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A coupled framework of ballistic simulations and an optimized machine learning (ML) model was developed to accurately predict the kinetic energy reduction of a projectile impacting a target. ML models can require a significant number of data points for proper training, testing, and validation. High-performance computing (HPC) resources can be used to simulate the ballistic impacts of various projectiles against several different target materials using appropriate physics-based hydrocodes. Computational modeling can explore areas where experiments would naturally be cost-prohibitive. These hydrocodes can evaluate large parametric spaces varying the projectile and target variables that are required to train an ML model. In this study a large, generated set of data points was used to develop an optimized artificial neural network (ANN) algorithm to create a fast-running model without prior knowledge of the mathematical relationships between all the input and output variables. The optimized ANN model was developed using Optuna in an HPC environment to tune the hyperparameters needed for the ANN model. This fast-running ML model could then be leveraged to investigate designing optimized targets that could protect against different types of projectiles. The results of this work showed that the optimized ANN model predicted the kinetic energy reduction with a mean absolute percentage error of 2.7% across the validation data. Overall, the optimized ANN model showed excellent agreement across the range of data considered by the computational models. [ABSTRACT FROM AUTHOR]

Computed tomography (CT) may have a crucial role in the forensic documentation and analysis of firearm injuries. The aim of this forensic ballistics case study was to explore whether two types of expanding bullets and a full metal-jacketed bullet could be differentiated by inspecting bullet fragments and fragmentation pattern in CT. Three types of.30 caliber bullets (full metal-jacketed Norma Jaktmatch, expanding full-copper Norma Ecostrike, and expanding soft-point Norma Oryx) were test fired from a distance of 5 m to blocks of 10% ballistic gelatine. CT scans of the blocks were obtained with clinical equipment and metal artifact reduction. Radiopaque fragments were identified and fragmentation parameters were obtained from the scans (total number of fragments, maximum diameter of the largest fragment, distance between entrance and the closest fragment, length of the fragment cloud, and maximum diameters of the fragment cloud). The fragmentation patterns were additionally visualized by means of 3D reconstruction. In CT, the bullet types differed in several fragmentation parameters. While the expanding full-copper bullet Ecostrike left behind only a single fragment near the end of the bullet channel, the soft-point Oryx had hundreds of fragments deposited throughout the channel. For both expanding bullets Ecostrike and Oryx, the fragments were clearly smaller than those left behind by the full metal-jacketed Jaktmatch. This was surprising as the full metal-jacketed bullet was expected to remain intact. The fragment cloud of Jaktmatch had similar mediolateral and superoinferior diameters to that of Oryx; however, fragments were deposited in the second half of the gelatine block, and not throughout the block. This case study provides a basis and potential methodology for further experiments. The findings are expected to benefit forensic practitioners with limited background information on gunshot injury cases, for example, those that involve several potential firearms or atypical gunshot wounds. The findings may prove beneficial for both human and wildlife forensics. [ABSTRACT FROM AUTHOR]

Low velocity ballistic deformation behavior of closed-cell aluminum metal foam targets fabricated by powder metallurgy technique has been investigated. The metal matrix of aluminum (60 micron) was mixed with carbamide (CH4N2O) particles of size one mm. Green samples were obtained by compacting the mixture followed by sintering process using a muffle furnace and the metallic foam thus obtained had an average pore size of 1.5 mm. Compared to metallic material, significant reduction in hardness and density was observed when the porosity was increased from 5 to 30%. Using a gas gun setup, low velocity (100 m/s and conical projectile) ballistic experiments were conducted on metal foam targets to understand the deformation behavior. Not any penetration of the projectile was observed when the percentage of porosity was less than 5%. When the percentage of porosity was increased, the projectile was able to perforate the target as the fracture toughness decreases. The size of fragmented areas of the perforated targets and depth of penetration (DoP) of the projectile were measured. Decrease in DoP (improved ballistic resistance) was observed with the increase in relative density of the closed foam target. Even though the projectile could perforate the foam target, no cracks were observed which enhances the suitability of the metal foams to be used as structural applications of defense vehicles. [ABSTRACT FROM AUTHOR]

At present, compound targets are usually used to evaluate the mechanism of weapon injury and killing efficiency as well as the protective performance of soft armor. In order to study the ballistic impact response of the skin-gelatin composite target under the protection of UHMWPE panel, the structural design scheme of UHMWPE panel with different specifications was drawn up and prepared. Ballistic impact experiments were carried out on the UHMWPE panel with 7.62 mm pistol projectile, and the damage morphology, residual velocity and energy absorption mechanism of the target plate were analyzed. The finite element models of 7.62 mm pistol bullet penetrating UHMWPE panel and UHMWPE panel-skin-gelatin were constructed, and the impact response characteristics and damage morphology of the composite target were analyzed under different area densities, incident velocities and angles of attack. The results showed that different specifications and processes will affect the protective performance of UHMWPE panel. With the increase of incident velocity and angle of attack, the concave depth of the panel becomes larger and the damage becomes more serious. Furthermore, in the process of penetration, the constraint definition of the model will affect the stress propagation of the composite target. This study provides a new idea for the evaluation of weapon injury mechanism and killing efficiency and the evaluation of protective performance of body armor. [ABSTRACT FROM AUTHOR]

The problems of the motion and destruction of large cosmic bodies under the influence of thermal and force loads in the Earth's atmosphere are considered. Based on the modified physical theory of meteors, a mathematical model of the trajectories of the motion of such bodies during the penetration of the planet's atmosphere is constructed. A computational experiment is carried out for known meteoroids selected as the reference ones in order to determine the effect of the ballistic parameters of the entry of these meteoroids (the angle of inclination of the trajectory to the Earth's surface and velocity) on the process of their destruction in the Earth's atmosphere. It is shown that these characteristics have a significant influence on the motion and destruction of cosmic bodies. [ABSTRACT FROM AUTHOR]

A detailed mapping of volcanic ballistic projectiles emplaced in a defined area, represents the starting point to derive preparatory data in hazard and risk studies of ballistics phenomena. Considering as case study the 3rd July 2019 paroxysmal eruption occurred at Stromboli volcano, we map and analyse at very high spatial resolution (8 cm) the distribution of the ballistic spatter clasts emplaced on the E flank of the volcano. The resulting map identifies and reproduces as geospatial polygon elements 152,228 spatter clasts with areal dimensions from 0.03 to 4.23 m2. Dispersed on 0.407 km2, the spatters cover an area of 29,000 m2 corresponding to an erupted products volume from 2.3 to 7.0 × 103 m3, calculated here for the first time. Spatial analyses indicate that the area mostly affected by the clasts emplacement is between N67.5 and N135 directions, identifying a preferential deposition between N112.50 and N123.75 directions. The clasts size distribution rapidly decreases with the size increase, highlighting a nearly constant ratio small/large clasts regardless the distance from the vent. Finally, additional investigations reveal that clasts dispersion parameters decrease progressively with the distance from the vent only along one direction (N67.5), highlighting how the morphology influences the deposition and remobilisation of mapped ballistics. [ABSTRACT FROM AUTHOR]

