Gear

A gear is a wheel with teeth around its circumference, the purpose of the teeth being to mesh with similar teeth on another mechanical device possibly another gear wheel so that force can be transmitted between the two strategies in a direction tangential to their surfaces. A non-toothed wheel can transmit some tangential force but will slip if the force is large; teeth put off slippage and permit the transmission of large forces.

A gear can mesh with any device having teeth friendly with the gear's teeth. Such devices include racks and other non-rotating policy; however, the most common condition is for a gear to be in mesh with another gear. In this case revolution of one of the gears necessarily causes the other gear to rotate. In this way, rotational motion can be transferred from one position to another. While gears are sometimes used simply for this reason to transmit rotation to another shaft perhaps their most significant feature is that, if the gears are of asymmetrical sizes, a mechanical advantage is also achieved, so that the rotational speed, and torque, of the second gear are dissimilar from that of the first. In this way, gears provide a means of increasing or decreasing a turning speed, or a torque.

Bond

In finance, a bond is a debt security, in which the authorized issuer owes the holders a debt and is grateful to repay the principal and interest at a later date, termed maturity. Other conditions may also be attached to the bond issue, such as the obligation for the issuer to provide certain information to the bond holder, or limitations on the behavior of the issuer. Bonds are generally issued for a permanent term longer than ten years. U.S Treasury securities issue debt with life of ten years. New debt between one year and ten years is a note, and new debit less than a year is a bill.

A bond is simply a loan, but in the form of a security, although expressions used is rather different. The issuer is equivalent to the borrower, the bond holder to the lender, and the voucher to the interest. Bonds enable the issuer to finance long-term investments with external funds. Certificates of deposit (CDs) or commercial paper are measured money market instruments.

Social network

A social network is a social structure made of nodes that are tied by one or more specific types of relatives, such as values, visions, idea, financial exchange, friends, kinship, dislike, trade, web links, sexual relations, disease communication or airline routes.Social network analysis views common relationships in terms of nodes and ties. Nodes are the individual actors within the networks, and ties are the associations between the actors. Research in a number of academic fields has shown that social networks operate on many levels, from families up to the level of nations, and play a serious role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals.

In its simplest form, a social network is a map of all of the appropriate ties between the nodes being studied. The network can also be used to decide the social capital of individual actors. These concepts are often displayed in a shared network diagram, where nodes are the points and ties are the lines.

Electron

In relativistic quantum mechanics, the electron is described by the direct Equation which defines the electron as a point. In quantum field theory, the activities of the electron are described by quantum electrodynamics, a gauge theory. In Dirac's model, an electron is defined to be a mathematical point, a point-like, exciting bare particle surrounded by a sea of interacting pairs of virtual particles and antiparticles. The extraordinarily precise agreement of this forecast with the experimentally resolute value is viewed as one of the great achievements of modern physics.

In the Standard Model of particle physics, the electron is the first-generation stimulating lepton. It forms a weak isospin doublet with the electron neutrino, these two particles cooperate with each other through both the charged and neutral current weak interaction. The electron is very similar to the two more massive particles of higher generations, the muon and the tau lepton, which are identical in charge, spin, and interface but differ in mass.