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Artillery designers are always searching for means of improving a gun's external and internal ballistic properties and this resulted in both new theories surrounding gun construction based on the properties of materials and new methods of building guns capable of firing heavier projectiles to greater ranges. The concept of the accelerator gun sought to achieve the same result without the need for larger and heavier guns and reducing recoil through the use of multiple propellant charges fired sequentially, thus accelerating the projectile without the need for a single high-pressure discharge. It was a quest initiated in France, pursued in the United States and then adopted by a desperate Germany during the latter years of World War 2. [ABSTRACT FROM AUTHOR]

This article proposes an interior ballistic interval optimization method with the consideration of parameter uncertainty. Interior ballistic parameters such as charge mass, web thickness, powder aperture and chamber volume are considered as design variables and described by interval number. A one-dimensional two-phase interior ballistic model is constructed, and the MacCormack scheme is used to calculate the interior ballistic parameters. A Chebyshev surrogate model is constructed to replace the one-dimensional two-phase interior ballistic model and applied to the optimization process. For each set of design variables, affine arithmetic is introduced to calculate the interval bounds of the performance index of the interior ballistic, avoiding nested double-loop optimization and improving computational efficiency. The Pareto-optimal solution is searched for by an improved non-dominant sorting genetic algorithm. An example is given to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Few firearms have attracted as much attention, curiosity, and mythical attributes as the blunderbuss. Indeed, it often seems that fiction has overwhelmed the facts. To add to the mystery, the literature is conflicting with regard to defining exactly what a blunderbuss is, what it was used for, and how it performed. What is the difference between a blunderbuss and a musketoon? Is the blunderbuss really designed as a weapon of defence using whatever ammunition one might find in the garden? What was the real purpose of the flared bell mouth of the blunderbuss? Despite the extraordinary interest, the many extant examples of blunderbusses found in public and private collections, and the numerous related publications over centuries, it appears that virtually no properly controlled scientific studies have been carried out to address blunderbuss ballistics. Unfortunately, it was not possible for the author to carry out the carefully designed comprehensive experiments required for such a study. Thus, this article is a modest attempt to combine what information is available from some published blunderbuss 'tests', together with the results from more scientific forensic studies of the performance of sawn-off shotguns, and the addition some ballistic science and suggested scaling laws, to improve our understanding of blunderbuss ballistics. [ABSTRACT FROM AUTHOR]

This project looks at the intersection between gunshot damage to road signs and the use of geographic information systems (GIS) for forensic intelligence. The project has surveyed several distinct regions in Victoria Australia (residential, semi-rural and rural) in order to establish the level and distribution of gunshot damage to signs. The study assesses the correlation between population densities, land use and road type and the types of gunshot damage associated with road signs. The study includes a temporal aspect with the aid of backdated GIS image data and assessment is made on the potential benefits for crime scene information gathering. Further, a software tool has been established that enables photographic analysis of the gunshot impact points to be used to help determine the scale of damage associated with the signs in order to help establish the types of weapons used. This information is presented in the context of the typical registered guns in the community to correlate the key types of weapons used in this type of activity. [ABSTRACT FROM AUTHOR]

A one-dimensional model is introduced in this paper for problems of internal ballistics involving solid propellant combustion. First, the work presents the physical approach and equations adopted. Closure relationships accounting for the physical phenomena taking place during combustion (interfacial friction, interfacial heat transfer, combustion) are deeply discussed. Secondly, the numerical method proposed is presented. Finally, numerical results provided by this code (UXGun) are compared with results of experimental tests and with the outcome from a well-known zero-dimensional code. The model provides successful results in firing tests of artillery guns, predicting with good accuracy the maximum pressure in the chamber and muzzle velocity what highlights its capabilities as prediction/design tool for internal ballistics. [ABSTRACT FROM AUTHOR]