A mathematical simulation of the internal ballistics of a shot from a gun, depending on the design of the charge of the gun, has been performed. A general system of equations defining the unsteady movement of a two-phase gas–powder mixture in the channel of the barrel of a gun in the one-dimensional approximation is presented. Results of simulation of a shot from a gun charged with tubular powder or chopped powder are presented. The influence of the gradual ignition of a powder in a gun and of its nonstationary and erosion burning in it on the parameters of the ballistic process in the gun and the influence of the mass and disposition of an igniter in the gun on the dynamics of a shot from it were investigated. [ABSTRACT FROM AUTHOR]

In the era of unmanned war, with the increasing muzzle velocity requirement, the design of gun is significantly restricted by recoil, especially for guns installed on unmanned aerial vehicles. A recoilless gun with combustible cartridge was designed to eliminate recoil and increase projectile velocity, and the influence of main parameters on recoil was studied. First, a design of a recoilless gun with high projectile velocity is proposed based on combustible cartridge case. Next, a classical interior ballistic model is developed during the recoilless gun firing cycle, and the effect of main parameters of interior ballistics on the performance is investigated. Additionally, simple nonlinear fitting formulae are defined to highlight the variation of recoil momentum with the time of interior ballistic model. Finally, numerical simulation results are compared with the test results to validate the feasibility of the design. The experimental results demonstrate that the classical interior ballistic model can be used to accurately analyze the effect of the parameters on the projectile velocity and the recoil reduction efficiency. The projectile velocity of the recoilless gun could raised to 1200 m/s and the recoil momentum could be eliminated almostly. Therefore, the newly designed recoilless gun effectively eliminates the recoil momentum and significantly improves the projectile velocity. The findings should make an important contribution to the field of engineering applications of recoilless gun. [ABSTRACT FROM AUTHOR]

Background: Ballistics deals with the study of projectile propulsion, flight, and impact in any medium. Different garment materials can have varying effects when it comes to the penetration of pellets into the body. Body armor has been around for a long time. Dhal, a curving strip of rhino hide, was possibly the first armor in India, used for sword fighting or defense against arrows and spears. It gave way to steel armor, which protected the body's essential organs from spear and arrow strikes. The current study is primarily concerned with how jeans material, when employed as body armor, contributes to the inquiry. The present study also examines how airgun pellets fired at various ranges affect jeans clothing wrapped around gel blocks. Results: The study concluded that when fired at varied ranges, there was no significant variation in the diameters of the entry holes on clothing material. The gel block covered with jeans clothing was not found to be more damaged. Conclusions: The findings also indicate that pellets had larger track lengths regardless of the range from which they were fired. [ABSTRACT FROM AUTHOR]

To date, various designs have been proposed to increase the efficiency of radiative coolers with approaches such as changes in materials and their properties, size and shape of the elements, and structures geometry. In the present work, an attempt has been made to obtain this important issue by presenting an innovative strategy from a new perspective. In this strategy, by keeping the face exposed to solar energy away from the body, heat distribution can be inhibited, which leads to a decrease in body temperature. This act simultaneously provides a higher operating temperature for the emitter section, thereby enhancing the exergy of the system. On the other hand, the presence of the thermal diode allows the surface of the object to continue to radiate its heat. Hence, several experiments were designed and performed to evaluate the performance of the strategy by an experimental apparatus built for this purpose. Initially, the rectification ratio results of constructed rectifier mirrors showed that the light transmission amount in the forward path is nearly 44% higher than in the reverse direction. In the next step, the temperature measurement of the samples showed the sub-ambient temperature for the present work with a difference of 9 and 2 °C, against direct sunlight and the night sky, respectively. This model also has a high-temperature difference of about 13, 11, and 6.5 °C during the day and 1.6, 0.5, and 0.5 °C at night below the other three samples. This superiority was maintained in cloudy weather conditions as well as thermal shock stability. One of the most important applications of radiation coolers is in the aerospace industry. In this particular application, in addition to cooling, it is vital to protect the equipment against thermal shock caused by sudden and extreme temperature differences in space. Due to obtaining results such as efficient cooling rate, and high resistance to thermal shock, this concept provides a practical vision for improving the spacecraft's cooling systems. [ABSTRACT FROM AUTHOR]

A promising direction in barrel ballistics aimed at increasing the muzzle velocity of a projectile is the use of new propellants as an attached charge. This paper presents an experimental and theoretical method for determining the law of propellant combustion in a manometric experiment (in a closed volume). Within the framework of this method, a small number of experiments could be sufficient to determine a change in the law of combustion during the propellant burnout and depending on pressure. This method is demonstrated on the example of processing three experiments with model high-density propellant. The laws of combustion of high-density propellants, obtained in this study, can later be used to calculate the gas-dynamic parameters of a shot from a barrel system or a nozzle bomb (in a semi-closed volume) using these propellants. [ABSTRACT FROM AUTHOR]

In the frame of an experimental setting, the formation of round-shaped compounded glass fragments on the exit site after gunshots through a windshield was examined. For that purpose, a 9 × 19 mm pistol (HK P30) and two different cartridges containing (a) a full metal jacketed round-nosed projectile and (b) a deformation projectile were used. On the basis of 52 gunshots, the morphology, impact angles and terminal ballistics of occurring compounded glass fragments were examined. The results showed that the compounded glass fragments' morphology allowed for the differentiation of two used projectiles. Fragments were able to cause round-shaped defects in a single cotton layer (T-shirt) with subsequent penetration of up to 2.4 cm into ballistic gelatin (10%, 4 °C). As a function of the projectile type, the compounded glass fragments showed different reproducible impact angles that differed notably from the known conical pattern of expelled glass fragments after bullet penetration. These findings might help to explain the atypical morphology of gunshot wounds with laminated glass as an intermediate target and prevent possible misinterpretations when reconstructing the sequence of events. [ABSTRACT FROM AUTHOR]

