Explosive Devices Research Articles

Study on the characteristics parameters of magnesium dust explosion suppression by various inert gases

Alongside the extensive use of magnesium, dust explosion accidents have become increasingly frequent. Conducting research on suppressing magnesium dust explosions is of great significance for the healthy development of the magnesium industry. In this paper, the effects of four inert gases (CO2, N2, Ar, and He) on the explosion characteristics parameters of magnesium dust clouds with different concentrations were investigated using a closed explosion device. It was observed that at low volume fractions of inert gases in the explosion system, there were no significant differences in their effects on the explosion characteristics parameters and the combustion time of magnesium particles. In situations where there was a high level of oxygen, N2 was more effective than Ar in suppressing explosions. However, when the concentration of magnesium dust cloud was higher and the oxygen content was lower within the hybrids, N2 reacted with magnesium dust that was unable to react with oxygen. As a result, the explosion suppression effect gradually shifted from N2 being better than Ar to Ar being better than N2. Moreover, the differences in the effects of four inert gases on particle combustion time became increasingly prominent. However, in all operating conditions, CO2 demonstrated the most effective suppression of magnesium dust explosions, while He exhibited the least effective suppression effect. Furthermore, by employing a chemical reaction kinetics calculation model, it has been discovered that the content of inert gases significantly affected the combustion time and reaction mode of particle combustion, thereby causing variations in the propagation behavior of magnesium dust cloud flames.

Injuries Due to Improvised Explosive Devices

Illegal possession of improvised explosive devices (IEDs) is not uncommon. In Sri Lanka, they are commonly used for hunting, protecting cultivation, etc. Further, they are also used to commit homicides. An IED called “Hakka Patas” is produced by the material available in firecrackers and causes pressure-sensitive blasts. Another IED “Ali Wedi”, a kind of larger firecracker, may cause accidental injuries. However, the injuries caused by “Hakka Patas” and “Ali Wedi” are not reported in the forensic literature.Case 1: A child received severe crush injuries of the foot following a “Hakka Patas” explosion while walking. The wound was grossly contaminated and on the second day, a below knee amputation was done. Case 2: A farmer received injuries to his right hand while he was throwing an “Ali Wedi”. Due to gross crush injuries, the right index finger was amputated.Strict rules and regulations should be implemented to control illegal, locally-made explosive devices to prevent morbidity and mortality. Forensic pathologists should be familiar with the atypical patterns of injuries produced by improvised explosive devices.

Chemical sensors on unmanned aerial vehicles: new possibilities for searching for mines and explosive devices

Increasing the effectiveness of anti-mine protection of troops, timely detection and marking of mine-explosive devices in the area, prompt informing of personnel of units operating in the area, search for methods and means that increase the reliability of the search and reduce the level of false detections, possible identification and marking of mines (explosive objects) are extremely relevant and, given the scale of demining that will need to be carried out on the territory of Ukraine after the end of hostilities, promising tasks. This can be achieved through the introduction of modern, reliable, effective, remote methods and means of searching, detecting, identifying and marking mine-explosive devices that work in real time with a fairly high speed. The purpose of the research is to justify the need to use chemical modules (equipped with a set of chemical sensors) installed on unmanned aerial vehicles for conducting engineering and reconnaissance actions for the search, detection and marking of mine-explosive devices. It has been established that the combination of unmanned aerial vehicles of the multi-rotor type with the appropriate chemical module will prevail over other means of reconnaissance of mine-explosive devices (barrages) in service and will meet such criteria as mobility, speed (operational), sensitivity, reliability, selectivity, reliability, stability. It is recommended that the chemical module include various appropriate sensors that will complement each other and cover the entire range of explosives used to equip mines and explosive objects. Chemical sensors that work on the principle of suppression of fluorescent radiation by the vapor of an explosive substance are promising. The effectiveness of demining with the help of unmanned aerial vehicles with a chemical module will depend on the probability of explosive vapors entering the chemical module's area of operation and the probability of detecting mine-explosive devices. At the same time, the equipment of unmanned aerial vehicles intended for conducting engineering reconnaissance not only with a chemical module, but also with other, additional sensors for detecting mines (explosive objects) by secondary signs will allow to increase the reliability of the search and detection of mine-explosive devices.

