mining at Hongshun Limestone Quarry in Xinjiang. This study provided blasting schemes for hillside OPMs with different heights and slopes. These schemes involve the use of vertical deep holes, oblique shallow holes, and downslope hole-by-hole sublevel or simultaneous detonation techniques. In each bench, the detonations of holes in a detonation unit occur at intervals of 25-50 milliseconds. The research findings can offer technical guidance on how to blast heterogeneous rocks in hillside limestone quarries.

  20. The Mechanism and Application of Deep-Hole Precracking Blasting on Rockburst Prevention

    Directory of Open Access Journals (Sweden)

    Zhenhua Ouyang

    2015-01-01

    Full Text Available The mechanism of preventing rockburst through deep-hole precracking blasting was studied based on experimental test, numerical simulation, and field testing. The study results indicate that the deep-hole precracking could change the bursting proneness and stress state of coal-rock mass, thereby preventing the occurrence of rockburst. The bursting proneness of the whole composite structure could be weakened by the deep-hole precracking blasting. The change of stress state in the process of precracking blasting is achieved in two ways: (1 artificially break the roof apart, thus weakening the continuity of the roof strata, effectively inducing the roof caving while reducing its impact strength; and (2 the dynamic shattering and air pressure generated by the blasting can structurally change the properties of the coal-rock mass by mitigating the high stress generation and high elastic energy accumulation, thus breaking the conditions of energy transfer and rock burst occurrence.

  1. 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.

  2. Condition for Contur Blasting use on Openpit Mines

    OpenAIRE

    Krsmanovic, I; Dambov, Risto

    2010-01-01

    For purpose of obtaining a stable final slope in open pit mines practice, the most common approach is the contour blasting method and investigation of possible applications of various primary blasting methods for purpose of gaining the optimal techno-economical effects. This paper presents one of the contour blasting methods, drilling and blasting parameters, construction of explosive charges and method of initiation.

  3. 30 CFR 780.13 - Operation plan: Blasting.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Operation plan: Blasting. 780.13 Section 780.13... SURFACE MINING PERMIT APPLICATIONS-MINIMUM REQUIREMENTS FOR RECLAMATION AND OPERATION PLAN § 780.13 Operation plan: Blasting. (a) Blasting plan. Each application shall contain a blasting plan for the proposed...

  4. Anorectal injury in pelvic blast.

    Science.gov (United States)

    Brogden, Tom G; Garner, J P

    2013-03-01

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

  5. Characterization of Pseudomonas syringae pv. syringae, Causal Agent of Citrus Blast of Mandarin in Montenegro

    OpenAIRE

    Ivanovi?, ?arko; Perovi?, Tatjana; Popovi?, Tatjana; Blagojevi?, Jovana; Trkulja, Nenad; Hrn?i?, Snje?ana

    2017-01-01

    Citrus blast caused by bacterium Pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. Considering the above fact, this study reports genetic characterization of 43 P. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (Citrus reticulata) in Montenegro, using multilocus sequence analysis of gyrB, rpoD, and gap1 gene sequences. Gene sequences from...

  6. Dry Ice Blast Decontamination to in-service equipment in Japanese PWR plant

    International Nuclear Information System (INIS)

    2016-01-01

    MHI had developed several mechanical decontamination methods. Mechanical decontamination is beneficial when it is applied to equipment whose surface is narrow. Especially in terms of secondary waste reduction, MHI started the study of application of Dry Ice Blast Decontamination to actual PWR plant. This paper provides an introduction to Dry Ice Blast Decontamination principle, its system and actual application result to PWR plant. (J.P.N.)

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

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

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

  8. Blast response of corroded steel plates

    Energy Technology Data Exchange (ETDEWEB)

    Eslamimajd, Alireza; RahbarRanji, Ahmad [AmirKabir University of Technology, Tehran (Korea, Republic of)

    2014-05-15

    Numerical results for one- and both-sided corroded steel plates subjected to blast loading are presented. Finite element analysis, with ABAQUS software, is employed to determine the deformation and stress distributions. The results for the case of triangular pulse pressure on un-corroded plates are validated against literature-based data and then, detailed parametric studies are carried-out. The effects of influential parameters including, plate aspect ratio, degree of pit and different ratio of pit depth at each sides of the plate are investigated. The results show that position of pitted surface in respect to applied pressure is the most influential parameter on reduction of dynamic load carrying capacity of pitted plates. By increasing degree of pitting, reduction of dynamic load carrying capacity decrease more.

  9. Finite Element Simulation of Medium-Range Blast Loading Using LS-DYNA

    Directory of Open Access Journals (Sweden)

    Yuzhen Han

    2015-01-01

    Full Text Available This study investigated the Finite Element simulation of blast loading using LS-DYNA. The objective is to identify approaches to reduce the requirement of computation effort while maintaining reasonable accuracy, focusing on blast loading scheme, element size, and its relationship with scale of explosion. The study made use of the recently developed blast loading scheme in LS-DYNA, which removes the necessity to model the explosive in the numerical models but still maintains the advantages of nonlinear fluid-structure interaction. It was found that the blast loading technique could significantly reduce the computation effort. It was also found that the initial density of air in the numerical model could be purposely increased to partially compensate the error induced by the use of relatively large air elements. Using the numerical approach, free air blast above a scaled distance of 0.4 m/kg1/3 was properly simulated, and the fluid-structure interaction at the same location could be properly duplicated using proper Arbitrary Lagrangian Eulerian (ALE coupling scheme. The study also showed that centrifuge technique, which has been successfully employed in model tests to investigate the blast effects, may be used when simulating the effect of medium- to large-scale explosion at small scaled distance.

  10. 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

  11. Energy absorption capabilities of composite sandwich panels under blast loads

    Science.gov (United States)

    Sankar Ray, Tirtha

    , ET) was suggested to compare energy absorption capabilities of the structures under blast loading. In addition, AEweb/ET (where AEweb is the energy absorbed by the middle core) was also employed to evaluate the energy absorption contribution from the web. Taking advantage of FEA and the simplified analytical model, the influences of material properties as well as core architectures and geometries on energy absorption capabilities (quantified by AET/ ET and AEweb/E T) were investigated through parametric studies. Results from the material property investigation indicated that density of the front face sheet and strength were most influential on the energy absorption capability of the composite sandwich panels under blast loading. The study to investigate the potential effectiveness of energy absorbed via inelastic deformation compared to energy absorbed via progressive failure indicated that for practical applications (where the position of bomb is usually unknown and the panel is designed to be the same anywhere), the energy absorption via inelastic deformation is the more efficient approach. Regarding the geometric optimization, it was found that a core architecture consisting of vertically-oriented webs was ideal. The optimum values for these parameters can be generally described as those which cause the most inelasticity, but not failure, of the face sheets and webs.

  12. Osteogenic differentiation of periosteum-derived stromal cells in blast-associated traumatic loading

    Science.gov (United States)

    Sory, David R.; Amin, Harsh D.; Rankin, Sara M.; Proud, William G.

    2017-06-01

    One of the most recurrent medical complications resulting from blast trauma includes blast-induced heterotopic ossification. Heterotopic ossification refers to the pathologic formation of extraskeletal bone in non-osseous tissue. Although a number of studies have established the interaction between mechanics and biology in bone formation following shock trauma, the exact nature of the mechanical stimuli associated to blast-loading and their influence on the activation of osteogenic differentiation of cells remain unanswered. Here we present the design and calibration of a loading platform compatible with living cells to examine the effects of mechanical stress pulses of blast-associated varying strain rates on the activation of osteogenic differentiation of periosteum (PO) cells. Multiaxial compression loadings of PO cells are performed at different magnitudes of stress and ranges of strain rate. A proof of concept is presented so as to establish a new window to address fundamental questions regarding blast injuries at the cellular level. This work was conducted under the auspices of the Royal British Legion Centre for Blast Injury Studies at Imperial College London. The authors would like to acknowledge the financial support of the Royal British Legion.

  13. 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.

  14. A Blast Wave Model With Viscous Corrections

    International Nuclear Information System (INIS)

    Yang, Z; Fries, R J

    2017-01-01

    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. (paper)

  15. Blast casting requires fresh assessment of methods

    Energy Technology Data Exchange (ETDEWEB)

    Pilshaw, S.R.

    1987-08-01

    The article discusses the reasons why conventional blasting operations, mainly that of explosive products, drilling and initiation methods are inefficient, and suggests new methods and materials to overcome the problems of the conventional operations. The author suggests that the use of bulk ANFO for casting, instead of high energy and density explosives with high velocity detonation is more effective in producing heave action results. Similarly the drilling of smaller blast holes than is conventional allows better loading distribution of explosives in the rock mass. The author also suggests that casting would be more efficient if the shot rows were loaded differently to produce a variable burden blasting pattern.

  16. Membranes replace irradiated blast cells as growth requirement for leukemic blast progenitors in suspension culture

    International Nuclear Information System (INIS)

    Nara, N.; McCulloch, E.A.

    1985-01-01

    The blast cells of acute myeloblastic leukemia (AML) may be considered as a renewal population, maintained by blast stem cells capable of both self-renewal and the generation of progeny with reduced or absent proliferative potential. This growth requires that two conditions be met: first, the cultures must contain growth factors in media conditioned either by phytohemagglutinin (PHA)-stimulated mononuclear leukocytes (PHA-LCM), or by cells of the continuous bladder carcinoma line HTB9 (HTB9-CM). Second, the cell density must be maintained at 10(6) blasts/ml; this may be achieved by adding irradiated cells to smaller numbers of intact blasts. The authors are concerned with the mechanism of the feeding function. They present evidence that (a) cell-cell contact is required. (b) Blasts are heterogeneous in respect to their capacity to support growth. (c) Fractions containing membranes from blast cells will substitute for intact cells in promoting the generation of new blast progenitors in culture. (d) This membrane function may be specific for AML blasts, since membranes from blasts of lymphoblastic leukemia or normal marrow cells were inactive

  17. Application of micro blasting technique to demolition of biological shield wall of reactor building

    International Nuclear Information System (INIS)

    Kontani, Osamu

    2016-01-01

    Although heavily reinforced concrete structures in nuclear facilities could be dismantled effectively with the controlled blasting technique, the noises and vibrations caused by blasting were matters of concern. Recently, in the building replacement at urban areas, there are increasing cases of demolition of large reinforced concrete members below ground. Instead of applying heavy weight breakers, the micro blasting technique that enables to lower noises and vibrations has developed and applied to demolition work of large reinforced concrete members in urban areas. In this report, the features of the micro blasting technique is reviewed by comparing with existing controlled blasting technique and its applicability to demolition work of nuclear facilities is investigated. The results of those study find that it is confirmed that the micro blasting technique could be applicable to large reinforced concrete structures in nuclear facilities because of the low levels of noises and vibrations. However, it is recommended to perform mock-up tests to confirm the demolition efficiency and levels of the noises and vibrations since the rebar used in nuclear facilities is larger in diameters and in rebar ratio compared with ordinary reinforced concrete structures. (author)

  18. 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

  19. 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

    Science.gov (United States)

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

    2013-12-01

    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.

  20. Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

    International Nuclear Information System (INIS)

    Riesemann, W.A. von; Parks, M.B.

    1995-01-01

    In the US, concrete containment buildings for commercial nuclear power plants have steel liners that act as the internal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented.This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions).An overpressurization test of a 1:6 scale reinforced concrete containment at Sandia National Laboratories resulted in a failure mechanism in the liner that was not fully anticipated. Post-test analyses and experiments have been conducted to understand the failure better. This work and the activities that followed the test are reviewed. Areas in which additional research should be conducted are given. (orig.)

  1. 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.