The high recoil force of a high-power gun produces a strong impact on the carrier, which severely limits the application of the high-power gun mounted on vehicles. A gas-controlled side-jet gun was designed to reduce the recoil force, and the gas-solid transient flow in the bifurcated tube of the gun was studied. First, a one-dimensional two-phase interior ballistics model was established considering the gas-solid coupling between the propellant gas and the valve in the front gas tube. Then, the propagation of the rarefaction wave in the barrel was studied, and the flow field distribution in the bifurcated tube was obtained. Finally, the mechanism of recoil reduction was analyzed. Results show that the bifurcated two-phase flow model can be used to accurately analyze the effect of the gas-controlled side-jet gun's parameters on the projectile velocity and the recoil reduction efficiency. The projectile velocities of the gas-controlled side-jet gun and the traditional gun are 955.7 m/s and 960 m/s, respectively. The projectile velocity loss of the gas-controlled side-jet gun is less than 0.5 %. The recoil momentum of the traditional gun and the gas-controlled side-jet gun are 538.62 N·s and 336.68 N·s, respectively. The recoil momentum of the gas-controlled side-jet gun decreases by 37.49 %. Additionally, the single firing time of the gas-controlled side-jet gun (18.91 ms) is less than that of the traditional single-barrel gun (more than 60 ms). Therefore, the newly designed gas-controlled side-jet gun significantly reduces the recoil momentum without losing the projectile velocity and continuous firing mode. [ABSTRACT FROM AUTHOR]

This paper describes the method and results of an experimental study of unsteady burning rate of high-energy materials containing metal powder additives under depressurization at a rate of 140–160 MPa/s. The method based on stating and solving the inverse problem of internal ballistics is used to determine the unsteady burning rate. The studies are carried out for high-energy materials, including energy additives in the form of metal powders (ASD-4, ASD-6, and Alex aluminum powders), aluminum diboride, and dodecaboride. It is shown by analyzing the this study that the unsteady burning rate of high-energy materials under sharp depressurization is oscillatory and depends on the energy additive type. [ABSTRACT FROM AUTHOR]

Secondary blast injuries may result from high-velocity projectile fragments which ultimately increase medical costs, reduce active work time, and decrease quality of life. The role of skin penetration requires more investigation in energy absorption and surface mechanics for implementation in computational ballistic models. High-speed ballistic penetration studies have not considered penetrating and non-penetrating biomechanical properties of the skin, including radial wave displacement, resultant surface wave speed, or projectile material influence. A helium-pressurized launcher was used to accelerate 3/8″ (9.525 mm) diameter spherical projectiles toward seventeen whole porcine legs from seven pigs (39.53 ± 7.28 kg) at projectile velocities below and above V50. Projectiles included a mix of materials: stainless steel (n = 26), Si3N4 (n = 24), and acetal plastic (n = 24). Tracker video analysis software was used to determine projectile velocity at impact from the perpendicular view and motion of the tissue displacement wave from the in-line view. Average radial wave displacement and surface wave speed were calculated for each projectile material and categorized by penetrating or non-penetrating impacts. Two-sample t-tests determined that non-penetrating projectiles resulted in significantly faster surface wave speeds in porcine skin for stainless steel (p = 0.002), plastic (p = 0.004), and Si3N4 ball bearings (p = 0.014), while ANOVA determined significant differences in radial wave displacement and surface wave speed between projectile materials. Surface wave speed was used to quantify mechanical properties of the skin including elastic modulus, shear modulus, and bulk modulus during ballistic impact, which may be implemented to simulate accurate deformation behavior in computational impact models. [ABSTRACT FROM AUTHOR]

Pepper spray launchers are more precise and wind stable compared to conventional pepper sprays and are commonly used as a self-defensive tool. With the advanced potential, they may also harbour a greater risk for injuries, especially if they are not used within the suggested safety distance. If the shooting distance is below 1.5 m, energy densities may exceed the threshold energy density for the penetration of skin leading to skin laceration. We present a case where a man is hit by the liquid jet of a JPX Jet Protector® with an estimated shooting distance of 0.3 m. The man suffered from a bleeding skin laceration, which had to be sewed in the hospital. This case report furthermore outlines the potentially dangerous effect of pepper spray launchers and thereby their role in forensic investigations. [ABSTRACT FROM AUTHOR]

Gunshot residues (GSRs) play an important role in forensic investigations of gun-related violence. The presence of GSRs has been described to help to identify the bullet entry area, as it was supposed not to be found at exit wounds. This report details the suicidal headshot of an 84-year-old male where unburned tube-like, cuboid and flake-formed powder particles have been found not only at the inside of the muzzle but also circular around the exit wound. With very short-barrelled weapons, it must be expected that part of the propellant charge leaves the barrel unburned behind the bullet. In contrast to that, the barrel length of the used weapon should lead to a complete burn-up of powder particles. The surprisingly large number of unburned powder particles present at the exit wound of the injury gave reason for further investigation to understand the underlying ballistic aspects and outlines the importance of having a close look at incidence scene photos during an investigation. [ABSTRACT FROM AUTHOR]

In the paper we apply asymptotic technique based on the method of stationary phase and obtain the approximate analytical description of thermal motions caused by a source on an isotopic defect of an arbitrary mass in a 1D harmonic crystal. It is well known that localized oscillation is possible in this system in the case of a light defect. We consider the unsteady heat propagation and obtain formulae, which provide continualization (everywhere excepting a neighbourhood of a defect) and asymptotic uncoupling of the thermal motion into the sum of the slow and fast components. The slow motion is related to ballistic heat transport, whereas the fast motion is energy oscillation related to transformation of the kinetic energy into the potential one and in the opposite direction. To obtain the propagating component of the fast and slow motions we estimate the exact solution in the integral form at a moving point of observation. We demonstrate that the propagating parts of the slow and the fast motions are "anti-localized" near the defect. The physical meaning of the anti-localization is a tendency for the unsteady propagating wave-field to avoid a neighbourhood of a defect. The effect of anti-localization increases with the absolute value of the difference between the alternated mass and the mass of a regular particle, and, therefore, more energy concentrates just behind the leading wave-front of the propagating component. The obtained solution is valid in a wide range of a spatial co-ordinate (i.e. a particle number), everywhere excepting a neighbourhood of the leading wave-front. [ABSTRACT FROM AUTHOR]

A crime scene can provide valuable evidence critical to explain reason and modality of the occurred crime, and it can also lead to the arrest of criminals. The type of evidence collected by crime scene investigators or by law enforcement may accordingly effective involved cases. Bullets and cartridge cases examination is of paramount importance in forensic science because they may contain traces of microscopic striations, impressions and markings, which are unique and reproducible as "ballistic fingerprints". The analysis of bullets and cartridge cases is a complicated and challenging process, typically based on optical comparison, leading to the identification of the employed firearm. New methods have recently been proposed for more accurate comparisons, which rely on three-dimensionally reconstructed data. This paper aims at further advancing recent methods by introducing a novel immersive technique for ballistics comparison by means of Virtual Reality. Users can three-dimensionally examine the cartridge cases shapes through intuitive natural gestures, from any vantage viewpoint (including internal iper-magnified views), while having at their disposal sets of visual aids which could not be easily implemented in desktop-based applications. A user study was conducted to assess viability and performance of our solution, which involved fourteen individuals acquainted with the standard procedures used by law enforcement agencies. Results clearly indicated that our approach lead to faster adaptation of users to the UI/UX and more accurate and explainable ballistics examination results. [ABSTRACT FROM AUTHOR]

