Holography

  Holography Holography, means of creating a unique photographic image without the use of a lens. The photographic recording of the image is called a hologram, which appears to be an unrecognizable pattern of stripes and whorls but which—when illuminated by coherent light, as by a laser beam—organizes the light into a three-dimensional representation of … Read more Holography

Carbohydrates (glucose, sucrose and cellulose)

Carbohydrates (glucose, sucrose and cellulose) Carbohydrates (also called saccharides) are molecular compounds made from just three elements: carbon, hydrogen and oxygen. Monosaccharides (e.g. glucose) and disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars. Other carbohydrate molecules are very large (polysaccharides such as starch and cellulose). Carbohydrates are: a source of energy for the … Read more Carbohydrates (glucose, sucrose and cellulose)

Elementary idea of LASER

Elementary idea of LASER Laser, a device that stimulates atoms or molecules to emit light at particular wavelengths and amplifies that light, typically producing a very narrow beam of radiation. The emission generally covers an extremely limited range of visible, infrared, or ultraviolet wavelengths. Many different types of lasers have been developed, with highly varied … Read more Elementary idea of LASER

Engineering plastics (ABS and poly carbonates)

Engineering plastics Engineering plastics are a group of plastic materials that have better mechanical and/or thermal properties than the more widely used commodity plastics (such as polystyrene, PVC, polypropylene and polyethylene).  Being more expensive, engineering plastics are produced in lower quantities and tend to be used for smaller objects or low-volume applications (such as mechanical … Read more Engineering plastics (ABS and poly carbonates)

Rubbers (polyisoprene and polybutadiene)

Rubbers There are many different kinds of rubber, but they all fall into two broad types: natural rubber (latex—grown from plants) and synthetic rubber (made artificially in a chemical plant or laboratory). Commercially, the most important synthetic rubbers are styrene butadiene (SBR), polyacrylics, and polyvinyl acetate (PVA); other kinds include polyvinyl chloride (PVC), polychloroprene (better … Read more Rubbers (polyisoprene and polybutadiene)

Blood groups

Blood groups Blood group, classification of blood based on inherited differences (polymorphisms) in antigens on the surfaces of the red blood cells (erythrocytes). Inherited differences of white blood cells (leukocytes), platelets (thrombocytes), and plasma proteins also constitute blood groups. English physician William Harvey announced his observations on the circulation of the blood in 1616 and … Read more Blood groups

Electric power plant

Electric power plant Electricity is produced at a an electric power plant. Some fuel source, such as coal, oil, natural gas, or nuclear energy produces heat. The heat is used to boil water to create steam. The steam under high pressure is used to spin a turbine. The spinning turbine interacts with a system of … Read more Electric power plant

Microscope

Microscope Microscope, instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis. Although optical microscopes are the subject of this article, an image may also be enlarged by many other wave forms, including acoustic, X-ray, or electron beam, and … Read more Microscope

Concept of pressure, atmospheric and hydrostatic pressure and their utility in daily life

Concept of pressure Pressure is the perpendicular force per unit area, or the stress at a point within a confined fluid. The pressure exerted on a floor by a 42-pound box the bottom of which has an area of 84 square inches is equal to the force divided by the area over which it is … Read more Concept of pressure, atmospheric and hydrostatic pressure and their utility in daily life

Electric transformers

Electric transformers Electrical transformers are machines that transfer electricity from one circuit to another with changing voltage level but no frequency change. Today, they are designed to use AC supply, which means that fluctuation in supply voltage is impacted by the fluctuation in the current. So, an increase in current will bring about an increase … Read more Electric transformers