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The identification of firearms is of paramount importance for investigating crimes involving firearms, as it establishes the link between a particular firearm and firearm-related elements found at a crime scene, such as projectiles and cartridge cases. This identification relies on the visual comparison of such elements against reference samples from suspect firearms or those existing in databases. Whenever this approach is not possible, the chemical analysis of the gunpowder and gunshot residue can provide additional information that may assist in establishing a link between samples retrieved at a crime scene and those from a suspect or in the identification of the corresponding model and manufacturer of the ammunition used. The most commonly used method for the chemical analysis of gunshot residue is scanning electron microscopy with energy dispersive X-ray, which focuses on the inorganic elements present in ammunition formulation, particularly heavy metals. However, a change in the legal paradigm is pushing changes in these formulations to remove heavy metals due to their potential for environmental contamination and the health hazards they represent. For this reason, the importance of the analysis of organic compounds is leading to the adoption of a different set of analytical methodologies, mostly based on spectroscopy and chromatography. This manuscript reviews the constitution of primer and gunpowder formulations and the analytical methods currently used for detecting, characterising, and identifying their compounds. In addition, this contribution also explores how the information provided by these methodologies can be used in ammunition identification and how it is driving the development of novel applications within forensic ballistics. [ABSTRACT FROM AUTHOR]

An excellent flame suppression effect can be achieved using a novel porous brake. To understand the flame-suppression mechanism of a porous brake, combustion using a muzzle brake is investigated. A set of internal ballistic equations is employed to provide accurate velocity and pressure for a projectile moving to the muzzle. The multispecies transport Navier–Stokes equations, which incorporate complex chemical reactions, are solved by coupling a real gas equation of state, the Soave–Redlich–Kwong model, and a detailed chemical reaction kinetic model. The development of muzzle flow with a chemical reaction is simulated, and the interaction between chemical reactions with the muzzle flow field is numerically calculated to explain the muzzle combustion mechanism with a porous brake. The underlying mechanism is analyzed in detail. The results demonstrate that, first, the gas is fully expanded in the brake, leading to a reduction in pressure and temperature at the muzzle, thereby reducing the initial flame. In addition, the shock wave weakens due to the expansion and separation process, leading to a reduction in the mixture of gas and air, ultimately resulting in a reduction in the intermediate and secondary flames. [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]

In criminal investigations, the Directorate for Investigation and Detective Management – Police investigators are required by Philippine National Police orders to conduct forensic science-based crime scene investigations. In order to ensure that every government employee adheres to the accepted belief that public office is a public trust, it is challenging to assess the work of police detectives performing crime scene investigations using forensic technology. This essential value of forensic science in police investigations is undeniable. This study discusses the scope of police forensic methods in ballistics, photography, and dactyloscopy, specifically in the Province of Antique. These issues regarding the scope of practices in conducting investigations and forensic examinations are expressed via a survey questionnaire and a series of statistical tests. In addition, the report outlines the difficulties experienced by these Philippine National Police investigators. The results of the study found that police investigators had a high level of forensic experience with ballistics and photography. Further, results revealed low level of forensic experience with dactyloscopy.. Therefore, Police investigators, among many solutions, may consider the following to be of great help: 1-attending relevant seminars and trainings involving dactyloscopy, and 2- specifying budget allocation for lacking equipment.

Fluctuations in outer space's temperature would affect the spacecraft's regular operation. This paper aims to study the temperature influences of the aluminum honeycomb buffer in the tether-net launcher. Firstly, a buffer structure was designed to attenuate the pyroshock generated by the pyrotechnic device. Secondly, the mechanical properties of aluminum honeycomb at different temperatures were obtained through quasi-static compression experiments. Then, the internal ballistic responses of the launcher were gained by the closed bomb tests and the equivalent classical interior ballistic model. Finally, the recoil performance of the launcher with aluminum honeycomb buffer at different temperatures was studied. It is revealed that the aluminum honeycomb crushing force gradually decreases with the temperature increases. The peak pressure, burning rate coefficient and velocity increase while the peak time decreases with the temperature increase for the interior ballistics. For the launcher recoil responses, the average launch recoil decreases if the aluminum honeycomb doesn't enter the dense stage. The impact acceleration, projectile velocity and displacement increase as the temperature increase. The paper spotlights the temperature's influence on the recoil characteristics of the aluminum honeycomb buffer, which provides a new idea for buffering technology of pyrotechnic devices in a complex space environment. [ABSTRACT FROM AUTHOR]

