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Kieval, Tamar S. (Tamar Shoshana) 1980. "Structural blast design". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/29414.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004."June 2004."
Includes bibliographical references (leaf 45).
Blast design is a necessary part of design for more buildings in the United States. Blast design is no longer limited to underground shelters and sensitive military sites, buildings used by the general public daily must also have satisfactory blast protection. Integrating blast design into existing norms for structural design is a challenge but it is achievable. By looking at the experience of structural designers in Israel over the past several decades it is possible to see successful integration of blast design into mainstream buildings. Israel's design techniques and policies can be used as a paradigm for the United States. A structural design for a performing arts center is analyzed within the context of blast design. Improvements in the design for blast protection are suggested. These design improvements include camouflaging the structural system, using blast resistant glass, reinforced concrete, and hardening of critical structural members. It is shown that integration of blast design into modem mainstream structures is achievable. New techniques and creative problem solving must be used to adapt blast design to work alongside current design trends.
by Tamar S. Kieval.
M.Eng.
2
Macleod, David. "ROACH accelerated BLAST". Master's thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/12234.
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Includes abstract.Includes bibliographical references (p. 115-118).
Reconfigurable computing, in recent years, has been taking great strides in becoming part of mainstream computing largely due to the rapid growth in the size of FPGAs and their ability to adapt to certain complex applications efficiently. This dissertation investigates the reuse of application specific hardware developed for radio astronomy in accelerating a popular bioinformatics algorithm.
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Ownbey, Danielle M. "The Blast-Off Inn". Digital Commons at Loyola Marymount University and Loyola Law School, 2015. https://digitalcommons.lmu.edu/etd/165.
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Garner, Jeffrey Philip. "Resuscitation after blast and haemorrhage". Thesis, University of Newcastle upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440563.
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Singh, Ajit 1951. "Photographic evaluation of blast fragmentation". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63380.
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Liang, Yue Hua. "Plated structures under blast loading". Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423293.
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Exadaktylos, George E. "Computer aided blast fragmentation prediction". Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/43590.
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The complex and non-linear nature of blast fracturing have restricted common blast design mostly to empirical approaches. The code developed for this investigation avoids both empiricism and large memory requirement in order to simulate the pattern of interacting radial fractures from an array of shotholes, at various burdens and spacings, and in simultaneous and delayed modes. The resultant pattern is analyzed and a fragment size distribution calculated.
The rules governing the distribution of radial cracks and the way in which they interact are based on model scale experiments conducted by various investigators. Calculated fragment size- distribution agree with data from the field. Powder factor dependence of fragmentation results is also well described by the model.
The effect of discontinuities on rock fragmentation by blasting is also incorporated into the model. Discontinuities which are open and filled with air or soil-like material affect destructively the transmission of strain waves and propagation of cracks in the rock mass. These discontinuities can be incorporated into the simulation by inserting cracks to represent them. The cracks representing discontinuities will then terminate the cracks produced by blasting where they intersect. On the other hand, tight joints without filling material or with filling material but with a high bond strength and acoustic impedance close to that of the medium do not affect in a negative way the transmission of shock waves in the rock mass. A mathematical model was developed to treat these discontinuities which was based on principles from Linear Elastic Fracture Mechanics theory and Kuznetsov's equation which relates the mean fragment size obtained to the blast energy, hole size and rock characteristics.
Master of Science
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Malan, Danie F. "Empirical investigation of underwater blast". Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5512.
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Background Most demolition practitioners seem to accept that an explosive charge is placed in direct contact with the target surface. Placing the charge in this way may be very convenient, but from an under water demolition point of view, this may not be the most effective placement. It should be noted that an underwater charge can be used in two distinctly different types of application against a target ' a large charge at a distance from the target (eg a torpedo) or a small charge in direct contact (eg demolition charge or limpet mine). In the first type of application a very large charge is detonated at a relatively large offset distance (typically 500kg at 10 meters or more). This type of application relies on extensive damage to and subsequent disruption of equipment on board a ship. The second type of application involves a small charge (typically 10 to 50kg) in direct contact with the target. The effect of this type of application is very localised and very severe, causing flooding and/or local structural failure. The work of this dissertation focuses on the second type of application which is a relatively small charge in contact or at very close offset distance (as opposed to a large charge at a large distance). It is often stated by experienced users in underwater explosions, that the damage caused by an underwater explosion is greater when the close proximity charge is physically slightly offset from the target surface. At the same time, none of these users could offer any specific rule or guideline that can be used to determine the optimum offset distance for any given charge or target. Most demolition users believe that a contact charge is the best way. In addition, they follow a rule of thumb: 'If in doubt, double the charge'. An important tendency of modern demolition work is to achieve better results with a smaller charge by improving the efficiency of the application. This implies either a better result with the same charge mass or the required effect with a smaller charge mass. If the demolition objective is well defined, the mass of explosive can be minimised. This would save cost and, in case of man-carried munition, save effort by the carrier. The principles, phenomena and effects of demolition in an air environment are very different from demolition under water. A principle difference is that a submerged detonation creates a pulsating gas bubble. Such a bubble is absent in an explosion in air. This thesis is focused on underwater detonations. It is well known that about half of the energy of an underwater detonation is transferred to the gas bubble (see Figure A), therefore it is fair to assume that the gas bubble associated with an underwater detonation should cause significant damage to a target (over and above the effect of the shock impulse). This 'significant damage' is a term that is usually used in a casual way and is hardly ever quantified.
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Akin, Faith W. "Audiovestibular Consequences of Blast Exposure". Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etsu-works/2446.
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Curry, Richard. "Response of plates subjected to air-blast and buried explosions". Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/26877.
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Explosive threats have become more prevalent in both military and terrorist theatres of conflict, showing up largely in the form of Improvised Explosive Devices (IED) which are often buried in soil to conceal them and increase their effectiveness. The response of a structure subjected to a blast load is influenced by many factors, namely stand off distance, mass of explosive, degrees of confinement and medium surrounding the charge. This study focuses on characterizing the transient deformation of test plates which have been exposed to different explosive loading conditions including free air blasts (AIR), backed charge (VBP) and buried charge (SBP) configurations. In the three loading configurations, four charge masses are considered, utilizing 10g, 15g, 20g and 25g masses of PE4 plastic explosive which were moulded into cylindrical charges of a constant 38mm diameter. The transient deformation of the test plates was captured using high speed Digital Image Correlation (DIC), which utilized two high speed cameras to record the experiments. Extensive modifications to the blast pendulum to incorporate the cameras was necessary to adapt this technique in a different method to that used in previous literature. The mounting method proposed allowed the cameras to record the experiment while capturing the impulse imparted on a test plate using a blast pendulum. The experimental plates exhibited only Mode I failure, which is plastic deformation, enabling the effect of different loading configurations on the transient and final plate deformation profiles to be identified. Numerical simulations of the experiments were developed to further the understanding of the load arising from the three configurations and the deformation mechanisms involved. The experimental results are used to validate the numerical models, which allow for a better understanding of the evolution of the deformation and strains across the plate. The transient data for the numerical simulation and the experiments were found to match closely. This work clearly shows the effect that the different loading conditions have on the tests plates, specifically the impulse distributions and transient strain in the plates. It was observed in this study that the impulse imparted on a test plate increases with the addition of sand while keeping other test conditions constant. The impulse recorded was observed to increase by 490-540% and 19-100% when compared to AIR and VBP 50mm SOD tests respectively. The loading profile acting on the test plate as a result of the specific impulse changes significantly with the inclusion of sand. The midpoint deflection increases with a decrease in stand off distance, increase in charge mass, increase in level of confinement or the inclusion of an overburden of sand. The observed increase in midpoint deflection of between 90-160% and 30-40% when compared to AIR and VBP 50mm SOD tests respectively was reported. The transient plate profile does not match the final deformation profile.
