External ballistics

Abstract: The wounding potential and mechanisms of tissue damage of firearms are reviewed. Internal ballistics is the study of projectile flight within a firearm while external ballistics describes projectile flight through air to the target. Terminal ballistics characterizes the final effects of the bullet after it has impacted its target. Upon impact, three tissue phenomena are noted: sonic wave formation, temporary cavitation, and permanent cavitation. Subsequent tissue damage is dependent on the characteristics of the firearm that fired the projectile (e.g. rifle versus handgun), the nature of the projectile itself (e.g. fully jacketed versus expanding bullet), and the attributes of the target tissue (e.g. tissue elasticity).

Abstract: Whereas the demand for missiles and rockets has exponentially augmented, but the difficulties related to the gas dynamics of these vehicles remains to be a threat. Whenever there is a sudden expansion, the pressure in the downstream is subatmospheric. This low pressure in the recirculation zone leads to a considerable amount of drag, which is nearly two-thirds of the net drag of the aerospace vehicles. Hence, in view of the above problem, many researchers tried to control the base pressure depending upon the mission requirements. For example, in case of combustion chamber, we would like to decrease the base pressure as low as possible to have better mixing and efficient combustion, whereas, in case of the external ballistics application we would like to increase the base pressure as high as possible to reduce the drag of the projectiles to enhance the range. In this paper, investigated the effects of an area ratio in suddenly expanded duct and base pressure control with microjets using the computational fluid dynamics (CFD) method. A 1 mm orifice diameter of microjets placed at the pitch circle diameter (PCD) of 13 mm, located at 90 degrees for active control. The Mach number is M = 2.2, the L/D ratio is 8, the nozzle pressure ratio’s (NPR) is 9 and the area ratios are 2.56, 3.24, 4.86 and 6.25 considered in the present study. The design and modeling of convergent-divergent (CD) nozzle simulated using K-e turbulence model for standard wall function. From the present results, it has been observed that the area ratio plays a crucial role in fixing the base pressure values.

