useful cross section
71Stone Age — the period in the history of humankind, preceding the Bronze Age and the Iron Age, and marked by the use of stone implements and weapons: subdivided into the Paleolithic, Mesolithic, and Neolithic periods. [1860 65] * * * First known period of… …
72fibre, man-made — Introduction fibre whose chemical composition, structure, and properties are significantly modified during the manufacturing process. Man made fibres are spun and woven into a huge number of consumer and industrial products, including… …
73Eastern span replacement of the San Francisco — San Francisco – Oakland Bay Bridge (eastern span replacement) Artistic rendition of the new eastern span of the Bay Bridge seen from Treasure Island (ca. 2014) Official name To be determ …
74Diffraction topography — (short: topography ) is an X ray imaging technique based on Bragg diffraction. Diffraction topographic images ( topographs ) record the intensity profile of a beam of X rays (or, sometimes, neutrons) diffracted by a crystal. A topograph thus… …
75Sediment Profile Imagery — (SPI) is an underwater technique for photographing the interface between the seabed and the overlying water. The technique is used to measure or estimate biological, chemical, and physical processes occurring in the first few centimetres of… …
76Glossary of botanical terms — Many of the terms used in Wikipedia glossaries (often most) are already defined and explained within Wikipedia itself. However, lists like the following indicate where new articles need to be written and are also useful for looking up and… …
77solids, mechanics of — ▪ physics Introduction science concerned with the stressing (stress), deformation (deformation and flow), and failure of solid materials and structures. What, then, is a solid? Any material, fluid or solid, can support normal forces.… …
78Hafnium — lutetium ← hafnium → tantalum Zr ↑ Hf ↓ Rf …
79Nuclear fission — For the generation of electrical power by fission, see Nuclear power. Splitting the atom redirects here. For the EP, see Splitting the Atom. Nuclear physics Radioactive decay Nuclear fission Nuclear fusio …
80Anechoic chamber — An anechoic chamber An anechoic chamber (an echoic meaning non echoing or echo free) is a room designed to stop reflections of either sound or electromagnetic waves. They are also insulated from exterior sources of noise. The combination of both… …