  2. Blast Mitigation Using Water - A Status Report

    National Research Council Canada - National Science Library

    Kailasanath, K

    2002-01-01

    ..., and aggressive research and development', this report reviews the current knowledge base on blast mitigation using water and identifies the key issues that need to be resolved in order to develop...

  3. International blast furnace hearth and raceway symposium

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Papers presented discussed some of the physical and chemical processes occuring in the raceway and hearths of blast furnaces. The injection of coal or fuel slurries to replace some of the coke was also covered. Fourteen papers are abstracted separately.

  4. 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...

  5. 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...

  6. Bomb blast imaging: bringing order to chaos.

    Science.gov (United States)

    Dick, E A; Ballard, M; Alwan-Walker, H; Kashef, E; Batrick, N; Hettiaratchy, S; Moran, C G

    2018-06-01

    Blast injuries are complex, severe, and outside of our everyday clinical practice, but every radiologist needs to understand them. By their nature, bomb blasts are unpredictable and affect multiple victims, yet require an immediate, coordinated, and whole-hearted response from all members of the clinical team, including all radiology staff. This article will help you gain the requisite expertise in blast imaging including recognising primary, secondary, and tertiary blast injuries. It will also help you understand the fundamental role that imaging plays during mass casualty attacks and how to avoid radiology becoming a bottleneck to the forward flow of severely injured patients as they are triaged and treated. Copyright © 2018. Published by Elsevier Ltd.

  7. 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.

  8. 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.

  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. 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

  11. Experimental study on steam gasification of coal using molten blast furnace slag as heat carrier for producing hydrogen-enriched syngas

    International Nuclear Information System (INIS)

    Duan, Wenjun; Yu, Qingbo; Wu, Tianwei; Yang, Fan; Qin, Qin

    2016-01-01

    Highlights: • New method for producing HRG by gasification using BFS as heat carrier was proposed. • The continuous experiment of steam gasification in molten BFS was conducted. • The hydrogen-enriched syngas was produced by this method. • The molten BFS waste heat was utilized effectively by steam gasification. • This method could be widely used in steam gasification of different types of coal. - Abstract: The new method for producing hydrogen-enriched syngas (HRG) by steam gasification of coal using molten blast furnace slag (BFS) as heat carrier was established. In order to achieve the HRG production, a gasification system using this method was proposed and constructed. The carbon gasification efficiency (CE), hydrogen yield (YH_2) and cold gasification efficiency (CGE) in the molten slag reactor were measured, and the effects of temperature, S/C (steam to coal) ratio and coal type on the reaction performance were accessed. The results indicated that the preferred temperature was 1350 °C, which ensured the miscibility of coal–steam–slag, the diffusion of reactant in molten BFS as well as recovering waste heat. The optimal S/C ratio was 1.5–2.0 for producing HRG. Under these conditions, the hydrogen fraction was higher than 63% and the gas yield reached to 1.89 Nm"3/kg. The CE and CGE were higher than 96% and 102%, respectively. The YH_2 also reached to 1.20 Nm"3/kg. Meanwhile, different types of coal were successfully gasified in molten BFS reactor for producing HRG. The proposed method enhanced the gasification efficiency of different types of coal, recovered the BFS waste heat effectively, and had important guidance for industrial manufacture.

  12. Erythroleukemia shares biological features and outcome with myelodysplastic syndromes with excess blasts: a rationale for its inclusion into future classifications of myelodysplastic syndromes.

    Science.gov (United States)

    Calvo, Xavier; Arenillas, Leonor; Luño, Elisa; Senent, Leonor; Arnan, Montserrat; Ramos, Fernando; Ardanaz, María Teresa; Pedro, Carme; Tormo, Mar; Montoro, Julia; Díez-Campelo, María; Arrizabalaga, Beatriz; Xicoy, Blanca; Bonanad, Santiago; Jerez, Andrés; Nomdedeu, Benet; Ferrer, Ana; Sanz, Guillermo F; Florensa, Lourdes

    2016-12-01

    Erythroleukemia was considered an acute myeloid leukemia in the 2008 World Health Organization (WHO) classification and is defined by the presence of ≥50% bone marrow erythroblasts, having <20% bone marrow blasts from total nucleated cells but ≥20% bone marrow myeloblasts from nonerythroid cells. Erythroleukemia shares clinicopathologic features with myelodysplastic syndromes, especially with erythroid-predominant myelodysplastic syndromes (≥50% bone marrow erythroblasts). The upcoming WHO revision proposes to eliminate the nonerythroid blast cell count rule and to move erythroleukemia patients into the appropriate myelodysplastic syndrome category on the basis of the absolute blast cell count. We conducted a retrospective study of patients with de novo erythroleukemia and compared their clinico-biological features and outcome with those of de novo myelodysplastic syndromes, focusing on erythroid-predominant myelodysplastic syndromes. Median overall survival of 405 erythroid-predominant myelodysplastic syndromes without excess blasts was significantly longer than that observed in 57 erythroid-predominant refractory anemias with excess blasts-1 and in 59 erythroleukemias, but no significant difference was observed between erythroid-predominant refractory anemias with excess blasts-1 and erythroleukemias. In this subset of patients with ≥50% bone marrow erythroblasts and excess blasts, the presence of a high-risk karyotype defined by the International Prognostic Scoring System or by the Revised International Prognostic Scoring System was the main prognostic factor. In the same way, the survival of 459 refractory anemias with excess blasts-2, independently of having ≥20% bone marrow blasts from nonerythroid cells or not, was almost identical to the observed in 59 erythroleukemias. Interestingly, 11 low-blast count erythroleukemias with 5 to <10% bone marrow blasts from total nucleated cells showed similar survival than the rest of erythroleukemias. Our data

  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. 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.

  15. 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.)

  16. Genetic analysis and identification of SSR markers associated with rice blast disease in a BC2F1 backcross population.

    Science.gov (United States)

    Hasan, N; Rafii, M Y; Abdul Rahim, H; Nusaibah, S A; Mazlan, N; Abdullah, S

    2017-01-23

    Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are vital to increase our understanding of the molecular basis of blast disease resistance. The present study set out to elucidate the resistance pattern and identify potential simple sequence repeat markers linked with rice blast disease. A backcross population (BC 2 F 1 ), derived from crossing MR264 and Pongsu Seribu 2 (PS2), was developed using marker-assisted backcross breeding. Twelve microsatellite markers carrying the blast resistance gene clearly demonstrated a polymorphic pattern between both parental lines. Among these, two markers, RM206 and RM5961, located on chromosome 11 exhibited the expected 1:1 testcross ratio in the BC 2 F 1 population. The 195 BC 2 F 1 plants inoculated against M. oryzae pathotype P7.2 showed a significantly different distribution in the backcrossed generation and followed Mendelian segregation based on a single-gene model. This indicates that blast resistance in PS2 is governed by a single dominant gene, which is linked to RM206 and RM5961 on chromosome 11. The findings presented in this study could be useful for future blast resistance studies in rice breeding programs.

  17. BLAST: Building energy simulation in Hong Kong

    Science.gov (United States)

    Fong, Sai-Keung

    1999-11-01

    The characteristics of energy use in buildings under local weather conditions were studied and evaluated using the energy simulation program BLAST-3.0. The parameters used in the energy simulation for the study and evaluation include the architectural features, different internal building heat load settings and weather data. In this study, mathematical equations and the associated coefficients useful to the industry were established. A technology for estimating energy use in buildings under local weather conditions was developed by using the results of this study. A weather data file of Typical Meteorological Years (TMY) has been compiled for building energy studies by analyzing and evaluating the weather of Hong Kong from the year 1979 to 1988. The weather data file TMY and the example weather years 1980 and 1988 were used by BLAST-3.0 to evaluate and study the energy use in different buildings. BLAST-3.0 was compared with other building energy simulation and approximation methods: Bin method and Degree Days method. Energy use in rectangular compartments of different volumes varying from 4,000 m3 to 40,000 m3 with different aspect ratios were analyzed. The use of energy in buildings with concrete roofs was compared with those with glass roofs at indoor temperature 21°C, 23°C and 25°C. Correlation relationships among building energy, space volume, monthly mean temperature and solar radiation were derived and investigated. The effects of space volume, monthly mean temperature and solar radiation on building energy were evaluated. The coefficients of the mathematical relationships between space volume and energy use in a building were computed and found satisfactory. The calculated coefficients can be used for quick estimation of energy use in buildings under similar situations. To study energy use in buildings, the cooling load per floor area against room volume was investigated. The case of an air-conditioned single compartment with 5 m ceiling height was

  18. Effect of blasting on output increase of bucket wheel excavators

    Energy Technology Data Exchange (ETDEWEB)

    Musil, P.

    1987-12-01

    In brown coal surface mines, consolidated sediments become a problem as mining operations advance into greater depth below the original terrain. Owing to higher digging resistance, the output of bucket wheel excavators drops. This problem may be solved by blasting technology and using drilling machines with higher digging force. This paper describes the blasting operations at the Nastup Mines in Tusmice, Czechoslovakia. About 60% of blasting explosives used is a simple mixture of ammonium nitrate and fuel (ANFO), the rest falls on classic blasting gelatines and blasting explosives plasticized by slurry. It is found that blasting improves output by 30% while electric energy consumption is reduced.

  19. Proceedings of the twenty-seventh annual conference on explosives and blasting techniques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Various aspects of explosives and blasting techniques are covered. Those of particular interest to the coal industry buffer blasting versus cast blasting, post-blast cast profile shape prediction, fragmentation model to estimate ROM size distribution of soft rocks, blasting accidents, blast vibrations, ANFO explosives and carbon monoxide poisoning.

  20. Examination of the protective roles of helmet/faceshield and directionality for human head under blast waves.

    Science.gov (United States)

    Sarvghad-Moghaddam, Hesam; Jazi, Mehdi Salimi; Rezaei, Asghar; Karami, Ghodrat; Ziejewski, Mariusz

    2015-01-01

    A parametric study was conducted to delineate the efficacy of personal protective equipment (PPE), such as ballistic faceshields and advanced combat helmets, in the case of a blast. The propagations of blast waves and their interactions with an unprotected head, a helmeted one, and a fully protected finite element head model (FEHM) were modeled. The biomechanical parameters of the brain were recorded when the FEHM was exposed to shockwaves from the front, back, top, and bottom. The directional dependent tissue response of the brain and the variable efficiency of PPE with respect to the blast orientation were two major results of this study.

  1. DYNAMIC TIME HISTORY ANALYSIS OF BLAST RESISTANT DOOR USING BLAST LOAD MODELED AS IMPACT LOAD

    Directory of Open Access Journals (Sweden)

    Y. A. Pranata

    2012-06-01

    Full Text Available A blast resistant single door was designed to withstand a 0.91 bar blast pressure and 44 ms blast duration. The analysis was done using Dynamic Time History Analysis using Blast Load modeled as Impact Load for given duration. The material properties used have been modified to accommodate dynamic effects. The analysis was done using dynamic finite element method (fem for time of the blast duration, and the maximum/minimum internal forces and displacement were taken from the time history output, in order to know the behavior under blast load and estimate the safety margin of the door. Results obtained from this research indicated that the maximum z-displacement is 1.709 mm, while in the term of serviceability, the permitted is 25 mm. The maximum reaction force is 73,960 N, while the maximum anchor capacity is 82,069 N. On blast condition, the maximum frame stress is 71.71 MPa, the maximum hinge shear stress is 45.28 MPa. While on rebound condition, the maximum frame stress is 172.11 MPa, the maximum hinge shear stress is 29.46 MPa. The maximum door edge rotation is 0.44 degree, which is not exceed the permitted boundary (1.2 degree. Keywords: Dynamic time history, blast resistant door, single door, finite element method.

