Showing posts from October, 2022

History and Development of Firearms

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

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

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

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