Internal ballistics
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Internal ballistics is the study of a projectile's behavior from ignition until it exits the gun barrel. It examines factors like lock time, ignition time, and barrel time. Piobert's law states that gunpowder burns layer by layer. Newton's third law means that for every action there is an equal and opposite reaction, causing recoil. Recoil velocity can be calculated using the projectile and gun masses and velocities. Rusting and erosion over time degrade the gun barrel and reduce accuracy.
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Internal ballistic
This document discusses the topic of internal ballistics, which is the science of what occurs inside a firearm when it is discharged. It begins with a brief history of ballistics and defines internal ballistics. Some key phenomena of internal ballistics discussed include ignition, combustion of propellants, barrel length, atmospheric conditions, the shape of cartridge cases, and heat problems during combustion. Lock time and barrel time are also defined. The document provides details on each of these topics as they relate to internal ballistics and ballistic performance.
External ballistics
The document discusses external ballistics and the factors that affect the trajectory of a bullet. It defines external ballistics as dealing with the motion of a projectile from the muzzle of a weapon to the target. The main factors that influence a bullet's flight are gravity, which pulls it downward, and air resistance, which reduces its velocity. In a vacuum with no air resistance or gravity, a bullet would travel in a straight line at a constant velocity. However, in reality bullets follow a parabolic trajectory due to these forces. The document also discusses other factors like velocity, spin, angle of fire, yaw, drift, and temperature that can impact a bullet's trajectory.
Improvised Firearms
This document discusses various types of improvised firearms, also known as zip guns. It provides examples such as zip guns, pen guns, pipe guns, and guns disguised as everyday objects like flashlights, cell phones, cigarettes, briefcases, and keychains. It describes how some of these firearms are constructed in a rudimentary way from available materials to function as a weapon. The document cautions that these improvised firearms can be unstable and pose safety risks due to improper materials or assembly.
Internal Ballistics
Internal ballistics refers to what occurs within a weapon's barrel from firing to bullet exit. Key phenomena include:
- Ignition starts when the firing pin strikes the primer, igniting propellant which burns to form high-pressure gas.
- Propellant combustion and barrel length impact velocity - short barrels require fast-burning powder while long barrels use progressive-burning powder.
- Atmospheric conditions like temperature affect ballistics, as ammunition is manufactured for a specific temperature range and velocities vary with temperature.
External ballistics
The document discusses the factors that affect the trajectory of a bullet, including both internal and external factors. The main internal factors are the velocity of the projectile, spin of the bullet, angle of fire, structural features, and gravity. The main external factors are wind, air resistance, and the Coriolis effect. The trajectory takes the form of a parabola, being affected most significantly by the bullet's velocity, as well as air resistance and gravity acting upon it during flight.
Firearms
This document discusses principles and practices of firearm identification in forensic science. It defines key ballistics terms and describes how class and individual characteristics can be used to identify firearms. Specific characteristics examined include rifling marks, firing pin impressions, breech face marks, and striations. Methods of comparing bullets and cartridge cases using comparison microscopes, stereomicroscopes, test firing, and automated databases like NIBIN and IBIS are summarized. The document provides an overview of the field of forensic ballistics and firearm identification.
Types of Bullet
Bullets come in a variety of shapes, constructions, and materials depending on their intended application. They can be categorized based on their manufacturing process or shape. In terms of manufacturing, bullets include unjacketted bullets made of hardened lead, jacketed bullets with a metallic jacket enclosing a lead core, wire-patched bullets with a copper wire envelope, and paper-patched bullets formerly made with paper jackets. They also include armor-piercing, tracer, and incendiary bullets. Bullets are further distinguished by their shape, such as hollow-point, sharp nose, round nose, boat-tailed, and split-nose bullets. The type of bullet chosen depends on the gun used and its intended range.
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Internal ballistic
This document discusses the topic of internal ballistics, which is the science of what occurs inside a firearm when it is discharged. It begins with a brief history of ballistics and defines internal ballistics. Some key phenomena of internal ballistics discussed include ignition, combustion of propellants, barrel length, atmospheric conditions, the shape of cartridge cases, and heat problems during combustion. Lock time and barrel time are also defined. The document provides details on each of these topics as they relate to internal ballistics and ballistic performance.
External ballistics
The document discusses external ballistics and the factors that affect the trajectory of a bullet. It defines external ballistics as dealing with the motion of a projectile from the muzzle of a weapon to the target. The main factors that influence a bullet's flight are gravity, which pulls it downward, and air resistance, which reduces its velocity. In a vacuum with no air resistance or gravity, a bullet would travel in a straight line at a constant velocity. However, in reality bullets follow a parabolic trajectory due to these forces. The document also discusses other factors like velocity, spin, angle of fire, yaw, drift, and temperature that can impact a bullet's trajectory.
Improvised Firearms
This document discusses various types of improvised firearms, also known as zip guns. It provides examples such as zip guns, pen guns, pipe guns, and guns disguised as everyday objects like flashlights, cell phones, cigarettes, briefcases, and keychains. It describes how some of these firearms are constructed in a rudimentary way from available materials to function as a weapon. The document cautions that these improvised firearms can be unstable and pose safety risks due to improper materials or assembly.