  2. Influence of steel fibers on the shear and flexural performance of high-strength concrete beams tested under blast loads

    Science.gov (United States)

    Algassem, O.; Li, Y.; Aoude, H.

    2017-09-01

    This paper presents the results of a study examining the effect of steel fibres on the blast behaviour of high-strength concrete beams. As part of the study, a series of three large-scale beams built with high-strength concrete and steel fibres are tested under simulated blast loading using the shock-tube testing facility at the University of Ottawa. The specimens include two beams built with conventional high-strength concrete (HSC) and one beam built with high-strength concrete and steel fibres (HSFRC). The effect of steel fibres on the blast behaviour is examined by comparing the failure mode, mid-span displacements and, overall blast resistance of the specimens. The results show that the addition of steel fibres in high-strength concrete beams can prevent shear failure and substitute for shear reinforcement if added in sufficient quantity. Moreover, the use of steel fibres improves flexural response under blast loading by reducing displacements and increasing blast capacity. Finally, the provision of steel fibres is found to improve the fragmentation resistance of high-strength concrete under blast loads.

  3. Directed blasts and blast-generated pyroclastic density currents: a comparison of the Bezymianny 1956, Mount St Helens 1980, and Soufrière Hills, Montserrat 1997 eruptions and deposits

    Science.gov (United States)

    Belousov, Alexander; Voight, Barry; Belousova, Marina

    2007-01-01

    We compare eruptive dynamics, effects and deposits of the Bezymianny 1956 (BZ), Mount St Helens 1980 (MSH), and Soufrière Hills volcano, Montserrat 1997 (SHV) eruptions, the key events of which included powerful directed blasts. Each blast subsequently generated a high-energy stratified pyroclastic density current (PDC) with a high speed at onset. The blasts were triggered by rapid unloading of an extruding or intruding shallow magma body (lava dome and/or cryptodome) of andesitic or dacitic composition. The unloading was caused by sector failures of the volcanic edifices, with respective volumes for BZ, MSH, and SHV c. 0.5, 2.5, and 0.05 km3 . The blasts devastated approximately elliptical areas, axial directions of which coincided with the directions of sector failures. We separate the transient directed blast phenomenon into three main parts, the burst phase, the collapse phase, and the PDC phase. In the burst phase the pressurized mixture is driven by initial kinetic energy and expands rapidly into the atmosphere, with much of the expansion having an initially lateral component. The erupted material fails to mix with sufficient air to form a buoyant column, but in the collapse phase, falls beyond the source as an inclined fountain, and thereafter generates a PDC moving parallel to the ground surface. It is possible for the burst phase to comprise an overpressured jet, which requires injection of momentum from an orifice; however some exploding sources may have different geometry and a jet is not necessarily formed. A major unresolved question is whether the preponderance of strong damage observed in the volcanic blasts should be attributed to shock waves within an overpressured jet, or alternatively to dynamic pressures and shocks within the energetic collapse and PDC phases. Internal shock structures related to unsteady flow and compressibility effects can occur in each phase. We withhold judgment about published shock models as a primary explanation for the

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

    Science.gov (United States)

    Bhagwat, Vaibhab Pramod; Dey, Kaushik

    2016-04-01

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

  5. Use of molecular markers in identification and characterization of resistance to rice blast in India.

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Yadav

    Full Text Available Rice blast disease caused by Magnaporthe oryzae is one of the most destructive disease causing huge losses to rice yield in different parts of the world. Therefore, an attempt has been made to find out the resistance by screening and studying the genetic diversity of eighty released rice varieties by National Rice Research Institute, Cuttack (NRVs using molecular markers linked to twelve major blast resistance (R genes viz Pib, Piz, Piz-t, Pik, Pik-p, Pikm Pik-h, Pita/Pita-2, Pi2, Pi9, Pi1 and Pi5. Out of which, nineteen varieties (23.75% showed resistance, twenty one were moderately resistant (26.25% while remaining forty varieties (50% showed susceptible in uniform blast nursery. Rice varieties possessing blast resistance genes varied from four to twelve and the frequencies of the resistance genes ranged from 0 to 100%. The cluster analysis grouped the eighty NRVs into two major clusters at 63% level of genetic similarity coefficient. The PIC value for seventeen markers varied from 0 to 0.37 at an average of 0.20. Out of seventeen markers, only five markers, 195R-1, Pi9-i, Pita3, YL155/YL87 and 40N23r corresponded to three broad spectrum R genes viz. Pi9, Pita/Pita2 and Pi5 were found to be significantly associated with the blast disease with explaining phenotypic variance from 3.5% to 7.7%. The population structure analysis and PCoA divided the entire 80 NRVs into two sub-groups. The outcome of this study would help to formulate strategies for improving rice blast resistance through genetic studies, plant-pathogen interaction, identification of novel R genes, development of new resistant varieties through marker-assisted breeding for improving rice blast resistance in India and worldwide.

  6. Use of molecular markers in identification and characterization of resistance to rice blast in India.

    Science.gov (United States)

    Yadav, Manoj Kumar; S, Aravindan; Ngangkham, Umakanta; Shubudhi, H N; Bag, Manas Kumar; Adak, Totan; Munda, Sushmita; Samantaray, Sanghamitra; Jena, Mayabini

    2017-01-01

    Rice blast disease caused by Magnaporthe oryzae is one of the most destructive disease causing huge losses to rice yield in different parts of the world. Therefore, an attempt has been made to find out the resistance by screening and studying the genetic diversity of eighty released rice varieties by National Rice Research Institute, Cuttack (NRVs) using molecular markers linked to twelve major blast resistance (R) genes viz Pib, Piz, Piz-t, Pik, Pik-p, Pikm Pik-h, Pita/Pita-2, Pi2, Pi9, Pi1 and Pi5. Out of which, nineteen varieties (23.75%) showed resistance, twenty one were moderately resistant (26.25%) while remaining forty varieties (50%) showed susceptible in uniform blast nursery. Rice varieties possessing blast resistance genes varied from four to twelve and the frequencies of the resistance genes ranged from 0 to 100%. The cluster analysis grouped the eighty NRVs into two major clusters at 63% level of genetic similarity coefficient. The PIC value for seventeen markers varied from 0 to 0.37 at an average of 0.20. Out of seventeen markers, only five markers, 195R-1, Pi9-i, Pita3, YL155/YL87 and 40N23r corresponded to three broad spectrum R genes viz. Pi9, Pita/Pita2 and Pi5 were found to be significantly associated with the blast disease with explaining phenotypic variance from 3.5% to 7.7%. The population structure analysis and PCoA divided the entire 80 NRVs into two sub-groups. The outcome of this study would help to formulate strategies for improving rice blast resistance through genetic studies, plant-pathogen interaction, identification of novel R genes, development of new resistant varieties through marker-assisted breeding for improving rice blast resistance in India and worldwide.

  7. FY 1999 report on the feasibility study on dissemination of the technologies for effective utilization of blast furnace top pressure in China; 1999 nendo Chugoku ni okeru koro rochoatsu yuko riyo gijutsu no fukyu kanosei chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Described herein are the FY 1999 results of the feasibility study on the blast furnace top pressure recovery turbine (TRT) technology in China. Government of China is promoting the steel industry policies to weed out outdated, inefficient production systems while preparing the priority guidance list to promote introduction of advanced technologies, for which the government is implementing or planning the preferential measures, including exemption from the import taxes and VAT, and subsidization of interest on investment. This feasibility study predicts the commercial based investment in the case where the dry dust collector and TRT that are the principal components of a dry type TRT system are manufactured in China and its acquisition ratio is increased on the condition that a suitable number of the systems are installed and on the premise that a dissemination model project is implemented. The results indicate that the system can be introduced at a cost a little less than 60% of the predicted investment in the dissemination model project. The cost-effect ratio varies with power price, which widely varies by region in China, and the dissemination feasibility is studied over a wide range of power price. The system has high dissemination potential, because almost all of the Chinese steel makers will have a sufficient cost-effect ratio which satisfies their investment standards, if they are granted the preferential measures from the government. (NEDO)

  8. Alkali-activated blast furnace slag-zeolite cements and concretes

    International Nuclear Information System (INIS)

    Rakhimov, R.; Rakhimova, N.

    2012-01-01

    The aim of this work has been the study of alkali-activated slag-zeolite cements and concretes based on them. Various compositions have been tested and some characteristics such as the compressive strength have been measured versus zeolite additions. A table lists the specific surface area and particle size distributions of different cements. The conclusions of the study are the following. First, alkali-activated slag cements and concretes based on them are effective for immobilization of radioactive wastes and the production of building structures, designed for high radiation load. Secondly, zeolite-containing mineral additions are able to increase the immobilization capacity and radiation resistance of alkali-activated blast furnace slag cements and concretes. Thirdly, the efficiency of different zeolite-containing additions - 10% to increase alkali-activated blast furnace slag-zeolite cement strength was established. It is with alkaline components of water-glass, sodium carbonate, sodium sulphate. Fourth, the effective way of introducing zeolite additions in alkali-activated blast furnace slag-zeolite cement is inter-grinding of the slag and addition. Increase in strength of alkali-activated blast furnace slag-zeolite cement stone is 40% higher than that of the stone of a mixture of separately milled components. Fifth, Alkali-activated blast furnace slag-zeolite cements with zeolite-containing additions with a compressive strength of 10.1 to 140 MPa; alkali-activated blast furnace slag-zeolite cements mortars with compressive strength from 35.2 to 97.7 MPa; alkali-activated blast furnace slag-zeolite cements concretes with compressive strength up to 84.5 MPa and frost resistant up to 800 cycles were obtained

  9. 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.

  10. Effects of blast wave to main steam piping under high energy line break condition by TNT model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Lee, Eung Seok; Chang, Yoon Suk [Kyung Hee University, Yongin (Korea, Republic of)

    2016-05-15

    The aim of this study is to examine effect of the blast wave according to pipe break position through FE (Finite Element) analyses. If HELB (High Energy Line Break) accident occurs in nuclear power plants, not only environmental effect such as release of radioactive material but also secondary structural defects should be considered. Sudden pipe rupture causes ejection of high temperature and pressure fluid, which acts as a blast wave around the break location. The blast wave caused by the HELB has a possibility to induce structural defects around the components such as safe-related injection pipes and other structures.

  11. 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.

  12. FACILITIES PLANNING WORKSHOP FOR BLASTING SUPPORT THE ACTIVITY OF DEVELOPMENT AND REPAIR SHIP IN PT. JASA MARINA INDAH UNIT II

    Directory of Open Access Journals (Sweden)

    Samuel Samuel

    2012-07-01

    Full Text Available Blasting in the process of planning the workshop production of new building and ship repair to play a role in providing blasting and paint on the block that will be of erection. As a result of blasting workshop facilities that do not have resulted in low production capacity that can be achieved by this workshop, namely three block ships per month. Capacity blasting and paint shop in this low resulted in low productivity process stage (stage the previous workshops which of course result in a decrease in vessel productivity in general.                 In penelitiaan aims to plan for blasting and paint shop facility which has been adjusted to the planned production capacity of PT. JASA MARINA INDAH II units.                 In this study it - thing to note is to understand the data - the data field for research conducted in terms of both technical and economic terms, with the blasting and paint shop facilities on the construction or repair of ships that have been planned, then the effectiveness of the work and production flow at. Jasa Marina Indah II units can be known.                 Based on the analysis and calculation of both technical and economical it can be identified by the workshop on the process of blasting Blasting efficiency is obtained for 2.55 hours, at 10.16 hours during the painting process, while economical in terms of labor costs can be reduced blasting cost is Rp.930000    for          paint       and         Rp.1.23million

  13. 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

  14. 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

  15. 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

  16. 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

  17. Current state of knowledge on the behavior of steel liners in concrete containments subjected to overpressurization loads

    International Nuclear Information System (INIS)

    von Riesemann, W.A.; Parks, M.B.