This study employs a structural contingency theory framework to assess the influence of the formal organizational structure of crime laboratories and their environments, on the productivity of labs’ ballistics imaging systems. We contribute to the nascent evolution of organizational focus in forensics while exploring different ways in which overall lab performance can be conceptualized. We analyze data provided by the Bureau of Alcohol, Tobacco, Firearms and Explosives’ (ATF) National Integrated Ballistics Information Network (NIBIN), and data from the Bureau of Justice Statistics, Census of Publicly Funded Forensic Crime Laboratories, 2009. Three Negative Binomial models regressed the organizational and environmental variables on the productivity of crime labs, operationalized as their ability to produce bullet, brass, and total hits. Results indicate that in addition to the number of bullet and brass inputs, local labs are more productive in identifying ballistics imaging hits. Additionally, larger labs with a greater proportion of firearms requests and the ability to process those requests produce more hits. Although the current research did not find that organizational structure significantly predicted labs’ productivity, the importance of the population of bullet and brass inputs was clearly evident. Additionally, jurisdiction plays a vital role in the production of hits. [ABSTRACT FROM AUTHOR]

The solid fuel ramjet is one of the simplest air-breathing engines, characterized by increased specific impulse. This study focuses on a parametric investigation of the internal ballistics of a boron-containing solid fuel ramjet. A 2-D axisymmetric model of a ramjet combustor flying at Mach 2.5 was developed and solved numerically utilizing a commercial computational fluid dynamics code modified to address the specific issues of the problem. The simulation results were compared to the theoretical performance calculated by the chemical equilibrium code. The solid fuel regression rate was found to depend on the port diameter and thus decreases with time. Thrust regulation of ramjet engine was demonstrated using bypass air. The specific impulse was found to decrease with boron content, probably because of low combustion efficiency caused by either insufficient oxygen supply or short residence time of the boron particles. [ABSTRACT FROM AUTHOR]

A novel interior ballistic model was established by revising actual combustion characteristics describing the relationship between burned propellants (ψ) and pressure impulse (It). The discrepancy between theory and experiment for gas releasing of porous propellant was investigated. Furthermore, the model was tested for multiperforated propellants, with relative errors less than 1 and 3% for the maximum pressure and velocity, respectively, indicating that this is a good model to estimate the interior ballistics performance for multiperforated propellants. [ABSTRACT FROM AUTHOR]

Ballistics is an area of flight, and fewer subjects were of greater importance to nation states in the eighteenth century. William Mountaine who published on the topic in 1747 and 1781, wrote: 'It is not possible in the nature of things for any one kingdom to continue long in a state of peace and tranquility', and 'the art of gunnery has from time to time engaged the attention of the most eminent mathematicians'. This paper describes the slow up-take of ideas, first put forward explicitly by Benjamin Robins in 1742, which challenged the belief that air resistance could be neglected in the flight of cannon balls, and asks why it could be, that for a topic so pressing, a clearly wrong mathematical theory was upheld for so long. While considering a number of factors, it argues the attraction of beautiful and simple geometry can be beguiling. [ABSTRACT FROM AUTHOR]

Keywords: Olympic archery; shaft; recurve bow; ballistics EN Olympic archery shaft recurve bow ballistics S526 S528 3 01/29/21 20191002 NES 191002 1. When the archer reaches full draw, potential elastic energy (Graph HT ht ) is stored in the bow limbs. [Extracted from the article]

A set of non-linear optimisation algorithms are combined with a finite element simulation code to analyse the energy absorption and elastic stress wave propagation problem in multilayer/multimaterial armour systems under ballistic impacts. An Abaqus Python script is used to simulate the ballistic event and to generate the variables and post-processing outputs necessary for the integration with the optimisation algorithms. A number of modelling strategies are considered and three optimisation algorithms are used: Particle Swarm Optimisation (PSO), Genetic Algorithm (GA) and Simulated Annealing (SA). The performance and efficiency of each algorithm are assessed through four benchmark tests with different levels of complexity. A multi-objective optimisation procedure is proposed that uses the most efficient algorithm based on every single-objective formulation, variables and constraints from the benchmark tests, resulting in a highly non-linear problem. The proposed optimisation methods successfully achieve the study purposes both in the simulation of generic ballistic impacts and in the quality of the optimised solutions, demonstrating the potential for this type of optimisation method on terminal ballistic applications, serving as a standpoint for further studies into higher energy impacts and material non-linearities. [ABSTRACT FROM AUTHOR]