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Shangase, Thobani Paul. "Changes in material characteristics of AISI 430 stainless steel plates subjected to repeated blast loading". Master's thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27391.
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Structures deform at high strain rates and temperatures when exposed to impulsive loads. To accommodate the macro change there are microstructural changes that occur, i.e., grain morphology and shear banding. Most studies report on macroscopic response, i.e., large inelastic deformation and tearing of the structure, while limited studies have reported on microscopic changes that develop in the structure. The microstructure is directly related to the mechanical properties and performance of the material. Therefore, understanding the effect of high strain rate loadings on the microstructural evolution and subsequent mechanical properties of metals and alloys is necessary for mechanical design. The main objective of this research was to investigate microstructural changes to characterise the strain distribution and plastic deformation, owing to impulsive loading. Features within the microstructure that could be used to characterise deformation included grain size morphology changes, the presence of shear bands and sub-grain networks. The electron backscatter diffraction (EBSD) technique, which used Kikuchi patterns to characterise the strain distribution in the crystal of the deformed material, was also used as a characterisation tool. The first step in the experimental procedure was to select the appropriate material to investigate these microstructural changes. There was also the systematic investigation into the use of single and double heat treatments. These were used to achieve a large equiaxed grain structure, which was desirable from a microstructural point of view but was not desirable for blast-resistant material selection. The two-step heat treatment was concluded to be the most suitable heat treatment for the annealing and homogenisation of the AISI 430 stainless steel plates. The AISI 430 stainless steel plates used were 244 mm by 244 mm in size and had a circular exposed area of 106 mm. These plates were subjected to repeated explosive blasts, using a plastic explosive (PE4). The charge mass was varied for each test and the stand-off distance was kept constant at 150 mm for uniform loads and 13 mm for localised loads. Two plates were selected to investigate the uniform loading scenario. The first plate, a torn plate, used a charge mass of 30 g and one blast and the second plate, an inelastically-deformed plate, used a charge mass of 10 g and was exposed to three blasts. These two plates offered the same overall charge load with a different strain path. A further two plates were chosen for the investigation into the localised loading scenario. One plate, a petalled plate, used a 6 g charge mass and was exposed to two blasts and the second plate, an inelastically-deformed plate, used a 5 g charge mass and was also exposed to two blasts. The latter two plates offered an investigation into the effect of an increased charge load, where charge load affected the strain rate of the deformation resulting from the blast load. All four plates were sectioned across the midline of the dome and then ground and polished to a mirror finish, using OP-S. The polished samples were analysed, using optical microscopy and EBSD. In addition, Vickers hardness tests were carried out along the midline of the sectional plate profiles, in order to evaluate the extent of strain hardening. All the plates showed either a response of inelastically deforming or of complete or partial tearing failures when subjected to blast loads. For inelastic deformation failures, a global dome was characteristic of the uniform loading condition and an inner dome superimposed by the global dome was characteristic of the localised loading condition. Variation of charge mass and the number of blasts showed an increasing linear relationship between the impulse and midpoint deflection. The macrostructure showed a large variation of failures in the localised condition. The microstructural characterisation results produced micrographs showing regions of long, flat grains with multiple sub-grain networks, indicating deformed microstructures of the blast loaded plates. Parts of the microstructures displayed equiaxed/recrystallised grains characteristic of restoration processes, owing to high temperatures. Vickers hardness tests indicated an increase in material hardness as the number of blasts was increased, with a maximum hardness in the central region of the plates. In the first investigation, into uniform loading, the material characterisation results, combined with the fractography results, indicated brittle failure modes typical of high strain rate failures in strain rate sensitive materials, such as the chosen AISI 430 stainless steel plates. In the second investigation, into localised loading, the material characterisation results, combined with the fractography results, indicated a more ductile failure, owing to a 1 g incremental increase of charge mass, which confirmed the strain rate sensitivity of this material.
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Ghoor, Ismail B. "The response of concave singly curved fibre reinforced moulded sandwich and laminated composite panels to blast loading". Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/27811.
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Composite materials are increasingly being used in a wide range of structural applications. These applications range from bicycle frames and building facades to hulls of marine ships. Their popularity is due to the high specific strength and stiffness properties, corrosion resistance, and the ability to tailor their properties to a required application. With the increasing use of composites, there is a need to better understand the material and damage behaviour of these structures. In recent years, the increased frequency of wars and terror attacks have prompted investigations into composite failure processes resulting from air-blast. Most of the research has been focused on flat panels, whereas there is relatively little on curved structures. This dissertation reports on the effect of air-blast loading on concave, singly curved fibre reinforced sandwich and composite panels. Sandwich panels and equivalent mass glass fibre laminates were manufactured and tested. Three types of curvature namely a flat panel (with infinite curvature), a curvature of 1000 mm radius and a curvature of 500 mm radius were produced, to determine the influence of curvature on panel response. The laminates were made from 16 layers of 400 g/m² plain weave glass fibre infused with Prime 20 LV epoxy resin. The sandwich panels consisted of a 15 mm thick Airex C70:75 core sandwiched between the 12 layers of 400 g/m² plain weave glass fibre and infused with Prime 20 LV epoxy resin. This arrangement produced a balanced sandwich panel with 6 layers of glass fibre on the front and back respectively. For all panels, vacuum infusion was used to manufacture in a single shot process. Mechanical properties of samples were tested for consistency in manufacturing. It was found that mechanical properties of the samples tested were consistent with low standard deviations on tensile and flexural strength. The panels were tested in the blast chamber flat the University of Cape Town. Blast specimens were clamped onto a pendulum to facilitate impulse measurement. Discs of plastic explosive, with charge masses ranging from 10 g to 25 g, were detonated. After blast testing, a post-mortem analysis of the damaged panels was conducted. Post-mortem analysis revealed that the failure progression was the same irrespective of curvature for both the sandwich panels and the laminates. Sandwich panels exhibited the following failure progression: delamination, matrix failure, core crushing, core shear, core fragmentation, core penetration and fibre fracture. The laminates displayed the following progression: delamination, matrix failure and fibre fracture. Curved panels exhibited failure initiation at lower charge masses than the flat panels. As the curvature increased, the failure modes initiated at lower charge masses. For example, as the charge mass was increased to 12.5 g the front face sheets of the flat and the 1000 mm radius sandwich panels exhibited fibre fracture, but the 500 mm radius sandwich panel exhibited fibre fracture and rupture through the thickness of the front face sheet. The 500 mm radius laminate exhibited front face failure earlier (15 g) than the 1000 mm radius (22.5 g) and flat panel (20 g). Curved laminates exhibited a favoured delamination pattern along the curved edges of the panel for both 1000 mm and 500 mm radii laminates. As the curvature increased, more delamination was evident on the curved edges. The curved panels displayed more severe damage than flat panels at identical charge masses. Curved sandwich panels experienced through thickness rupture at 20 g charge mass whereas the curved laminates did not exhibit rupture at 25 g charge mass. The flat laminates were the most blast resistant, showing no through-thickness penetration at 25 g (the highest charge mass tested) and initiated failure modes at higher charge masses when compared to the other configurations.