    1993-01-01

    In the United States, concrete containment buildings for commercial nuclear power plants have steel liners that act as the intemal pressure boundary. The liner abuts the concrete, acting as the interior concrete form. The liner is attached to the concrete by either studs or by a continuous structural shape (such as a T-section or channel) that is either continuously or intermittently welded to the liner. Studs are commonly used in reinforced concrete containments, while prestressed containments utilize a structural element as the anchorage. The practice in some countries follows the US practice, while in other countries the containment does not have a steel liner. In this latter case, there is a true double containment, and the annular region between the two containments is vented. This paper will review the practice of design of the liner system prior to the consideration of severe accident loads (overpressurization loads beyond the design conditions)

  18. EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

    Directory of Open Access Journals (Sweden)

    MAHSHAD YAZDANIPOUR

    2011-03-01

    Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.

  19. Blast densification trials for oilsands tailings

    Energy Technology Data Exchange (ETDEWEB)

    Port, A. [Klohn Crippen Berger Ltd., Vancouver, BC (Canada); Martens, S. [Klohn Crippen Berger Ltd., Calgary, AB (Canada); Eaton, T. [Shell Canada Ltd., Calgary, AB (Canada)

    2010-07-01

    The Shell Canada Muskeg River Mine External Tailings Facility (ETF) is an upstream constructed tailings facility located near Fort McMurray, Alberta. Raises have incrementally stepped out over the beach since construction of the starter dam and deposition within standing water has left some parts of the beach in a loose state. In order to assess the effectiveness of blast densification, a blast densification trial program that was conducted in 2006 at the ETF. The primary purpose of the test program was to determine the effectiveness of blast densification in tailings containing layers and zones of bitumen. The paper described the site characterization and explosive compaction trial program, with particular reference to test layout; drilling methodology; and blasting and timing sequence. The paper also described the instrumentation, including the seismographs; high pressure electric piezometers; low pressure electric piezometers; vibrating wire piezometers; inclinometers; settlement gauges; and surveys. Trial observations and post-trial observations were also presented. It was concluded that controlled blasting techniques could be used to safely induce liquefaction in localized areas within the tailings deposit, with a resulting increase in the tailings density. 5 refs., 1 tab., 14 figs.

  20. Spalling of concrete walls under blast load

    International Nuclear Information System (INIS)

    Kot, C.A.

    1977-01-01

    A common effect of the detonation of explosives in close proximity of concrete shield walls is the spalling (scabbing) of the back face of the wall. Spalling is caused by the free surface reflection of the shock wave induced in the wall by high pressure air blast and occurs whenever the dynamic tensile rupture strength is exceeded. While a complex process, reasonable analytical spall estimates can be obtained for brittle materials with low tensile strengths, such as concrete, by assuming elastic material behavior and instantaneous spall formation. Specifically, the spall thicknesses and velocities for both normal and oblique incidence of the shock wave on the back face of the wall are calculated. The complex exponential decay wave forms of the air blast are locally approximated by simple power law expressions. Variations of blast wave strength with distance to the wall, charge weight and angle of incidence are taken into consideration. The shock wave decay in the wall is also accounted for by assuming elastic wave propagation. For explosions close-in to the wall, where the reflected blast wave pressures are sufficiently high, multiple spall layers are formed. Successive spall layers are of increasing thickness, at the same time the spall velocities decrease. The spall predictions based on elastic theory are in overall agreement with experimntal results and provide a rapid means of estimating spalling trends of concrete walls subjected to air blast. (Auth.)

  1. 30 CFR 75.1316 - Preparation before blasting.

    Science.gov (United States)

    2010-07-01

    ... two working faces are approaching each other, cutting, drilling and blasting shall be done at only one... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Preparation before blasting. 75.1316 Section 75... HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1316 Preparation...

  2. Understanding behavioural intention to play online game: The case of VocBlast

    Science.gov (United States)

    Ali, Z.

    2018-04-01

    Research has shown that mobile learning enables its users to learn at any time and place. The current study investigates the use of VocBlast; an app that integrates technical and engineering vocabulary, in terms of understanding the behavioural intention of its players. The study employs 129 engineering and technical students from Universiti Malaysia Pahang (UMP). Online survey was used to collect their opinions; in particular male and female students’ opinions on the use of the app in the future. The results of the study indicated that there was no significant difference pertaining to their behavioural intention using VocBlast in the course of time. The study implies that more time needs to be given to the students in playing VocBlast as it is believed that playing the game repetitively would promote positive perceptions among its players.

  3. 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.

  4. 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.

  5. New techniques for improved performance in surface blasting operation and optimisation of blast design parameters

    Energy Technology Data Exchange (ETDEWEB)

    Roy, P.P. [Central Mining Research Institute, Dhanbad (India). Blasting Dept.

    1999-02-01

    Experimental blasts were conducted for optimisation of blasting parameters using separate technologies involving non-electric initiation systems, air decking accessories in conjunction with different explosive products like emulsion (cartridge and site-mixed), slurries (cartridge and site-mixed) and ANFO. The cost associated with each such technology was then compared with the conventional methods of drilling and blasting operations. The results of cost analyses are given. Theoretical and practical aspects of such technologies and their best possible usage in order to establish the desired fragmentation, muck profile, wall control and ultimately the accepted level of costs are mentioned in subsequent sections. 16 refs., 17 figs., 8 plates, 11 tabs.

  6. FastBLAST: homology relationships for millions of proteins.

    Directory of Open Access Journals (Sweden)

    Morgan N Price

    Full Text Available BACKGROUND: All-versus-all BLAST, which searches for homologous pairs of sequences in a database of proteins, is used to identify potential orthologs, to find new protein families, and to provide rapid access to these homology relationships. As DNA sequencing accelerates and data sets grow, all-versus-all BLAST has become computationally demanding. METHODOLOGY/PRINCIPAL FINDINGS: We present FastBLAST, a heuristic replacement for all-versus-all BLAST that relies on alignments of proteins to known families, obtained from tools such as PSI-BLAST and HMMer. FastBLAST avoids most of the work of all-versus-all BLAST by taking advantage of these alignments and by clustering similar sequences. FastBLAST runs in two stages: the first stage identifies additional families and aligns them, and the second stage quickly identifies the homologs of a query sequence, based on the alignments of the families, before generating pairwise alignments. On 6.53 million proteins from the non-redundant Genbank database ("NR", FastBLAST identifies new families 25 times faster than all-versus-all BLAST. Once the first stage is completed, FastBLAST identifies homologs for the average query in less than 5 seconds (8.6 times faster than BLAST and gives nearly identical results. For hits above 70 bits, FastBLAST identifies 98% of the top 3,250 hits per query. CONCLUSIONS/SIGNIFICANCE: FastBLAST enables research groups that do not have supercomputers to analyze large protein sequence data sets. FastBLAST is open source software and is available at http://microbesonline.org/fastblast.

  7. Drilling-and-blasting method of demolition

    Directory of Open Access Journals (Sweden)

    Sinitsyn Denis

    2018-01-01

    Full Text Available This article analyzes the experience and gives the examples of dismantling and demolition of the construction structures of the buildings and facilities using the drilling-and-blasting method. The drilling-and-blasting method is widely used in construction and reconstruction. The demolition means may be classified according to impact on a material of structures to be demolished and to forces application, where, by virtue of an impact energy type, we choose the blasting method. This method is used during the complete demolition or fragmentation of concrete, reinforced concrete, masonry structures, of old buildings and facilities demolition to their base or in the intended direction. Blasting method may be used as well during the steel and reinforced concrete structures demolition to the smaller easy-to-move parts. Reviewed are the organizational-process activities, which are performed during the various structures dismantling. Given are the areas of application for the various methods of structures demolition. Given is the example of demolition of “Sevemaya” boiler house brick chimney at the territory of Murmansk DSK using the blast in confined spaces of the operating company. Subject of research: methods of construction structures demolition in alarm situations and acts of God. Objects: determination of the most efficient demolition methods in the present conditions of construction operations development. Materials and methods: the developed activities on the construction structures dismantling are given. Results: the most efficient methods and ways of construction structures demolition are defined. Conclusions: it is required for improvement of methods and ways of the structures drilling-and-blasting demolition.

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chang Qi

    2014-01-01

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

  11. Mathematical models of blast induced TBI: current status, challenges and prospects

    Directory of Open Access Journals (Sweden)

    Raj K Gupta

    2013-05-01

    Full Text Available Blast induced traumatic brain injury (TBI has become a signature wound of recent military activities and is the leading cause of death and long-term disability among U.S. soldiers. The current limited understanding of brain injury mechanisms impedes the development of protection, diagnostic and treatment strategies. We believe mathematical models of blast wave brain injury biomechanics and neurobiology, complemented with in vitro and in vivo experimental studies, will enable a better understanding of injury mechanisms and accelerate the development of both protective and treatment strategies. The goal of this paper is to review the current state of the art in mathematical and computational modeling of blast induced TBI, identify research gaps and recommend future developments. A brief overview of blast wave physics, injury biomechanics and the neurobiology of brain injury is used as a foundation for a more detailed discussion of multiscale mathematical models of primary biomechanics and secondary injury and repair mechanisms. The paper also presents a discussion of model development strategies, experimental approaches to generate benchmark data for model validation and potential applications of the model for prevention and protection against blast wave TBI.

  12. 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

  13. 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.

  14. Implementations of BLAST for parallel computers.

    Science.gov (United States)

    Jülich, A

    1995-02-01

    The BLAST sequence comparison programs have been ported to a variety of parallel computers-the shared memory machine Cray Y-MP 8/864 and the distributed memory architectures Intel iPSC/860 and nCUBE. Additionally, the programs were ported to run on workstation clusters. We explain the parallelization techniques and consider the pros and cons of these methods. The BLAST programs are very well suited for parallelization for a moderate number of processors. We illustrate our results using the program blastp as an example. As input data for blastp, a 799 residue protein query sequence and the protein database PIR were used.

  15. Dry blasting decontaminating method for radioactive waste

    International Nuclear Information System (INIS)

    Nishiwaki, Hitoshi.

    1993-01-01

    In the present invention, when abrasives are dry blasted on the surface of radioactive wastes and the recovered abrasives are classified for re-use, abrasives having a microvicker's hardness (HMV) of greater than 600 and a grain size of greater than 1mm are used in a case where the radioactive wastes to be abraded are stainless steels. This enables dry blasting decontamination for stainless steels which has been considered to be impossible. In addition since the amount of secondary wastes are reduced, it is extremely effective. (T.M.)

  16. Predictive control of thermal state of blast furnace

    Science.gov (United States)

    Barbasova, T. A.; Filimonova, A. A.

    2018-05-01

    The work describes the structure of the model for predictive control of the thermal state of a blast furnace. The proposed model contains the following input parameters: coke rate; theoretical combustion temperature, comprising: natural gas consumption, blasting temperature, humidity, oxygen, blast furnace cooling water; blast furnace gas utilization rate. The output parameter is the cast iron temperature. The results for determining the cast iron temperature were obtained following the identification using the Hammerstein-Wiener model. The result of solving the cast iron temperature stabilization problem was provided for the calculated values of process parameters of the target area of the respective blast furnace operation mode.