Internal Ballistics
Internal ballistics refers to what occurs within a weapon's barrel from firing to bullet exit. Key phenomena include:
- Ignition starts when the firing pin strikes the primer, igniting propellant which burns to form high-pressure gas.
- Propellant combustion and barrel length impact velocity - short barrels require fast-burning powder while long barrels use progressive-burning powder.
- Atmospheric conditions like temperature affect ballistics, as ammunition is manufactured for a specific temperature range and velocities vary with temperature.
External ballistics
The document discusses the factors that affect the trajectory of a bullet, including both internal and external factors. The main internal factors are the velocity of the projectile, spin of the bullet, angle of fire, structural features, and gravity. The main external factors are wind, air resistance, and the Coriolis effect. The trajectory takes the form of a parabola, being affected most significantly by the bullet's velocity, as well as air resistance and gravity acting upon it during flight.
Firearms
This document discusses principles and practices of firearm identification in forensic science. It defines key ballistics terms and describes how class and individual characteristics can be used to identify firearms. Specific characteristics examined include rifling marks, firing pin impressions, breech face marks, and striations. Methods of comparing bullets and cartridge cases using comparison microscopes, stereomicroscopes, test firing, and automated databases like NIBIN and IBIS are summarized. The document provides an overview of the field of forensic ballistics and firearm identification.
Types of Bullet
Bullets come in a variety of shapes, constructions, and materials depending on their intended application. They can be categorized based on their manufacturing process or shape. In terms of manufacturing, bullets include unjacketted bullets made of hardened lead, jacketed bullets with a metallic jacket enclosing a lead core, wire-patched bullets with a copper wire envelope, and paper-patched bullets formerly made with paper jackets. They also include armor-piercing, tracer, and incendiary bullets. Bullets are further distinguished by their shape, such as hollow-point, sharp nose, round nose, boat-tailed, and split-nose bullets. The type of bullet chosen depends on the gun used and its intended range.
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Chemical tests for GSR
Gunshot residue analysis examines tiny particles of primer and gunpowder that are expelled from guns when fired. These particles can be detected on clothing using chemical tests that identify compounds like barium, antimony, and lead which are components of primer, as well as nitrates from gunpowder. The sodium rhodizonate, Walker, Greiss, Marshall, and Tewari tests are chemical methods used to detect these compounds and determine if gunshot residue is present. If found, the location, shape, and appearance of any gunshot residue patterns on clothing can provide information about a shooting incident.
History of firearms
The document provides a history of firearms, describing their evolution from early hand cannons in China in the 13th century to modern centerfire weapons. It outlines key developments like the matchlock, wheellock, flintlock, percussion cap, pinfire, rimfire systems. Each new system improved ignition reliability, accuracy, and rate of fire, culminating in centerfire cartridges that enabled self-contained ammunition and rapid reloading.
IBIS
The Integrated Ballistics Identification System (IBIS) is a program controlled by the ATF that uses sophisticated electronic and optical technology to digitally compare and store images of bullets, casings, and cartridges from crime scenes. The system searches its database of images using advanced algorithms to find potential matches for new evidence. A forensic examiner then visually compares any matched images and confirms matches by microscope examination of the actual evidence. IBIS has been used to link multiple crimes to a single weapon and help solve violent firearm crimes.
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Terminal ballistics focuses on the behavior of projectiles after impact with a target. It involves studying how projectiles interact with and damage targets, as well as their stopping power. Factors like bullet design, velocity, mass, and shot placement influence a bullet's stopping power and ability to incapacitate. An unstable bullet may have reduced accuracy, an unpredictable trajectory, and wider shot groupings. Bullet instability can arise from issues like improper twist rate, design flaws, extreme velocities, barrel wear, and environmental conditions. Upon impact, an unstable bullet tumbling sideways increases its surface area and thus the size of the entry wound.
GSR
Gunshot residue is composed of burnt and unburnt particles from the firearm's primer, propellant, bullet, cartridge case, and firearm. There are three types of gunpowder burning - degressive, neutral, and progressive. Gunshot residue can be detected through analytical methods like neutron activation analysis and atomic absorption spectrophotometry, and qualitatively identified with scanning electron microscopy and atomic force microscopy. Gunshot residue is collected using carbon-coated adhesive stubs or alcohol swabs, with stubs having fewer false negatives. Firing distance can be determined using tests like the Greiss test, which can help identify homicide versus suicide or entrance versus exit wounds. Each gunshot residue case must be individually evaluated as test results alone do
Internal Ballistics
Internal ballistics is the study of what happens inside the barrel of a firearm from the moment of ignition until the projectile exits. When fired, the projectile is accelerated to high velocity by the burning of propellant gases trapped behind it in the barrel. There are three types of propellant powders - progressive powders increase burning surface as they burn, degressive powders decrease burning surface, and neutral powders maintain a constant burning surface.
Introduction to Forensic Ballistics
1. Ballistics is the science dealing with the motion, impact, launching and flight behavior of projectiles. It includes interior, exterior and terminal ballistics.
2. A firearm uses an assembly of a primer, propellant and projectile(s) to generate power and discharge the projectile(s) at high velocity. Common firearms include revolvers, self-loading rifles, and shotguns.
3. A cartridge contains the primer, propellant and projectile(s) assembled into a container. It uses the energy from burning propellant gases to launch the projectile(s) down the barrel of the firearm.