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Baxter, D. "Blast Injury Outcome Study in Armed forces Personnel (BIOSAP) and Blast Injury In Pigs study (BIIPs)". Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1546198/.
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Fleetwood, Kelly Gene. "Near-field blast vibration monitoring and analysis for prediction of blast damage in sublevel open stoping". Thesis, Curtin University, 2010. http://hdl.handle.net/20.500.11937/519.
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The work presented in this thesis investigates near-field blast vibration monitoring, analysis, interpretation and blast damage prediction in sublevel open stoping geometries. As part of the investigation, seven stopes at two Australian sublevel open stoping mines were used as case studies. The seven stopes represented significant ranges in stope shapes, sizes, geotechnical concerns, extraction sequences, stress conditions, blasting geometries and rock mass properties.The blast damage investigations at the two mine sites had three main components. The first component was rock mass characterisation, which was performed using static intact rock testing results, discontinuity mapping, mining-induced static stress modelling and geophysical wave propagation approaches. The rock mass characterisation techniques identified localised and large-scale variations in rock mass properties and wave propagation behaviours in relation to specified monitoring orientations and mining areas. The other components of the blast damage investigations were blast vibration monitoring and analysis of production blasting in the seven stopes and stope performance assessments.The mine-based data collection period for the case studies lasted from January, 2006 to February, 2008. A key element of the data collection program was near-field blast vibration monitoring of production blasts within the seven study stopes. The instrumentation program consisted of 41 tri-axial accelerometers and geophone sondes, installed at distances from 4m to 16m from the stope perimeters. A total of 59 production firings were monitored over the course of the blast vibration monitoring program. The monitoring program resulted in a data set of over 5000 single-hole blast vibration waveforms, representing two different blasthole diameters (89mm and 102mm), six different explosive formulations and a wide range in charge weights, source to sensor distances, blasthole orientations and blasting geometries.The data collected in the blast vibration monitoring program were used to compare various near-field charge weight scaling relationships such as Scaled Distance and Holmberg-Persson prediction models. The results of these analyses identified that no single charge weight scaling model could dependably predict the measured near-field peak amplitudes for complex blasting geometries. Therefore, the general form of the charge weight scaling relationship was adopted in conjunction with nonlinear multivariable estimation techniques to analyse the data collected in the study stopes and to perform forward vibration predictions for the case studies.Observed variations in the recorded near-field waveforms identified that instantaneous peak amplitude such as peak particle velocity (PPV) did not accurately describe the characteristics of a large portion of the data. This was due to significant variations in frequency spectra, variable distributions of energy throughout the wave durations and coupling of wave types (e.g. P- and S-wave coupling). The wave properties that have been proposed to more accurately characterise complex nearfield vibrations are the total wave energy density (ED[subscript]W-tot), stored strain energy density (ED[subscript]W-SS) and the wave-induced mean normal dynamic strain (ε[subscript]W-MN). These wave properties consider the activity of the blast-induce wave at a point in the rock mass over the entire duration instead of the instantaneous amplitude.A new analytical approach has been proposed to predict blast-induced rock mass damage using rock mass characterisation data, blast vibration monitoring results and rock fracture criteria. The two-component approach separately predicts the extent of blast-induced damage through fresh fracturing of intact rock and the extent from discontinuity extension. Two separate damage criteria are proposed for the intact rock portion of the rock mass based on tensile and compressive fracture strain energy densities and compressive and tensile fracture strains. The single criterion for extension of existing discontinuities is based on the required fracture energy density to activate all macro-fractures in a unit volume of the rock mass.The proposed energy-based criteria for intact rock fracture and extension of discontinuities integrate strain rate effects in relation to material strength. The strainbased criterion for intact rock fracture integrates the existing mining-induced static strain magnitudes. These factors have not been explicitly considered in existing empirical or analytical blast damage prediction models. The proposed blast damage prediction approach has been applied to two stopes during the two mine site case studies.
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Soleiman, Fallah Arash. "Behaviour of blast resistant composite structures". Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/11919.
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Lloyd, Alan Eric Walker. "Blast Retrofit of Reinforced Concrete Columns". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32389.
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Explosives place large demands on the lateral load carrying capacity of structures. If these loads are applied on columns, the high pressure transient loads from explosives can result in significant damage to the primary gravity load carrying elements. The loss of these elements, which are responsible from overall strength and stability of the structure, may cause collapse of all or parts of the structure. Therefore, it is important to mitigate the blast loads effects on columns. A comprehensive research study into the design, application, and use of different retrofit systems to mitigate damage to columns under blast loads has been undertaken. This research program, consisting of experimental testing and analytical investigation, sought out retrofits that address the strength of columns as well as those that enhance ductility are explored. Different materials and resistance mechanisms are used to increase column capacity. An experimental testing program was conducted using a shock tube to test the capacity of columns under blast loads. For this program, a total of sixteen reinforced concrete columns were constructed and the data from a further two columns from a previous study was compiled. Of these columns, a total of thirteen were retrofitted to mitigate the effects of blast. Carbon fibre reinforced polymer (CFRP) was applied to eight of the columns in the form of jacketing, longitudinal reinforcement, or the combination of the two. The other retrofits included steel prestressed confinement applied to one column, steel bracing acting as compression members applied to one column, and steel bracing acting as tension members applied to three columns. The columns were tested under incrementally increasing shock tube induced shock wave loading up to failure of the specimen or capacity of the shock tube. The performance of the retrofitted columns was compared with the control columns and against other retrofits. Quantitative comparisons of displacements and strains were made along with qualitative assessments of damage. The results indicated that all the retrofits increased capacity to the column, however, certain retrofits out performed others. The best FRP retrofit technique was found to be the combination of longitudinal and transverse FRP. The prestressed steel jacketing proved to be effective at increasing ductility capacity of the column. The compression brace retrofit was found to be effective in significantly increasing capacity of the column. The tension brace retrofits had the best performance over all the retrofits including the compression brace retrofit. The experimental data was used to validate analysis techniques to model the behaviour of the specimens. This technique reduced the columns to an equivalent single-degree-of-freedom (SDOF) system for dynamic analysis purposes. The reduction to the SDOF system was achieved by computing a resistance to lateral load and lateral displacement relationship. Each retrofit was carefully considered in this analysis including the retrofit’s possible effect on material and sectional properties as well as any force resistance mechanism that the retrofit introduces. The results of the modeling and experimental program were used to develop retrofit design guidelines. These guidelines are presented in detail in this thesis.