  17. Study on the blasting demolition of steel construction. Part 2. Demolition work of steel tower; Tekkotsu kozobutsu no bakuha kaitai ni kansuru kenkyu. 2. Koro yagura happa kaitai koji

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Y.; Wada, Y.; Katsuyama, K. [National Institute for Resources and Environment, Tsukuba (Japan); Nishida, T.; Hoshino, M.; Nagano, M. [Kacoh Co. Ltd., Tokyo (Japan)

    1997-06-30

    This paper describes the blasting demolition of steel tower of iron works. The steel tower had four columns, and its dimension was 17 mtimes17 m in cross section and 77.6 m height. The total weight was about 1,724 t. The 18.4 kg V-type linear shaped charge was fixed around columns with box weld structures, and initiated using 16 seismograph electric detonators. Vibration and noise were measured during blasting and collapse of the tower. In the both case, the vibration levels were between 67 and 71 dB, which were low and under 75 dB, the standard level during specific construction works of the regulation act of vibration. The noise level was 120 dB(A) at the point 200 m away from the blasting source, which was over 85 dB(A), the standard level. The collapse process of steel tower was simulated using discontinuous deformation analysis. The results agreed well with those from the actual collapse. The steel tower landed about 6 seconds after the initiation, and it took about 15 seconds to complete the collapse. Before the demolition, the 6 t parts of forefeet of two columns in the collapse direction were cut and removed by blasting. Thus, the collapse was controlled in the given direction. 5 refs., 13 figs., 2 tabs.

  18. Effects of granulocyte-macrophage colony-stimulating factor and interleukin 6 on the growth of leukemic blasts in suspension culture.

    Science.gov (United States)

    Tsao, C J; Cheng, T Y; Chang, S L; Su, W J; Tseng, J Y

    1992-05-01

    We examined the stimulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 6 (IL)-6 on the in vitro proliferation of leukemic blast cells from patients with acute leukemia. Bone marrow or peripheral blood leukemic blast cells were obtained from 21 patients, including 14 cases of acute myeloblastic leukemia (AML), four cases of acute lymphoblastic leukemia (ALL), two cases of acute undifferentiated leukemia, and one case of acute mixed-lineage leukemia. The proliferation of leukemic blast cells was evaluated by measuring the incorporation of 3H-thymidine into cells incubated with various concentrations of cytokines for 3 days. GM-CSF stimulated the DNA synthesis (with greater than 2.0 stimulation index) of blast cells in 9 of 14 (64%) AML cases, two cases of acute undifferentiated leukemia and one case of acute mixed-lineage leukemia. Only two cases of AML blasts responded to IL-6 to grow in the short-term suspension cultures. GM-CSF and IL-6 did not display a synergistic effect on the growth of leukemic cells. Moreover, GM-CSF and IL-6 did not stimulate the proliferation of ALL blast cells. Binding study also revealed the specific binding of GM-CSF on the blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia. Our results indicated that leukemic blast cells of acute undifferentiated leukemia and acute mixed-lineage leukemia possessed functional GM-CSF receptors.

  19. Deformation Analyses and Lithologic Characterization in Overpressured Basins Based on Logging While Drilling and Wireline Results from the Gulf of Mexico

    Science.gov (United States)

    Iturrino, G. J.; Pirmez, C.; Moore, J. C.; Reichow, M. K.; Dugan, B. E.; Sawyer, D. E.; Flemings, P. B.; Shipboard Scientific Party, I.

    2005-12-01

    IODP Expedition 308 drilled transects along the Brazos-Trinity IV and Ursa Basins in the western and eastern Gulf of Mexico, respectively, for examining how sedimentation, overpressure, fluid flow, and deformation are coupled in passive margin settings. A total of eight holes were logged using either logging while drilling (LWD) or wireline techniques to evaluate the controls on slope stability, understand the timing of sedimentation and slumping, establish the petrophysical properties of shallow sediments, and provide a better understanding of turbidite systems. Overall, the log responses vary for the different lithostratigraphic units and associated regional seismic reflectors. The data acquired also make bed-to-bed correlation between sites possible, which is valuable for the study of sandy turbidites and studies of regional deformation. The thick sedimentary successions drilled at these basins show records of the evolution of channel-levee systems composed of low relief channels that were incapable of confining the turbidity currents causing an overspill of sand and silt. In addition, mass transport deposits at shallow depths, and transitions between interbedded silt, sand, and mud units are common features identified in many of the downhole logging data. In the Ursa Basin sediments, resistivity-at-the-bit images show significant deformation of the overlying hemipelagic drape and distal turbidites that were drilled in these areas. Numerous dipping beds throughout these intervals with dips ranging from 5 to 55 degrees confirm core observations. Steeply deformed beds, with dips as high as 65 degrees, and folded and faulted beds suggest down slope remobilization as mass-transport deposits. Resistivity images also show evidence of these mass-transport deposits where steep dips and folds suggest the presence of overturned beds within a series of cyclic intervals that we interpret as a succession of sand-silt-mud lamina. Preliminary structural analyses suggest that

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

    Science.gov (United States)

    2013-01-01

    overpressure positive phase was not affected by the anomalous effect of the rarefaction wave coming from the open-end of the tube. Calibrations were...experience the overpressure. The representative curves are seen below from the 1537 mm sensor, which represents the exposed absolute overpressure on the...the cross-section of the shock tube is constant, the shockwave moves at a constant speed unattenuated down the tube until the reflected rarefaction

  1. Blast damage predictions from vibration measurements at the SKB underground laboratories at Aespoe in Sweden

    International Nuclear Information System (INIS)

    Ouchterlony, F.; Sjoeberg, C.; Jonsson, B.A.

    1993-01-01

    This contribution reports an investigation of the blasting damage in the contour of an access ramp to a Swedish underground laboratory for nuclear waste related studies. Near zone vibration measurements were made for 7 rounds and the results converted to a site specific scaling law. A simple engineering correction for the influence of the charge length was developed and the resulting equations used to predict the damage zone depths of three different drilling and charging patterns. These predictions were then compared with actual blast damage measurements. The agreement with geophysical borehole logging results is remarkably good. This gives good support to the engineering method in which a critical vibration velocity is used to predict the zones of blast damage around bore holes

  2. Reliability Analysis of Retaining Walls Subjected to Blast Loading by Finite Element Approach

    Science.gov (United States)

    GuhaRay, Anasua; Mondal, Stuti; Mohiuddin, Hisham Hasan

    2018-02-01

    Conventional design methods adopt factor of safety as per practice and experience, which are deterministic in nature. The limit state method, though not completely deterministic, does not take into account effect of design parameters, which are inherently variable such as cohesion, angle of internal friction, etc. for soil. Reliability analysis provides a measure to consider these variations into analysis and hence results in a more realistic design. Several studies have been carried out on reliability of reinforced concrete walls and masonry walls under explosions. Also, reliability analysis of retaining structures against various kinds of failure has been done. However, very few research works are available on reliability analysis of retaining walls subjected to blast loading. Thus, the present paper considers the effect of variation of geotechnical parameters when a retaining wall is subjected to blast loading. However, it is found that the variation of geotechnical random variables does not have a significant effect on the stability of retaining walls subjected to blast loading.

  3. 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)

  4. 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.

  5. Marker-assisted introgression of broad-spectrum blast resistance genes into the cultivated MR219 rice variety.

    Science.gov (United States)

    Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

    2017-07-01

    The rice cultivar MR219 is famous for its better yield and long and fine grain quality; however, it is susceptible to blast disease. The main objective of this study was to introgress blast resistance genes into MR219 through marker-assisted selection (MAS). The rice cultivar MR219 was used as the recurrent parent, and Pongsu Seribu 1 was used as the donor. Marker-assisted foreground selection was performed using RM6836 and RM8225 to identify plants possessing blast resistance genes. Seventy microsatellite markers were used to estimate recurrent parent genome (RPG) recovery. Our analysis led to the development of 13 improved blast resistant lines with Piz, Pi2 and Pi9 broad-spectrum blast resistance genes and an MR219 genetic background. The RPG recovery of the selected improved lines was up to 97.70% with an average value of 95.98%. Selected improved lines showed a resistance response against the most virulent blast pathogen pathotype, P7.2. The selected improved lines did not express any negative effect on agronomic traits in comparison with MR219. The research findings of this study will be a conducive approach for the application of different molecular techniques that may result in accelerating the development of new disease-resistant rice varieties, which in turn will match rising demand and food security worldwide. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. 8 Museve NBI BombBlast.indd

    African Journals Online (AJOL)

    Professionals, executives, managers, semi professionals and skilled workers comprised 89.5% of the victims when ... dependants. Being inside a building and within 100 metres from the blast carried the largest risk of injury. A ... Kenya had never experienced a suicidal terrorist bombing ..... Rapid assessment of Injuries.

  7. Ice blasting device for washing pump

    International Nuclear Information System (INIS)

    Hirose, Yasuo.

    1992-01-01

    In a nuclear power plant, when the inside of a pump casing such as a recycling pump is scrubbed, since operator's safety should be ensured, it requires a large-scaled operation. Then, a cover is attached to a flange of the pump casing, in which a driving portion is disposed passing through the cover vertically movably and rotatably, an arm is disposed bendably to the top end of the arm, and a blast nozzle is disposed to the top end of the arm for jetting ice particles, with a camera being disposed to the blast nozzle. The inside of the casing can be scrubbed safely and rapidly by an ice blast method by remote operation while monitoring the state of scrubbing for the inside of the casing by a camera. Further, since the flange of the pump casing for installing the ice blast device is covered by the cover, mists are not scattered to the outside. In addition, mists may be sucked and removed by an exhaustion duct. (N.H.)

  8. Modeling of Near-Field Blast Performance

    Science.gov (United States)

    2013-11-01

    The freeze-out temperature is chosen by comparison of calorimetry experiments (2, 3) and thermoequilibrium calculations using CHEETAH (4). The near...P.; Vitello, P. CHEETAH Users Manual; Lawrence Livermore National Laboratory: Livermore, CA, 2012. 5. Walter, P. Introduction to Air Blast

  9. Blast Injuries: What Clinicians Need to Know

    Centers for Disease Control (CDC) Podcasts

    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.

  10. Behavior and evaluation of an existing underground structure subjected to impulsive loads from an internal explosion

    International Nuclear Information System (INIS)

    Keller, M.D.; Khan, P.K.

    1997-12-01

    An explosion is the result of a rapid chemical reaction which generates transient air pressure waves called blast waves. There has been much research on the processes of blast wave formation, propagation of blast waves, and quantification of the incident and reflected blast overpressures. The magnitude of blast overpressure, in a partially vented environment, is mainly a function of the type and quantity of detonating material, the amount of available venting, and the orientation and configuration of the reflecting surfaces. In addition to blast overpressure, an explosion can also generate high energy missiles (such as fragments), shock loads, and rapid rise of temperature in the confined space. This study concentrates on the effects of blast overpressure on a 40 feet diameter reinforced concrete cylinder with a hemispherical dome roof, supported on a 3 feet thick reinforced concrete pad, and buried under a minimum of 15 feet of soil used for radiation shielding at the top of the dome. The scope of this study is to determine whether the structure can withstand the blast overpressure generated by the postulated explosion without exceeding allowable design criteria

  11. 29 CFR 1926.906 - Initiation of explosive charges-electric blasting.

    Science.gov (United States)

    2010-07-01

    ...) After firing an electric blast from a blasting machine, the leading wires shall be immediately... 29 Labor 8 2010-07-01 2010-07-01 false Initiation of explosive charges-electric blasting. 1926.906... Use of Explosives § 1926.906 Initiation of explosive charges—electric blasting. (a) Electric blasting...