Determining the type of explosive item using a decision tree

The present circumstances in Ukraine delineate specific areas of study. The imperative to identify an explosive device is increasingly paramount for adults and particularly for children. Failing to recognize this danger poses a threat to health and life. The paper presents a decision tree method for classifying the type of explosive objects. This allows you to draw conclusions about the type of explosive object hidden depending on the type of soil. This problem is relevant, as it allows to reasonably explain the type of danger depending on various external factors. The paper offers a general representation of the construction of a decision tree for determining the type of explosive objects. In addition, the work provides a visualization of the division into nodes for a visual representation of the construction of a decision tree, taking into account the division into subtrees and nodes. The nodes are the main attributes: voltage, sensor height above ground level, soil type. The decision tree construction algorithm and the structural block diagram of the ID3 algorithm are given. A study was conducted based on who was chosen to measure the entropy decision tree split chaos. The main characteristics of the ID3 algorithm were listed, taking into account the subject area in which it is used. The paper presents one of the built decision trees, which was built as part of research to determine the type of explosive object depending on the possible type of soil, for example, it is dry and sandy soil. Moreover, the paper provides a comparative analysis of the decision tree model against existing methodologies, shedding light on its efficacy, accuracy, and potential advancements in enhancing threat detection capabilities. This comprehensive analysis not only showcases the model's strengths but also offers insights into potential areas for refinement and improvement

Counter-Improvised Explosive Devices (C-IED) mission support capabilities

Actions and activities taken against the IED threat comprise complex tasks. In thebeginning, the focus was on the deactivation and destruction of IEDs, as the only wayto fight against them. As time has passed, more existing capabilities were included inthe field of C-IED, which were able to contribute to the mitigation of the effectivenessof an IED attack.Due to the fact that the first type of response to IED-threat was tasked to combatengineers, particularly to EOD personnel, that was rather obvious that C-IED missionsand responsibilities fell to combat engineers. Nowadays, however, capabilities andcapacities in the C-IED can be identified that exceed the competence of engineer unitsand commanders. The C-IED requires a comprehensive approach. In a staff andheadquarters lots of capabilities and capacities should be involved in C-IED activities,which requires coordination and cooperation. The involvement of those capabilitiesdepends on the type of mission, its phases, and the nature of IED threat. Thus amission commander needs to understand which are the C-IED enablers that cancontribute to C-IED tasks, when and how they influence or mitigate IED threats.

A REVIEW ON IMPROVISED EXPLOSIVE DEVICES AND THE HUMANITARIAN HARM CAUSED BY THEM

Improvised explosive devices (IEDs) in all their forms have emerged as the most serious threat. These devices can range from simple explosive devices to complex military systems using high-grade explosives. A thorough grasp of the many types of devices and their effects is required for proper mass casualty event planning and management of the complex poly trauma victims that they usually bring. They may wreak havoc on a landscape. Depending on the desired target, they can be initiated in a variety of ways. As a result, there is a pressing need to research and ameliorate the mechanism of extremities harm induced by these devices. These improvised explosive devices are generally uncommonly encountered outside the battlefield. The majorities of vulnerability evaluations presume that an improvised explosive device would attain maximal TNT equivalency and detonate effectively. They are still a popular terrorist weapon. These are unusual explosive weapons that can be used in a variety of ways to cause injury, fatalities, and destruction of property in both military and civilian conditions. IEDs continue to be a domestic menace. The science and damage profile of these devices are described in this review. The humanitarian devastation inflicted by IEDs is thus depicted. KEYWORDS: - improvised explosive devices, explosives, detonation, injury, impact testing, biomechanics, ground penetrating radar, detection, prevention, National Bomb Data Centre

Evaluating Pelvis Response During Simulated Underbody Blast Loading.