In this research, the ballistic behavior of the ceramic-reinforced aluminum matrix composite plates is investigated to provide an optimal design for protecting against 7.62 mm bullet at the speed of 800 m/s experimentally and numerically. The target materials are Al5083 alloy as the metal matrix and alumina ceramic balls as the reinforcement. To simulate a 3D numerical model, ABAQUS FE code has been utilized. After validation the numerical model by experiments, the effect of ceramic ball weight percentage include 15%, 30% and 45% and the target thickness 20, 25 and 30 mm is considered on the ballistic results like the kinetic energy, residual velocity and depth of penetration. Finally, it was found that the specimen with 25 mm thickness and 30% alumina is optimum based on existing ballistic protection criteria. [ABSTRACT FROM AUTHOR]

A methodology is developed based on the coupling of a finite element code with an optimisation module for the design of land vehicle armouring composed of lightweight aluminium alloy and high strength steel plate. Following an experiment/simulation correlation, a numerical model has been built and calibrated considering monolithic plates and then verified considering a bi-metal protection against tungsten carbide projectile mimicking the core of a 7.62x51 AP8 ammunition. In addition, a method is proposed to obtain the vres - vi curve for the full 7.62x51 AP8 bullet from the vres - vi curve obtained from the core only. [ABSTRACT FROM AUTHOR]

The trade e off between protection and weight is a constant consideration when designing a portable protective solution. Greater mobility is a desirable attribute and protection must therefore adapt, prompting a demand for lightweight, simple to construct, low-cost and effective ballistic protection systems. High strength and ductility, wave spreading capability and good energy absorption are key properties for ballistic protection. Four materials, polycarbonate, Kevlar®-epoxy, polyurethane foam, and aluminium alloy, possess these properties and were selected for analysis by numerical simulation. Multilayered configurations were proven to be an optimal solution, by exploiting the advantages of each material without having large penalties of mass and cost. Numerical modelling using ANSYS AUTODYN® is used to simulate monolithic and multi-layered target configurations, to obtain the penetration mitigation performance. The results are analysed to select configurations based on different requirements, such as lowest cost, lowest mass, best performance, and optimal configuration which balanced the three key parameters mentioned. The optimal configuration of Aluminium, Kevlar-Epoxy, Polyurethane, and Polycarbonate has layers with thickness of 7, 3, 38, 2 mm respectively with a total mass of 7.97 kg, total cost of $39.86 and penetration of 29.34% (14.67 mm). Polynomial relationships between performance and mass/cost are also determined. [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]

The presented work discusses performing a V/L (Vulnerability/Lethality) analysis on an armored tank based on an RHA (Rolled Aomogeneous Armour) equivalence. It is shown how the approach works using small examples verified with hand calculations. Other more complex examples include a set of welded plates protecting a HYBRID III 50 Percentile Male ATD (Anthropomorphic Test Device). Considered response parameters are the VAA (Vulnerable Area Assessment) damage maps, expected protection capability plot, and damage area fractions. Furthermore, different V/L analyses of the Russian T-80 tank are displayed. It is illustrated how to apply the concept of explicit finite element models to find the critical RHA equivalent armor thickness at normal impact. It is done with terminal ballistic models for three materials: RHA, Aluminum 5083-H116, and Armox 500T. [ABSTRACT FROM AUTHOR]

Interior ballistics modelling intends to calculate physical quantities by solving equations requiring a set of input like thermodynamical properties linked to propellant or mechanical properties like friction coefficients, linked to the system, that are often difficult to assess experimentally. Using a consequent and high‐quality dataset of thousands of 155 mm modular charge experiments, we investigated how deep and machine learning approaches could build an efficient model for predicting muzzle velocity, pressure, and ignition time. After identifying the main variables influencing the physics and several potentially relevant to the machine learning and deep learning algorithms, a stacking ensemble learning model (SEL) was built. It is composed of eight machine learning algorithms and one deep learning algorithm, all as weak learner, reaching a consensus for predicting experimental outputs through a strong learner. The performance assessment, on a 900 experiments test data set that were not used in training, shows a prediction accuracy of 97 % at 1 % accuracy for muzzle velocity, 93 % at 3 % for pressure and 72 % at 5 ms for ignition time. The prediction ability for muzzle velocity within 2 m/s reaches 73 % that can be considered as sufficient. Furthermore, the SEL model even having zero knowledge about physics can discriminate gun barrel erosion effect at high and low pressure. This approach allows to imagine a way of modelling physical phenomena poorly described by physical equations or requiring unmeasurable figures. [ABSTRACT FROM AUTHOR]

