Name: Teoh Kai Xiang
Class: 1i3
Plasma
What is plasma?
In Blood :
Plasma is the liquid part of blood (including dissolved chemicals but not the cells and platelets).
This straw-coloured fluid serves as the blood's transport medium, helps maintain blood pressure, distributes body heat, and maintains the pH balance in the bloodstream and body. More than 90% consists of water, about 7% proteins, and the rest other substances, including waste products of metabolism. Important plasma proteins include albumin, coagulation factors, and globulins, including gamma globulin and a hormone that stimulates erythrocyte formation. Serum is the liquid part of the blood that remains after clotting.
In Physics :
Electrically conducting medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized .
Plasma is sometimes called the fourth state of matter (the first three being solid, liquid, and gas). A plasma is unique in the way it interacts with itself, with electric and magnetic fields, and with its environment. It can be thought of as a collection of ions, electrons, neutral atoms and molecules, and photons in which some atoms are being ionized at the same time as electrons are recombining with other ions to form neutral particles, while photons are continuously being produced and absorbed. It is estimated that more than 99% of the matter in the universe exists in the plasma state.
Interesting fact: More than 99% of the matter in the universe exists in the plasma state. It is common even here on earth. The sun is the biggest matter that is plasma.
Definition of a plasma
Plasma is loosely described as an electrically neutral medium of positive and negative particles (i.e. the overall charge of a plasma is roughly zero). It is important to note that although they are unbound, these particles are not ‘free’. When the charges move they generate electrical currents with magnetic fields, and as a result, they are affected by each other’s fields. This governs their collective behavior with many degrees of freedom. A definition can have three criteria:
The plasma approximation: Charged particles must be close enough together that each particle influences many nearby charged particles, rather than just interacting with the closest particle (these collective effects are a distinguishing feature of a plasma). The plasma approximation is valid when the number of charge carriers within the sphere of influence (called the Debye sphere whose radius is the Debye screening length) of a particular particle is higher than unity to provide collective behavior of the charged particles. The average number of particles in the Debye sphere is given by the plasma parameter, "Λ" (the Greek letter Lambda).
Bulk interactions: The Debye screening length (defined above) is short compared to the physical size of the plasma. This criterion means that interactions in the bulk of the plasma are more important than those at its edges, where boundary effects may take place. When this criterion is satisfied, the plasma is quasineutral.
Plasma frequency: The electron plasma frequency (measuring plasma oscillations of the electrons) is large compared to the electron-neutral collision frequency (measuring frequency of collisions between electrons and neutral particles). When this condition is valid, electrostatic interactions dominate over the processes of ordinary gas kinetics.
Degree of Ionization
For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost (or gained) electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, α is defined as α = ni/(ni + na) where ni is the number density of ions and na is the number density of neutral atoms. The electron density is related to this by the average charge state <Z> of the ions through ne = <Z> ni where ne is the number density of electrons.
Uses of plasma
Since plasmas are very good conductors, there are most commonly used to emit light on computer displays and in electrical appliances that emit light, such as plasma lamps, plasma globes,etc.
Plasma lamps are a type of electrodeless lamp energized by radio frequency (RF) power. They are distinct from the novelty plasma lamps that were popular in the 1980s.
The electrode-less lamp was invented by Nikola Tesla after his experimentation with high-frequency currents in an evacuated glass tube for the purpose of studying high voltage phenomena. The first practical plasma lamps were the sulfur lamps manufactured by Fusion Lighting. This lamp suffered a number of practical problems and did not prosper commercially. These problems have gradually been overcome by manufacturers such as Ceravision and Luxim, and high-efficiency plasma (HEP) lamps have been introduced to the general lighting market.
Immunoglobulins
Used in the treatment of immunological disorders, such as congenital and acquired primary immune deficiency as well as many diseases that strike healthy people due to some change in the body’s defense system.
Coagulation
Therapies Used in treatment of bleeding disorders, including hemophilia and von Willebrand disease.
Critical Care Products
Used in critical care settings for treatment of shock and burns, during surgery, and for fluid replacement therapy.
Wound Healing
Used in surgery and the treatment of wounds to facilitate healing.
Respiratory
Used in the treatment of alpha1-antitrypsin deficiency (A genetic condition resulting in liver and lung failure).