In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED detonates under a vehicle (an under-body blast), the seat acceleration rapidly transmits a high load to the pelvis of the occupants, resulting in torso and pelvic injury. Pelvic fractures have high mortality rates, yet their injury mechanism has been poorly researched. Three (3) fresh-frozen male pelvic specimens were tested under axial impact loading. The pelvis was impacted mounted upside down by dropping a 12 kg mass at target impact velocities ranging from 1 to 8.6 m/s with time to peak velocity ranging from 3.8 to 5.8 ms. Resulting fractures were broadly categorized as involving a bilateral pubis rami fracture, a bilateral ischium fracture, and sacroiliac joint disruption. The study provides insights into the type and severity of pelvic injury that may occur over a range of under-body blast (UBB)-relevant loading profiles.

Development of fragility models for process equipment affected by physical security attacks

The vulnerability of chemical and process facilities toward physical security attacks depends on the equipment resistance against such attacks and on the performance of Physical Protection Systems (PPS) in place. To enhance the protection against intentional attacks, the development of quantitative vulnerability metrics is essential, nevertheless current standard approaches only offer qualitative or semi-quantitative evaluations. The aim of the present work is to develop a quantitative methodology for the assessment of chemical and process facilities vulnerability towards external acts of interference. The proposed methodology is based both on the evaluation of equipment structural integrity in response to different types of specific impact vectors characterizing intentional attacks and on the quantitative performance assessment of related PPS. In particular, specific fragility models were developed for impact vectors associated with improvised explosive devices, firearms, and incendiary weapons. The novel fragility models were implemented in a comprehensive security vulnerability assessment (SVA) based on Bayesian Networks, in which the contribution of PPS performance was also considered. A case study was defined and analyzed to exemplify the application of the proposed approach. The results obtained allowed for the identification of the most critical security-related escalation scenarios and thus for an improved quantitative SVA.

A comparison of fracture response in female and male lumbar spine in simulated under body blast component tests

Underbody blasts (UBB) from mines and improvised explosive devices in military combat can cause debilitating spine injuries to vehicle mounted soldiers. Due to the exclusion of females in combat roles in prior US Department of Defense policy, UBB exposure and injury have predominantly affected male soldiers. Recent policy changes have opened many combat roles to women serving in the US Military (Carter, 2015) and have increased the need to understand the injury potential for female Warfighters. The goal of this study was to investigate the fracture response of adult female lumbar spines compared to adult male spines in UBB relevant loading to identify potential differences in either fracture mechanism or force. Results are presented for 15 simulated UBB spine compression tests using three small female (SF), five large female (LF), and seven mid-sized male (MM) post-mortem human subjects (PMHS). These PMHS groups align to 5th- and 75th-percentile female and 50th-percentile males, based on height and weight from the 2012 Anthropometric Survey of U.S. Army Personnel (Gordon et al., 2014). Both small females and large females (similar in size to the males) were included to assess the role of size and/or sex in the response. Tests were conducted at Virginia Tech on a cam-driven linear compression rig, which included a 6-axis load cell and ram accelerometer to evaluate the fracture. Fracture was visualized through high-speed x-ray video. All female and male spines exhibited similar fracture initiation at the end plates and progression through the vertebral body. The resulting severe compression and burst fractures were representative of reported theatre injuries (Freedman et al., 2014). Mean axial fracture forces were −4182 ± 940 N (SF), −6225 ± 1180 N (LF), −5459 ± 1472 N (All Females) and −7993 ± 2445 N (MM). The SF group was found to have statistically significant differences in mean fracture force compared to both LF and MM groups, while no significant difference was found between LF and MM groups, although the mean force at initial fracture was lower for the LF group. The All-Females group Fz mean was significantly different from the MM group. These data suggest that the significant difference in weight between the SF and LF groups, did have an influence on the Fz outcome, when controlling for sex. Conversely, controlling for size in the LF and MM comparison, sex did influence the mean Fz, but was not statistically significant. Groups with combined sex and size differences, however, did show significant differences in mean Fz. Further study is warranted to understand whether sex or size has a larger effect on fracture force. Mean ram displacement (spine compression) values at fracture initiation were −6.0 ± 5.3 mm (SF), −4.4 ± 0.8 mm (LF), −5.0 ± 3.0 mm (All Females), −6.2 ± 4.5 mm (MM). Spine compression did not seem to be largely influenced by either sex or size, and none of the groups was found to have significant differences in mean displacement values.

