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Blowback (forensics)
In forensics, blowback is the vacuum effect created in the barrel of a firearm when it is discharged. After the weapon is fired, air races into the barrel once the bullet has left the muzzle. This vacuum can pull in trace amounts of materials from the environment. Police can use blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ... and tissue which have entered a gun barrel through blowback in an investigation. References * Firearm terminology {{forensics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forensics
Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and cause of death through autopsies. This evidence can then be used for proof towards a crime. Forensic science, often confused with criminalistics, is the application of science principles and methods to support legal decision-making in matters of criminal and civil law. During criminal investigation in particular, it is governed by the legal standards of admissible evidence and criminal procedure. It is a broad field utilizing numerous practices such as the analysis of DNA, fingerprints, bloodstain patterns, firearms, ballistics, toxicology, microscopy, and fire debris analysis. Forensic scientists collect, preserve, and analyze evidence during the course of an investigation. While some forensic scientists travel to the scene of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum (: vacuums or vacua) is space devoid of matter. The word is derived from the Latin adjective (neuter ) meaning "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gun Barrel
A gun barrel is a crucial part of gun-type weapons such as small arms, small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle (firearms), muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its calibre, usually measured in inches or millimetres. The first firearms were made at a time when metallurgy was not advanced enough to cast tubes capable of withstanding the explosive forces of early cannons, so the pipe (often built from staves of metal) needed to be braced periodically along its length for structural reinforcement, producing an appearance somewhat reminiscent of storage barrels being stacked together, hence the English name. History Gun barrels are usually made of some type of metal or Alloy, metal alloy. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearm
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other explosive propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weapon
A weapon, arm, or armament is any implement or device that is used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime (e.g., murder), law enforcement, self-defense, warfare, or suicide. In a broader context, weapons may be construed to include anything used to gain a tactical, strategic, material, or mental advantage over an adversary or enemy target. While ordinary objects such as rocks and bottles can be used as weapons, many objects are expressly designed for the purpose; these range from simple implements such as clubs and swords to complicated modern firearms, tanks, missiles and biological weapons. Something that has been repurposed, converted, or enhanced to become a weapon of war is termed ''weaponized'', such as a weaponized virus or weaponized laser. History The use of weapons has been a major driver of cultural evolution and human history up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bullet
A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. They are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax; and are made in various shapes and constructions (depending on the intended applications), including specialized functions such as hunting, target shooting, training, and combat. Bullets are often tapered, making them more aerodynamic. Bullet size is expressed by weight and diameter (referred to as "caliber") in both imperial and metric measurement systems. Bullets do not normally contain explosives but strike or damage the intended target by transferring kinetic energy upon impact and penetration. Description The term ''bullet'' is from Early French, originating as the diminutive of the word ''boulle'' (''boullet''), which means "small ball". Bullets are available singly (as in muzzle-loading and cap and ball firearms) but are more often packaged with propellant as a cartri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Police
The police are Law enforcement organization, a constituted body of Law enforcement officer, people empowered by a State (polity), state with the aim of Law enforcement, enforcing the law and protecting the Public order policing, public order as well as the public itself. This commonly includes ensuring the safety, health, and possessions of citizens, and to prevent crime and civil disorder. Their lawful powers encompass arrest and the use of force legitimized by the state via the monopoly on violence. The term is most commonly associated with the police forces of a sovereign state that are authorized to exercise the Law enforcement agency powers, police power of that state within a defined legal or territorial area of responsibility. Police forces are often defined as being separate from the military and other organizations involved in the defense of the state against foreign aggressors; however, gendarmerie are military units charged with civil policing. Police forces are usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). The most abundant cells are red blood cells. These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Blood is circulated around the body through blood vessels by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Tissue
In biology, tissue is an assembly of similar cells and their extracellular matrix from the same embryonic origin that together carry out a specific function. Tissues occupy a biological organizational level between cells and a complete organ. Accordingly, organs are formed by the functional grouping together of multiple tissues. The English word "tissue" derives from the French word "", the past participle of the verb tisser, "to weave". The study of tissues is known as histology or, in connection with disease, as histopathology. Xavier Bichat is considered as the "Father of Histology". Plant histology is studied in both plant anatomy and physiology. The classical tools for studying tissues are the paraffin block in which tissue is embedded and then sectioned, the histological stain, and the optical microscope. Developments in electron microscopy, immunofluorescence, and the use of frozen tissue-sections have enhanced the detail that can be observed in tissues. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