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Firing Marks
Firing marks left on bullets and cartridge cases can be used to identify the firearm used. There are several types of marks including:
1. Rifling marks on the bullet from the grooves in the barrel. These marks are unique to each gun.
2. Firing pin marks on the primer from the firing pin striking it. Imperfections in the firing pin can be transferred.
3. Breech face marks on the cartridge from the cartridge striking the breech face on firing. Imperfections are imprinted.
4. Extractor and ejector marks on the cartridge case from the mechanisms removing the spent case from the firearm.
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introductory information related to the field of firearms identification; the evidences, the principles involeved in their examination and the categories of guns.
History of firearms
The document provides a history of the development of firearms from early hand cannons to modern systems. It describes the major innovations in ignition mechanisms from matchlock guns to flintlock guns to percussion caps. Important developments included the wheel lock mechanism, snaphaunce, muzzleloaders, Colt's revolver, breechloaders, and the introduction of cartridges using rimfire, pinfire, and centerfire systems. Modern firearms are categorized based on their bore, loading, firing, and handling characteristics.
Internal ballistics
This document discusses the topic of internal ballistics, which deals with the motion of projectiles inside a weapon's barrel. It provides information on factors that affect muzzle velocity, such as the quantity and quality of powder, barrel length, and bullet fit. The Le Duc empirical formula is presented, which approximates the velocity-space curve of a projectile in a gun based on distance traveled. The concept of the "all burnt point", where all of the propellant has been consumed, is explained.
Terminal ballistics
1. Terminal ballistics deals with the behavior and effects of projectiles when they impact targets and transfer energy. It studies penetration potential and wound ballistics.
2. When a projectile strikes the body, it compresses tissues until they tear beyond their elastic limits if the projectile has enough energy. It continues through an exit wound, causing internal damage.
3. Factors affecting wounding include the target site, velocity, projectile construction, and range. Frontal wounds cause more damage due to shallow tissue depth. Higher velocities increase energy and damage.
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This document discusses gunshot residue (GSR) and its detection in forensic investigations. It defines GSR as chemical and particulate components released when a gun is fired. GSR can be found on hands, skin, clothing, and nearby surfaces. Various techniques are described for collecting and detecting GSR, including dry collection methods using wax or tape lifts, wet collection using swabs or solvent washes, and analytical detection using microscopy, X-ray fluorescence, chemical tests for nitrates, lead and barium. The composition of GSR depends on factors like the gun's propellant and projectile materials. Detection of GSR can help answer questions in shooting investigations like whether a suspect fired a gun or if a wound was caused by
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Tool marks are impressions left on a softer surface by a tool due to forcible contact. They can be individually unique due to wear and tear on tools. There are four main types of tool marks: compression, striated, combination, and repetitive/multi-stroke marks. Tool marks are examined based on their class, sub-class, and individual characteristics. Proper collection involves photography, tracing, and lifting impressions. A variety of chemical reagents can be used to restore obliterated tool marks on different material surfaces like metals, wood, leather, and rubber.
Examination of glass
Glass is a hard, brittle material produced by cooling molten silica, soda, and lime. There are several types of glass including float glass commonly used in windows, laminated glass used in windshields, and tempered safety glass used in car windows. Physical properties like density and refractive index can be used to analyze glass evidence. Examination methods include physical matching of broken edges, measuring density through flotation or using a density gradient column, and determining refractive index through immersion or hot stage methods. Chemical analysis like SEM-EDX can also identify elemental composition. Fracture patterns in glass can provide information about the force and direction that caused the break.
Forensic analysis of tool marks
Tool marks evidence plays an important role in forensic science. Tool marks are impressions or marks left on surfaces by tools and can be used to identify the specific tool that made the mark. There are different types of tool marks such as impressions, abrasions, cuts, and drill holes. Tool marks contain both class characteristics common to groups of tools and unique individual characteristics. Tool marks are collected using methods like photography, casting, and test marks. Examiners compare both class and individual characteristics of tool marks using various techniques like microscopy and superimposition to determine if two marks have a common origin.
Firearm and its classification.
The document discusses the classification of firearms. It describes firearms as being classified based on their bore (smooth bore vs rifled), loading mechanism (muzzleloader, breechloader, magazine loader), action (lever, bolt, self-loading), firing capability (single shot vs repeater), how they are handled (handguns vs shoulder arms) and their use (service vs sporting). Primitive firearms discussed include matchlock, wheel-lock, flintlock and muzzleloaders. Modern firearms are classified based on these various characteristics.
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Ballistics is the science of projectile motion and the factors that affect it. It was originally studied mainly for firearm manufacture but is now applied in forensic investigations involving firearms. Ballistics can be divided into four branches: interior ballistics examines projectile motion inside the firearm; exterior ballistics covers motion from the muzzle to the target; terminal ballistics analyzes impact effects; and forensic ballistics applies the science to justice cases. Projectile motion involves direct, rotary, and transitional movement.
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ammunition and its classification
This document discusses forensic ballistics and ammunition. It begins by defining forensic ballistics as the branch of science dealing with shooting incidents for legal purposes. It then discusses different types of ammunition such as rimfire, centerfire, caseless, and blank ammunition. It describes the components of ammunition including primers, propellants, and bullets. Various bullet types are outlined like full metal jacket, hollow point, ballistic tip, open tip, dum-dum, wire patched, rubber, and incendiary bullets. Improvised ammunition is also briefly discussed.