КОНЦЕПЦІЯ ПІДВИЩЕННЯ БЕЗПЕКИ ВУЗЛІВ РОЗПОДІЛЬНОЇ ЕНЕРГЕТИЧНОЇ ІНФРАСТРУКТУРИ УКРАЇНИ

The issue of one of the problems that arose in the energy infrastructure of Ukraine as a result of the regular destruction of its facilities during the war is considered. It concerns ways of increasing the security of nodes of the distribution system of the energy infrastructure of Ukraine during its further restoration and modernization. An overview of the relevant issues that arise when using different methods to achieve the set goal is made. The importance of the problem of protection of electrical substations of the energy distribution infrastructure and the need for appropriate research and development to create an optimal method of protection are indicated. The urgency of developing a method and means of protection of an important element of substations (power transformer) is noted. One of the variants of the optimal concept of the corresponding protection is described. It provides for the location of transformers in an earthen niche, accordingly formed and decorated with auxiliary elements. This option is simple, technological and economically beneficial. This method of protecting transformers should protect them from fragments of explosive devices and blast waves. The proposed concept has room for improvement. Ref. 4, fig. 2. Keywords: power grid, transformer, safety, shelter, concept.

On the material object of the criminal offences provided by art. 290, art. 291, art. 292 CC RM: penal analysis, conclusions and recommendations

This scientific article is devoted to the criminal law analysis of firearms, their components, explosive devices and explosives from the point of view of their consideration as material objects of crimes committed in the field of their illicit trafficking (Art. 290, Art. 291, Art. 292 of the Criminal Code of the Republic of Moldova) . It has been proven that the main parts of firearms fall out of the legislator’s field of vision, and the structure of Articles 290 and 292 of the Criminal Code of the Republic of Moldova should be revised in terms of systematizing the material objects of crimes.In modern conditions, illicit trafficking in weapons, their components, explosive devices and explosives is an international crime, and, obeying the principle of universality in criminal law, the states parties to international conventions in the designated area are obliged to prosecute and punish all persons (organizers, instigators, authors and accomplices) at all stages (preparation, attempt, completed crime) of the commission of any crime in the sphere of illegal circulation of these items.In turn, we analyzed the legislative experience of some countries of the Anglo-Saxon system of law (USA and India) in order to clarify and identify the features of the criminalization of illicit trafficking in weapons, their components, explosive devices and explosives in these states.

Студенческая молодежь и терроризм: представления, оценки, эффективность противостояния

The article examines students’ ideas about terrorism, its causes, the scale and possible ways to reduce the terrorist threat. The authors conducted a sociological study, a questionnaire and a series of in-depth interviews among students and security guards of Yaroslavl universities. Students were tested to determine their readiness to survive in an extreme situation. During testing, it was found that most of the students, regardless of gender and age, do not know how to properly navigate and act in extreme and emergency situations. Boys are more prepared than girls for extreme situations and psychologically ready for self-defense. It was revealed that boys know better than girls the signs of explosive standard devices. In addition, it was found that not all students, regardless of gender, age, direction of study, know the main features of improvised explosive devices. Students tend to be more vigilant in public transport and at home (on the house territory) than at the university and near the university, believing that public places (universities) are well protected from terrorism. Most of the students are not satisfied with the work of electronic entrances at universities. It is revealed that the majority of students are aware of the main methods of carrying out terrorist acts by terrorists. The majority of students believe that the level of terrorist threat in the city has increased over the past year. According to a significant part of students, war and military conflicts are the main reasons why people become members of terrorist groups; as well as the presence of illegal, banned religious or ideological sects in the country, through which terrorists recruit people into their ranks, usually from marginals. Based on the results of the study, measures are proposed to improve the effectiveness of the fight against terrorism.

