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Digital Forensics and it's Branches

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What is Digital Forensics? The branch of forensic science that deals with the identification, collection, preservation, analysis, and reporting of any valuable digital evidence found at the scene of the crime is called digital forensics. It is also based on Locard's principle of exchange which states that "when a person comes into contact with an object, a mutual transfer of pieces of evidence takes place".  Here, digital forensic evidence like temporary files, commands, history, deleted data, etc can be found in the computer. Digital forensics helps the court of law in the conviction of criminals by studying digital evidence and maintaining a proper chain of custody. Branches of Digital Forensics Following are the branches of digital forensics: (i) Mobile forensics Mobile forensics is the branch of digital forensics that deals with the identification, collection, preservation, analysis, and reporting of any mobile device like a smartphone, tablet, etc found at the s

Death: Definition, Types, Causes and Signs

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What is Death? Death is the irreversible cessation of all biological functions that helps to sustain an organism. The remains of a dead organism normally begin to decompose shortly after death. Death is an inevitable, a universal process that eventually occurs in all living organisms. Types of Death There are mainly two types of death 1. Somatic Death It is also known as clinical death . It refers to the complete and irreversible cessation of the function of the brain followed by the cessation of the function of the heart and lungs. 2. Molecular death It is also known as cell death. It refers to the complete and irreversible cessation of individual tissues of the cells. It takes place after the somatic death and in this type of death individual cells and other biomolecules in the system die.  This happens due to the loss of blood flow and oxygen for the survival of cells and tissues. Causes of death 1. Asphyxia The death of an individual due to interference with the intake of oxygen is

Mechanical Injuries: Definition, Types and Factors Affecting

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What are Mechanical Injuries? Injuries that are produced by any kind of mechanical force like blunt, sharp objects, firearms, etc are known as mechanical injuries. Injuries are defined as any harm to any person in body, mind, reputation, or property. Types of mechanical Injuries (A) Blunt force mechanical injuries Injuries caused by blunt force impact by objects like bat pipe, rod, etc are known as blunt force mechanical injuries. The injuries by blunt force produce abrasion, bruise, laceration, etc. 1. Abrasion Injury caused by the removal of the superficial epithelial layer of skin (generally epidermis) by friction against the rough surface is called abrasion. Following are the types of abrasion: (a) Scratch/ Linear Abrasion Linear abrasion is caused by a sharp or pointed object like a fingernail, thorn, or pin on the surface of the skin. It has some length but no significant width. (b) Graze abrasion (sliding/scrape/grinding abrasion) Graze abrasion is caused by horizontal or ta

Classification of Explosives

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What are explosives? An explosive is a chemical substance that tends to release a great amount of potential energy that can produce an explosion if released suddenly. It is accompanied by the production of light, heat, sound, and pressure. The explosives can be classified based on their chemical composition, velocity of detonation, sensitivity towards heat and light, and physical forms. But broadly explosives are of three types: low explosives , high explosives , and miscellaneous . The latter is subdivided into IEDs and nuclear explosives. Classification of explosives 1. Low explosives Low explosives are chemical compounds in which the rate of decomposition through the material is less than the speed of sound. The deflagration rate in low explosives is less than 4000 m/sec. The proportion of burning of explosives depends on combustion gas, pressure, grain size, form, and composition. Examples of low explosives are gunpowder, flash powder, pyrotechnics, smokeless powder, etc. (a) Gu

Classification of Controlled Substance

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Based on origin Based on their origin, drugs of abuse can be classified into the following three categories: 1. Natural Drugs Drugs that are obtained from plants and require little or no processing at all are known as natural drugs. Eg: Cannabis, opium, coca paste, etc. 2. Semi-synthetic Drugs Drugs that are obtained from plants but undergo the same chemical process are known as semi-synthetic drugs. Eg: Heroin, Cocaine, etc . 3. Synthetic Drugs Drugs that are synthesized absolutely through a chemical process are known as synthetic drugs. Eg: Amhetamine, diazepam, etc. Based on their use Based on the purpose of their use, different drugs can be classified into the following categories: 1. Therapeutic Drugs Drugs that have a certain therapeutic effect in terms of healing and prevention of certain diseases are known as therapeutic drugs. They are further classified into four categories: (i) Analgesics and Antipyretics Drugs that are used to relieve or decrease pain without the loss of