Chemical tests for GSR
Gunshot residue analysis examines tiny particles of primer and gunpowder that are expelled from guns when fired. These particles can be detected on clothing using chemical tests that identify compounds like barium, antimony, and lead which are components of primer, as well as nitrates from gunpowder. The sodium rhodizonate, Walker, Greiss, Marshall, and Tewari tests are chemical methods used to detect these compounds and determine if gunshot residue is present. If found, the location, shape, and appearance of any gunshot residue patterns on clothing can provide information about a shooting incident.
History of firearms
The document provides a history of firearms, describing their evolution from early hand cannons in China in the 13th century to modern centerfire weapons. It outlines key developments like the matchlock, wheellock, flintlock, percussion cap, pinfire, rimfire systems. Each new system improved ignition reliability, accuracy, and rate of fire, culminating in centerfire cartridges that enabled self-contained ammunition and rapid reloading.
IBIS
The Integrated Ballistics Identification System (IBIS) is a program controlled by the ATF that uses sophisticated electronic and optical technology to digitally compare and store images of bullets, casings, and cartridges from crime scenes. The system searches its database of images using advanced algorithms to find potential matches for new evidence. A forensic examiner then visually compares any matched images and confirms matches by microscope examination of the actual evidence. IBIS has been used to link multiple crimes to a single weapon and help solve violent firearm crimes.
TERMINAL BALLISTICS.pptx EFFECT OF PROJECTILE ON HIYYING THE TARGET
Terminal ballistics focuses on the behavior of projectiles after impact with a target. It involves studying how projectiles interact with and damage targets, as well as their stopping power. Factors like bullet design, velocity, mass, and shot placement influence a bullet's stopping power and ability to incapacitate. An unstable bullet may have reduced accuracy, an unpredictable trajectory, and wider shot groupings. Bullet instability can arise from issues like improper twist rate, design flaws, extreme velocities, barrel wear, and environmental conditions. Upon impact, an unstable bullet tumbling sideways increases its surface area and thus the size of the entry wound.
GSR
Gunshot residue is composed of burnt and unburnt particles from the firearm's primer, propellant, bullet, cartridge case, and firearm. There are three types of gunpowder burning - degressive, neutral, and progressive. Gunshot residue can be detected through analytical methods like neutron activation analysis and atomic absorption spectrophotometry, and qualitatively identified with scanning electron microscopy and atomic force microscopy. Gunshot residue is collected using carbon-coated adhesive stubs or alcohol swabs, with stubs having fewer false negatives. Firing distance can be determined using tests like the Greiss test, which can help identify homicide versus suicide or entrance versus exit wounds. Each gunshot residue case must be individually evaluated as test results alone do
Internal Ballistics
Internal ballistics is the study of what happens inside the barrel of a firearm from the moment of ignition until the projectile exits. When fired, the projectile is accelerated to high velocity by the burning of propellant gases trapped behind it in the barrel. There are three types of propellant powders - progressive powders increase burning surface as they burn, degressive powders decrease burning surface, and neutral powders maintain a constant burning surface.
Introduction to Forensic Ballistics
1. Ballistics is the science dealing with the motion, impact, launching and flight behavior of projectiles. It includes interior, exterior and terminal ballistics.
2. A firearm uses an assembly of a primer, propellant and projectile(s) to generate power and discharge the projectile(s) at high velocity. Common firearms include revolvers, self-loading rifles, and shotguns.
3. A cartridge contains the primer, propellant and projectile(s) assembled into a container. It uses the energy from burning propellant gases to launch the projectile(s) down the barrel of the firearm.
Glass fractures
The document discusses different types of glass and forensic analysis of glass evidence. It provides information on the physical, optical, and chemical properties of glass that can be analyzed forensically. Specific techniques mentioned include refractive index testing, density determination, microscopic analysis of fractures, and elemental analysis. The document also discusses how analysis of glass evidence can help reconstruct crime scenes and connect suspects to crimes by matching glass fragments.
Firing Marks
Firing marks left on bullets and cartridge cases can be used to identify the firearm used. There are several types of marks including:
1. Rifling marks on the bullet from the grooves in the barrel. These marks are unique to each gun.
2. Firing pin marks on the primer from the firing pin striking it. Imperfections in the firing pin can be transferred.
3. Breech face marks on the cartridge from the cartridge striking the breech face on firing. Imperfections are imprinted.
4. Extractor and ejector marks on the cartridge case from the mechanisms removing the spent case from the firearm.
Paint analysis
Paint evidence can provide important clues in criminal investigations. Proper collection and packaging of paint samples is crucial to prevent contamination and loss of evidence. Paint analysis may identify the make, model and year of a vehicle by matching paint chips and smears. For example, analysis of yellow paint flakes found on a tree helped convict a serial rapist by matching the paint to the rare car model he owned.
introduction to forensic ballistics
introductory information related to the field of firearms identification; the evidences, the principles involeved in their examination and the categories of guns.