  12. Leaching of Carbothermic Reduced Titanium-bearing Blast Furnace Slag by Acid

    Institute of Scientific and Technical Information of China (English)

    ZHEN Yulan; ZHANG Guohua; CHOU Kuochih

    2016-01-01

    The kinetics of the leaching of carbothermic reduced titanium-bearing blast furnace slag in Panzhihua Iron and Steel Company with acid system under atmosphere pressure was studied. The results show that the temperature and concentration have significant influence on leaching of carbothermic reduced titanium-bearing blast furnace slag by ac-id. The experimental data of leaching indicate that the shrinking core model with chemical reaction controlled process is most applicable for the acid leaching. The apparent activation energy can be estimated to be from 23 to 32 kJ/mol. Fur-thermore, the main products are TiC and SiO2 after leaching.

  13. Evaluation of refractory lining wear of Companhia Siderurgica Nacional (CSN) blast furnaces

    International Nuclear Information System (INIS)

    Santos, N.J. dos; Mello, A.H.B. de; Pereira, C.L.; Paula Sarkis, D. de; Martins Filho, D.I.; Banados Perez, H.E.; Carvalho, G.; Daltro, T.F.L.

    1984-01-01

    The blast furnace refractory linings are submitted to unfavourable conditions such as alkalis attack, temperature, top pressure, abrasion and so forth... After studies on distribution and installation of radioactive sources with low activities in the refractory lining, it was possible to develop a new technique of thickness evaluation and attendance of wearing in the furnace lining. The viability analysis, simulated laboratory tests, localization, identification, installations and periodical measurements of the radioactive sources are described, as well the results obtained on the present campaign of CSN Blast Furnaces. (Author) [pt

  14. Numerical Analyses of the Influence of Blast-Induced Damaged Rock Around Shallow Tunnels in Brittle Rock

    Science.gov (United States)

    Saiang, David; Nordlund, Erling

    2009-06-01

    Most of the railway tunnels in Sweden are shallow-seated (rock cover) and are located in hard brittle rock masses. The majority of these tunnels are excavated by drilling and blasting, which, consequently, result in the development of a blast-induced damaged zone around the tunnel boundary. Theoretically, the presence of this zone, with its reduced strength and stiffness, will affect the overall performance of the tunnel, as well as its construction and maintenance. The Swedish Railroad Administration, therefore, uses a set of guidelines based on peak particle velocity models and perimeter blasting to regulate the extent of damage due to blasting. However, the real effects of the damage caused by blasting around a shallow tunnel and their criticality to the overall performance of the tunnel are yet to be quantified and, therefore, remain the subject of research and investigation. This paper presents a numerical parametric study of blast-induced damage in rock. By varying the strength and stiffness of the blast-induced damaged zone and other relevant parameters, the near-field rock mass response was evaluated in terms of the effects on induced boundary stresses and ground deformation. The continuum method of numerical analysis was used. The input parameters, particularly those relating to strength and stiffness, were estimated using a systematic approach related to the fact that, at shallow depths, the stress and geologic conditions may be highly anisotropic. Due to the lack of data on the post-failure characteristics of the rock mass, the traditional Mohr-Coulomb yield criterion was assumed and used. The results clearly indicate that, as expected, the presence of the blast-induced damage zone does affect the behaviour of the boundary stresses and ground deformation. Potential failure types occurring around the tunnel boundary and their mechanisms have also been identified.

  15. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J; Tervola, K [Oulu Univ. (Finland). Dept. of Process Engineering

    1997-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  16. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Tervola, K.; Haerkki, J.

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquids temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) (14 refs.)

  17. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Tervola, K. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  18. Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns

    Directory of Open Access Journals (Sweden)

    XinPing Li

    2017-01-01

    Full Text Available Aiming at surrounding rock damage induced by dynamic disturbance from blasting excavation of rock-anchored beam in rock mass at moderate or far distance in underground cavern, numerical model of different linear charging density and crustal stress in underground cavern is established by adopting dynamic finite element software based on borehole layout, charging, and rock parameter of the actual situation of a certain hydropower station. Through comparison in vibration velocity, contour surface of rock mass excavation, and the crushing extent of excavated rock mass between calculation result and field monitoring, optimum linear charging density of blast hole is determined. Studies are also conducted on rock mass vibration in moderate or far distance to blasting source, the damage of surrounding rock in near-field to blasting source, and crushing degree of excavated rock mass under various in situ stress conditions. Results indicate that, within certain range of in situ stress, the blasting vibration is independent of in situ stress, while when in situ stress is increasing above certain value, the blasting vibration velocity will be increasing and the damage of surrounding rock and the crushing degree of excavated rock mass will be decreasing.

  19. Immunophenotype of leukemic blasts with small peroxidase-positive granules detected by electron microscopy.

    Science.gov (United States)

    Vainchenker, W; Villeval, J L; Tabilio, A; Matamis, H; Karianakis, G; Guichard, J; Henri, A; Vernant, J P; Rochant, H; Breton-Gorius, J

    1988-05-01

    Forty-three cases of undifferentiated leukemias by light microscopy examination were diagnosed as acute myeloblastic leukemias by ultrastructural revelation of peroxidase and were subsequently studied by immunological markers. In 41 of these cases, blasts were labeled by at least one of the antimyeloid MoAbs (My 7, My 9, and 80H5). An antimyeloperoxidase polyclonal antibody was used in 23 cases and was clearly positive in 11 of them, while cytochemistry by light microscopy was negative. These myeloblasts were frequently mixed with a minority of blasts from other lineages especially promegakaryoblasts. It is noteworthy that in 6 cases myeloid and lymphoid markers (E rosette receptor, common acute lymphoblastic leukemia antigen (cALLA), CD 9, CD 19 antigens (anti-B4 MoAb] were detected on a fraction of blast cells, suggesting a bilineage leukemia. However, in double labeling experiments, blasts with myeloperoxidase coexpressed lymphoid and myeloid markers including cALLA and CD 19 antigen. In one case, blasts had a typical non-B, non-T acute lymphoblastic leukemia phenotype (HLA-DR, CD 9, CD 19, cALLA positive) without staining by any of the antimyeloid MoAbs. However, 70% of the blasts were labeled by the antimyeloperoxidase antibody and expressed peroxidase-positive granules at ultrastructural level. In conclusion, most of the AML undiagnosed by optical cytochemistry are identified by antimyeloid antibodies. Some of these cases are also stained by some antilymphoid MoAbs. Use of antibodies against myeloperoxidase may improve the diagnosis of difficult cases of acute myeloblastic leukemia.

  20. Natural variation of rice blast resistance gene Pi-d2

    Science.gov (United States)

    Studying natural variation of rice resistance (R) genes in cultivated and wild rice relatives can predict resistance stability to rice blast fungus. In the present study, the protein coding regions of rice R gene Pi-d2 in 35 rice accessions of subgroups, aus (AUS), indica (IND), temperate japonica (...

  1. Blasting as a method for abandoned mine land reclamation

    International Nuclear Information System (INIS)

    Workman, J.L.; Fletcher, L.R.

    1991-01-01

    Blasting methods have been proposed for reclaiming abandoned underground coal mine sites having unstable conditions. The objective of blasting is twofold: the permanent stabilization of an area by the collapse of underground workings to prevent any future subsidence, and the use of blasting to close existing sinkholes. This paper presents the results of two research projects funded by the Bureau of Mines Abandoned Mine Land Research Program to investigate the feasibility of blasting to assist in the reclamation of shallow abandoned coal mine sites. Blasting tests were conducted at Beulah, North Dakota and at Scobey, Montana, involving different configurations. The first test was a 10-acre site where blasting was used to collapse regular room and pillar panels for which good mine layout information was available. The second test involved a one acre site containing very irregular workings for which there was little available information. Finally, blasting techniques were used to close 13 individual vertical openings. The depths to the coal seams were 60 feet or less at all sites. When blasting for Abandoned Mine Land Reclamation, material must be cast downward into the abandoned developments or laterally into the sinkhole. Designs based on cratering concepts and spherical charges worked well. The blasting techniques successfully collapsed and stabilized the test areas. Cost of reclamation for the two test sites are presented. Data from blast vibration monitoring are presented because control of vibrations is of concern when mitigation efforts are conducted near homes

  2. 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.

  3. Simulation of overpressure events with a Laguna Verde model for the RELAP code to conditions of extended power up rate

    International Nuclear Information System (INIS)

    Rodriguez H, A.; Araiza M, E.; Fuentes M, L.; Ortiz V, J.

    2012-10-01

    In this work the main results of the simulation of overpressure events are presented using a model of the nuclear power plant of Laguna Verde developed for the RELAP/SCDAPSIM code. As starting point we have the conformation of a Laguna Verde model that represents a stationary state to similar conditions to the operation of the power station with Extended Power Up rate (EPU). The transitory of simulated pressure are compared with those documented in the Final Safety Analysis Report of Laguna Verde (FSAR). The results of the turbine shot transitory with and without by-pass of the main turbine are showed, and the event of closes of all the valves of main vapor isolation. A preliminary simulation was made and with base in the results some adjustments were made for the operation with EPU, taking into account the Operation Technical Specifications of the power station. The results of the final simulations were compared and analyzed with the content in the FSAR. The response of the power station to the transitory, reflected in the model for RELAP, was satisfactory. Finally, comments about the improvement of the model are included, for example, the response time of the protection and mitigation systems of the power station. (Author)

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

    International Nuclear Information System (INIS)

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

    1978-01-01

    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

  5. The pattern of paediatric blast injury in Afghanistan.

    Science.gov (United States)

    Thompson, Daniel C; Crooks, R J; Clasper, J C; Lupu, A; Stapley, S A; Cloke, D J

    2017-10-21

    Between 2009 and 2015, 3746 children died, and 7904 were injured as a result of armed conflict within Afghanistan. Improvised explosive devices (IEDs) and explosive remnants of war accounted for 29% of child casualties in 2015. The aim of this study was to review the burden of paediatric blast injuries admitted to Camp Bastion, Afghanistan, and to investigate the hypothesis that children suffer proportionally more head injuries than adults. A retrospective analysis was undertaken of prospectively collected data derived from the UK Joint Theatre Trauma Registry of ambulant paediatric (aged 2-15 years) admissions with blast injuries at the Role 3 Field Hospital, Camp Bastion from June 2006 to March 2013. The data set included demographic information, injury profile and severity (New Injury Severity Score) and operative findings. The pattern of injuries were investigated by looking at trends in the number and severity of injuries sustained by each body region. During this period, 295 admissions were identified, 76% of whom were male, with an overall mortality rate of 18.5%. The most common blast mechanism was an IED (68%) causing 80% of fatalities. The lower extremities were the most commonly injured body region, accounting for 31% of total injuries and occurring in 62% of cases. 24.3% of children between 2 and 7 years suffered severe head or neck injuries compared with 19.8% of children aged between 8 and 15 years. 34% of head injuries were rated unsurvivable and accounted for 88% of fatalities. 77% of cases required an operation with a mean operating time of 125 min. The most common first operations were debridement of soft tissues (50%), laparotomy (16%) and lower limb amputation (11%). Although paediatric blast casualties represented a small percentage of the overall workload at Camp Bastion Role 3 Medical Facility, the pattern of injuries seen suggests that children are more likely to sustain severe head, face and neck injuries than adults. © Article author

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

    Science.gov (United States)

    1974-05-01

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

  7. 77 FR 31878 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Blasting...

    Science.gov (United States)

    2012-05-30

    ... requirements designed to protect covered employees working with and around blasting operations. Inventories of... for OMB Review; Comment Request; Blasting Operations and Use of Explosives Standard ACTION: Notice... (OSHA) sponsored information collection request (ICR) titled, ``Blasting Operations and Use of...