In this study, the ballistic resistance of SiC (silicon carbide) and a SiC mixture S80B20 (80% SiC/20% B4C) backed with UHMWPE (ultra-high-molecular-weight-polyethylene) fiber board was investigated by striking it with a.30-06 armor piercing projectile. The front plate of the high hardness ceramics is intended to passivate the bullet and limit the bullet's impact kinetic energy, and the high strength backing plate undergoes plastic deformation, absorbing the bullet's residual energy. Ballistic tests revealed that an 8 mm thick S80B20 ceramics produced at a sintering temperature of 2120° or 2140°C, combined with a composite plate, can successfully resist.30-06 armorpiercing rounds with energy greater than 3900 J. The optimal SiC plate meeting the NIJ 0101.06 Level IV was an 8 mm thick SiC sheet backed with 9 mm of fiber board (total thickness, 17 mm; areal density, 33.217 g/m2). The 8 mm thick 80% SiC/20% B4C plate sintered at 2120°C, backed with 7 mm fiber board, had an areal density of only 29.615 kg/m2. If the depth of penetration is less than 44 mm, the fiber board thickness must be increased from 7 to 8 mm, increasing the areal density to 30.552 kg/m2. Compared with the SiC ballistic plate, the density of the composite is 2.665 kg/m2 lower. [ABSTRACT FROM AUTHOR]

In previous work, a time-stepped numerical algorithm to compute particle trajectories consisting of lunar soil blown by the engine exhaust of a lunar lander was developed. The time-stepped integration method relies on the gas density, velocity, and temperature fields, calculated by computational fluid dynamics simulations, to compute the forces and accelerations acting on single noninteracting particles. In this paper, a computationally efficient particle ballistics model is presented where the trajectory is estimated by computing the vertical position (axial coordinate x) as a function of the horizontal position (radial coordinate y) using a constant horizontal velocity and a vertical acceleration approximated as a power-law. The unknown parameters of the model are determined by fitting the ballistics trajectory path to a matrix of trajectories generated by the time-step integration method using the rocket exhaust gas properties predicted by computational fluid dynamics software. Also in previous work, a strictly empirical trajectory model was developed to satisfy the need for a computationally efficient method of computing particle trajectories. This new model (like the previous model) is expressed as a time-independent trajectory path function. However, the method of this current work is based on physical laws of motion, unlike the previous empirical model. [ABSTRACT FROM AUTHOR]

A nonlinear stochastic programming method is proposed in this article to deal with the uncertain optimization problems of overall ballistics. First, a general overall ballistic dynamics model is achieved based on classical interior ballistics, projectile initial disturbance calculation model, exterior ballistics and firing dispersion calculation model. Secondly, the random characteristics of uncertainties are simulated using a hybrid probabilistic and interval model. Then, a nonlinear stochastic programming method is put forward by integrating a back-propagation neural network with the Monte Carlo method. Thus, the uncertain optimization problem is transformed into a deterministic multi-objective optimization problem by employing the mean value, the standard deviation, the probability and the expected loss function, and then the sorting and optimizing of design vectors are realized by the non-dominated sorting genetic algorithm-II. Finally, two numerical examples in practical engineering are presented to demonstrate the effectiveness and robustness of the proposed method. [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]

We use a case study approach to explore the facilitators and impediments to effectively using forensics ballistics imaging technology to improve police investigations in a developing country. The study site, Trinidad and Tobago, a nation located in the Caribbean basin, was experiencing a homicide epidemic during the time of this study. The homicide epidemic involved the repeated use of a limited number of firearms, conditions that are ideal for ballistics imaging technology. This nation also possessed a professionalized forensic crime lab and advanced ballistic imaging technology. The analysis reveals that the effective use of ballistics imaging was impeded by inefficient processes and backlogs at the national crime lab, time delays in identifying ballistics hits, and an inefficient system of transmitting hit reports to police investigators. In sum, organizational arrangements in the forensic crime lab and police in the focal country blunted the effectiveness of a proven forensic technology. [ABSTRACT FROM PUBLISHER]

Focuses on the theory of Evangelista Torricelli on ballistics. Invention of Torricelli on measuring instruments; Contributions of Torricelli on astronomy; Views of Torricelli on the application of mathematics in physics.