History of firearms
The document provides a history of the development of firearms from early hand cannons to modern systems. It describes the major innovations in ignition mechanisms from matchlock guns to flintlock guns to percussion caps. Important developments included the wheel lock mechanism, snaphaunce, muzzleloaders, Colt's revolver, breechloaders, and the introduction of cartridges using rimfire, pinfire, and centerfire systems. Modern firearms are categorized based on their bore, loading, firing, and handling characteristics.
Internal ballistics
This document discusses the topic of internal ballistics, which deals with the motion of projectiles inside a weapon's barrel. It provides information on factors that affect muzzle velocity, such as the quantity and quality of powder, barrel length, and bullet fit. The Le Duc empirical formula is presented, which approximates the velocity-space curve of a projectile in a gun based on distance traveled. The concept of the "all burnt point", where all of the propellant has been consumed, is explained.
Terminal ballistics
1. Terminal ballistics deals with the behavior and effects of projectiles when they impact targets and transfer energy. It studies penetration potential and wound ballistics.
2. When a projectile strikes the body, it compresses tissues until they tear beyond their elastic limits if the projectile has enough energy. It continues through an exit wound, causing internal damage.
3. Factors affecting wounding include the target site, velocity, projectile construction, and range. Frontal wounds cause more damage due to shallow tissue depth. Higher velocities increase energy and damage.
Gun shot residue
This document discusses gunshot residue (GSR) and its detection in forensic investigations. It defines GSR as chemical and particulate components released when a gun is fired. GSR can be found on hands, skin, clothing, and nearby surfaces. Various techniques are described for collecting and detecting GSR, including dry collection methods using wax or tape lifts, wet collection using swabs or solvent washes, and analytical detection using microscopy, X-ray fluorescence, chemical tests for nitrates, lead and barium. The composition of GSR depends on factors like the gun's propellant and projectile materials. Detection of GSR can help answer questions in shooting investigations like whether a suspect fired a gun or if a wound was caused by
TOOL MARKS
Tool marks are impressions left on a softer surface by a tool due to forcible contact. They can be individually unique due to wear and tear on tools. There are four main types of tool marks: compression, striated, combination, and repetitive/multi-stroke marks. Tool marks are examined based on their class, sub-class, and individual characteristics. Proper collection involves photography, tracing, and lifting impressions. A variety of chemical reagents can be used to restore obliterated tool marks on different material surfaces like metals, wood, leather, and rubber.
Examination of glass
Glass is a hard, brittle material produced by cooling molten silica, soda, and lime. There are several types of glass including float glass commonly used in windows, laminated glass used in windshields, and tempered safety glass used in car windows. Physical properties like density and refractive index can be used to analyze glass evidence. Examination methods include physical matching of broken edges, measuring density through flotation or using a density gradient column, and determining refractive index through immersion or hot stage methods. Chemical analysis like SEM-EDX can also identify elemental composition. Fracture patterns in glass can provide information about the force and direction that caused the break.
Forensic analysis of tool marks
Tool marks evidence plays an important role in forensic science. Tool marks are impressions or marks left on surfaces by tools and can be used to identify the specific tool that made the mark. There are different types of tool marks such as impressions, abrasions, cuts, and drill holes. Tool marks contain both class characteristics common to groups of tools and unique individual characteristics. Tool marks are collected using methods like photography, casting, and test marks. Examiners compare both class and individual characteristics of tool marks using various techniques like microscopy and superimposition to determine if two marks have a common origin.
Firearm and its classification.
The document discusses the classification of firearms. It describes firearms as being classified based on their bore (smooth bore vs rifled), loading mechanism (muzzleloader, breechloader, magazine loader), action (lever, bolt, self-loading), firing capability (single shot vs repeater), how they are handled (handguns vs shoulder arms) and their use (service vs sporting). Primitive firearms discussed include matchlock, wheel-lock, flintlock and muzzleloaders. Modern firearms are classified based on these various characteristics.
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2) It describes various methods used to measure internal ballistics pressures, including copper crusher gauges, strain gauges, piezoelectric pressure transducers, and Serbert's velocimeter.
3) Measuring internal pressures is important for testing barrel strength, propellant charges, bore and driving band accuracy, estimating range and velocity, and checking for technical issues. However, pressure measurement is complex and variations between rounds are common.
Chapter15 Firearms
Firearms identification experts can identify key details about firearms from ballistic evidence:
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- Firing pin and breechblock markings on cartridge casings are also unique to each gun.
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Human hair is commonly found evidence at crime scenes and can provide a link between a criminal and their crime. Analysis of hair, called trichology, is important in forensic investigations as hair can easily be left behind at a crime scene and adhere to surfaces. This document outlines the equipment and process used to estimate the hair index of a human hair sample, which involves mounting hair on a slide, treating it with hydrogen peroxide and hydrochloric acid, and examining it under a microscope to measure the medulla and cortex.
Barbiturates
Barbiturates are classified as CNS depressants and are often prescribed to treat conditions like anxiety, depression, and insomnia. They produce effects like sleepiness, nausea, and breathing problems when consumed, and in higher doses can cause coma or death. Barbiturates come in many colors and are also abused for their ability to produce euphoria and treat withdrawal symptoms from other drugs. They can be consumed orally or via other routes of administration. Tests like chromatography, spectroscopy, and color tests are used to qualitatively and quantitatively analyze samples suspected to contain barbiturates. The salt or acid form of the barbiturate present affects how it can be identified.