  8. Application of Carbon Composite Bricks for Blast Furnace Hearth

    Science.gov (United States)

    Zuo, Haibin; Wang, Cong; Zhang, Jianliang; Zhao, Yongan; Jiao, Kexin

    Traditional refractory materials for blast furnace hearth lining are mainly composed of carbon bricks and the ceramic cup. However, these materials can't meet the demands for long service life design of blast furnaces. In this paper, a new refractory called carbon composite brick (CCB) was introduced, which combined the advantages of carbon bricks and the ceramic cup. In this case, the resistance of the CCB against corrosion was equal to the ceramic cup and the thermal conductivity of the CCB was equal to carbon bricks. From the results of more than 20 blast furnaces, the CCB could be well used in small blast furnaces and large blast furnaces. In the bad condition of low grade burden and high smelting intensity, the CCB gave full play to the role of cooling system, and effectively resisted the erosion of hot metal to improve the service life of blast furnaces.

  9. Safety management system during rock blasting at FRFCF construction site

    International Nuclear Information System (INIS)

    Vijayakumaran, C.; Kandasamy, S.; Satpathy, K.K.

    2016-01-01

    Blasting is an important activity during rock excavation to reach required depth for obtaining stability of the civil structure. For the construction of various Plant Buildings of Fast Reactor Fuel Cycle Facility (FRFCF), IGCAR at Kalpakkam, based on the geological survey it is required to reach a depth of 21.4 meters from existing ground level. This paper details about the procedures and precaution adopted during the rock blasting activities at FRFCF site. The volume of rock removed by blasting was 3 lakh cubic meters. The total number of blasting carried out was 304 using 105.73 tons of blasting material. The entire blasting work could be completed within 174 days without any incident. (author)

  10. Positive /sup 111/In-granulocyte scintigraphy in a patient with focal leukemic blast cell infiltrations

    Energy Technology Data Exchange (ETDEWEB)

    Syrjaelae, M; Remes, K; Paavonen, T; Liewendahl, K

    1985-06-01

    A patient with acute myeloid leukemia was investigated with /sup 111/In-granulocyte scintigraphy to reveal possible sites of infection. /sup 111/In-granulocytes accumulated in areas of leukemia blast cell infiltration leading to a false-positive scintigram. This possibility must be kept in mind when studying leukemic patients using labeled leukocytes.

  11. Hot metal temperature prediction by neural networks in the blast furnace

    International Nuclear Information System (INIS)

    Cantera, C.; Jimenez, J.; Varela, I.; Formoso, A.

    2002-01-01

    Based on a simplified model, the underlying temperature criteria is proposed as a method to study the temperature trends in a blast furnace. As an application, a neural network able to forecast hot metal temperatures from 2 to 16 h in advance (with decreasing precision) has been built. This neural network has been designed to work at real time in a production plant. (Author)

  12. Physics of IED blast shock tube simulations for mTBI research

    NARCIS (Netherlands)

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

    2011-01-01

    Shock tube experiments and simulations are conducted with a spherical gelatin filled skull- brain surrogate, in order to study the mechanisms leading to blast induced mild traumatic brain injury. A shock tube including sensor system is optimized to simulate realistic impro-vised explosive device

  13. Innovation based on tradition : Blast furnace slag cement for durable concrete structures in Norway?

    NARCIS (Netherlands)

    Polder, R.B.; Nijland, T.; De Rooij, M.; Larsen, C.K.; Pedersen, B.

    2014-01-01

    Blast furnace slag cement (BFSC) has been used to build reinforced concrete structures in marine and road environment in The Netherlands for nearly a century. The experience is good and structures with long service lives can be obtained, as has been shown by several field studies. This is caused by

  14. Aspergillus flavus Blast2GO gene ontology database: elevated growth temperature alters amino acid metabolism

    Science.gov (United States)

    The availability of a representative gene ontology (GO) database is a prerequisite for a successful functional genomics study. Using online Blast2GO resources we constructed a GO database of Aspergillus flavus. Of the predicted total 13,485 A. flavus genes 8,987 were annotated with GO terms. The mea...

  15. A Fluid Helmet Liner for Protection Against Blast Induced Traumatic Brain Injury

    Science.gov (United States)

    2010-05-01

    Xs- V 0 A \\ /I \\ A // ^> cV- if- y1 ^H5^ ay< $? ̂ fta 11 13 1.3 1 d H 1 R 1.7 1 R 1 q Time (ms) Fig. 11 Pressure profiles: Solid... clinical trials. Furthermore, the data obtained can be used in computational validation. The blast mitigation aspect of the study was accomplished

  16. Modeling of a self-healing process in blast furnace slag cement exposed to accelerated carbonation

    NARCIS (Netherlands)

    Zemskov, S.V.; Ahmad, B.; Copuroglu, O.; Vermolen, F.J.

    2013-01-01

    In the current research, a mathematical model for the post-damage improvement of the carbonated blast furnace slag cement (BFSC) exposed to accelerated carbonation is constructed. The study is embedded within the framework of investigating the effect of using lightweight expanded clay aggregate,

  17. 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

  18. Simulation of crack propagation in rock in plasma blasting technology

    Science.gov (United States)

    Ikkurthi, V. R.; Tahiliani, K.; Chaturvedi, S.

    Plasma Blasting Technology (PBT) involves the production of a pulsed electrical discharge by inserting a blasting probe in a water-filled cavity drilled in a rock, which produces shocks or pressure waves in the water. These pulses then propagate into the rock, leading to fracture. In this paper, we present the results of two-dimensional hydrodynamic simulations using the SHALE code to study crack propagation in rock. Three separate issues have been examined. Firstly, assuming that a constant pressure P is maintained in the cavity for a time τ , we have determined the P- τ curve that just cracks a given rock into at least two large-sized parts. This study shows that there exists an optimal pressure level for cracking a given rock-type and geometry. Secondly, we have varied the volume of water in which the initial energy E is deposited, which corresponds to different initial peak pressures Ppeak. We have determined the E- Ppeak curve that just breaks the rock into four large-sized parts. It is found that there must be an optimal Ppeak that lowers the energy consumption, but with acceptable probe damage. Thirdly, we have attempted to identify the dominant mechanism of rock fracture. We also highlight some numerical errors that must be kept in mind in such simulations.

  19. Pathological Fingerprints, Systems Biology and Biomarkers of Blast Brain Injury

    Science.gov (United States)

    2010-06-01

    changes after blast injury. J. Trauma 56, 393–403. Murthy, J.M., Chopra, J.S., and Gulati, D.R. (1979). Subdural hematoma in an adult following a blast...neuronal damage), diffuse brain injury, and subdural hemorrhage. It is still controversial whether primary blast forces directly damage the brain, and if...emboli, leading to infarction (Guy et al., 2000a; Guy et al., 2000b). The most common types of TBI are diffuse axonal injury, contusion, and subdural

  20. Pattern of external injuries sustained during bomb blast attacks in Karachi, Pakistan from 2000 to 2007.

    Science.gov (United States)

    Surani, Arif Anwar; Ali, Salman; Surani, Asif; Zahid, Sohaib; Shoukat, Akber; Varon, Joseph; Surani, Salim

    2015-07-01

    To evaluate patterns of external injury resulting from bomb blasts in Karachi, and compare the injury profile resulting from explosions in open versus semi-confined blast environments. The retrospective, cross-sectional study was conducted in Karachi and comprised relevant data from January 2000 to October 2007. Casualty medical records and medico-legal certificates of the victims presented to three large public-sector hospitals were evaluated using a self-designed proforma. SPSS 17 was used for statistical analysis. Of the 1146 victims, data of 481(42%) represented the final study sample. Of these, 306(63.6%) were injured in open spaces and 175(36.4%) in semi-confined spaces. Of the 896 recorded injuries, lacerations were encountered as external injury in 427(47.7%) cases, followed by penetrating wounds in 137(15.3%). Lower and upper extremities were injured in 348(38.8%) and 170(19%) victims respectively. Open and semi-confined blast environments produced specific injury pattern and profile (pbomb blast attacks in Karachi demonstrated specific injury patterns and profiles. Further studies are required to account for internal injuries and classification of injuries based on standardised scoring systems.

  1. 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.

  2. 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

  3. Collapse of rocks by blasting. Razrusheniye gornykh porod Vzryvom

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, A F; Kutuzov, B N

    1983-01-01

    Information is provided about drilling boreholes and wells, explosives and the means for initiating them, storage, transporting and calculation of the explosive materials. Physical essence of the destructive, scientific and air effect of the blast are presented, principles of arrangement and calculation of the charges, reasons for malfunctions and methods of eliminating them, measures for protecting the surrounding objects from harmful effect of the industrial blast. Questions are examined of planning, organization and safety of the blasting operations. The second edition (first edition 1967) has been revised with regard for changes that occurred in the field of blasting operations.

  4. 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.

  5. Prevention of Blast-Related Injuries

    Science.gov (United States)

    2017-09-01

    in a canvas harness. The harness was further supported by a steel frame which was suspended from a metal beam (3.7 m off the ground) mounted on...direction of the wave propagation (Figure 5). After proper alignment of the head with respect to the center of the C4 charge, the steel frame was...further tied to four hooks cemented to the concrete ground with straps to prevent excessive motion during the blast exposure. The intensity of the two

  6. Blast vibration monitoring, July to December, 1983

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The complexity of the vibration waveforms produced appears at this stage to preclude simple comparison of different blasts. A modelling approach is indicated from the preliminary experiments. The required elemental charge length and the steady state column length of ANFO in 381 mm holes must be determined for further development of a model. This information may be acquired by firing a number of charges of varying lengths with all other variables held constant.

  7. 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

  8. 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.

  9. 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)

  10. Regulatory T cells-derived IL-35 promotes the growth of adult acute myeloid leukemia blasts.

    Science.gov (United States)

    Tao, Qianshan; Pan, Ying; Wang, Yiping; Wang, Huiping; Xiong, Shudao; Li, Qing; Wang, Jia; Tao, Lili; Wang, Zhitao; Wu, Fan; Zhang, Rui; Zhai, Zhimin

    2015-11-15

    Tumor immune escape mechanism mediated by CD4+CD25+regulatory T cells (Tregs) is a key factor in the pathogenesis of acute myeloid leukemia (AML). IL-35, as a novel inhibitory cytokine, is produced by Tregs specially and regulates functions of Tregs in murine. However, IL-35 expression of Tregs in human is still disputed, and its role in AML is yet to be elucidated. In this study, we found that IL-35 was expressed highly in peripheral blood plasma of adult patients with AML and significantly correlated with the clinical stages of malignancy. Tregs-derived from adult AML patients produced IL-35 in a stimulation-dependent manner. IL-35 promoted AML blasts immune escape by expanding Tregs and inhibiting CD4+CD25-effector T cells (Teffs). Furthermore, IL-35 directly promoted the proliferation of AML blasts and reduced the apoptosis of AML blasts. Together, our study demonstrates that IL-35-derived from Tregs promotes the growth of adult AML blasts, suggesting that IL-35 has an important role in the pathogenesis of AML. © 2015 UICC.

  11. Blast-Wave Generation and Propagation in Rapidly Heated Laser-Irradiated Targets

    Science.gov (United States)

    Ivancic, S. T.; Stillman, C. R.; Nilson, P. M.; Solodov, A. A.; Froula, D. H.

    2017-10-01

    Time-resolved extreme ultraviolet (XUV) spectroscopy was used to study the creation and propagation of a >100-Mbar blast wave in a target irradiated by an intense (>1018WWcm2 cm2) laser pulse. Blast waves provide a platform to generate immense pressures in the laboratory. A temporal double flash of XUV radiation was observed when viewing the rear side of the target, which is attributed to the emergence of a blast wave following rapid heating by a fast-electron beam generated from the laser pulse. The time-history of XUV emission in the photon energy range of 50 to 200 eV was recorded with an x-ray streak camera with 7-ps temporal resolution. The heating and expansion of the target was simulated with an electron transport code coupled to 1-D radiation-hydrodynamics simulations. The temporal delay between the two flashes measured in a systematic study of target thickness and composition was found to evolve in good agreement with a Sedov-Taylor blast-wave solution. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and Department of Energy Office of Science Award Number DE-SC-0012317.