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Mortimer, Mark F. "Numerical calculations of ellipsoidal blast waves". Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5880.
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This thesis investigates the progression of a blast wave created by the volumetric explosion of a pressurized ellipsoidal region. The use of numerical methods on a digital processing machine is made. Eight cases of four different ellipticities and two different overpressures were examined to determine the influence of the shape of the blast sources. It is shown that, for an ellipsoidal cold region generated from a volumetric explosion, the peak pressure through the intermediate fields would be up to three times greater than the peak pressure for an equivalent spherical region and occurs along the initially minor axis of the blast source. The static impulse and the dynamic impulse were also up to two to three times greater than those for an equivalent spherical region, through most of the intermediate and near far fields. A corresponding decrease in the values of these parameters was noted along the major axis.
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Sobhanmanesh, Fariborz School of Electrical Engineering And Telecommunications UNSW. "Hardware implementation of V-BLAST MIMO". Awarded by:University of New South Wales. School of Electrical Engineering And Telecommunications, 2006. http://handle.unsw.edu.au/1959.4/24198.
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The exploitation of the theoretically enormous capacity achieved by the multiple transmit and receive antennas systems (MIMO) in a rich scattering communication channel has been the subject of vast body of research on the field of MIMO. In particular, the Vertically-layered Bell Laboratories Layered Space-Time (V-BLAST) is a well known MIMO architecture which has demonstrated the enormous capacity of 20-40 bit/s/Hz in an indoor propagation environment with realistic SNR and error rates. However, due to the intensive computation involved, it would be difficult to implement this architecture for high data rate communication systems. Some works have been done to improve the receiver complexity and performance by coding techniques, by different detection architectures. In this thesis, we have focused on QR-based decoders for V-BLAST MIMO. For a suitable V-BLAST detection implementation, we need to carefully consider the problem from algorithmic, arithmetic and architectural aspects. At the algorithmic level, the numerical stability and robustness should be considered. At the arithmetic level, signal quantization is important, and, at the architectural level, parallelism and pipelining require attention. We have performed the above mentioned optimization on the 1-pass QR factorization with back substitution SIC (Symbol Interference Cancellation) decoder in chapter 3. At first optimizations are made on the proposed algorithm and architecture using MATLAB simulations. Then a new architecture for the QR-factorizer as the core processor of the V-BLAST decoder is developed in chapter 4. This architecture uses only two low complexity CORDIC (Coordinate rotation digital computer) processors. The parameterized feature of the controller and address generator blocks of this architecture has provided a scalable architecture for the implementation of QR factorization for square matrix of any dimension. The reduced hardware complexity of the processors and its simple parameterized controller are two outstanding features of the architecture, resulting in a more suitable alternative architecture for QR factorization than traditional triangular systolic arrays. In the next phase of the research, new hardware architectures of the back substitution SIC decoder was developed for a 4 X 4 MIMO system with 16-QAM constellation scheme in chapter 5. The division operation for back substitution needs a complex hardware, and results in the numerical instability. In the proposed hardware the elimination of division and modification of multiplier has reduced the hardware complexity and led to numerical stability. In addition the pre decoding block was designed and optimized in terms of number of the pipeline registers and CORDIC rotator processors. The developed hardware is capable of processing 20 vectors data burst and results in a throughput of 149 Mb/s. The FPGA (Field Programmable Gate Array) and ASIC (Application specific Integrated Circuit) implementations of the proposed optimized architecture are presented in Chapter 5. We found that the equivalent gates and the core area in our design is less than 30% of other designs and the maximum clock frequency and the throughput is higher (175 %) than other works. Finally the improvements of the BER performance using the branching method and parallel architectures are presented in chapter 6. In this supplementary part to back substitution OSIC decoder, the final symbol vector is selected from 2 or 8 potential candidates based on the minimum Euclidean norm, which improves the BER between 3 to 7 db and gives a very close match to the original V-BLAST performance.
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Nerenberg, Jeffery G. "Blast wave loading of polymeric foams". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0024/MQ50647.pdf.
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Lee, Wayne Y. "Numerical modeling of blast-induced liquefaction /". Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1431.pdf.
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McClendon, Mark Andrew. "Blast resistant design for roof systems". Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/7974.
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Thesis (M.S.)--University of Missouri-Columbia, 2007.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 1, 2008) Includes bibliographical references.
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Tang, Xue-Wei. "A pre-blast hole survey system". Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182872398.
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Matthews, Debra Sue. "Blast effects on prestressed concrete bridges". Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/D_Matthews_072908.pdf.
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Uriarte, Toboso Alain. "Optimum Ordering for Coded V-BLAST". Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23509.
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The optimum ordering strategies for the coded V-BLAST system with capacity achieving temporal codes on each stream are studied in this thesis. Mathematical representations of the optimum detection ordering strategies for the coded V-BLAST under instantaneous rate
allocation (IRA), uniform power/rate allocation (URA), instantaneous power allocation(IPA) and instantaneous power/rate allocation (IPRA) are derived. For two transmit
antennas, it is shown that the optimum detection strategies are based on the per-stream before-processing channel gains. Based on approximations of the per-stream capacity
equation, closed-form expressions of the optimal ordering strategy under the IRA at low and high signal to noise ratio (SNR) are derived. Necessary optimality conditions under the IRA are given. Thresholds for the low, intermediate and high SNR regimes in the 2-Tx-antenna system under the IPRA are determined, and the SNR gain of the ordering is studied for each regime. Performances of simple suboptimal ordering strategies are analysed, some of which perform very close to the optimum one.
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Del, Linz Paolo. "Blast resistance of laminated glass facades". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/25145.