Drug abuse in sports
This document discusses the history and science of drug testing in sports. It provides background on the types of performance enhancing drugs used by athletes and their effects. It then describes the anti-doping agencies and rules established to regulate drug use in sports. The document outlines the banned substances and methods according to their classifications. It details the sample collection and testing process, including the analytical methods used to detect drugs in urine and blood samples. Finally, it mentions some notable doping cases that have occurred in sports over time.
Sex determination using anthropometric methods
This document summarizes methods for determining sex from skeletal remains using anthropometric analysis. It outlines key sexual dimorphisms in the skull, pelvis, and long bones that can be used to identify whether remains are from a male or female. For the skull, traits like robustness, orbital shape, and mastoid process size can indicate sex. In the pelvis, characteristics such as the subpubic angle, sciatic notch width, and pubic arch shape provide clues. Measurements and morphological features of long bones like the femur, tibia, humerus and ulna also differ between males and females. Anthropologists can use these multiple lines of evidence from the skeleton to assign sex with 90-95%
Introduction to Anthropology
This document is a submission from Manshwine Bandor, a student in the 4th semester of the 2nd year of a BSc program at Shree Vaishnav Vidyapeeth Vishwavidyalaya. The topic of the submission is Anthropology and it has been submitted to assistant professor Ketan Patil.
Anthropology
Human evolution is a gradual process that has occurred over a long period of time. Key stages included Dryopithecus, which is considered the common ancestor of apes and humans around 25 million years ago. Ramapithecus and Kenyapithecus, dated to between 12-5 million years ago, displayed traits that were ancestral to humans. Australopithecus, the first upright walking species around 4 million years ago, had a brain capacity of around 500cc. Homo habilis began making tools around 2.4 million years ago. Later species such as Homo erectus had larger brains and used fire. Homo sapiens emerged around 200,000 years ago, with modern humans
Theories of organic evolution
The document discusses theories of organic evolution, including Darwin's theory of evolution by natural selection and Lamarck's theory of inheritance of acquired characteristics. Darwin's theory proposes that organisms evolve over generations through natural selection of inheritable traits that aid survival and reproduction. Lamarck's theory suggests that organisms can pass on traits acquired in their lifetime to offspring, such as giraffes inheriting long necks from ancestors that stretched their necks to reach leaves. Modern understanding incorporates genetics and shows how random mutations in DNA can provide variation for natural selection to act upon.
Anthropology
This document discusses the field of anthropology and its branches. It begins by defining anthropology as the study of humans, their origins, and cultural variations throughout history. The document then outlines the major branches of anthropology, including socio-cultural anthropology, physical/biological anthropology, archaeological anthropology, linguistic anthropology, and applied anthropology. For each branch, it provides a brief description of the areas of focus and goals of study.
Study of Soil and Paint
This document provides information about soils and paints. It defines soil as a mixture of organic matter, minerals, gases, liquids, and organisms that support life. The four main components of soil are identified as minerals, water, organic matter, and gases. Key soil types like sand, silt, clay and loam are described. Methods for analyzing soils like determining moisture content and particle size distribution are outlined. The document also defines paint as a liquid that converts to a solid film after application. The main components of paint are identified as pigments, binders, liquids, and additives. Common types of paints like water-based and oil-based are described. Forensic analysis methods for soils and paints are mentioned
Microscope and its types
This document provides information about different types of microscopes. It discusses simple microscopes, which use a single lens for magnification, and their basic parts and working principle. Compound microscopes are then introduced as using multiple lenses to achieve higher magnification than is possible with a simple lens alone. The key parts of a compound microscope are described, including the eyepiece, objective lenses, body tube, arm, and focus adjustments. It explains that light from the illuminator passes through these parts to produce a magnified image for viewing.
History of firearms
The document outlines the 7 phases of development in firearms technology:
1. Cannon lock - An early matchlock design with a pan and touch hole for ignition.
2. Matchlock - Used a slow-burning match cord for ignition which had disadvantages of visibility and damp weather.
3. Wheel lock - The first self-igniting design using a rotating flint mechanism.
4. Snaphaunce - An early flintlock design with a spring-loaded flint arm for ignition.
5. Flintlock - Rapidly replaced earlier designs using flint and steel for reliable ignition.
6. Percussion lock - Introduced in 1820, it used fulminate of
Hair and fiber
Hairs and fibers are important forms of trace evidence that can provide clues in forensic investigations. Hair has a cuticle, cortex, and sometimes a medulla, and characteristics like these can be used to identify a sample's origin. Fiber analysis examines properties such as the fiber's structure, color, and chemical composition to determine its type (natural or synthetic) and match it to a potential source. Due to their tendency to shed easily, fibers are commonly found as trace evidence and can link a suspect to a crime scene or victim.
Hair and fiber
This document discusses hair and fibers in forensic science. It provides details on:
- The structure and composition of hair, including the cuticle, cortex, and medulla layers. Hair characteristics like color, length and shape can indicate where on the body it came from. Nuclear and mitochondrial DNA can be extracted from hair roots or cuticles.
- Fibers are long thin strands that can be spun into yarn and woven into fabrics. Matching unique fibers between a victim and suspect's clothing can provide evidence of contact.