Empirical assessment of cetacean welfare to inform stranding interventions is lacking. Here, potential welfare indicators are described for two stranded pygmy killer whales (Feresa attenuata), along with euthanasia procedures and pathology of potential relevance. The animals were filmed for 3.5 and 1.5 hr, respectively, allowing assessment of 19 indicators, including animal behaviors and human interventions. Eight interventions and 19 animal behaviors were identified; 17 and 11 behaviors were displayed by animal 1 and 2, respectively. Examination of ballistics euthanasia revealed atypical projectile placement and characterized animal behavioral responses, but welfare implications could not be assessed as insensibility was not verified in-field. Pulmonary edema and renal degeneration were documented in both animals; differential etiologies include ischemia-reperfusion, shock, and/or myopathy. Potential relationships among histopathology and welfare indicators are explored to infer affective experiences. For example, simultaneous head-lifting with respiration increased over time which, alongside pulmonary edema, suggests these animals experienced breathlessness. Other likely affective states include fatigue and discomfort; there are insufficient data to estimate the intensity or duration of these experiences or to provide an overall welfare grade/score. Further data are required to validate the proposed welfare indicators and to progress development of holistic approaches to welfare assessment at cetacean strandings. [ABSTRACT FROM AUTHOR]

Featured Application: These research results can be applied in forest fire suppression. This paper focuses on improving fire suppression performance through the use of compressed-air launching technology. A launch dynamics calculation model of a compressed-air launcher is presented, developed using VC++ programming, to simulate the acceleration process of a fire-extinguishing bomb in a barrel. By analyzing the influences of various structural and initial parameters on interior ballistics variations, the effectiveness of the calculation model and program in accurately simulating the launching process is demonstrated. The calculation results indicate that the bore pressure follows a similar trend to that of traditional gunpowder launching. Additionally, it is found that specific structural parameters, such as nozzle diameter and gas cylinder volume, have a direct impact on interior ballistics variations. Notably, the nozzle diameter positively affects the peak pressure, muzzle velocity, gas transfer efficiency, and launch efficiency. To ensure an optimal launch effect and efficiency, the nozzle diameter should be selected to be more than half of the launcher caliber. Similarly, the gas cylinder volume positively influences the peak pressure and muzzle velocity while negatively affecting the gas transfer efficiency and launch efficiency. Furthermore, the initial pressure in the gas cylinder exhibits a positive linear relationship with both the peak pressure and muzzle velocity but a negative linear relationship with the gas transfer efficiency and launch efficiency. The loading position minimally impacts the peak pressure and muzzle velocity but slightly enhances the gas transfer efficiency and launch efficiency. Finally, it is observed that launch angles do not affect the interior ballistic process. The research findings provide valuable theoretical guidance for determining the working parameters of compressed-air accelerated fire-extinguishing bombs. [ABSTRACT FROM AUTHOR]

Evolution of contemporary military conflicts has revealed some shortcomings of existing individual small arms ammunition. The first attempts to undertake research and development works on new weapons and ammunition were made in the USA, however, some projects are also being launched in other countries. This paper presents a short review of the newly developed rounds for perspective small arms systems as well as an attempt to determine a caliber of perspective individual weapon. For this purpose, some preliminary external and terminal ballistic analyses were conducted for various diameter projectiles of the same design.