Forensic science plays a critical role in the United States criminal legal system. For decades, many featurebased fields of forensic science, such as firearm and toolmark identification, developed outside the scientific community’s purview. The results of these studies are widely relied on by judges nationwide. However, this reliance is misplaced. Black-box studies to date suffer from inappropriate sampling methods and high rates of missingness. Current black-box studies ignore both problems in arriving at the error rate estimates presented to courts. We explore the impact of each type of limitation using available data from blackbox studies and court materials. We show that black-box studies rely on unrepresentative samples of examiners. Using a case study of a popular ballistics study, we find evidence that these nonrepresentative samples may commit fewer errors than the wider population from which they came. We also find evidence that the missingness in black-box studies is non-ignorable. Using data from a recent latent print study, we show that ignoring this missingness likely results in systematic underestimates of error rates. Finally, we offer concrete steps to overcome these limitations. Supplementary materials for this article are available online. [ABSTRACT FROM AUTHOR]

This paper investigates the firing of seventeenth Century musket balls. Prior to this research, the main concerns with making range predictions were associated with the deformed shape of the musket balls affecting their drag coefficient and therefore their distance to ground impact. However, the distance due to bounce and roll after initial impact has been unknown. In this work, the distance travelled after the first ground impact greatly exceeded expectations, with the musket balls approximately doubling the distance to their final resting positions. From these findings the initial factors thought to have had high relevance to the final resting position of the musket ball (velocity variation and drag co-efficient) become less significant and factors such as ground hardness become more prominent. The knowledge gained during this investigation will allow more accurate information to be obtained on the firing positions of opposing forces during conflicts in the English Civil War. [ABSTRACT FROM AUTHOR]

Vocational knowledge originates from both research and from practice, each of which is transformed across several epistemic levels to become vocational knowledge. The several transformations of research to vocational knowledge have been described by Young and Bernstein as recontextualisations. Less well described are the successive transformations of practice to become vocational knowledge. This paper observes that practical knowledge has to be transformed across several epistemic levels to become vocational knowledge. It examines different types of literature on European artillery in the early modern period: scholarly books on ballistics which were printed in Latin, gunners' manuals which were manuscripts in the vernacular, and artillery books for non specialist readers which were printed in the vernacular. It finds that practical knowledge didn't have to be transformed just to apply it to a new context. Knowledge is transformed to a different epistemic level when it is expressed for use by a different type of actor for a qualitatively different purpose from the initial use. The paper concludes by arguing that vocational colleges and institutes have a potentially valuable role in developing vocational knowledge from practice. [ABSTRACT FROM AUTHOR]

The application of series dual burning rate grain can improve specific impulse of nozzleless solid rocket motor (NSRM). In this paper, burning-rate ratio is the ratio of main propellant burning rate and nozzle propellant burning rate in dual burning rate grain, which has significant influence on NSRM performance. Focusing on relationship between burning-rate ratio and motor performance, internal ballistics simulation of NSRM with different burning-rate ratios has been carried out. Results show that, with the increase of burning-rate ratio, total impulse grows monotonically, while maximum head pressure has two variation stages – the stable stage and the increasing stage. By analyzing the head pressure curves, it is known that maximum head pressure is almost equal to the higher one of initial stage head pressure (p1) and combustion ending stage head pressure (p2). Relationship between p2/p1 and burning-rate ratio has been established by linear fitting, and the critical burning-rate ratio, which is the maximum burning-rate ratio to ensure that maximum head pressure almost is kept invariant, has been obtained. Critical burning-rate ratio has no significant change when geometry size remains invariant. Utilizing critical burning-rate ratio in NSRM with series dual burning rate grain, specific impulse can be enhanced with nearly no sacrifice of maximum head pressure performance. These results can provide references for NSRM designing and optimizing. [ABSTRACT FROM AUTHOR]

This paper examines the complex and evolving relationship between science and the military in the development of listening technologies by British, French and German combatants during the First World War to combat increasingly effective ballistics and artillery on the Western Front. Land-based combat changed from the visual to the aural with an increasing selection of audio-based surveillance technologies being made available, notably sound-ranging, in part to combat the physical limitations of the human ear in the battlefield space. The article concludes by analyzing how post-war physics responded to these developments in sound-based battlefield technologies. [ABSTRACT FROM PUBLISHER]

