Artificial gravity is the varying of gravity using artificial means. It is used largely in space, but also on Earth. It can be achieved by the use of different forces, in particular centrifugal force and (for short periods) linear acceleration. The creation of artificial gravity is considered desirable for long-term space travel or habitation. It allows for ease of mobility, …
Read More »What is arterial grafting?
This is technique whereby a diseased or damaged section of artery is replaced with tubing prepared either from synthetic materials, or with a section of healthy artery from the patient or from another person.
Read More »What is argemone oil?
Argemone oil is extracted from argemone seeds. It is mixed with sunflower oil and sesame oil to increase their quantity. Consumption of this oil leads to health disorders among children. To avoid this, we must check the contents of the cooking oil. Many oil brands mention ‘no argemone oil’ on their packs.
Read More »What is apomixis? How does it differ from amphimixis?
Apomixis is asexual reproduction without fertilization — developing or producing without sexual union. This is a botanical term (also known as apogomy) used with respect to many plants. Apomixis can occur in two ways: when the embryo arises from unfertilized egg produced without meiosis, called agamugenesis; a nucellar embryo is formed from surrounding nucellus tissues. The seeds produced are generally …
Read More »What is apogee?
The apogee is the point at which a body is at its furthest orbit from the Earth. The opposite of the apogee, the point at which an orbiting body is nearest to the earth, is the perigee. Apogee is an Earth-specific term, and other terms exist for different celestial bodies. The apsis, for example, is a generic term used to …
Read More »What is anthropocene epoch?
The current geological epoch we live in is called Holocene, which began around 9600 BC. However, considering the way humans have altered the course of the Earth scientists suggest that the epoch be renamed anthropocene. Nobel-prize winning chemist Paul Crutzen coined this term in a casual remark in 2002, while talking about how the Earth was entering a new epoch …
Read More »What is an epicenter?
The point of origin of an earthquake inside the Earth is called the focus, and the point on the surface directly above it is the epicenter. Severe earthquakes are usually shallow focus-that is, they occur within 60 km (37 miles) of the surface.
Read More »What is an emulsifier?
A colloidal system involving one liquid dispersed in another is known as emulsion. Any two immiscible liquids (those that cannot be mixed) can form an emulsion, like oil and water. An emulsifier is an agent that stabilizes the emulsion by lowering the interfacial tension between the constituents of the emulsion. Examples of emulsifiers are soaps, detergents and gelatine.
Read More »What is an electron gun?
It is a device in the back of a “cathode ray tube” television or computer monitor (pre-plasma or LCD flat-panel). The electron gun fires a stream of electrons from the back of the TV onto the inside face of the screen, which is coated with a material that glows when hit by electrons. By using powerful magnets to direct the …
Read More »What is an electrocardiograph?
When a doctor takes a pulse he is feeling the patient’s heart-beat. If the heart is beating faster than normal it may be a sign like a rise in temperature of illness somewhere in the body. For signs of illness in the heart itself a more careful check is usually needed. The working of the heart is controlled by electrical …
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