A letter published in the Journal of Translational Medicine discusses the immune response triggered by radiation therapy (RT). The letter explains that RT can have both immunomodulatory and immunosuppressive effects on the immune system. The authors conducted a study comparing two types of RT, shield RT (SRT) and conformal RT (CRT), and found that CRT was more effective at delaying tumor growth and improving survival due to a stronger CD8+ TIL-mediated immune response. The study also revealed that monocytes played a critical role in activating CD8+ TILs after CRT. The authors emphasize the importance of accurately describing the irradiation technique used in preclinical studies and highlight the need for further research on the immune mechanisms underlying RT efficacy. [Extracted from the article]

A recent study published in the journal Nature has provided new insights into the charge-transfer processes that occur in photocatalytic reactions. The researchers used unique methods involving time-resolved and spatiotemporally resolved measurements to monitor these processes in Cu2O semiconductors. They found that quasi-ballistic inter-facet electron transfer and spatially selective trapping are the predominant processes that facilitate efficient charge separation in photocatalysts. This knowledge could lead to the development of high-performance semiconductors for various applications. The study utilized surface photovoltage microscopy and time-resolved photoemission electron microscopy to observe the charge-transfer processes spatially and temporally. [Extracted from the article]

A recently published modeling approach for the penetration into adobe and previous approaches implicitly criticized are reviewed and discussed. This article contains a note on the paper titled "Ballistic model for the prediction of penetration depth and residual velocity in adobe: A new interpretation of the ballistic resistance of earthen masonry" (DOI: https://doi.org/10.1016/j.dt.2018.07.017). Reply to the Note from Li Piani et al is linked to this article. [ABSTRACT FROM AUTHOR]

The objective of the paper was to compare values of the muzzle brake efficiency coefficient for a rifle with active or inactive automatics systems. Special laboratory stand designed for investigating the recoil process was used. The motion of the rifle was detected by the use of the laser interferometer and the optical camera. The recoil velocity time courses were determined by smoothing and differentiation of experimental position records. The results of the experiments indicated that in the case of an active automatics system two values of the recoil velocity can be used for calculation of the energetic efficiency coefficient: the maximum recoil velocity and the final recoil velocity at the end of the automatics action cycle. The values of the coefficient, calculated using these two values of the recoil velocity, distinctly differ. However, it was shown that their values indicate the same relation between the efficiency of various muzzle brakes. The value of the efficiency coefficient, determined on the basis of the final recoil velocity value, is practically the same as that determined on the basis of the final recoil velocity value for the rifle with an inactive automatics system.

The subject of the analysis involves the trajectories of 7.62 mm Lapua Scenar GB432 projectiles and “Ball” lead core projectiles manufactured by MESKO S.A. (Poland) fired at different initial velocities from 16, 20 and 26 inch long barrels. Calculations in the scope of the external ballistics concerning the characteristics of the trajectories of projectile fired from the analysed weapons were made using the PRODAS 3.5 software by Arrow Tech, using a mathematical model of the solid body movements with six degrees of freedom. During the analyses, the phenomena of the internal and transient ballistics and barrel vibrations were not taken into account. The subject of the study was only the trajectory of a projectile fired with a specific initial velocity corresponding to a barrel of a given length. The impact of wind was assessed by modifying the atmosphere model by adding a side wind blowing at a constant velocity throughout the distance. The results allowed the analysis of the effect of the barrel length and the associated initial velocity of the projectile on the nature of the projectile trajectory, especially the obtained overheight path and projectile range. The impact of the side wind on different types of projectiles was also assessed. When shooting precision rifles, it is better to use rounds with heavy projectiles, optimized for long-distance shooting. Lightweight-projectile rounds can be successfully used in the semi-automatic rifles used for support at the lowest levels, where more manoeuvrability (including barrels with a length not exceeding 20 inches) and higher fire rate is required, and, at the same, where shooting at distances exceeding 500 m is not necessary. Lightweight-projectile rounds can also be successfully used for marksmanship training at distances below 500 m, where the differences between the trajectories of different projectiles are the least.

Abstract 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.