Weapons and past weapon systems are important research topics in Paleolithic archaeology. Its popularity stems from its relevance for understanding broader technological evolution, subsistence strategies, and human behavior. However, identifying what weapon system was used has proven to be a significant methodological challenge over the last few decades and in spite of what some titles of recent publications suggest, the question is still not resolved. In this paper, we present the results of a ballistic analysis of the four modes of propulsion that are traditionally considered for the Paleolithic period (bow, spear-thrower, hand-cast and thrusting spear). We advocate a stepwise approach to the problem given the multiple variables involved. The goal of this study is to add an essential building block to current understanding by exploring the notion of reactional impact stress (RIS) on the basis of the angle of incidence developed by the different projectiles. Our results show the importance of RIS for accurately understanding the projectile impact phenomenon and the existence of a reproducible and mutually distinct RIS between the four tested weapon systems. These results shed a new light on approaches that have been used previously to examine weapon systems archaeologically, such as those relying on the length of "diagnostic impact fractures". Our results allow the proposition of an alternative approach that appears to hold great potential, in particular for identifying the use of the bow. While a reliable method for recognizing past propulsion modes is not yet established, we conclude that the solution lies within the integration of several fields, more in particular use-wear analysis, fracture mechanics in brittle solids, and ballistics and we progressively move forward in identifying the key building blocks of such a method. [ABSTRACT FROM AUTHOR]

This article describes fine tuning of wear diagnostics of a laboratory smooth barrel with a length of 5 m and diameter of 30 mm during tests. The devices are developed for measurements of internal diameter and force of pulling a piston prototype through the entire barrel length. An analog–digital instrument for measurement of internal diameter allows one to detect and to measure defects of arbitrary deformed barrel. The dimensions of the sensors used in the device allow us to scale it up for measurements of barrel of both lower and higher diameter. The device of force measurements allows us to estimate the friction parameters before experiments to clarify the mathematical model of gas dynamic processes accompanying the shot and to adjust loading conditions, if necessary. It has been demonstrated that their use allows us to estimate wear and to diagnose the state of the barrel system. Significant broadening of bore on the side of the breech end of the barrel has been detected. There is a correlation of measured data from both instruments. A ballistic experiment has been carried out using the updated measuring and recording complex. On the basis of the results the friction parameters of the piston–barrel couple obtained before the experiments have been accounted in the mathematical model of gas dynamic processes. This has allowed us to reduce the number of matching parameters upon simulation and to perform more accurate analysis of gas dynamic processes accompanying a shot with plotting respective time dependences of piston pressure and speed as well as distribution of maximum gas temperatures and pressure along the barrel length. Thus, the coefficient of the law of gunpowder burning has increased by 10%. [ABSTRACT FROM AUTHOR]

Background: In forensic ballistics, the phenomenon of tandem bullets occurs when two or more bullets are ejected from the barrel of a firearm in a single shot. The injuries caused by these bullets have been described in the literature and include several possibilities, whose severity seems to be especially related to the mass increase of the exploded cartridges and to the distance at which the shots are fired, as a result of the sudden drop in kinetic energy that occurs. Case presentation: We report the case of a subject hit by a tandem bullet, during an attempted robbery, describing the injury reported in relation to the ballistic analysis of the case and examining the dynamics in which this circumstance occurred. Conclusions: The ballistic analysis conducted in our case confirmed that the harmful potential of “tandem bullets” is inversely correlated to the mass of the fired bullets. In our case, the exploded shot, consisting of two 38 Special caliber bullets fused together, hit the body of the subject involved with minimal kinetic energy and penetrating potential. We believe that further ballistic studies should be conducted on a cadaveric model by exploiting cadaveric donation programs for scientific research purposes, in order to investigate the wide spectrum of possible injuries that can occur, also simulating the effects of unjacketed tandem bullets. [ABSTRACT FROM AUTHOR]

Ballistic devices that generate radial pressure waves are used for the treatment of different therapeutic indications. In order to assess the effectiveness of these devices and to interpret and transfer the results of clinical trials, it is important to know their acoustic output. In this paper, two ballistic devices and their reproducibility at different clinically relevant settings were investigated in the same in-vitro test setup. Pressure curves were measured in water at different intensity levels and pulse repetition rates. The sound field parameters (peak pressures, positive pulse intensity integral) were calculated from the pressure curves. Additionally, the surface velocity of the applicator was determined in air using a vibrometer. Both devices show a good pulse-to-pulse reproducibility. While the peak maximum pressure and the positive pulse intensity integral decrease only slightly (pmax up to 12%, PII+ up to 18.8%) comparing 1 Hz and 25 Hz for one device, they drop sharply (pmax up to 68.4%, PII+ up to 90.2%) for the other device comparing 1 Hz to 21 Hz. The same effect was observed in the vibrometer measurements. The results show that with increasing pulse repetition rate the stability of the parameters varies between different devices. Hence, all sound field parameters should be compared before transferring settings from one device to another. [ABSTRACT FROM AUTHOR]

Launching large (> 1 g) well-characterized projectiles to velocities beyond 10 km s - 1 is of interest for a number of scientific fields, but is beyond the reach of current hypervelocity launcher technology. This paper reports the development of an explosively driven light-gas gun that has demonstrated the ability to launch 8-mm-diameter 0.36-g magnesium projectiles to 10.4 km s - 1 . The implosion-driven launcher (IDL) uses the linear implosion of a pressurized tube to shock-compress helium gas to a pressure of 5 GPa, which then expands to propel a projectile to hypervelocity. The launch cycle of the IDL is explored with the use of down-bore velocimetry experiments and a quasi-one-dimensional internal ballistics solver. A detailed overview of the design of the 8-mm launcher is presented, with an emphasis on the unique considerations which arise from the explosively driven propellant compression and the resulting extreme pressures and temperatures. The high average driving pressure results in a launcher that is compact, with a total length typically less than a meter. The possibility to scale the design to larger projectile sizes (25 mm diameter) is demonstrated. Finally, concepts for a modified launch cycle which may allow the IDL to reach significantly greater projectile velocities are explored conceptually and with preliminary experiments. [ABSTRACT FROM AUTHOR]