THE LEGAL REGULATION OF ANTI-MINING ACTIVITIES: INTERNATIONAL EXPERIENCE

Ukraine is among the countries with the largest quantity victims from field mines and others explosive devices. That demands from state authorities to conduct measures related to search, detection and disposal explosive items on the contaminated (probably contaminated) territory of Ukraine, water areas and objects infrastructure. Comprehensive and effective solution of problems is possible only by creation effective organizational and legal systems humanitarian demining using best international experience which should become important component part of State Strategy of anti-mining activities.
 The purpose of the article is to analyse the current state of legal regulation anti-mine activities in Ukraine and find out directions for implementation of international experience, in particular, the NATO member states, to create modern organizational and legal system of anti-mining activity in our the state.
 During the research the general scientific and special methods were applied, in particular methods of system analysis and synthesis, comparative legal methods etc.
 The analysis of current legislation anti-mining activities in Ukraine is done, the gaps and shortcomings of legal regulation are defined and directions of impact of international law on national standards using better international experience are formulated.

Development of a Reusable Solid-Propellant Pulsating Explosive Device for Drilling Rocks of Various Hardness Categories

Development of a Reusable Solid-Propellant Pulsating Explosive Device for Drilling Rocks of Various Hardness Categories

Использование различных вычислительных подходов к моделированию показателя санитарных потерь при террористических актах в мире на период до 2030 г.

Summary. The aim of the study is to investigate and to justify the application of various computational approaches to forecasting the value of probable sanitary losses as a result of terrorist acts in the world for the period up to 2030. Materials and research methods. Materials of the study were archival data of the generalized database (GTD, Global Terrorism Database), containing information on more than 200 thousand cases of terrorist activities registered in 1970-2020. The methods and ways of committing terrorist attacks, as well as the objects they were aimed at were analyzed. The forecast model of the probable sanitary losses as a result of terrorist acts was built for the period from 2021 to 2030 inclusive. The data set was analyzed by various operators of MS Excel spreadsheet aggregator using the functions “FORECAST SHEET”, “FORECAST”, “TREND”, “GROWTH”, “LINEST” and “LOGEST “. Results of the study and their analysis. It is observed that the number of probable sanitary losses due to terrorist attacks in the world may increase by 35.28% by 2030. The methods of committing terrorist acts most significant in the long term were identified. These are the use of explosives in the form of industrial and improvised explosive devices, as well as firearms, especially against the military and police. It is concluded: the obtained results of the study should be used to correct the established structure of the incoming flow of sanitary losses and to determine the optimal composition of multidepartmental medical forces and means necessary to eliminate medical and sanitary consequences of terrorist acts.

Effective resistance design and performance evaluation of energy conversion components

The safety and reliability of the initiating explosive devices (IEDs) are critical for the weapon system. As the core components of IEDs, the method of resistance designing and the performance of conversion energy of energy conversion components (ECCs) are worth being studied. In this paper, the design method for the resistance of ECCs is established based on the finite element discrete method, and the currents of melting and electric explosion are presented for evaluating the performance of ECCs. The results show that the resistance of the ECCs is 1 ± 0.05 Ω with consistency. The ECCs were designed by the established design method of resistance and manufactured by the established machining method. The melting current of ECCs is 1.8 A, which is calculated by the infrared temperature measurement and finite element simulation. The electric explosion current of ECCs is 5 A, which was obtained by combining the snapshot obtained via the high-speed camera and finite element simulation.