Effective structural design to resist ballistic effects such as small arms or fragmenting weapons has been a goal since weapons were developed. Approaches currently in use for ballistic design are predominantly deterministic and allow designers to decide what wall thickness should be used to stop a prescribed projectile impacting at a predefined velocity. The research presented in this paper provides a framework for conducting reliability analysis of structures subjected to bullet and fragment demands. Thus, pseudo-fragility curves are developed for the limit states related to spall and perforation of wall panels, residual velocities of bullets and fragments, and injury to personnel. The pseudo-fragility analysis provides engineers and owners with a tool to quickly assess the reliability of a wall system subjected to high velocity, low mass projectiles. In particular, the proposed analysis method allows designers and owners to determine the probability of spall and perforation, residual velocity, and injury as a function of wall thickness or threat standoff distance. Abbreviations:Cumulative distribution function (CDF): Gives the probability that a stochastic variable ‘X’, with a proper probability density function, is equal to or less than a value (x). Coefficient of variation (COV): The quotient of the standard deviation and the mean [ABSTRACT FROM PUBLISHER]

Fit-for-purpose operational equipment for women undertaking law enforcement has generated significant discussion and research internationally over several years. This research addresses the need to ensure optimum safety and fit for women who require ballistic vests as part of their policing roles. It examined whether bras can improve the performance of unisex ballistic vests for women of all bust sizes. A survey of 273 female Victoria Police officers was conducted. The results showed that unisex ballistic vests are not suitable for women with larger breasts when combined with commercial sports bras. Conversely, women with smaller breasts experienced limited issues. Although wire-free bras are recommended for use with ballistic vests, officers with larger breasts reported that they preferred to wear underwire bras. Women with larger breasts experienced more problems with unisex ballistic vests than women with small breasts. Sports bras are not designed to be worn under body armour for prolonged periods. [ABSTRACT FROM AUTHOR]

While the use of ballistics data and principles to clarify historical experience of firearms is to be encouraged, their application is not always straightforward. This paper emphasizes the need for care. An example is given of too sanguine reliance on period studies, specifically of muzzle velocity, and of inadequate appreciation of the physics, in particular of the Magnus force. [ABSTRACT FROM PUBLISHER]

A chronological synopsis of the history of the technology used in experimental and testing work relating to artillery pieces is presented. The period covered is from the mid-seventeenth century up to the Cold War era of the mid-twentieth century. Although the focus is on the development of ballistics measurement in Britain, there are important links to related work in continental Europe. The locus for much of what is described is the Royal Artillery proof and experimental range at Shoeburyness and the key individuals and groups of men and women who worked there. There are longitudinal connections between the very earliest technologies of mechanical chronometry, with paper screens and paper-based calculations, and the later technology where timings, screens and calculations had all become electronic. [ABSTRACT FROM AUTHOR]

This article presents a new method of metaheuristic optimization, the algorithm of the innovative gunner (AIG), inspired by the choice of artillery parameters that sends a shot precisely to a target. The applied correction of the cannon's setting parameters differs from that defined by classic artillery theory. The innovativeness of the AIG results from the fact that at each step of the iterative process, the previous solution is corrected by means of specially selected multiplication factors. This is a major difference from most methods in which, at each successive step, a corrective element is added to the previous solution. The AIG is characterized by high efficiency and speed in solving various optimization problems having nothing to do with ballistics. It is extremely simple in description and implementation. The algorithm was tested on several known test-optimization tasks. The results are noticeably better than those achieved by other methods and prove the practical usefulness of the AIG. [ABSTRACT FROM AUTHOR]

Automated ballistics imaging and analysis systems, such as the integrated ballistic identification system (IBIS), have advanced gun law enforcement operations by allowing images of gun crime evidence to be rapidly compared to a large inventory of evidence collected from other crime scenes. After firearm examiners confirm candidate matches, detectives can use the information generated by the links among gun crimes to help solve their cases. Links between recovered cartridge casings represent the vast majority of ballistic matches made through IBIS. Unfortunately, the two-dimensional grayscale digital photography used by the original IBIS equipment was often not refined enough to suggest potential matches between often highly damaged bullets from separate crime scenes. Through the acquisition of three-dimensional measurements, the BulletTrax-3-D image acquisition technology was specifically designed to improve the ability of law enforcement agencies to make bullet matches through automated ballistic imaging and analysis. This study examines the impact of 3-D imaging technology on the productivity of the Boston Police Department's Ballistics Unit in making bullet matches. When directly compared with 2-D imaging technology, we find that the 3-D imaging technology acquired larger amounts of crime bullet evidence and was associated with a nearly fivefold increase in the cold bullet matches by the Ballistics Unit. Interviews with Boston Police detectives confirmed the considerable investigative value of the cold bullet matches. [ABSTRACT FROM AUTHOR]