In contrast to cranial gunshot trauma, diagnosis and interpretation of gunshot trauma to long bones remains difficult and controversial. The aim of this study is to review the published literature on fracture patterns resulting from gunshot trauma in human long bones, and to use the described characteristics to provide practical guidance for the forensic anthropologist. In order to achieve this, medical and forensic publications on this topic were reviewed. Several types of fractures, such as linear, oblique, comminuted and butterfly fractures, have been observed in either the shaft or the ends of long bones. Indirect fractures that are not caused by bullets striking bone directly but by bullet-induced forces to the surrounding soft tissue have been found as well. Some of these fractures are related to a specific context or mechanism which might help in the forensic reconstruction of events. It is recommended that future research should focus on available medical data to provide more detailed descriptions on fracture patterns for forensic purposes. Experimentation with bone surrogates and computer modelling might also provide better and more realistic reconstructions of gunshot trauma in the future and provide valuable insights for its diagnosis and interpretation in forensic anthropology. [ABSTRACT FROM AUTHOR]

Ballistic injuries to peripheral nerves are devastating injuries frequently encountered in modern conflicts and civilian trauma centers. Such injuries often produce lifelong morbidity, mainly in the form of function loss and chronic pain. However, their surgical management still poses significant challenges concerning indication, timing, and type of repair, particularly when they are part of high-energy multi-tissue injuries. To help trauma surgeons, this article first presents basic ballistic concepts explaining different types of missile nerve lesions, described using the Sunderland classification, as well as their usual associated injuries. Current controversies regarding their surgical management are then described, including nerve exploration timing and neurolysis's relevance as a treatment option. Finally, based on anecdotal evidence and a literature review, a standardized management strategy for ballistic nerve injuries is proposed. This article emphasizes the importance of early nerve exploration and provides a detailed method for making a diagnosis in both acute and sub-acute periods. Direct suturing with joint flexion is strongly recommended for sciatic nerve defects and any nerve defect of limited size. Conversely, large defects require conventional nerve grafting, and proximal injuries may require nerve transfers, especially at the brachial plexus level. Additionally, combined or early secondary tendon transfers are helpful in certain injuries. Finally, ideal timing for nerve repair is proposed, based on the defect length, associated injuries, and risk of infection, which correlate intimately to the projectile velocity. [ABSTRACT FROM AUTHOR]

Firearm injuries are a preventable epidemic in the USA. Extremities are commonly affected in gunshot injuries. Such injuries may be complex with concomitant osseous, soft tissue, and neurovascular components. The maximum wounding potential of a projectile is determined by its kinetic energy and the proportion of the kinetic energy that is transmitted to the target. Accurate assessment of ballistic injuries is dependent on utilizing the principles of wound ballistics, accurate bullet count, and ballistic trajectory analysis. The goals of this article are to review wound ballistics and the imaging evaluation of extremity civilian firearm injuries in the adult population, with emphasis on ballistic trajectory analysis, specific ballistic fracture patterns, and diffuse, secondary soft tissue ballistic injuries. [ABSTRACT FROM AUTHOR]

Contact shots to the head often leave behind biological traces inside firearm barrels, a phenomenon of great forensic interest. Until now, the visualization and preservation of these traces presented a significant challenge, lacking a reliable method. This study addresses this gap by searching for a suitable method to extract the traces within a casting. Using alginate or gelatine as suitable materials, the results were hampered by serious adhesion issues and their extraction out of the firearm barrel was impeded. Finally, the combination of 11% gelatine with 1% alginate, introduced into the barrel around a ‘central spine’, succeeded to consistently produce replicable castings. Experimental contact shots displayed a distinct staining gradient from the muzzle to the rear of the barrel, as revealed through endoscopy and proved in the macroscopic casting. The technique proved effective for various common handgun barrels and successfully preserved blood and gunshot residue (GSR) patterns within the barrel. This method offers the dual benefits of visually mapping staining patterns and securing localized samples for targeted molecular genetic analysis in forensic investigations. [ABSTRACT FROM AUTHOR]

Rifles are often involved in violent deaths such as homicide and suicide. Consequently, expert knowledge and experimental forensic investigations are important to clarify the nature of ballistic trauma when applied to the human head and neurocranium. This study investigated differences in entrance wound morphology with Synbone® spheres which are described as being comparable to human flat bones. A series of ballistic experiments were conducted using two different rifle calibers (5.56 × 45 mm and 7.62 × 39 mm Full Metal Jacket (FMJ)). Synbone® spheres were used for close-range 0.3 m simulated executions as well as at 25 m and 35 m to simulate urban and military engagements. Results were compared with previously published experimental studies using similar military ammunition. In our study, entry wound morphology closely resembles real forensic cases compared to exit wound and overall shape morphology independently of the distance and the caliber. Circumferential delamination was clearly visible with full metal jacket (FMJ) rounds, yielding similar damage pattern morphology to the human crania. This study documented the presence of hydraulic burst or shock in all ten rounds from all three distances. Krönlein shots were also observed in some cases. Synbone® spheres constitute an acceptable synthetic surrogate for ballistic experiments. The present study offers new initial data on the behavior of Synbone® proxies in ballistic testing of military ammunitions; FMJ gunshot injuries to the human head, for distances that have not previously been published, suggesting that efficient tests can take place under these conditions. Further research on experimental ballistics with a larger number of controlled factors and multiple repetitions is recommended to verify the results of this pilot study before applied in forensic simulations. [ABSTRACT FROM AUTHOR]

Forensic reconstructions and ballistic testing requires the use of consistent and repeatable simulants. Synthetic bone has been developed to be mechanically similar to human bone; however, it does not have the same viscoelastic properties. Bone acts as brittle and stiff material and fails instantly under high-energy events such as ballistic impacts. Consequently, bone simulants for use in ballistic testing should show comparable energy deposition to mammalian bones. This study aims to determine if Synbone® flat plates could be a viable proxy for Sus scrofa (domesticus) ribs in ballistic testing with 7.62 × 51 mm Full Metal Jacket ammunition. 5 mm, 6 mm and 12 mm quartered Synbone® plates were embedded into 10% ballistic gelatin and shot using 7.62 mm ammunition. The models were then analysed to compare the Synbone® to a previous Sus Scrofa (domesticus) rib study and focused on energy deposition, the number of fragments within the block, angle of deviation, onset of yaw, the temporary cavity, and the permanent wound channel. No significant difference was seen between the Sus Scrofa (domesticus) and the 5 mm Sybone®. There were significant differences observed between Sus Scrofa (domesticus) ribs and 6 mm Synbone® for the number of fragments, energy deposition and projectile tract diameter, and significant differences seen between Sus scrofa (domesticus) ribs and 12 mm Synbone® for the depth of onset of yaw, energy deposition and projectile tract diameter. This study indicates that the 5 mm Synbone® plate is a suitable proxy for Sus scrofa (domesticus) ribs for use with 7.62 × 51 mm FMJ ammunition in ballistic testing. [ABSTRACT FROM AUTHOR]