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The aim of this thesis is to improve the understanding of the behaviour of Polyvinyl Butyral (PVB) laminated annealed glass façade panels subjected to blast loading. A full scale blast test was performed. During this, deflection and strain data were collected employing digital image correlation techniques (DIC). Local reaction forces were measured using several pairs of strain gauges on the support. The full field deflection and strain data obtained were in line with those observed in historical tests. The strain gauge data available showed that the reaction forces varied along the edge, with higher values being reached at the quarter length gauge locations. The results from this test and from other historical experiments were used to calculate the reaction forces along the entire perimeter of the glass pane. The results showed that the forces reach an early peak before the glass failure, and then rise gradually approaching a plateau at high central deflections. To explain the specific form of this force time history, the detailed behaviour of the laminated material after the glass skins failed was studied. Existing experimental data was employed to fit a material model to the PVB material. Two Prony series models with different hyperelastic springs and a model employing a full finite deformation viscoelastic law derivation were employed. It was found that the finite deformation viscoelastic model could represent the material's behaviour more accurately and fully include its rate dependency. One of the PVB models was employed to study the delamination between the glass and the membrane. Delamination energies were found for different speeds of deformation, and these parameters were employed to study the delamination of samples presenting different crack arrangements. The results showed that these had only a limited influence on the behaviour of the composite.
26
Bailey, Zachary S. "Epigenetic Mechanisms in Blast-Induced Neurotrauma". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/78813.
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Blast-induced neurotrauma (BINT) is a prevalent brain injury within both military and civilian populations due to current engagement in overseas conflict and ongoing terrorist events worldwide. In the early 2000s, 78% of injuries were attributable to an explosive mechanism during overseas conflicts, which has led to increased incidences of BINT [1a]. Clinical manifestations of BINT include long-term psychological impairments, which are driven by the underlying cellular and molecular sequelae of the injury. Development of effective treatment strategies is limited by the lack of understanding on the cellular and molecular level [2a]. The overall hypothesis of this work is that epigenetic regulatory mechanisms contribute to the progression of the BINT pathology and neurological impairments. Epigenetic mechanisms, including DNA methylation and histone acetylation, are important processes by which cells coordinate neurological and cellular response to environmental stimuli. To date, the role of epigenetics in BINT remains largely unknown.
To test this hypothesis, an established rodent model of BINT was employed [3a]. Analysis of DNA methylation, which is involved in memory processes, showed decreased levels one week following injury, which was accompanied by decreased expression of the enzyme responsible for facilitating the addition of methyl groups to DNA. The one week time point also showed dramatic decreases in histone acetylation which correlated to decline in memory. This change was observed in astrocytes and may provide a mechanistic understanding for a hallmark characteristic of the injury. Treatment with a specific enzyme inhibitor was able to mitigate some of the histone acetylation changes. This corresponded with reduced astrocyte activation and an altered behavioral phenotype, which was characterized by high response to novelty. The diagnostic efficacy of epigenetic changes following blast was elucidated by the accumulation of cell-free nucleic acids in cerebrospinal fluid one month after injury. Concentrations of these molecules shows promise in discriminating between injured and non-injured individuals.
To date, the diagnostic and therapeutic efforts of BINT have been limited by the lack of a mechanistic understanding of the injury. This work provides novel diagnostic and therapeutic targets. The clinical potential impact on diagnosis and therapeutic intervention has been demonstrated.Ph. D.
27
Walker, Graham. "Blast wave attenuation using liquid sheets". Thesis, University of Southampton, 1986. https://eprints.soton.ac.uk/52297/.
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Strong blast waves, such as those associated with gun fire or rocket exhausts, can cause serious physiological and/or structural damage. It is necessary, therefore, to develop ways in which to minimise this damage whilst still allowing the system that produces the blast waves to function normally. In an effort to develop such a system this study has examined, both theoretically and experimentally, the interaction that occurs when a shock wave is passed along a free unconstrained liquid tube before emerging into the surrounding atmosphere. In the theoretical analysis the problem was confined to the two-dimensional case and involved dividing the liquid sheet up into infinitesimal sections that were then regarded as small piston-cylinder systems, which were driven by the high pressure shocked gas behind the shock wave. The results from these one-dimensional systems were then used as input into a two-dimensional solution of the wave equation which predicted the gross changes in the remainder of the space. The experimental investigation involved laboratory experiments that examined, visually and with pressure transducers, the result of the shock/liquid interactions in two-dimensional and axi-symmetric cases, both between and external to the liquid sheets. The experimental investigation also included field trials that examined the pressure profiles of blast waves that were produced when a shock wave, which resulted from the ignition of a rocket motor, was passed along a liquid tube. From this work it was found that the high pressure gas, behind the shock wave, caused the liquid sheets to move perpendicularly from the line of travel of the shock wave which in turn caused expansion waves and compression waves to propagate out from the face of the water sheets, into the shocked gas and the surrounding atmosphere, respectively. These compression waves were then found to interact with the weak blast (produced when the shock, which had been weakened by the expansion waves, emerged into the atmosphere) in such a way that they produced a weaker blast field than would have been the case had the shock wave emerged directly into the atmosphere; the maximum observed reduction in the strength of the blast wave was 16.4 dB. Experiments were also performed that examined the effect of using rigid sheets in place of liquid sheets. From these experiments it was found that the differences between the liquid and rigid sheet cases was a function of the size of the inertial barrier (i.e. the mass of the water sheet) that the water presented to the shocked gas. Consequently, it was noted that, in terms of attenuating the blast wave, the rigid sheets proved to be inferior to the thicker water sheets and superior to the thinner water sheets. However, when the spectra of the pressure disturbances were examined it was found that, with regard to the attenuation of the 2-4 kHz region of the spectra, all the liquid sheet results showed an improvement in relation to the rigid sheet results.
28
Bailey, Zachary Stephen. "Epigenetic Mechanisms in Blast-Induced Neurotrauma". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/78813.
Pełny tekst źródłaStreszczenie:
Blast-induced neurotrauma (BINT) is a prevalent brain injury within both military and civilian populations due to current engagement in overseas conflict and ongoing terrorist events worldwide. In the early 2000s, 78% of injuries were attributable to an explosive mechanism during overseas conflicts, which has led to increased incidences of BINT [1a]. Clinical manifestations of BINT include long-term psychological impairments, which are driven by the underlying cellular and molecular sequelae of the injury. Development of effective treatment strategies is limited by the lack of understanding on the cellular and molecular level [2a]. The overall hypothesis of this work is that epigenetic regulatory mechanisms contribute to the progression of the BINT pathology and neurological impairments. Epigenetic mechanisms, including DNA methylation and histone acetylation, are important processes by which cells coordinate neurological and cellular response to environmental stimuli. To date, the role of epigenetics in BINT remains largely unknown.
To test this hypothesis, an established rodent model of BINT was employed [3a]. Analysis of DNA methylation, which is involved in memory processes, showed decreased levels one week following injury, which was accompanied by decreased expression of the enzyme responsible for facilitating the addition of methyl groups to DNA. The one week time point also showed dramatic decreases in histone acetylation which correlated to decline in memory. This change was observed in astrocytes and may provide a mechanistic understanding for a hallmark characteristic of the injury. Treatment with a specific enzyme inhibitor was able to mitigate some of the histone acetylation changes. This corresponded with reduced astrocyte activation and an altered behavioral phenotype, which was characterized by high response to novelty. The diagnostic efficacy of epigenetic changes following blast was elucidated by the accumulation of cell-free nucleic acids in cerebrospinal fluid one month after injury. Concentrations of these molecules shows promise in discriminating between injured and non-injured individuals.
