Strain (chemistry)In chemistry, a molecule experiences strain when its chemical structure undergoes some stress which raises its internal energy in comparison to a strain-free reference compound. The internal energy of a molecule consists of all the energy stored within it. A strained molecule has an additional amount of internal energy which an unstrained molecule does not. This extra internal energy, or strain energy, can be likened to a compressed spring.
BellfoundingBellfounding is the casting and tuning of large bronze bells in a foundry for use such as in churches, clock towers and public buildings, either to signify the time or an event, or as a musical carillon or chime. Large bells are made by casting bell metal in moulds designed for their intended musical pitches. Further fine tuning is then performed using a lathe to shave metal from the bell to produce a distinctive bell tone by sounding the correct musical harmonics.
Boat buildingBoat building is the design and construction of boats and their systems. This includes at a minimum a hull, with propulsion, mechanical, navigation, safety and other systems as a craft requires. Wood is the traditional boat building material used for hull and spar construction. It is buoyant, widely available and easily worked. It is a popular material for small boats (of e.g. length; such as dinghies and sailboats). Its abrasion resistance varies according to the hardness and density of the wood and it can deteriorate if fresh water or marine organisms are allowed to penetrate the wood.
Prelog strainIn organic chemistry, transannular strain (also called Prelog strain after chemist Vladimir Prelog) is the unfavorable interactions of ring substituents on non-adjacent carbons. These interactions, called transannular interactions, arise from a lack of space in the interior of the ring, which forces substituents into conflict with one another. In medium-sized cycloalkanes, which have between 8 and 11 carbons constituting the ring, transannular strain can be a major source of the overall strain, especially in some conformations, to which there is also contribution from large-angle strain and Pitzer strain.
Sculpture en bronzethumb|L'Âge d'airain bronze original de Rodin (1875-1876) Une sculpture en bronze est obtenue à partir d'un modèle original en terre, en cire ou en plâtre qui est fondue en bronze à partir d'un moule. En sculpture, cette technique remonte à la plus haute Antiquité, depuis au moins le . La technique de base n'a pas changé à travers les siècles : après avoir modelé un objet en cire, on le recouvre d'un mélange à base d'argile, on le fait cuire, ce qui fait fondre la cire, puis on y coule l'alliage de bronze.
Stress–strain curveIn engineering and materials science, a stress–strain curve for a material gives the relationship between stress and strain. It is obtained by gradually applying load to a test coupon and measuring the deformation, from which the stress and strain can be determined (see tensile testing). These curves reveal many of the properties of a material, such as the Young's modulus, the yield strength and the ultimate tensile strength. Generally speaking, curves representing the relationship between stress and strain in any form of deformation can be regarded as stress–strain curves.