THEO & MUFN: Defending Earth against the 2023 PDC hypothetical asteroid impact

Planetary defense is an emerging field among the aerospace community. As the rate of near-Earth object (NEO) discoveries increases, so too does the probability that we will discover a NEO on a collision course with Earth. This paper documents a planetary defense mission campaign design to defend against the hypothetical Earth impactor 2023 PDC. At its 90th percentile mass estimate, the asteroid could have a diameter of approximately 1120 m. The asteroid makes no close approaches until Earth impact and has the potential to affect over a billion people, depending on its actual size. This paper describes a mission campaign consisting of both reconnaissance and mitigation missions that will be deployed to neutralize the threat posed by the asteroid. The reconnaissance orbiter named THEO (Terrestrial Hazard Exploration Orbiter) will survey the asteroid to clarify its morphological, gravitational, and dynamical properties. This information will be used to inform the design of the subsequent mitigation mission. THEO will be designed to have a mission lifetime of 12 years which will enable it to observe the mitigation mission and confirm its success. Two 21-day launch periods have been identified that minimize post-launch ΔV requirements and include current launch vehicle capabilities. For the purposes of this paper, the mitigation mission has been designed assuming a geocenter impact for the 90th percentile mass estimate of the asteroid because a precise impact location and an accurate mass estimate will not be available until THEO reconnoiters 2023 PDC. The mitigation mission, named MUFN (Mitigation Using a Fission Nuclear device), will send three spacecraft to rendezvous with 2023 PDC and alter the asteroid’s trajectory prior to Earth impact through a series of standoff nuclear detonations. The MUFN spacecraft are identical in design, each employing a hypergolic bi-propellant thruster. Each MUFN spacecraft launches on a SpaceX Falcon Heavy Expendable launch vehicle between 2028 and 2030 and carries four 340 kt nuclear explosive device (NED) equipped orbiters, named BELA-Os (“Bull’s Eye, Later Asteroid” Orbiters). The BELA-Os are designed to sequentially deploy, maneuver to an optimal standoff distance anti-parallel to the asteroid velocity vector, and detonate the NED to impart a change-in-velocity to the asteroid. After arrival at 2023 PDC, each MUFN spacecraft will station-keep above the asteroid. The NED-equipped BELA-Os will deploy from the MUFN spacecraft and maneuver 180 degrees out of phase from MUFN to the ‘front’ of the asteroid. Once there, each BELA-O will detonate and impart 2.32 mm/s of velocity change to the asteroid. After the ablation debris has cleared, MUFN will complete a single orbit around the asteroid to survey the blast site and assess the effectiveness of the detonation. After MUFN has completed its survey, it will release another BELA-O. This process will repeat until all BELA-Os have been released by all MUFN spacecraft. All denotations will occur between 2029 and 2031. After all BELA-Os have detonated their NED payloads near the 2023 PDC asteroid to deflect its orbit, the asteroid will safely fly by Earth at a minimum altitude of 3500 km instead of colliding on October 22, 2036.

Realistic simulation of GPR for landmine and IED detection including antenna models, soil dispersion and heterogeneity

AbstractGround‐penetrating radar is an effective tool for detecting landmines and improvised explosive devices, but its performance is strongly influenced by subsurface properties as well as the characteristics of the target. To complement or replace labour‐intensive experiments on test sites, cost‐efficient electromagnetic wave propagation simulations using the finite‐difference time‐domain method are being increasingly used. However, to obtain realistic synthetic data, accurate modelling of signal alteration caused by dispersion, scattering from soil material, target contrast, shape, and inner setup, as well as the coupling effects of the antenna to the ground is required. In this study, we present a detailed three‐dimensional model of a shielded ground‐penetrating radar antenna applied to various scenarios containing metallic and non‐metallic targets buried in different soils. The frequency‐dependent intrinsic material properties of soil samples were measured with the coaxial transmission‐line technique, while a discrete random media was used to implement the heterogeneity of a gravel based on its grain‐size distribution. Our simulations show very good agreement with experimental validation data collected under controlled conditions. We accurately reproduce the amplitude, frequency, and phase of target signals, the subsurface background noise, antenna crosstalk and associated interference with target signals, and the effect of antenna elevation. The approach allows for a systematic investigation of the effects of soil, target, and sensor properties on detection performance, providing insight into novel and complex ground‐penetrating radar scenarios and the potential for a wide range of simulation possibilities for demining with ground‐penetrating radar. These investigations have the potential to improve the safety and effectiveness of landmine and improvised explosive device detection in the future, such as building a database for training deminers or developing automatic signal pattern recognition algorithms.