Two-dimensional topological insulators, and in particular quantum Hall states, are characterized by an insulating bulk and a conducting edge. Fractional states may host both downstream (dictated by the magnetic field) and upstream propagating edge modes, which leads to complex transport behavior. Here, we combine two measurement techniques, local noise thermometry and thermal conductance, to study thermal properties of states with counter-propagating edge modes. We find that, while charge equilibration between counter-propagating edge modes is very fast, the equilibration of heat is extremely inefficient, leading to an almost ballistic heat transport over macroscopic distances. Moreover, we observe an emergent quantization of the heat conductance associated with a strong interaction fixed point of the edge modes. Such understanding of the thermal equilibration on edges with counter-propagating modes is a natural route towards extracting the topological order of the exotic 5/2 state. The transport behaviour of counter-propagating edge modes in the hole-conjugate fractional quantum Hall state is not fully understood. Here, by combining local noise thermometry and thermal conductance measurements, the authors show the absence of thermal equilibration on the edge at macroscopic distances. [ABSTRACT FROM AUTHOR]

The past decade has been marked by an explosive growth in the number of missions with the use of small spacecraft weighing only about tens of kilograms, including CubeSats that are currently widely employed in various applications. For a scientific paper, it is no longer feasible to enumerate and properly analyze the accomplished missions as well as those under development and being planned: information changes so quickly that perhaps only websites with inline renovations can keep track of all the changes in this market. Near-Earth missions of CubeSats increasingly become the prerogative of engineers and production managers. Nowadays, even factories are built to mass-produce small spacecraft. However, interplanetary small-spacecraft missions stand apart because the technologies used to develop large spacecraft for interplanetary missions are not fully applicable to small spacecraft. The same is true of the ballistic aspects of such missions. This is primarily due to the low energy capability of small spacecraft for maneuvering and transmitting signals over long distances. The other equally important aspects are their self-sufficiency, navigation support, and radiation resistance in outer space. From the standpoint of the scientific novelty of the problems that spacecraft have to face and the fundamentals of ballistic implementation, it is interplanetary missions that attract attention of researchers. This paper discusses the opportunities for interplanetary transportation of small spacecraft and formulates the problems that need to be solved in the near future. [ABSTRACT FROM AUTHOR]

In shooting crimes, ballistics tests are often recommended in order to reproduce the wound characteristics of the involved persons. For this purpose, several "simulants" can be used. However, despite the efforts in the research of "surrogates" in the field of forensic ballistic, the development of synthetic models needs still to be improved through a validation process based on specific real caseworks. This study has been triggered by the findings observed during the autopsy performed on two victims killed in the same shooting incident, with similar wounding characteristics; namely two retained head shots with ricochet against the interior wall of the skull; both projectiles have been recovered during the autopsies after migration in the brain parenchyma. The thickness of the different tissues and structures along the bullets trajectories as well as the incident angles between the bullets paths and the skull walls have been measured and reproduced during the assemblage of the synthetic head models. Two different types of models ("open shape" and "spherical") have been assembled using leather, polyurethane and gelatine to simulate respectively skin, bone and soft tissues. Six shots have been performed in total. The results of the models have been compared to the findings of post-mortem computed tomography (PMCT) and the autopsy findings.Out of the six shots, two perforated the models and four were retained. When the projectile was retained, the use of both models allowed reproducing the wounds characteristics observed on both victims in terms of penetration and ricochet behaviour. However, the projectiles recovered from the models showed less deformation than the bullets collected during the autopsies. The "open shape" model allowed a better controlling on the shooting parameters than the "spherical" model. Finally, the difference in bullet deformation could be caused by the choice of the bone simulant, which might under-represent either the strength or the density of the human bone. In our opinion, it would be worth to develop a new, more representative material for ballistic which simulates the human bone. [ABSTRACT FROM AUTHOR]

Booming technological advances and turbulent military reforms have promoted the continuous advancement of weapons and equipment. High-power microwave (HPM) weapons have changed the damage modes of traditional guns, missiles and other kinetic energy weapons, as well as having the huge advantage of "changing the rules of the game." The study of exterior ballistics of high-power microwave weapons has theoretical support for the design and development of weapons and the verification of performance indicators and is also an important basis in the firing application of high-power microwave weapons. By studying the coupling mechanism between HPM weapons and targets, an exterior ballistics description of HPM weapons is given According to the description of exterior ballistics, the differences between HPM and traditional weapons in definitions, accuracies, space trajectories, space descriptions and "end points" are summarized, and the exterior ballistics space transmission is established. This study reveals the nine major transmission laws of the exterior ballistics of HPM weapons. The constructed model and related theories of the transmission laws for exterior ballistics lay a theoretical foundation for the in-depth study of key technologies of HPM weapons, such as fire control and damage assessment. [ABSTRACT FROM AUTHOR]

Molecular ballistics combines molecular biological, forensic ballistic, and wound ballistic insights and approaches in the description, collection, objective investigation, and contextualization of the complex patterns of biological evidence that are generated by gunshots at biological targets. Setting out in 2010 with two seminal publications proving the principle that DNA from backspatter collected from inside surfaces of firearms can be retreived and successfully be analyzed, molecular ballistics covered a lot of ground until today. In this review, 10 years later, we begin with a comprehensive description and brief history of the field and lay out its intersections with other forensic disciplines like wound ballistics, forensic molecular biology, blood pattern analysis, and crime scene investigation. In an application guide section, we aim to raise consciousness to backspatter traces and the inside surfaces of firearms as sources of forensic evidence. Covering crime scene practical as well as forensic genetic aspects, we introduce operational requirements and lay out possible procedures, including forensic RNA analysis, when searching for, collecting, analyzing, and contextualizing such trace material. We discuss the intricacies and rationales of ballistic model building, employing different tissue, skin, and bone simulants and the advantages of the "triple-contrast" method in molecular ballistics and give advice on how to stage experimental shootings in molecular ballistic research. Finally, we take a look at future applications and prospects of molecular ballistics. [ABSTRACT FROM AUTHOR]

Current methods used in terminal ballistics to determine the volume of temporary cavities created by projectiles in soft tissue simulants (such as ballistic soap) usually involve silicone-casting to obtain the cavity moulds. However, these methods have important drawbacks including their little sensitivity and precision, besides the fact that they are destructive. Imaging techniques such as computed tomography (CT) might not only overcome those limitations but also offer useful tools for digitally reporting the scientific results. This work accomplished the 3D digital reconstruction of the cavities created by different projectiles in ballistic soap blocks. This way, the total volume of the cavities, the projectile penetration depths, and other measurements were determined, rendering better capabilities when compared to the current silicone method. All these features were achieved through the CT analysis and 3D Slicer imaging software. In addition, it is worth mentioning that the method can preserve the evidence by digitally obtaining, signing, and storing the infographic videos displaying the 3D-reconstructed cavities. [ABSTRACT FROM AUTHOR]