Forensic ballistics a core field of forensic science, and focuses on locating the point and time of firing as well as matching the bullet to a specific firearm. The paper proposes a model for legally authorized firearms and bullets that enables instant determination of location and time of firing. This facilitates the identification of the bullet to the questioned firearm, eliminating the conduction of conventional methods of examination. This is achieved by the implementation of an in-built positioning system in the firearm utilizing a Global Positioning System (GPS) together with a means of identification of the projectile to the suspected firearm, employing Radio-Frequency Identification (RFID). A protective aspect of reducing the crime rate and more accurate method of analysing and examining the fired bullets from suspected firearms, this technique if used can also strengthen the judgements taken by law enforcement agencies. [ABSTRACT FROM AUTHOR]

Triple base propellant (TBP) containing mainly nitrocellulose, nitroglycerine, and nitroguanidine has been manufactured and coated with plasticizer in the present work. The aim was to study ballistics of di-butyl phthalate (DBP)-coated TBP. DBP solution in ethanol containing nitrocellulose dope was used for coating onto the propellant grains. DBP-deterred propellant showed inhibition to burning, resulting in lowering the values of ballistic parameters namely peak pressure (Pmax), dPmax, pressure index (α), and burning rate coefficient (β) during closed vessel firing. Increase in percentage of DBP in coating solution led to further decrease in ballistic parameters. Dynamic evaluation of the surface-moderated propellant showed comparatively lower muzzle velocity and chamber pressure for deterred propellant batches without leaving any unburnt particles in gun chamber at subzero temperatures with the lowest possible charge mass. The DBP-coated propellant can be useful in 155-mm artillery gun to achieve higher loading density as it has lower flame temperature and chamber pressure as compared to uncoated propellant which will result in increasing barrel life due to reduction in the barrel erosion. [ABSTRACT FROM AUTHOR]

Forensic investigation has the primary challenge of assessing cause from limited evidence. The use of computational modelling can play a role in assessing potential ballistic pathways in a crime investigation by analysing; (a) the entry wound and blood spatter patterns; (b) the influence of target materials; and (c) the cranial geometry, to inform the investigation process. In particular, the retrograde ejection of blood and tissue from the entry wound following projectile impact, called 'backspatter', and can help inform the proximity of the shooter and potentially differentiate between suicide and homicide, while providing other important forensic information. However, the 'backspatter' phenomenon is not well understood due to the lack of viable surrogate models and the difficulties of analysing the high-speed, extreme-force impact. This study presents (i) the development of an anatomically based model of cranial ballistic injury using the Smoothed Particle Hydrodynamics (SPH) method; (ii) the simulation of the tail splashing and temporary cavitation mechanisms and the effect of different cranial skin and cranium simulants on backspatter generation; (iii) an evaluation of anatomical geometry simulation results such as stress and strain and velocity of the particles ejected as backspatter; and (iv) a parametric study of the effect of bullet calibre and speed on the ballistic response of the anatomical geometry computational model. [ABSTRACT FROM AUTHOR]

Efforts to understand the trajectory of cannonballs are an interesting example of the tensions between practical and theoretical knowledge. Although Galileo's 1638 parabolic trajectory was an important theoretical step forward, field gunnery practice was guided by Tartaglia's 1537 'mixed motion' model until the eighteenth century. In 1742, Benjamin Robins published New principles of gunnery, and revolutionized the study of ballistics by suggesting the projectile's initial velocity—not its range—was the appropriate parameter to consider in accounting for air resistance. In 1745, Leonard Euler produced a German translation of New principles, adding his own extensive commentary. Euler's annotated translation quickly became a standard text—Napoleon Bonaparte studied ballistics from the French version—thereby influencing the education of artillery officers and, eventually, of all engineers. This paper surveys the contributions of Robins and Euler to mathematical ballistics theory, examines the influence of these developments on the education of eighteenth-century military engineers, and considers the extent to which the history of ballistics theory supports the thesis that the drive to reconcile practical knowledge with theoretical knowledge can be a critical element in shaping mathematical theory. We close with comments concerning the use of this history in today's classroom. [ABSTRACT FROM AUTHOR]