Gracie R Baum,1 Jaxon T Baum,2 Dan Hayward,2 Brendan J MacKay1 1Department of Orthopedic Hand Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, USA; 2School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USACorrespondence: Brendan J MacKay, Department of Orthopedic Hand Surgery, Texas Tech University Health Sciences Center, 808 Joliet Ave Suite 310, Lubbock, TX, 79415, USA, Tel +1 806 743 4600, Email brendan.j.mackay@ttuhsc.eduAbstract: As the epidemic of gunshot injuries and firearm fatalities continues to proliferate in the United States, knowledge regarding gunshot wound (GSW) injury and management is increasingly relevant to health-care providers. Unfortunately, existing guidelines are largely outdated, written in a time that high-velocity weapons and deforming bullets were chiefly restricted to military use. Advances in firearm technology and increased accessibility of military grade firearms to civilians has exacerbated the nature of domestic GSW injury and complicated clinical decision-making, as these weapons are associated with increased tissue damage and often result in retained bullets. Currently, there is a lack of literature addressing recent advances in the field of projectile-related trauma, specifically injuries with retained bullets. This review aims to aggregate the available yet dispersed findings regarding ballistics, GSW etiology, and treatment, particularly for cases involving retained projectiles.Keywords: ballistics, gunshot injuries, retained bullets, orthopedic surgery, trauma

Shear thickening fluid (STF) is a dense colloidal suspension of nanoparticles in a carrier fluid in which the viscosity increases dramatically with a rise in shear rate. Due to the excellent energy absorption and energy dissipation of STF, there is a desire to employ STFs in a variety of impact applications. In this study, a comprehensive review on STFs' applications is presented. First, several common shear thickening mechanisms are discussed in this paper. The applications of different STF impregnated fabric composites and the STF's contributions on improving the impact, ballistic and stab resistance performance have also been presented. Moreover, recent developments of STF's applications, including dampers and shock absorbers, are included in this review. In addition, some novel applications (acoustic structure, STF-TENG and electrospun nonwoven mats) based on STF are summarized, to suggest the challenges of future research and propose some more deterministic research directions, e.g., potential trends for applications of STF. [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]

Different charge structures have different interior ballistic performance. Existing research is based on experimental measurements or the lumped parameter method to obtain limited ballistic characteristics, which indirectly impacts the analysis of the parameters' distribution, requiring a complex modeling solution process. Besides this, the ignition performance of different charge structures needs to be further explored. The disadvantages of previous studies have limited the feasibility of further optimization of the composite charge structure. In this paper, we apply a two-dimensional two-phase flow method based on the Eulerian–Lagrangian model to study the performance of different composite charge structures. First, we establish the mathematical model of different particle types based on interior ballistics, which is directly related to the research foundation of subsequent ballistic performance. Next, we investigate the multi-scale reaction flow of complex charge structures by the two-phase flow method and obtain the distribution of parameters in the chamber. Finally, we conduct a study with different particle charge parameters to explore the sensitivity of ballistic characteristics to structural parameters. The results show that the tubular propellant has good ignition performance in different charge structures, and the ignition consistency can be improved by charging tubular propellant in the center of the chamber. However, more tubular propellants are ineffective at significantly improving ignition performance, and result in a decrease in combustion chamber pressure. These results may be promising for the optimization of various charge structures. [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]

Rare earth-doped zinc oxide (ZnO:RE) systems are attractive for future optoelectronic devices such as phosphors, displays, and LEDs with emission in the visible spectral range, working even in a radiation-intense environment. The technology of these systems is currently under development, opening up new fields of application due to the low-cost production. Ion implantation is a very promising technique to incorporate rare-earth dopants into ZnO. However, the ballistic nature of this process makes the use of annealing essential. The selection of implantation parameters, as well as post-implantation annealing, turns out to be non-trivial because they determine the luminous efficiency of the ZnO:RE system. This paper presents a comprehensive study of the optimal implantation and annealing conditions, ensuring the most efficient luminescence of RE3+ ions in the ZnO matrix. Deep and shallow implantations, implantations performed at high and room temperature with various fluencies, as well as a range of post-RT implantation annealing processes are tested: rapid thermal annealing (minute duration) under different temperatures, times, and atmospheres (O2, N2, and Ar), flash lamp annealing (millisecond duration) and pulse plasma annealing (microsecond duration). It is shown that the highest luminescence efficiency of RE3+ is obtained for the shallow implantation at RT with the optimal fluence of 1.0 × 1015 RE ions/cm2 followed by a 10 min annealing in oxygen at 800 °C, and the light emission from such a ZnO:RE system is so bright that can be observed with the naked eye. [ABSTRACT FROM AUTHOR]