To date, the diagnostic and therapeutic efforts of BINT have been limited by the lack of a mechanistic understanding of the injury. This work provides novel diagnostic and therapeutic targets. The clinical potential impact on diagnosis and therapeutic intervention has been demonstrated.Ph. D.
29
Palla, Leela Prasad. "Blast Response of Composite Sandwich Panels". University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1227216480.
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Sirivolu, Dushyanth. "Marine Composite Panels under Blast Loading". University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1467993101.
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Judge, Ryan. "Structural cables subjected to blast fragmentation". Thesis, University of Liverpool, 2012. http://livrepository.liverpool.ac.uk/12073/.
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In civil engineering, steel cables are widely used in the construction of bridges and sports stadia. However, their robustness and resilience against explosively formed fragment impact, whether accidental or malicious, remains largely unknown and very little research has been carried out on this subject to date. The concern is that small fragments projected from the explosion and travelling at high velocity may induce significant damage to the cables. This damage could rupture a cable releasing large amounts of kinetic energy into the surrounding structure and other damaged cables resulting in multiple cable loss and possible disproportionate collapse of the structure. To begin investigating this problem a good understanding of the localised damage sustained by the cables on impact is required. The work described within this thesis begins to address this problem by use of both physical tests and detailed finite element analysis. The tests involved firing fragment simulating projectiles at velocities ranging from 200 – 1400 m/s at un-tensioned spiral strand cables. Detailed finite element models have been developed for the spiral strand cables, with careful considerations given to the geometry of the cables, inter-wire contact mechanics, cable end boundary conditions and material modelling. The numerical results have been verified by comparison with the test results, with particular attention paid to the localised damage area, the fragment penetration depth, and the number of heavily damaged and totally broken wires. A global response study has also been undertaken on a case study structure to assess the effects of sudden cable loss. The work contained with this thesis forms part of larger research programme studying the robustness and resilience of cable supported structures subjected to highly transient loading conditions.
32
Lee, Wayne Yeung. "Numerical Modeling of Blast-Induced Liquefaction". BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/524.
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A research study has been conducted to simulate liquefaction in saturated sandy soil induced by nearby controlled blasts. The purpose of the study is to help quantify soil characteristics under multiple and consecutive high-magnitude shock environments similar to those produced by large earthquakes. The simulation procedure involved the modeling of a three-dimensional half-space soil region with pre-defined, embedded, and strategically located explosive charges to be detonated at specific time intervals. LS-DYNA, a commercially available finite element hydrocode, was the solver used to simulate the event. A new geo-material model developed under the direction of the U.S. Federal Highway Administration was applied to evaluate the liquefaction potential of saturated sandy soil subjected to sequential blast environments. Additional procedural enhancements were integrated into the analysis process to represent volumetric effects of the saturated soil's transition from solid to liquid during the liquefaction process. Explosive charge detonation and pressure development characteristics were modeled using proven and accepted modeling techniques. As explosive charges were detonated in a pre-defined order, development of pore water pressure, volumetric (compressive) strains, shear strains, and particle accelerations were carefully computed and monitored using custom developed MathCad and C/C++ routines. Results of the study were compared against blast-test data gathered at the Fraser River Delta region of Vancouver, British Columbia in May of 2005 to validate and verify the modeling procedure's ability to simulate and predict blast-induced liquefaction events. Reasonable correlations between predicted and measured data were observed from the study.
33
Chock, Jeffrey Mun Kong. "Review of Methods for Calculating Pressure Profiles of Explosive Air Blast and its Sample Application". Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/32066.
Pełny tekst źródłaStreszczenie:
Blast profiles and two primary methods of determining them were reviewed for use in the creation of a computer program for calculating blast pressures which serves as a design tool to aid engineers or analysts in the study of structures subjected to explosive air blast. These methods were integrated into a computer program, BLAST.F, to generate air blast pressure profiles by one of these two differing methods. These two methods were compared after the creation of the program and can conservatively model the effects of spherical air blast and hemispherical surface burst.
The code, BLAST.F, was used in conjunction with a commercial finite element code (NASTRAN) in a demonstration of method on a 30 by 30 inch aluminum 2519 quarter plate of fixed boundary conditions in hemispherical ground burst and showed good convergence with 256 elements for deflection and good agreement in equivalent stresses of a point near the blast between the 256 and 1024 element examples. Application of blasts to a hypothetical wing comprised of aluminum 7075-T6 was also conducted showing good versatility of method for using this program with other finite element models.
Master of Science
34
Fischer, Taylor Dawn. "Influence of freezing on the survival of Magnaporthe oryzae and weather conditions that favor blast epidemics in rice". Thesis, Kansas State University, 2016. http://hdl.handle.net/2097/32837.
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Master of ScienceDepartment of Plant Pathology
Erick D. DeWolf
Wheat blast, caused by Magnaporthe oryzae pathotype triticum, has emerged as a serious problem for wheat production in South America and recently emerged as a threat to wheat production in Bangladesh. To prepare for the possible introduction of wheat blast in to the United States, it would be helpful to identify areas of the country most at risk for blast epidemics. Because wheat blast occurs primarily in tropical and subtropical regions of the world, cold winter temperatures may restrict the establishment of the blast pathogen in the United States. Therefore, the first objective of this research was to quantify the freeze-thaw tolerance of the wheat blast pathogen in naturally infected wheat rachises from Bolivia and to measure the viability of the conidia after exposure to various treatments. The results indicate that exposing the fungus in moist residue to multiple freeze-thaw cycles is more damaging than exposing the fungus in moist residue to longer, single freezes. When in dry residue, the fungus was not harmed by the freeze-thaw cycles. Freezing and thawing of the wheat blast fungus in moist residue significantly affected its ability to produce viable conidia. The second objective of this research was to identify environmental conditions that could be conducive for wheat blast epidemics by examining historical epidemics of rice blast, caused by Magnaporthe oryzae pathotype oryza. The dataset used in this analysis consisted of 60 site-years of historical observations of rice blast levels from Arkansas, Louisiana, and Texas. These observations were coupled with monthly and weekly summaries of hourly weather variables based on temperature, relative humidity, precipitation, and regional moisture indices. Classification trees and logistic regression were used to identify variables associated with rice blast epidemics. The results indicate that rice blast epidemics are favored by cooler April temperatures and higher levels of precipitation in June. Preliminary models for rice blast based on these variables were able to correctly classify epidemic years with >75% accuracy. In the future, the results of this project will be used as part of a risk assessment for a wheat blast introduction and establishment in the United States.