Perceptual processes, in particular modular processes, have long been understood as being mandatory. But exactly what mandatoriness amounts to is left to intuition. This paper identifies a crucial ambiguity in the notion of mandatoriness. Discussions of mandatory processes have run together notions of automaticity and ballisticity. Teasing apart these notions creates an important tool for the modularist's toolbox. Different putatively modular processes appear to differ in their kinds of mandatoriness. Separating out the automatic from the ballistic can help the modularist diagnose and explain away some putative counterexamples to multimodal and central modules, thereby helping us to better evaluate the evidentiary status of modularity theory. [ABSTRACT FROM AUTHOR]

Discusses ballistics and ballistic trajectory, the use of geometry on parabola and its application on the science of motion. Overview of the Galilean model; Details on the resisted shot; Information on enveloping parabolas; Details on the mechanics.

On 18 July 1944, a convoy of German trucks was ambushed by the French Resistance near the village of Thorame-Haute in SE France. According to reports by French witnesses, the first German truck exploded. After a brief firefight, the Resistance pulled out without casualties, claiming that 58 Germans had been killed in the attack, including a high-ranking officer. The current project used witness interviews, archives materials, and metal detecting to validate the descriptions of the ambush. The project confirmed that at least nine German soldiers had been killed in the attack. The metal detecting survey recovered numerous small artefacts whose condition and dispersal indicated that a violent explosion had indeed occurred and had probably been preceded or followed by a fire. A grouping of fired cartridge casings was found in the former Resistance positions. The project was able to confirm the French accounts apart from the casualty figures. [ABSTRACT FROM AUTHOR]

In this study, a Heracron®aramid fiber-based helmet was made, and its ballistic properties were investigated. The effect of fiber density was studied in depth. For the same weight and number of plies, a helmet manufactured from the HT-2820-based composite showed improved ballistic properties compared with one made from the HT-15000-based composite. This result suggested that fiber density may strongly affect the ballistic properties of armor. HT-2820, containing more multifilament fibers, provides more efficient energy absorption and dissipation. The influence of fabrication method on the ballistic behavior of a helmet was studied. The V50of a helmet made by the film laminating method was 10% better than that for a helmet made by the resin dipping approach. Based on these findings, the film laminating method, which forms the composite by directly attaching aramid fabric to the matrix film, may be a good candidate for improving the ballistic behavior. The required composite interfacial strength will be application-dependent. Greater fiber-matrix adhesion may be advantageous in certain cases. [ABSTRACT FROM PUBLISHER]

The use of carbon nanotubes in composite hard armor is discussed in this study. The processing techniques to make various armor composite panels consisting of Kevlar®29 woven fabric in an epoxy matrix and the subsequent V50 test results for both 44 caliber soft-point rounds and 30 caliber FSP (fragment simulated projectile) threats are presented. A 6.5% improvement in the V50 test results was found for a combination of 1.65 wt% loading of carbon nanotubes and 1.65 wt% loading of milled fibers. The failure mechanism of carbon nanotubes during the ballistic event is discussed through scanning electron microscope images of the panels after the failure. Raman Spectroscopy was also utilized to evaluate the residual strain in the Kevlar®29 fibers post shoot. The Raman Spectroscopy shows a Raman shift of 25 cm−1for the Kevlar®29 fiber utilized in the composite panel that had an enhancement in the V50 performance by using milled fiber and multi-walled carbon nanotubes. Evaluating both scenarios where an improvement was made and other panels without any improvement allows for understanding of how loading levels and synergistic effects between carbon nanotubes and milled fibers can further enhance ballistic performance. [ABSTRACT FROM AUTHOR]

This paper reports a detailed numerical investigation of the geometrical and structural properties of three-dimensional heaps of particles. Our goal is the characterization of very large heaps produced by ballistic deposition from extended circular dropping areas. First, we provide an in-depth study of the formation of monodisperse heaps of particles. We find very large heaps to contain three new geometrical characteristics: they may display two external angles of repose, one internal angle of repose, and four distinct packing fraction (density) regions. Such features are found to be directly connected with the size of the dropping zone. We derive a differential equation describing the boundary of an unexpected triangular packing fraction zone formed under the dropping area. We investigate the impact that noise during the deposition has on the final heap structure. In addition, we perform two complementary experiments designed to test the robustness of the novel features found. The first experiment considers changes due to polydispersity. The second checks what happens when letting the extended dropping zone to become a point-like source of particles, the more common type of source. [ABSTRACT FROM PUBLISHER]