In this research, the numerical analysis is conducted to study the aerodynamic characteristics of the rocket target RT-400M with two motors arranged in parallel configuration with different nose cone shapes and performed ballistics analysis on drag values obtained from the finalised nose shape. Two RM 12K motors are used to increase range. This method reduces the R&D cost required to develop the new rocket motor with extended thrust. Reynolds averaged Navier-Strokes equation with k-ω SST model is adapted for the analysis. A parabolic nose shape produces the least values of drag, drag coefficient, and required velocities. A rocket target with a parabolic nose produces a maximum cd value of 0.29 and is used for the external ballistic calculation. Thrust values of the two motors are obtained from the experimental study. This rocket configuration reaches a maximum of 7800 m distance and a maximum of 3750 m in altitude. [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]

The paper presents the operating principle of the Man-Portable Counter Miniature Unmanned Aerial Vehicles System (MPC-MUAVS), with particular reference to the development of its firing solution settings and the methodology and structure of development of the firing tables implemented in the ballistic calculator of the MPC-MUAVS. This ballistic calculator has been applied in the MPC-MUAVS targeting sight assembly, while the entire MPC-MUAVS is intended to counter UAVs within 50 m of the MPC-MUAVS operator. The MPC-MUAVS is being developed under project DOB-1P/02/18/2016, funded by the Polish National Centre for Research and Development.

Superior ballistic performance and the lightweight character of Ti alloys are considered as main reasons for their use in armour applications against a broad spectrum of ballistic threats, e.g. bullet, fragment or blast impact. Because dynamic loading caused by typical penetrators is characterized by high strain rates, only specific test methods allow a closer investigation of the respective material behaviour. In the present study, quasi-static and dynamic compression tests as well as ballistic tests were conducted on a twophase α+β alloy Ti-6Al-4V (in m%) manufactured by hot-rolling. Post-deformation heat treatments, influencing microstructure and mechanical properties were applied in order to compare three different microstructural configurations: as-rolled, mill-annealed and bimodal. While, on the one hand, ballistic tests were employed for the determination of the ballistic limit velocity v50, compression tests, on the other hand, delivered essential input parameters for the application of the Johnson-Cook constitutive model in a finite element simulation of the impact event. The comparison of experimental results to simulation results was supplemented by means of microstructural characterization of tested samples with the focus set on the prevalently observed deformation and damage mechanisms, as for example adiabatic shearing. [ABSTRACT FROM AUTHOR]

Hybrid composite materials combine different fibers in preform and take advantages of different mechanical behaviors for improving ballistic impact damage tolerances. Here we report ballistic impact damages of plain-woven laminates with different hybrids and stacking sequences. Three kinds of hybrid laminates, i.e., carbon/Kevlar, carbon/ultra-high molecular weight polyethylene (UHMWPE), and UHMWPE/Kevlar, had been prepared and tested in ballistic penetration with fragment simulating projectiles (FSP). The residual velocities of the projectiles and impact damage morphologies of the laminates have been obtained to show impact energy absorptions for the different hybrid schemes. A microstructural model of the hybrid laminates had also been established to show impact damage mechanisms with finite element analysis (FEA). We found that the UHMWPE/Kevlar hybrid laminates with Kevlar layers as the front face have the highest energy absorption capacity, followed by the carbon/Kevlar hybrid laminates with carbon layers as the front face. The main damage modes are fiber breakages, matrix crack and interlayer delamination. The ballistic damage evolutions from the FEA results show that the major damage is shear failure for front layers, while tension failure for the back layers. We expect that the ballistic impact performance could be improved from the different hybrid schemes. [ABSTRACT FROM AUTHOR]

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The Novalis Tx Linear Accelerator is among the machines dedicated to radiosurgery that allow stereotactic radiotherapy based on Dynamic Conformal Arc Therapy (DCAT) or Volumetric Modulated Arc Treatment (VMAT), which are the conventional methods for treating brain metastases. Nevertheless, VMAT may reduce early or late complication probability by providing highly conformal dose distributions, increasing target volume coverage, and sparing normal tissues. A further enhancement of the conformation and dose gradient may be one of the possible benefits of the addition of non-coplanar arcs. The purpose of this article is to compare and analyse VMAT, DCAT, and VMAT with Non-Coplanar Arcs (NcVMAT). DCAT, CoVMAT, and NcVMAT modalities were created for 15 patients. Target conformal dose, target coverage, and normal brain tissue dose were evaluated among the three modalities. The NcVMAT modality greatly outperformed the others in terms of both conformal indices (RTOG-CI and IP-CI) and the dose gradient index. Dose comparisons to normal brain tissue revealed that the doses received by the healthy brain were significantly lower in the NcVMAT plans. The MUs of the DCAT and NcVMAT plans were larger than those of the CoVMAT plans. The NcVMAT modality dramatically increases the target conformal dose and gives a lower dose to normal brain tissue compared to the CoVMAT and DCAT modalities. [ABSTRACT FROM AUTHOR]