Introduction: Synthetic skin simulants are used both in wound ballistics and forensic investigations and should display similar mechanical properties to human tissue and therefore need to be validated. It is recognised that skin simulants may have a significantly different performance when different backing combinations are used; therefore, it is essential to specify and control the backing material. Roebuck 1518 synthetic chamois (RBK) backed by 20% ballistic gelatin has been validated as a suitable skin simulant; this study looks at validating the RBK simulant when backed by 10% ballistic gelatin. Methods: Two layers of RBK synthetic chamois backed by calibrated 10% ballistic gelatin were placed onto the long face of the block and secured. Steel spheres with various sectional densities were fired using a custom-made gas gun to determine the V50 of the simulants and compared with the predicted V50. Results: The results demonstrate that for a sectional density between 2.1 and 6.6 g/cm2, the skin simulants backed by 10% gelatin are within the 35% error bounds predicted by James' patent equation. All samples had a close fit to the regression line (R2 = 0.9738), and a Spearman rho test indicates that there is a "strong" negative correlation between sectional density and the V50 (Rs =− 0.957, p = 0.00). Conclusions: This validation study confirms that RBK synthetic simulant backed by 10% gelatin is a suitable skin simulant when testing non-deforming projectiles with sectional densities ranging from 2.1 to 6.6 g/cm2. A predictive trend line also indicates that the skin simulant is suitable for non-deforming projectiles with sectional densities ranging from 0.6 to 20 g/cm2 although this needs to be confirmed. [ABSTRACT FROM AUTHOR]

Suppression of the critical temperature in homogeneously disordered superconducting films is a consequence of the disorder-induced enhancement of Coulomb repulsion. We demonstrate that for the majority of thin films studied now this effect cannot be completely explained under the assumption of two-dimensional diffusive nature of electron motion. The main contribution to the suppression of Tc arises from the correction to the electron-electron interaction constant coming from small scales of the order of the Fermi wavelength that leads to the critical temperature shift δTc/Tc0 ∼ − 1/kFl, where kF is the Fermi momentum and l is the mean free path. Thus almost for all superconducting films that follow the fermionic scenario of Tc suppression with decreasing the film thickness, this effect is caused by the proximity to the three-dimensional Anderson localization threshold and is controlled by the parameter kFl rather than the sheet resistance of the film. [ABSTRACT FROM AUTHOR]

Compared to computed tomography (CT), magnetic resonance imaging (MRI) provides superior visualization of the soft tissue. Recently, the first 7 Tesla (7 T) MRI scanner was approved for clinical use, which will facilitate access to these ultra-high-field MRI scanners for noninvasive examinations and scientific studies on decedents. 7 T MRI has the potential to provide a higher signal-to-noise ratio (SNR), a characteristic that can be directly exploited to improve image quality and invest in attempts to increase resolution. Therefore, evaluating the diagnostic potential of 7 T MRI for forensic purposes, such as assessments of fatal gunshot wounds, was deemed essential. In this article, we present radiologic findings obtained for craniocerebral gunshot wounds in three decedents. The decedents were submitted to MRI examinations using a 7 T MRI scanner that has been approved for clinical use and a clinical 3 T MRI scanner for comparison. We focused on detecting tiny injuries beyond the wound tract caused by temporary cavitation, such as microbleeds. Additionally, 7 T T2-weighted MRI highlighted a dark (hypo intense) zone beyond the permanent wound tract, which was attributed to increased amounts of paramagnetic blood components in damaged tissue. Microbleeds were also detected adjacent to the wound tract in the white matter on 7 T MRI. Based on the findings of radiologic assessments, the advantages and disadvantages of postmortem 7 T MRI compared to 3 T MRI are discussed with regard to investigations of craniocerebral gunshot wounds as well as the potential role of 7 T MRI in the future of forensic science. [ABSTRACT FROM AUTHOR]

Gunshots to the human body can cause direct and indirect injuries. Direct injuries are a consequence of the projectile guiding its way through the body, creating a permanent wound channel and thereby damaging the penetrated as well as the adjacent tissue. In addition, the temporary wound cavity is responsible for indirect injuries occurring distant to the actual wound tract. This can potentially affect different types of tissue, like blood vessels, organs, or bones, that are not directly passed through by the projectile. For this case report, we describe a suicidal headshot to the temporal area where the extension of the temporary wound cavity and its subsequent collapse led to massive energy transfer to the surrounding tissue leading to breakage of the upper dental prosthesis and fractures of the lower jaw. Thereby outlining the ballistic mechanisms causing indirect injury pattern that have to be considered when examining gunshot wounds. [ABSTRACT FROM AUTHOR]

In this casuistry, two accidents from Germany and Switzerland are presented that happened during the shot of recoilless anti-tank weapons. In both cases, the injuries led to the death of two soldiers: A 22-year-old soldier in Germany was struck by the counter mass of a so-called Davis gun which had been fired by a comrade during a firing exercise; he died from his severe injuries, especially in the abdominal part of the body. As a peculiarity of the wound morphology, it was found to be a thick-layered, metallic, gray material in the wound cavity, which corresponded to the material of the counter mass that was ejected opposite to the shooting direction. The other case took place in Switzerland, where a 24-year-old soldier was seriously injured during an exercise with portable anti-tank rockets. At the time the shot was fired, he stood behind the launcher and was hit by the propulsion jet of the rocket motor. He died as well from his severe injuries, which were located at the chest done by the gas jet and by the very high pressure. In both cases, two different causes of death were present: massive blunt violence in the first case versus a jet of hot gases of very high speed and temperature in the second case. [ABSTRACT FROM AUTHOR]

A tandem bullet phenomenon is a rare situation in which two bullets travel nose-to-base towards the target. In terminal ballistics, a classic feature of the tandem bullet phenomenon is the presence of a single entrance wound with two or more bullets inside the body. During the autopsy, the phenomenon may result in confusion, especially related to the dynamics of the shooting. The present study reports a case of suicide by tandem bullets to the heart with subsequent bullet embolization into the aorta. A 40-year-old Caucasian woman, with a previous history of suicide, shot herself in the chest with a 0.32 revolver. During the autopsy, a single entrance wound (one centimeter in diameter) was observed in the sternal region. The injury was a close-range shot. Internally, a single wound was detected in the right atrium of the heart. Two 0.32 S&WL lead bullets were found inside the descending abdominal aorta. The bullets fitted each other perfectly in a nose-to-base position. Both bullets were tracked back to a single firearm that belonged to the victim's father using forensic ballistics. The forensic report suggested a suicide. A multidisciplinary approach involving crime scene investigation, forensic pathology and forensic ballistics is necessary to investigate tandem bullet cases. Forensic experts must be aware of this phenomenon and, more importantly, they must be aware of its unusual manifestations, such as embolization, in order to come to optimal conclusions. [ABSTRACT FROM AUTHOR]