History and Development of Firearms

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The history of firearms started in the 9th century when the Chinese accidentally developed gunpowder. After this, the gunpowder spread to the whole world from the middle east to Europe and Africa. So, here is the development of firearms since the 13th century. 1. Hand Canon (1271-1368) It was first used by the Chinese Yuan dynasty in 1300. These hand canons were made of bamboo and the projectile along with gunpowder was loaded through the muzzle end. Also, a small hole is placed at the breech end which is ignited that causes an explosion realizing the projectile from the canon. Hand cannons required much strength to hold for better stability. 2. Match lock (The early 1400s) In the matchlock firing mechanism, a wick was placed near the propellent/primer through the breech end of the weapon, and when that wick is ignited it causes a spark in the propellent which burns rapidly and pushes the projectile into a forward direction. The main disadvantage of this system is that it can'

Glass Transition Temperature (Tɡ): Definition, Significance and Factors Affecting

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What is glass transition temperature? When plastic or rubber is cooled up to a certain temperature, it becomes so hard and brittle that it breaks into pieces on the application of stress. So, the temperature below which the polymer becomes hard, brittle, and glassy and above which it is softener and flexible is known as glass transition temperature (Tɡ). The glass transition is a property of only the amorphous region of a semi-crystalline solid whereas the crystalline portion remains crystalline during the glass transition. It is important to note that the transition does not occur suddenly at a unique temperature but rather over a range of temperatures. The temperature in the middle of the inclined region is taken as the Tɡ. Significance of glass transition temperature (Tg) Glass transition temperature (Tɡ) is used as a measure for evaluating the flexibility of a polymer and the type of response the polymeric material would exhibit to mechanical stress. Glass transition temperature (

Raman Spectroscopy: Principle, Instrumentation and Applications

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What is Raman Spectroscopy? Raman spectroscopy was given by an Indian Physicist Sir C.V Raman , which is based on inelastic scattering of monochromatic light with the sample. The resulting light will have a different frequency than incident light due to this inelastic scattering.  This technique is widely used to analyze vibrational, rotational, and other low-frequency interactions in the molecule. This significantly helps in the elucidation of molecular structure, identifying functional groups, etc. Principle of Raman Spectroscopy Raman spectroscopy is based on the inelastic scattering of electromagnetic radiation with the molecule. We have two types of scattering that are elastic and inelastic scattering.  Elastic scattering obeys the Rayleigh law that states that there will be no loss of energy and momentum of the incidence radiation and scattered radiation. That's why this scattering is also known as Rayleigh scattering. Whereas, there will be some conditions (1 in million

Carbohydrates: Definition, Functions and Classification

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What are Carbohydrates ?  Carbohydrates are defined as optically active polyhydroxy aldehydes or polyhydroxy ketones or substances which give these on hydrolysis.  It is to be noted that aldehydic and ketonic groups in carbohydrates are not present as such but generally exist in combination with one of the hydroxyl groups of the molecule in the form of hemiacetals and hemiketals respectively. Carbohydrates include compounds like sugars, starches, glycogen, cellulose, dextrins, and gums. Though they are widely disturbed both in animal and plant kingdoms yet they are obtained mainly from plants by a process known as photosynthesis. Role of Carbohydrates in Biological System One of the primary functions of carbohydrates is to provide energy to the body. Carbohydrates are broken down into glucose which enters the bloodstream then it is taken up into the body's cell and used to produce ATP. These ATP's are used by cells to perform different metabolic tasks. Carbohydrates can b

Crystalline Melting Point: Definition, Factors Affecting and Determination

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What is Crystalline Melting Point ? When a polymer is treated beyond its glass transition temperature (T𝘨), it passes from a glassy state to a rubbery state and further heating causes melting of the polymer and starts flowing.  So we can say that the temperature below which the polymer is in a rubbery state and above which it is a liquid is called the crystalline melting point (T𝘮) of the polymer. Factors affecting crystalline melting point (T𝘮) Following are the factors which affect the crystalline melting point (T𝘮). 1. Chain Flexibility Chain flexibility and crystalline melting point (T𝘮) are inversely proportional to each other that is higher the flexibility, the lower will be the Tm . Also, the presence of double bond and aromatic group in the polymeric backbone lowers the flexibility which increases the crystalline melting point (T𝘮). 2. Size and type of side groups Size and type of size groups greatly influence the crystalline melting point (T𝘮). Bulky or large side g