Traumatic injuries from civilian gunshot injuries represent a significant clinical burden to orthopaedic surgeons worldwide. Furthermore, the incidence of such injuries is increasing. Having a sound understanding of the pathophysiology associated with gunshot injuries and the appropriate management algorithm is vital. This chapter aims to review the current evidence regarding the incidence and prevalence of civilian ballistic trauma, the pathophysiological processes associated with these injuries, and the recommended management from emergent care at the time of injury to definitive surgery and rehabilitation. [ABSTRACT FROM AUTHOR]

Sequential analysis concerns statistical evaluation in which the number, pattern, or composition of the data is not determined at the start of the investigation, but instead depends on the information acquired during the investigation. Although sequential analysis originated in ballistics testing for the Department of Defense (DoD)and it is widely used in other disciplines, it is underutilized in the DoD. Expanding the use of sequential analysis may save money and reduce test time. In this paper, we introduce sequential analysis, describe its current and potential uses in operational test and evaluation (OT&E), and present a method for applying it to the test and evaluation of defense systems. We evaluate the proposed method by performing simulation studies and applying the method to a case study. Additionally, we discuss challenges to address for sequential analysis in OT&E. Lastly, while operational testing is the focus in this paper, the methodology presented is applicable to campaigns of experimentation and general testing across numerous disciplines. [ABSTRACT FROM AUTHOR]

This article deals with Ballistic interpretation of gunshot traces by presenting the main theoretical and practical aspects, which are related to forensic ballistics, firearms, traces left by them and some elements of forensic tactics and technique. [ABSTRACT FROM AUTHOR]

This manuscript deals with life saving aspects of the pilot for escape aid explosive (EAX) system applications under emergency situation. During the ejection from the aircraft, the pilot is subjected to the various forces such as linear, angular and transverse accelerations, decelerations, wind drag accelerations, wind blast, dynamic forces, aerodynamic forces, spinning and tumbling. Linear accelerations (decelerations) of major interest in aviation are those of a high magnitude and a short duration that occur in emergency ejection from the aircraft or occasionally in a high altitude at high-speed parachute opening, as they tend to exceed the strength limitations of the skeletal structure of the pilot body. The human body is a heterogeneous mass that is made up of solid, liquid and visco elastic components. The effects of these forces on the pilot's body are crucial in nature and significant pertains to an injury. This article is described with some considerations of ballistics, kinematics with different forces and their effects on the pilot body for aircraft applications during an entire flight trajectory. In conclusion, this kind of study is very essential considering the pilots safety and its performance at low and high altitudes during an emergency. [ABSTRACT FROM AUTHOR]

To improve the tactical and technical performance of pulse correction projectiles while maintaining stability in uncertain conditions and considering practical engineering constraints, this study performs a multi-objective robust optimization design of the aerodynamic shape and external ballistics of a projectile. The study utilizes an aerodynamic force engineering algorithm and numerical trajectory calculations to obtain the projectile's performance responses within the Latin hypercube design space. To enhance optimization efficiency, a stochastic Kriging surrogate model is established to capture the inherent uncertainty of limited input data. Ultimately, a Pareto optimal solution for the projectile is obtained using a non-dominated sorting multi-objective sparrow search algorithm. The results of this study demonstrate that the consideration of design uncertainty in the robust optimization of pulse correction projectiles leads to significant enhancements in both lateral correction ability and range while satisfying flight stability requirements. Moreover, when compared to deterministic optimization, the performance variability of the design is markedly improved. This research methodology provides valuable insights for optimizing the performance of pulse correction projectiles. [ABSTRACT FROM AUTHOR]