- Both natural fibers like cotton and wool and synthetic fibers like nylon and polyester are important in forensic analysis and can be identified under a microscope.
Expert Witness Testimony
The document discusses the role and types of expert witnesses. An expert witness is a person with specialized knowledge or experience in a particular field who provides expert testimony. They may provide opinions on matters like injury severity, sanity, machine failures, damages, and authenticating electronic evidence. Expert testimony is important in many civil and criminal cases. Experts have a responsibility to provide unbiased opinions. There are testifying experts who present in court and non-testifying experts who advise lawyers. In ballistics cases, expert opinions on matching bullets to guns involve subjective assessments.
Terminal ballistics
This document discusses terminal ballistics and the different types of injuries caused by firearms. Terminal ballistics is the study of bullet behavior once it impacts the target. Factors like velocity, mass, size, and shape of the bullet affect the degree of injury. Rifled firearms can cause injuries at contact range (muzzle touching body), close shot (within flame distance), and distant shots over 50cm away. Shotgun wounds depend on range, with contact shots causing discoloration and burns and long range shots rarely being fatal. Entry wounds from firearms show more tissue destruction than exit wounds, which tend to be everted with split flaps. Specific injuries include abrasion collars, contusion collars, tattooing, and blackening
External ballistics
External ballistics deals with the flight path of a projectile from the moment it exits the barrel until impact with the target. The key factors that influence a projectile's trajectory are wind, vertical angle, and air density. Wind can cause horizontal deflection from crosswinds and vertical deflection from headwinds or tailwinds. The vertical angle of fire affects slant range and requires adjustments to hold-off points. Variations in air pressure, temperature, and humidity that determine air density also influence drag on the projectile and its trajectory.
Microscopy
The document discusses different types of microscopes, including compound microscopes and stereomicroscopes. It describes the key parts and principles of operation. Compound microscopes use multiple lenses to magnify specimens and provide a two-dimensional image. Stereomicroscopes use two optical paths to provide a three-dimensional view of surface details. Examples of uses include biology studies, forensics, manufacturing quality control, and more. The document also discusses who may have invented the compound microscope and provides references for further reading.
Chromatography
Chromatography is a technique used to separate mixtures and involves dissolving the mixture in a mobile phase that carries it through a structure containing a stationary phase. It was first developed in 1900 by Russian scientist Mikhail Tsvet and involves the interaction between a mobile and stationary phase resulting in separation. Common types include paper chromatography, thin layer chromatography, gas chromatography, and affinity chromatography. It has various applications in fields like clinical analysis, protein purification, forensic toxicology, and separation of amino acids, proteins, carbohydrates, and more.
RICOCHET
Ricochet refers to a bullet deflecting off a hard surface rather than penetrating it. Many factors influence ricochet behavior, including bullet shape, material, velocity, spin, target material, and angle of incidence. High velocity rifle bullets have a greater chance of penetrating rather than ricocheting. Elongated rifle bullets have higher sectional density than handgun bullets, influencing penetration. Harder target materials like bone are more likely to cause ricochet. The angle of ricochet is difficult to predict due to bullet deformation. Ricochets can cause unintended damage and be lethal if the bullet or fragments strike a person. Wounds from ricocheting bullets will have ragged, irregular edges. Ricoche
More from Ketan Patil (20)
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Post translation modification by Suyash Garg
overview of PTM helps to the students who wants to clear their basics about it.
seed production, Nursery & Gardening.pdf
This presentation offers a general idea of the structure of seed, seed production, management of seeds and its allied technologies. It also offers the concept of gene erosion and the practices used to control it. Nursery and gardening have been widely explored along with their importance in the related domain.
11.1 Role of physical biological in deterioration of grains.pdf
Storagedeteriorationisanyformoflossinquantityandqualityofbio-materials.
Themajorcausesofdeteriorationinstorage
•Physical
•Biological
•Mechanical
•Chemical
Storageonlypreservesquality.Itneverimprovesquality.
Itisadvisabletostartstoragewithqualityfoodproduct.Productwithinitialpoorqualityquicklydepreciates
Pests of Storage_Identification_Dr.UPR.pdf
InIndia-post-harvestlosses-unscientificstorage,insects,rodents,micro-organismsetc.,accountforabout10percentoftotalfoodgrains
Graininfestation
Directdamage
Indirectly
•theexuviae,skin,deadinsects
•theirexcretawhichmakefoodunfitforhumanconsumption
About600speciesofinsectshavebeenassociatedwithstoredgrainproducts
100speciesofinsectpestsofstoredproductscauseeconomiclosses
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDS
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
The cost of acquiring information by natural selection
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
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This is a presentation on understanding the age of adolescence.
Male reproduction physiology by Suyash Garg .pptx
Physiology of Male reproduction.