35
Calnan, Joshua. "EXPERIMENTAL COMPARISON STUDY OF THE RESPONSE OF POLYCARBONATE AND LAMINATED GLASS BLAST RESISTANT GLAZING SYSTEMS TO BLAST LOADING". UKnowledge, 2013. http://uknowledge.uky.edu/mng_etds/2.
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This thesis recounts the experimental study of the dynamic response of polycarbonate blast resistant glazing systems to explosive loading through the use of triaxial load cells, pressure sensors, and a laser displacement gauge. This instrumentation captured the response of the glazing systems to blast loading over three phases of testing. The first phase of testing characterizes the load distribution around the perimeter and the second phase examines the repeatability of the results. The final phase of testing pushes the samples to failure. The results are then compared to HazL, a commonly used blast resistant glazing system analysis software tool. The experimental data is also compared to data available characterizing the response of laminated glass.
36
Sarvghad-Moghaddam, Hesam. "Computational Biomechanics of Blast-Induced Traumatic Brain Injury: Role of Loading Directionality, Head Protection, and Blast Flow Mechanics". Diss., North Dakota State University, 2015. http://hdl.handle.net/10365/25381.
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In this dissertation, blast-induced traumatic brain injury (bTBI) is studied with respect to
the blast wave directionality, mitigation capability of helmet/faceshield, and blast flow
mechanics using finite element (FE) and computational fluid dynamics (CFD) schemes. For the
FE study, simulations are performed on a detailed FE head model using LS-DYNA, and CFD
simulations are carried out using the ANSYS-CFX to examine the underwash development by
analyzing the behavior of blast flow from different directions. The following tasks are
conducted.
First, the effects of the loading direction on the mechanical response of the head and
brain is investigated through impact and blast induced loading on the head. Due to the
differences in the shape, function, and tolerance of brain components, the response of the
head/brain varies with the direction of the impact and blast waves. In identical situations, the
head shows to have lower tolerance to side loading.
Second, the inclusion of the faceshield as a potential head protective tool against blast
threats is evaluated with respect to blast direction. The helmet-faceshield and helmeted
assemblies are shown to be most efficient when the head is exposed to blast from the front and
top sides, respectively. Faceshield is observed to be effective only in front blast as it might
impose either adverse or no effects in other directions. The shockwaves are seen to form a high
pressure region in head-helmet-faceshield gap (underwash effect) which induces elevated
pressures on the skull.
Third, the underwash effect?s mechanism is investigated through CFD simulations of
supersonic shockwave flow around the helmeted head assemblies. CFD results reveals that the
backpressure is produced due to the creation of a backflow in the exterior flow on the outgoing interior flow. The bottom and side shockwave directions predict the highest underwash
overpressures, respectively. Finally, the ICP and shear stress of the brain is evaluated in case of underwash incidence.
FEA results show that underwash overpressure greatly changes with the blast direction. It is
concluded that underwash clearly altered the tissue response of the brain as it increases ICP
levels at the countercoup site and imparts elevated skull flexure.
37
Hubbard, W. Brad. "Investigating Injury Pathology of Blast-induced Polytrauma and Assessing the Therapeutic Role of Hemostatic Nanoparticles after Blast Exposure". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/79722.
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Explosions cause the majority of injuries in the current conflicts, accounting for 79% of combat related injuries (Ramasamy et al. 2008). Blast overpressure from explosions can cause barotrauma to the lungs and the brain. Blast-induced mild traumatic brain injury has been labeled the "signature wound" of current military conflicts in Iraq and Afghanistan (Snell and Halter 2010). In addition to elevated number of blast-induced traumatic brain injuries due to increased military conflicts overseas and the usage of improvised explosive devices, the incidence of blast-induced polytrauma has risen due to the prevalence of terrorist events around the world (Arnold et al. 2004, Rodoplu et al. 2004). Blast-induced polytrauma is a major concern as lung injury can cause immediate mortality and brain injury causes long-lasting neurocognitive impairment. There is a critical lack of understanding the pathology of blast-induced polytrauma since the needs are multifaceted and therefore few options for treatment. Thus, the research presented in this dissertation required the development of a military-relevant blast polytrauma model to examine injury pathology and subsequently study the effects of hemostatic nanoparticle therapy after blast-induced polytrauma. The pre-clinical model was characterized and static overpressure thresholds were determined for lethality risk. It was confirmed to have many of the classic hallmarks of primary blast lung injury (PBLI), as well as blast-induced neurotrauma (BINT) (Clemedson 1950). Global hemorrhaging was found in the lungs and well as reduced oxygen saturation. Markers of astrogliosis and blood-brain barrier disruption were examined in the amygdala after blast. The novel nanoparticle configuration (hemostatic dexamethasone-loaded nanoparticles (hDNP) functionalized with a peptide that binds with activated platelets) was investigated and hypothesized to increase survival, reduce cellular injury and reduce anxiety-like disorders after blast polytrauma. After investigating hDNP, it was found that the hDNP treatment benefited survival percentage after injury as well as reduced percent hemorrhage in the lungs and improved physiology. Elevated anxiety parameters found in the controls were lower as compared to the hDNP group. Glial fibrillary acidic protein (GFAP) and cleaved caspase-3 were significantly elevated in the controls compared to the hDNP group in the amygdala. SMI-71 was also significantly elevated with the hDNP and hemostatic nanoparticle (hNP) treatments, similar to sham. In addition to the nanoparticles offering immediate life-saving qualities, administration of hemostatic nanoparticles improved amygdala pathology attributed to secondary mechanisms of blast injury, including blood-brain barrier disruption. This model of polytrauma can serve as a foundation for detailed pathological studies as well as testing therapeutics for injury modalities.
References (Abstract)
Arnold, J. L., P. Halpern, M. C. Tsai and H. Smithline (2004). "Mass casualty terrorist bombings: a comparison of outcomes by bombing type." Ann Emerg Med 43(2): 263-273.
Clemedson, C. J., Granstom, S.A. (1950). "Studies on the genesis of "rib markings" in lung blast injury." Acta Physiol Scand. 21: 131-144.
Ramasamy, A., S. E. Harrisson, J. C. Clasper and M. P. Stewart (2008). "Injuries from roadside improvised explosive devices." J Trauma 65(4): 910-914.
Rodoplu, U., Arnold, J. L., Tokyay, R., Ersoy, G., Cetiner, S., Yucel, T. (2004) "Mass-casualty terrorist bombings in Istanbul, Turkey, November 2003: reports of the events and the prehospital emergency response." Prehosp Disaster Med 19(2):133-145.
Snell, F. I. and M. J. Halter (2010). "A signature wound of war: mild traumatic brain injury." J Psychosoc Nurs Ment Health Serv 48(2): 22-28.Ph. D.