In molecular ballistics, where traces originating from the use of firearms against biological targets are investigated, "backspatter" traces are of particular importance. This biological material comprising blood and tissue from the victim is propelled back from the bullet entry site towards the direction of the shooter and can consolidate and persist on the inner and outer surfaces of the firearm, from where it can be collected and analyzed. Thus, a connection between the weapon and the victim can be established solely by molecular biological trace analysis. For the criminalistic investigation of gun-related crimes, the determination of the distance between the weapon and the victim can be of critical importance in reconstructing the circumstances of a crime. In this study, we investigated possible correlations between the shooting distance and the amount of backspatter in/on the used firearm. To this purpose, we employed a previously established skull model and performed shootings in triplicates from various distances up to 50 cm with two types of handguns (pistol and revolver). Backspatter was collected from various sampling locations, and DNA contents were quantified. A post-shooting wound channel evaluation was conducted by optical and radiological evaluation. The obtained DNA yields varied considerably between replicates from the same and from different distances. In contrast, apart from contact shots, no meaningful differences were observable in wound channel evaluations. In summary, no meaningful correlation between backspatter distribution and DNA yields, the shooting distance and the condition of the wound channel could be established. [ABSTRACT FROM AUTHOR]

Knowledge of material behaviour under impact is of key importance to understand ballistic impact events on tissue. Bone—with its complex underlying microstructure—is no exception; the microstructural network in bone is not only crucial to its integrity, but also provides a pathway for energy dispersion upon impact (Piekarski in J Appl Phys 41:215–225, 1970). Synbone®, a Swiss-made polyurethane bone simulant, has been considered as a potential bone analogue, particularly for cranial structures (Smith et al. in Leg Med 17(5):427–435, 2015; Riva et al. in Forensic Sci Int 294: 150–159, 2019). This study focused on long bone models and cylinders available from Synbone®, with the aim of determining their efficacy for use in ballistic testing and recreation. Comparisons were made between porcine bone and multiple Synbone® models regarding projectile energy loss and damaged surface area using high-speed video and high-resolution photography. CT and reverse ballistics techniques were also used as diagnostic tools. A significant correlation was made between real bone and Synbone®'s ballistic cylinders in all aspects of this study; however, it was observed that osteoporotic cylinders and anatomical models differ significantly in their reaction to impact. Consequently, the use of Synbone® as a ballistic target simulant—particularly when legal or practical accuracy is essential—will need to be treated carefully, giving due attention to these limitations. [ABSTRACT FROM AUTHOR]

Molecular ballistics connects the molecular genetic analysis of biological traces with the wounding events and complex forensic traces investigated in terminal ballistics. Backspatter, which originates from a projectile hitting a biological target when blood and/or tissue is propelled back into the direction of the gun, is of particular interest; those traces can consolidate and persist on the outer and inner surfaces of firearms and serve as evidence in criminal investigations. Herein, we are the first to present an anatomically correct head model for molecular ballistic research based on a polyurethane skull replica enclosing tissue-simulating sponge material that is doped with "triple-contrast" mixture (EDTA-blood, acrylic paint, and an x-ray contrast agent). Ten percent ballistic gelatin was used as brain simulant. We conducted contact and intermediate-range shots with a Glock 19 pistol (9 mm Luger), a pump-action shotgun (12/70 slugs), and blank cartridge handguns. Each shot was documented by a high-speed camera at 35,000 fps. Apart from the blank cartridge guns, all gunshots penetrated the skull model and created backspatter, which was recovered from the distal part of the barrels and analyzed. The pistol contact shots and one of three shotgun shots yielded full STR profiles. While the shotgun slugs destroyed the skulls, the remaining models could be used for radiological and optical fracture and wound channel evaluation. Known backspatter mechanisms and their respective timing could be confirmed visually by video analysis. Our complete model setup proved to be well applicable to molecular ballistic research as well as wound channel and fracture pattern investigation. [ABSTRACT FROM AUTHOR]

With no two gunshot wounds (GSW) being the same, novel research into wound ballistics is challenging. It is evident that the majority of previous wound ballistic research has been conducted without the presence of clothing. Whilst the effect of clothing on wound contamination has been explored, there is a paucity of literature examining the effect of clothing on GSW patterns. The aim of this study was to test the effect of Multi-Terrain Pattern (MTP) UK military clothing on GSW patterns within calibrated blocks of 10% by mass gelatine, using two types of ammunition commonly used in recent conflicts—7.62 × 39 mm and 5.45 × 39 mm. In total, 36 blocks were shot, 18 by each projectile type, further divided into 6 with no clothing layers (Cnil), 6 with a single clothing layer (Cmin) and 6 with maximum clothing layers (Cmax) worn on active duty. Blocks were analysed with high-speed video and dissection to capture measurements of damage, and results compared using analysis of variance (ANOVA). Results showed significantly different damage measurements within blocks with Cmax for both ammunition types compared to the other clothing states. This may result in GSWs that require more extensive surgical management, inviting further study. [ABSTRACT FROM AUTHOR]

Of the 48 volcanoes in Mexico listed as potentially active by the National Center for Disaster Prevention (CENAPRED), Ceboruco, located in the western Trans-Mexican Volcanic Belt, is considered among the 5 most hazardous. Its recent eruptive history includes a large magnitude Plinian (VEI 6) eruption ~ 1000 years ago and the historical 1870–1875 vulcanian (VEI 3) eruption, as well as recent fumarolic and seismic activity. Ceboruco is a relatively young (< 400,000 years) stratovolcano characterized by abrupt changes in eruptive behavior. Individual eruptive episodes have great variations in style (effusive andesitic to highly-explosive rhyodacitic) and duration. These factors complicate hazard assessment. Three main eruptive scenarios of different magnitudes (large, intermediate, small) and eruption characteristics (likelihood of occurrence: high, medium, small) have been identified and will be presented as a background to build the volcanic hazard map for Ceboruco volcano (presented in part II of this work). Here, we report on the detailed eruptive history, with emphasis on the volcanic products of each of the eruptions, in order to identify those deposits that can serve as a reference for calibrating the modeling software (Tephra2 and Hazmap for ash fallout, Eject! code for ballistics, Etna Lava Flow Model for lava flows, Titan2D for pyroclastic density currents, and Flo-2D and LaharZ for lahars) that will be used in further steps to simulate different volcanic phenomena and lead to the construction of the hazard map. [ABSTRACT FROM AUTHOR]

In the Renaissance new disciplines had reached scientific dignity thanks to the accuracy of mathematics. Some of these were: architecture, geography, ballistics and optics. In addition to mathematics there is another connection between these scientific fields; that is perspective as the scholar Daniele Barbaro highlighted throughout his career. The aim of this essay is to deal with the link between perspective and other disciplines to make the reader conscious of the importance that this subject assumed at Palladio's time. [ABSTRACT FROM AUTHOR]