Video mentioned at page no. 23 as summary for better understanding
Signatures of wave erosion in Titan’s coasts
The shorelines of Titan’s hydrocarbon seas trace flooded erosional landforms such as river valleys; however, it isunclear whether coastal erosion has subsequently altered these shorelines. Spacecraft observations and theo-retical models suggest that wind may cause waves to form on Titan’s seas, potentially driving coastal erosion,but the observational evidence of waves is indirect, and the processes affecting shoreline evolution on Titanremain unknown. No widely accepted framework exists for using shoreline morphology to quantitatively dis-cern coastal erosion mechanisms, even on Earth, where the dominant mechanisms are known. We combinelandscape evolution models with measurements of shoreline shape on Earth to characterize how differentcoastal erosion mechanisms affect shoreline morphology. Applying this framework to Titan, we find that theshorelines of Titan’s seas are most consistent with flooded landscapes that subsequently have been eroded bywaves, rather than a uniform erosional process or no coastal erosion, particularly if wave growth saturates atfetch lengths of tens of kilometers.
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11.1 Role of physical biological in deterioration of grains.pdf
11.1 Role of physical biological in deterioration of grains.pdf
Juaristi, Jon. - El canon espanol. El legado de la cultura española a la civi...
Juaristi, Jon. - El canon espanol. El legado de la cultura española a la civi...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆
The cost of acquiring information by natural selection
The cost of acquiring information by natural selection
Internal ballistics
- 1. INTERNAL BALLISTICS Submitted By – Shweta Tiwari B.Sc III Year Submitted To – Mr. Ketan Sir
- 2. Contents:- •Definition of internal ballistics •Piobert’s law •Recoil of the weapon •Rusting and corrosion
- 3. Internal Ballistics Internal Ballistics, a subfield of ballistics is the study of projectile’s behavior from the time its propellant’s ignites is initiated until it exits the gun barrel. The study of internal ballistics is important to designers and users of firearms of all types.
- 5. The three main factors are - Lock Time Ignition Time Barrel Time
- 6. Lock Time Lock time is the time interval between release of the sear and the impact of the striker on the percussion cap. A short time internal is advantageous in rapid fire. The lock time can be measured in a number of ways, in one such system the use of linear Motion sensors and an oscilloscope is made.
- 7. Ignition Time Ignition time is the duration or interval between the striking of the firing pin to blow the ignition of the first grain of powder. The ignition, under the normal conditions, takes place at an interval of about 0.002 seconds.
- 8. Barrel Time Barrel time is the time interval from the pressing of the trigger to the exit of the bullet from the muzzle end. In case of most of the weapons Lock time + Ignition time + barrel time varies from 0.003 to 0.007 seconds.
- 9. Piobert’s Law Piobert’s law of 1839 states that “burning takes place by parallel layers where the surface of the grain regresses layer by layer, normal to the surface at every point.”
- 10. Recoil of the Weapon This phenomenon acts on Newton’s Third Law of Motion – “To every action, there is an equal and opposite reaction” The Phenomenon of weapon getting a backward push (opposite to the direction of the projectile) is recoil and the shooter will get a kick on fire.
- 11. In terms of mathematics it is expressed that momentum of bullet and momentum of gun are equal and opposite, i.e. MV= M1V1 Where, M Represents the mass of the gun V Represents the velocity of recoil M1 Represents the mass of the projectile V1 Represents the velocity of the projectiles.
- 12. It indicates that weapon and the bullet will have equal velocities, if both of them have equal weight (or mass). In actual practice, the weapon has weight 300 times the weight of bullet hence the weapon recoils with a velocity, which is very small ( 1 300 of the velocity of bullet) in comparison to the velocity of bullet.
- 13. The recoil velocity V can be calculated when mass M of the weapon is known along with velocity V1 of the bullet and its mass M1 using MV = M1V1 or V= M1V1 M
- 14. Elements of Recoil There are three main causes due to which recoil of the weapon takes place and they are: Muzzle velocity of the projectiles consisting of forward motion of ejection consisting of bullet, wads and powder residue particles. The more the velocity of ejection, the greater the recoil of the weapon. The motion of outgoing gases. The muzzle blast, which pushes the firearm backward in the same manner as the blast, propels a jet aero plane or a rocket.
- 15. Measurement of Recoil of firearm There are several methods used by the manufacturers of firearms for measuring the recoil of a firearm and some of them are – Use of high speed camera : A high-speed camera is used to note the recoil velocity or backward movement velocity of the firearm suspended from fine wires, when fired.
- 16. Ballistics Pendulum method : The firearm is fixed to a ballistics pendulum and fired. The movement of the pendulum is measured and recoil velocity ascertained from the momentum.
- 17. Dynamometer method : Compression of a spring or depth of indentation in lead is measured by a dynamometer and compared with the standard or known compressions or indentations.
- 18. Recoil-less Gun These guns do not exhibit any recoil because this mechanism is completely eliminated by some techniques. To reduce the recoil action of the gun, muzzle brake devices can also reduce the recoil of the firearm.
- 19. Rusting and Corrosion Rusting or corrosion from lack of cleaning is the frequent cause, which shortens the life of a barrel. Rusting is oxidation and, therefore a slow combustion. Corrosion is the phenomenon of disintegration of metal by electrochemical reaction or by direct chemical attack. Obstruction
- 21. Erosion Erosion in a rifle barrel is due to the effects of thermal and mechanical stresses and the jet effects of hot powder gases which accentuate the mechanical stresses to wash metal away. This causes the yawing effect in rifle that affects the stability of the bullet in flight and accuracy is disturbed. The effect of erosion results in loss of grouping ability at long range.
- 23. Thank You