38
Bigikocin, Onur. "Presplit Blast Induced Air Overpressure Investigation At Usak Kisladag Gold Mine". Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608741/index.pdf.
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In presplit blasting operations airborne energy called air blast overpressure or
impulsive sound is produced. The air blast induced by blasting may vary
significantly at or around an open pit mine depending on several parameters such as
the amount of charge detonated, the physical distance between the blast and the
monitoring locations and the weather conditions. Therefore evaluation and
assessment of noise condition at or around an open pit mine is necessary.
The objective of this research study is to monitor and record the noise and to
investigate and assess the noise conditions that will be induced from presplit
blasting operations at Kisladag Gold Mine. In this research study, several
parameters such as the amount of charge, the physical distance to the location of
monitoring device or residential structures and the weather condition parameters
such as wind direction, wind speed were recorded, analyzed and evaluated.
It is observed that with increasing charge per delay air overpressure increases,
whereas with increasing scaled distances it decreases. It is also understood that
wind speed and the direction are effective in air overpressure propagation also, but
this subject needs further investigation. It is concluded that according to the U.S.
regulations there is no damage risk to the structures and no disturbance to the
inhabitants at present. Due to the uncertainties in weather conditions, in order not to
take any risks, the charge amount per delay should be kept at 35 kg or less for
presplit blasting at the mine.
39
Calder, Mark. "Accelerating the BLAST algorithm via parrallel computing /". [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18388.pdf.
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40
Hartmann, Dale Richard. "Feasibility of a blast wave attenuation structure". Springfield, Va. : Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA343630.
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41
Genson, Kevin William. "Vehicle shaping for mine blast damage reduction". College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3825.
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Thesis (M.S.) -- University of Maryland, College Park, 2006.Thesis research directed by: Dept. of Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
42
Zakrisson, Björn. "Numerical and experimental studies of blast loading /". Luleå : Luleå University of Technology, 2010. http://pure.ltu.se/ws/fbspretrieve/4485391.
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Hallset, Sindre, i Jarle Steenholdt Haagenrud. "Combined blast and fragment loading on plates". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for konstruksjonsteknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16051.
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This thesis was written at SIMLab at NTNU during 20 weeks of the spring semester of 2011. An increasing need for lightweight protective structures for both military and industrial applications has made the traditional use of concrete structures impractical, and has triggered increased research and development of steeland aluminium protective structures. The aim for this thesis is to investigate the synergetic effect of combined blast and fragment loading on thin steel plates. Experiments were performed using a pressure tank to simulate blast loading on plates with premade holes.The experiments were meant to imitate the effect of a blast wave hitting a thin steel plate penetrated by fragments travelling in front of the pressure wave. Largely the experiments were successful, though some results turned outto be deviant. Apart from decreasing the overall strength of the plates, the holes had no notable adverse effects. In order to investigate the problem further, numerical analyses were performed. A high number of simple analyses were run to establish a foundation upon which more complex analyses could be based. A reasonable level of similarity to the experiments was observed. Analyses were also run applying both uncoupled and coupled Eulerian and Lagrangian analyses. These analyses recreated recorded pressure levels from the experiments quite well, but resulted in exaggerated responses due tohigher loading rate.
44
Ketabi, Mohammad. "Blast loading of a cylindrical shell panel". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0021/MQ45230.pdf.
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Stephenson, Neil. "On-farm blast freezing of Saskatoon berries". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ57583.pdf.
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Shankar, Amitabh. "Studies on High Alumina Blast Furnace Slags". Doctoral thesis, Stockholm : Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4431.
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Gamber, Nathan K. "Shallow foundation systems response to blast loading". Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1176319209.
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48
Sun, Wei. "Surface mine blast design and consultant system". Ohio : Ohio University, 1987. http://www.ohiolink.edu/etd/view.cgi?ohiou1183062985.
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Sexton, Dane. "Coal agglomeration in blast furnace injection coals". Thesis, Cardiff University, 2019. http://orca.cf.ac.uk/119742/.
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In order to reduce expensive coke usage, blast furnace operators inject coal to replace a portion of the coke. However, the use of some injection coals can result in blast furnace instability and lowered permeability. This thesis is concerned with the injection of coal under entrained flow, high heating rate (104-106 °C/s) blast furnace conditions, namely the possibility of coal particle agglomeration via the use of caking coals. Methods of mitigating agglomeration via blending and pre-oxidation are tested, whilst the resultant performance implications of agglomerated coal chars are considered and analysed. A drop tube furnace (DTF) was used to experimentally test coal injection under conditions that are applicable to the blast furnace 'hot blast' region. Relatable DTF parameters include an operating temperature of 1100°C, and heating rate of 104 °C/s. Four industrial injection coals with varying volatile matter and caking properties were tested at both granulated and pulverised particle size specifications. It was found that coals defined as 'caking coals' showed consistent agglomeration during DTF injection, a potentially problematic effect regarding blast furnace injection. Agglomeration percentages (as defined by sieve classification) for the industrially problematic MV4 coal were 11% and 23% for the granulated and pulverised samples respectively. Blending of whole coals was effective in reducing the amount of agglomerated material in the char, as was sample pre-oxidation prior to injection. Regarding performance, agglomerated chars had greater combustion performance and gasification reactivity than the non-agglomerated samples. With agglomeration shown to be present under high heating rate conditions at temperatures akin to the blast furnace hot blast, it is concluded that agglomeration is a possibility during blast furnace injection. However, due to differing feed systems between the DTF and blast furnace, the precise form and extent of agglomeration in the blast furnace remains uncertain. Based on char combustion and gasification analysis, chars characterised by fine agglomerated material are not likely to be problematic for blast furnace operators relative to 'standard' injection coals.
50
DeRogatis, Austin (Austin Patrick). "Economical solutions to blast mitigation on bridges". Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43888.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2008.Includes bibliographical references (leaves 42-44).
Mitigating the energy created from a blast has been a topic of utmost importance in the terrorism-feared world of today. Main targets of concern are passageways that are significant to a specific area, such as bridges. These structures are expensive to construct and vulnerable to explosive loads which is why a cost-effective means of blast mitigation must be researched. There are many aspects of bridges that could be damaged when a blast load is applied. These susceptible areas can be strengthened using new-age, high-strength composite materials to ensure the security of the whole structure. These materials are able to sustain larger loads while dissipating higher amounts of energy when compared to conventional building materials. As a result, the response of the entire structure will be minimized when a blast load is applied. Despite the fact that these composites cost more than typical materials, the increase in project cost could be minimized by limiting the use of these high-strength materials for only the critical areas of the bridge. Other cost effective solutions to blast mitigation occur in the preliminary design phase. Eliminating all pressure-amplifying areas would save members and connections should a blast occur. Also, designing a bridge with high vertical clearances above areas of excessive boat traffic would also minimize the resultant forces and stresses from an explosion.
by Austin DeRogatis.
M.Eng.