Impact of Blast Overpressure on the Pharmacokinetics of Various Antibiotics in Sprague Dawley Rats.

Combat injuries are complex and multimodal. Most injuries to the extremities occur because of explosive devices such as improvised explosive devices. Blast exposure dramatically increases the risk of infection in combat wounds, and there is limited available information on the best antibiotic treatments for these injuries. We previously demonstrated that mice exposed to blast displayed a delayed clearance of cefazolin from the plasma and liver; further semi-mechanistic modeling determined that cefazolin concentrations in the skin of these mice were reduced. Our objective was to investigate the effects of blast on the pharmacokinetics of antibiotics of different types used for the treatment of combat wounds in the rat model. Male Sprague Dawley rats were exposed to blast overpressure followed by injection of a bolus of animal equivalent doses of an antibiotic (cefazolin, cefepime, ertapenem, or clindamycin) into the tail vein at 1-hour post-blast exposure. Blood was collected at predetermined time points via repeated sampling from the tail vein. Animals were also euthanized at predetermined time points, at which time liver, kidney, skin, and blood via cardiac puncture were collected. Antibiotic concentrations were determined by ultra-performance liquid chromatography-tandem mass spectrometry. Blast-exposed rats exhibited a similar rate of clearance compared to non-blasted rats in the blood, liver, kidney, and skin, which is inconsistent with the data regarding cefazolin in blast-exposed mice. Our results in rats do not recapitulate our previous observation of delayed cefazolin clearance in mice following the blast overpressure exposure. Although using rats permitted us to collect multiple blood samples from the same animals, rats may not be a suitable model for measuring the pharmacokinetics of antibiotics following blast. The interpretation of the results may be challenging because of variation in data among rat subjects in the same sample groups.

Pelvis-Sacrum-Lumbar Spine Injury Characteristics From Underbody Blast Loading.

Combat-related injuries from improvised explosive devices occur commonly to the lower extremity and spine. As the underbody blast impact loading traverses from the seat to pelvis to spine, energy transfer occurs through deformations of the combined pelvis-sacrum-lumbar spine complex, and the time factor plays a role in injury to any of these components. Previous studies have largely ignored the role of the time variable in injuries, injury mechanisms, and warfighter tolerance. The objective of this study is to relate the time or temporal factor using a multi-component, pelvis-sacrum-lumbar spinal column complex model. Intact pelvis-sacrum-spine specimens from pre-screened unembalmed human cadavers were prepared by fixing at the superior end of the lumbar spine, pelvis and abdominal contents were simulated, and a weight was added to the cranial end of the fixation to account for torso effective mass. Prepared specimens were placed on the platform of a custom vertical accelerator device and aligned in a seated soldier posture. An accelerometer was attached to the seat platen of the device to record the time duration to peak velocity. Radiographs and computed tomography images were used to document and associate injuries with time duration. The mean age, stature, weight, body mass index, and bone density of 12 male specimens were as follows: 65 ± 11 years, 1.8 ± 0.01 m, 83 ± 13 kg, 27 ± 5.0 kg/m2, and 114 ± 21 mg/cc. They were equally divided into short, medium, and long time durations: 4.8 ± 0.5, 16.3 ± 7.3, and 34.5 ± 7.5 ms. Most severe injuries associated with the short time duration were to pelvis, although they were to spine for the long time duration. With adequate time for the underbody blast loading to traverse the pelvis-sacrum-spine complex, distal structures are spared while proximal/spine structures sustain severe/unstable injuries. The time factor may have implications in seat and/or seat structure design in future military vehicles to advance warfighter safety.