Abstract: Theory and Practice of Shooting Reconstruction Shooting Reconstruction and the Scientific Method On-Scene Evidence: Evaluation and Documentation Off-Scene Evaluation and Investigation Goal of Shooting Reconstruction Limitations of Shooting Reconstruction Reenactment as Part of Reconstructing Shooting Incidents Developing Time Lines Exercises Suggested Readings Mathematics of Shooting Reconstruction Trigonometry, Geometry, and Shooting Incident Analysis Calculation of Impact Angles Other Calculations Distorted Bullet Base Measurements Exercises Suggested Readings Firearms and Ammunition Components Firearms Categories and Nomenclature Ammunition Components Scene Documentation of Weapons Exercises Suggested Readings Shooting Reconstruction Equipment and Use Documentation of Bullet Holes at Shooting Scenes Trajectory Rods and Use at Shooting Scenes Bullet Hole Basics Types of Trajectory Rods Trajectory Rod Accessories Other Required Equipment Substrate Considerations Proper Trajectory Rod Placement Uneven, Curved Surfaces Rod Extension via Laser Use of Lasers without Trajectory Rods Proper Examination and Documentation Key Points to Remember Tripod-Mounted Lasers Total Data Stations Chronographs Specialized Equipment for Shooting Reconstruction Exercises Suggested Readings Cartridge Case Ejection Pattern Testing Testing Considerations Methodology Interpretation of Results Problems Suggested Readings Shot Pattern Analysis and Testing Approximating Muzzle-to-Target Distance Angle of Impact Estimation Test Firing Graphical Analysis Shot Shell Buffer and Distance Estimation Reporting of Results Exercises Suggested Readings Examination and Testing of Weapons and Ammunition Components Trace Evidence Examination Function Testing Accuracy Determination Rate of Fire Determination Exercises Suggested Readings Gunshot Residue Testing Gunshot Residue Sources Primer Residues and Shooter Determination Particles Considered "Characteristic" of GSR Particles Considered "Unique" to GSR Muzzle-to-Target Distance Approximation Testing: Inanimate Objects Collection of Gunshot Residue from Fixed Inanimate Objects Procedure Muzzle-to-Target Distance Approximation Testing: HumanTissue Paraffin Test Determination of Time since Discharge Case Study Exercises Suggested Readings Bullet Hole and Wound Characteristics Bullet Holes in Clothing and Underlying Tissue Reconciling Bullet Holes in Clothing with Underlying Wounds Bullet Holes in Glass and Glass Injuries Glass Evidence Checklists Determination of Directionalities of Shots Determination of Shot Sequence Glass Evidence Collection Documentation of Bullet Holes in Glass Glass Injury Documentation Side Glass Position Determination Test Firing for Confirmation Purposes Bullet Holes in Tires and Other Elastic Materials Documentation Case Study Exercises Suggested Readings Bullet Ricochet Phenomena Terms Associated with Ricochets Producing Ricochet Directionality Based on Point of Impact Other Indicators of Directionality V Shape Fracture Lines on Painted Surfaces "Classic" Ricochet Mark "Pear" Effect Ricochet Crease Profiles Ricochet with Partial Penetration Internal Ricochet Ricochets off Glass Direction of Twist Determination from Ricochet Mark Establishing Critical Angles Establishing Ricochet Angles Establishing Deflection Angles Establishing Shooter Position Documentation Evidence of Ricochet Case Study Exercises Suggested Readings Bloodstains and Blood Spatter at Shooting Scenes Blood Characteristics and Drop Formation Blood Spatter Associated with Blood on Hands of Shooter Blood on Objects at Shooting Scene Non-Gunshot Dynamics That Mimic High Velocity Impact Blood Spatter Blood and Use in Timeline Development Case Studies Case 1: Blood Solves a Shooting Case 2: Bloodstains and Lividity Contradict a Suspect's Story Exercises Suggested Readings Officer-Involved Shootings General Considerations Protocol for Officer-Involved Shooting Unintentional Discharge of Weapon Accidental Discharge of Weapon Suicide by Cop Case Studies Attempted Suicide by Cop Charles Whitman and the University of Texas Tower Incident Exercises Suggested Readings Case Analysis General Considerations Shot Accounting Recognizing Staged and Misrepresented Crime Scenes Off-Scene Analysis of Crime Scene Data Homicide-versus-Suicide Issues Common Misconceptions Importance of Obtaining Participant Information Shots Fired into Vehicles Vehicle Bullet Hole Documentation and Trajectory Analysis Case Studies Case 1 Case 2 Case 3 Suggested Readings Ballistics Introduction Internal Ballistics External Ballistics Terminal Ballistics Common Misconceptions Regarding Wound Ballistics Sound Suppressors Case Study Suggested Readings Firearms and Ammunition Reference Collections and Other Resources Firearms and Ammunition Reference Collections Databases and Software Vehicle Information Architectural Information Weather and Meteorological Data Bullet Trajectory Data Imagery Crime Scene Software References Report Writing, Demonstrative Evidence, and Courtroom Presentation Standard Reporting Formats Suggested Summation Report Format Photographic Images, Drawings, and Diagrams Full-Scale Reproductions PowerPoint Presentations Court Testimony Suggested Readings Glossary Index

Abstract: Methods and apparatus for interacting carriers with a structure of matter employ an electrode for emitting said carriers at a distance from a surface of that structure, and cause such carriers to travel along ballistic trajectories inside that structure by providing along the mentioned distance a gap for performance of a process selected from the group of carrier tunneling and field emission and injecting carriers emitted by the mentioned electrode and that process ballistically into the structure through the gap and the mentioned surface. The carriers are collected or analyzed after their travel along ballistic trajectories in the structure of matter. Pertinent information on the inside of the structure is obtained by conducting inside that structure what conventionally would have been considered external ballistics, while performing the carrier-propelling internal ballistics conversely outside that structure.