We describe an optical system in which a vibration induced to a laser probe beam combined with a half-blocked photodiode allows determination of the position and width of objects buried in turbid media. Our system is based on the detection of an AC signal which drastically decreases under the presence of an obstructing buried object. We describe the technique and include experimental results showing that the system is capable of detecting 2 mm wide objects buried at depths up to 3 cm from the front surface of a sample simulating scattering properties of soft tissue. [ABSTRACT FROM PUBLISHER]

The authors describe a case in which a 21-year-old male committed suicide using a rifle equipped with a muzzle brake, placed in contact with his head. A muzzle brake for firearms is a device positioned at the mouth of a weapon, which dissipates the gases, that are generated subsequent to the gun being discharged. Generally, when a gun is pressed against an anatomical region, where the skin lies on the bone surface without interposition of other soft parts, the entrance wound consists of many lacerated branches, originating from a central lack of tissue. In this case report, the use of a rifle with a muzzle brake generated an unexpected wound, circular in shape, with a diameter of 0.8 cm. This lesion was surrounded by a bruised area, circular in shape, and an abrasion collar of the height of 0.5 cm. In addition, a muzzle imprint mark consisting of intradermal bruises, composed of a narrow red line concentrically encircling the entrance hole, was found. In order to analyze in detail if this particular entrance wound could be associated with a weapon equipped with the muzzle brake, ballistic tests – with weapons compatible with that used by the victim – were performed. [ABSTRACT FROM AUTHOR]

We present an analytical model for the subthreshold characteristic of ultra-thin independent double-gate (IDG) MOSFETs working in the ballistic regime. This model takes into account short-channel effects, quantisation effects and source-to-drain tunnelling (Wentzel-Kramers-Brillouin (WKB) approximation) in the expression of the subthreshold drain current. Important device parameters, such as off-state current or subthreshold swing, can be easily evaluated through this full analytical approach. The model can be successfully implemented in a Technologies Computer-Aided Design (TCAD) circuit simulator for the simulation of IDG MOSFET-based circuits. [ABSTRACT FROM AUTHOR]

Discusses the controversy over the nuclear weapons program of Iran, as of 2002. Details on its policy of nuclear and missile technology procurement from China, Russia and North Korea; Significance of the nuclear infrastructure in Iran; Background on the ballistic missile program of Iran.

The object of this study is to evaluate the applicability of photogrammetry and laser scanner techniques both on forensic ballistic reports and on reproduction of crime scene. In the first case, in a shooting range for small arms, photogrammetric and laser were used both for the acquisition of metric data related to the testing environment and for ballistic simulation on a suitable sample. The crime scene was specifically simulated in laboratory, while the room where a murder took place was re-created. Once the setting had been made, it was possible to perform the survey of the scene and the details in it by using laser scanner and photogrammetric techniques. Data acquisition has enabled authors to carry out a rapid reconstruction of the scene and detect several parameters using the available elements. Specifically, the processed data were also exported to a CAD and an image processing software. [ABSTRACT FROM PUBLISHER]

"High School and Undergraduate Physics Practicals with 3D Simulations" is a monograph written by Robert Lucas and published by CRC Press in 2022. The book provides a comprehensive collection of 34 physics experiments for high school and undergraduate students, along with background information and instructions on how to carry out each experiment. It also includes 3D simulations of the experiments for students who do not have access to a real laboratory. The book is written in a clear and concise manner and is aimed at students, lecturers, and researchers in the field of physics. It is recommended for those looking to enhance their experimental skills and broaden their knowledge in the subject. [Extracted from the article]

The desire to significantly reduce the weight of machine gun barrels while simultaneously increasing their operational life has led to the need to develop a transient heat transfer model that accurately addresses the thermal management problem while simultaneously supporting the execution of rapid trade studies of barrel geometry and material. To address this need, National Technical Systems Ordnance Sciences Division has created a detailed finite-difference based numerical model using the Mathematica software, developed and marketed by Wolfram Research, as the solution platform. This model solves the one-dimensional temperature profile through the thickness of the barrel at a specified axial location. [ABSTRACT FROM PUBLISHER]