  12. Myeloperoxidase mRNA detection for lineage determination of leukemic blasts: retrospective analysis.

    Science.gov (United States)

    Crisan, D; Anstett, M J

    1995-07-01

    Myeloperoxidase (MPO) mRNA is an early myeloid marker; its detection in the morphologically and immunophenotypically primitive blasts of acute undifferentiated leukemia (AUL) establishes myeloid lineage and allows reclassification as acute myelogenous leukemia with minimal differentiation (AML-MO). We have previously reported a procedure for MPO mRNA detection by RT-PCR (reverse transcription-polymerase chain reaction) and an adaptation for use of routine hematology smears. This variant procedure allows retrospective analysis of mRNA and is used in the present study to evaluate the lineage of leukemic blasts in seven cases with morphology and cytochemistry consistent with AUL. All hematology smears used in this study were air-dried, unstained or Wright-stained and stored at room temperature for periods varying between 3 days and 2 years. MPO mRNA was detected in six cases, establishing the myeloid lineage of the blasts and the diagnosis of AML-MO. In the remaining case, the blasts were MPO mRNA negative, confirming the diagnosis of AUL. The RT-PCR procedure for retrospective mRNA analysis is useful in the clinical setting, due to its high specificity and sensitivity, speed (less than 24 h), safety (no radioactivity) and convenient use of routine hematology smears; it is particularly attractive in clinical situations when fresh or frozen specimens are no longer available at the time when the need for molecular diagnostics becomes apparent.

  13. Effect of root and leaf applications of soluble silicon on blast development in rice

    Directory of Open Access Journals (Sweden)

    Isaias Severino Cacique

    2013-01-01

    Full Text Available Blast, caused by Pyricularia oryzae, is the most important fungal disease of rice worldwide. This study aimed to compare root and foliar supply of soluble silicon (Si on rice resistance to blast. The application of soluble Si to the roots increased Si concentration in leaf tissues as compare to plants grown in soil amended with calcium silicate. There was no increase in leaf Si concentration after soluble Si spray, regardless if the leaves were washed or not before analysis. X-ray microanalysis revealed that Si deposition was very similar on the leaf epidermis of plants sprayed with soluble Si, root amended with soluble Si or grown in soil amended with calcium silicate. The lesion size, the number of lesions per cm² of leaf and the area under blast progress curve were reduced for rice plants grown in soil that received the application of soluble Si or was amended with calcium silicate. The results of this study showed that the supply of soluble Si to the roots or its spray onto to the rice leaves can decrease blast symptoms.

  14. Evidence of central and peripheral vestibular pathology in blast-related traumatic brain injury.

    Science.gov (United States)

    Scherer, Matthew R; Burrows, Holly; Pinto, Robin; Littlefield, Philip; French, Louis M; Tarbett, Aaron K; Schubert, Michael C

    2011-06-01

    To prospectively assay the vestibular and oculomotor systems of blast-exposed service members with traumatic brain injury (TBI). Prospective, nonblinded, nonrandomized descriptive study. Tertiary care facility (Department of Defense Medical Center). Twenty-four service members recovering from blast-related TBI sustained in Iraq or Afghanistan. Focused history and physical, videonystagmography (VNG), rotational chair, cervical vestibular-evoked myogenic potentials, computerized dynamic posturography, and self-report measures. Vestibular testing confirms a greater incidence of vestibular and oculomotor dysfunction in symptomatic (vestibular-like dizziness) personnel with blast-related TBI relative to asymptomatic group members. VNG in the symptomatic group revealed abnormal nystagmus or oculomotor findings in 6 of 12 subjects tested. Similarly, rotational chair testing in this group revealed evidence of both peripheral (4/12) and central (2/12) vestibular pathology. By contrast, the asymptomatic group revealed less vestibular impairment with 1 of 10 rotational chair abnormalities. The asymptomatic group was further characterized by fewer aberrant nystagmus findings (4/12 abnormal VNGs). Computerized dynamic posturography testing revealed no significant differences between groups. Self-report measures demonstrated differences between groups. Vestibular function testing confirms a greater incidence of peripheral vestibular hypofunction in dizzy service members with blast-related TBI relative to those who are asymptomatic. Additionally, oculomotor abnormalities and/or nystagmus consistent with central involvement were present in 10 of the 24 study participants tested. The precise cause of these findings remains unknown.

  15. Large-Scale Experimental and Numerical Study of Blast Acceleration Created by Close-In Buried Explosion on Underground Tunnel Lining

    Directory of Open Access Journals (Sweden)

    Mohamad Reza Soheyli

    2016-01-01

    Full Text Available Despite growing demands for structures in water transportation tunnels, underground installations, subsurface dams, and subterranean channels, there is limited field knowledge about the dynamic behavior of these structures in the face of near-fault earthquakes or impulse excitations. This study conducted a large-scale test on underground tunnel excited by two close-in subsurface explosions. The horizontal and vertical acceleration were recorded on the vertical wall of the tunnel and the free field data including the acceleration on the ground surface at 11-meter distance from the tunnel. The frequency domain analysis of recorded results determined the frequency 961 Hz and 968 Hz for 1.69 kg and 2.76 kg equivalent T.N.T., respectively. Then, finite element analysis results were compared with the test data. The comparisons demonstrated a good correlation and satisfied the field data. Finally, based on numerical modeling, a parametric study was applied to determine the effects of shear wave velocity distance of the crater with respect to the tunnel on impulse response of the tunnel.

  16. Evaluation of Blast Resistance of Fiber Reinforced Composite Specimens under Contact Blast Load

    Science.gov (United States)

    Janota, O.; Foglar, M.

    2017-09-01

    This paper presents results of experimental programme which took place in 2014, 2015 and 2016. Experiments were focused on the resistance of full scale concrete panels subjected to contact blast loading. Specimens were loaded by contact blast by plastic explosive. All specimens were reinforced concrete slabs made of fiber concrete. Basalt mesh and textile sheets were added to some of the experiments for creating more heterogeneous material to achieve better resistance of the specimens. Evaluation of experiments was mainly focused on the damaged area on the contact side and soffit of the specimens. Dependency of the final damage of concrete panels on the weight of explosive and concrete strength was assessed.

  17. Antimicrobial Activity of Plant Extracts from Aloe Vera, Citrus Hystrix, Sabah Snake Grass and Zingiber Officinale against Pyricularia Oryzae that causes Rice Blast Disease in Paddy Plants

    Science.gov (United States)

    Uda, M. N. A.; Harzana Shaari, N.; Shamiera. Said, N.; Hulwani Ibrahim, Nur; Akhir, Maisara A. M.; Khairul Rabani Hashim, Mohd; Salimi, M. N.; Nuradibah, M. A.; Hashim, Uda; Gopinath, Subash C. B.

    2018-03-01

    Rice blast disease, caused by the fungus known as Pyricularia oryzae, has become an important and serious disease of rice worldwide. Around 50% of production may be lost in a field moderately affected by infection and each year the fungus destroys rice, which is enough to feed an estimated 60 million people. Therefore, use of herbal plants offer an alternative for the management of plant diseases. Herbal plant like Aloe vera, Citrus hystrix, Sabah snake grass and Zingiber officinale extracts can be used for controlling disease of rice blast. In this study, these four herbal plants were used for evaluating antimicrobial activity against rice plant fungus Pyricularia oryzae, which causes rice blast disease.

  18. Development of transgenic finger millet (Eleusine coracana (L.) Gaertn.) resistant to leaf blast disease.

    Science.gov (United States)

    Ignacimuthu, S; Ceasar, S Antony

    2012-03-01

    Finger millet plants conferring resistance to leaf blast disease have been developed by inserting a rice chitinase (chi11) gene through Agrobacterium-mediated transformation. Plasmid pHyg-Chi.11 harbouring the rice chitinase gene under the control of maize ubiquitin promoter was introduced into finger millet using Agrobacterium strain LBA4404 (pSB1). Transformed plants were selected and regenerated on hygromycin-supplemented medium. Transient expression of transgene was confirmed by GUS histochemical staining. The incorporation of rice chitinase gene in R0 and R1 progenies was confirmed by PCR and Southern blot analyses. Expression of chitinase gene in finger millet was confirmed by Western blot analysis with a barley chitinase antibody. A leaf blast assay was also performed by challenging the transgenic plants with spores of Pyricularia grisea. The frequency of transient expression was 16.3% to 19.3%. Stable frequency was 3.5% to 3.9%. Southern blot analysis confirmed the integration of 3.1 kb chitinase gene. Western blot analysis detected the presence of 35 kDa chitinase enzyme. Chitinase activity ranged from 19.4 to 24.8. In segregation analysis, the transgenic R1 lines produced three resistant and one sensitive for hygromycin, confirming the normal Mendelian pattern of transgene segregation. Transgenic plants showed high level of resistance to leaf blast disease compared to control plants. This is the first study reporting the introduction of rice chitinase gene into finger millet for leaf blast resistance.

  19. Simulation and scaling analysis of a spherical particle-laden blast wave

    Science.gov (United States)

    Ling, Y.; Balachandar, S.

    2018-05-01

    A spherical particle-laden blast wave, generated by a sudden release of a sphere of compressed gas-particle mixture, is investigated by numerical simulation. The present problem is a multiphase extension of the classic finite-source spherical blast-wave problem. The gas-particle flow can be fully determined by the initial radius of the spherical mixture and the properties of gas and particles. In many applications, the key dimensionless parameters, such as the initial pressure and density ratios between the compressed gas and the ambient air, can vary over a wide range. Parametric studies are thus performed to investigate the effects of these parameters on the characteristic time and spatial scales of the particle-laden blast wave, such as the maximum radius the contact discontinuity can reach and the time when the particle front crosses the contact discontinuity. A scaling analysis is conducted to establish a scaling relation between the characteristic scales and the controlling parameters. A length scale that incorporates the initial pressure ratio is proposed, which is able to approximately collapse the simulation results for the gas flow for a wide range of initial pressure ratios. This indicates that an approximate similarity solution for a spherical blast wave exists, which is independent of the initial pressure ratio. The approximate scaling is also valid for the particle front if the particles are small and closely follow the surrounding gas.

  20. Simulation and scaling analysis of a spherical particle-laden blast wave

    Science.gov (United States)

    Ling, Y.; Balachandar, S.

    2018-02-01

    A spherical particle-laden blast wave, generated by a sudden release of a sphere of compressed gas-particle mixture, is investigated by numerical simulation. The present problem is a multiphase extension of the classic finite-source spherical blast-wave problem. The gas-particle flow can be fully determined by the initial radius of the spherical mixture and the properties of gas and particles. In many applications, the key dimensionless parameters, such as the initial pressure and density ratios between the compressed gas and the ambient air, can vary over a wide range. Parametric studies are thus performed to investigate the effects of these parameters on the characteristic time and spatial scales of the particle-laden blast wave, such as the maximum radius the contact discontinuity can reach and the time when the particle front crosses the contact discontinuity. A scaling analysis is conducted to establish a scaling relation between the characteristic scales and the controlling parameters. A length scale that incorporates the initial pressure ratio is proposed, which is able to approximately collapse the simulation results for the gas flow for a wide range of initial pressure ratios. This indicates that an approximate similarity solution for a spherical blast wave exists, which is independent of the initial pressure ratio. The approximate scaling is also valid for the particle front if the particles are small and closely follow the surrounding gas.