First of all, thermal loads are sometimes called hidden or locked-in loads and caused by daily or seasonal change in air temperature. To clarify its effect, let´s assume that a steel bridge 100 m long was erected in winter at an average temperature of 2oC. On a summer day, when the air temperature reaches 32oC, the bridge lengthens, since all bodies expand when heated. The increase in length of the bridge can be computed to be only 3 cm. It is indeed small, one three thousandths of the bridge´s length, however, if the bridge is anchored to abutments that do not allow this thermal expansion, the abutments will push on the bridge to reduce its length by 3 cm. And unfortunately steel is so stiff that the compressive load uses up half the strength of the steel therefore, the bridge´s resistance weakens. And for engineers, there is only one way of avoiding this dangerous overstress: one of the bridge´s ends must be allowed to move - to permit the thermal expansion.
and are provided with heavy base and thin blade. The edges and sides are accurately finished. There are different squares: adjustable square, which consists of three parts with screw hinge, centering square and flange square. Feeler Gauges are used to measure distances or clearances between two surfaces. They are usually made of hardened steel and provided with conical blades. The length of blades is 100 mm. The number stamped on each blade is the thickness of that particular blade in thousandths of an inch. Radius Gauges are concave and convex gauges for checking raised and recessed curvatures forming part of a circle. Screw Pitch Gauge can be used if there is any doubt as to the number of threads on a bolt, screw, nut, etc. Each blade of finger is stamped with the number of threads cut on it. It may be used either for external and internal measurements. Vernier Calipers are used for measuring diameters, lengths, depths, and distances.
1950 Engineering Research Associates of Minneapolis built the ERA 1101, the first commercially produced computer; the company's first customer was the U.S. Navy. It held 1 million bits on its magnetic drum, the earliest magnetic storage devices. Drums registered information as magnetic pulses in tracks around a metal cylinder. Read/write heads both recorded and recovered the data. Drums eventually stored as many as 4,000 words and retrieved any one of them in as little as five-thousandths of a second. 1951 The UNIVAC I delivered to the U.S. Census Bureau was the first commercial computer to attract widespread public attention. Although manufactured by Remington Rand, the machine often was mistakenly referred to as the "IBM UNIVAC." Remington Rand eventually sold 46 machines at more than $1 million each. SPEED: 1,905 operations per second INPUT/OUTPUT: magnetic tape, unityper, printer MEMORY SIZE: 1,000 12-digit words in delay lines MEMORY TYPE: delay lines, magnetic tape
1950 Engineering Research Associates of Minneapolis built the ERA 1101, the first commercially produced computer; the company's first customer was the U.S. Navy. It held 1 million bits on its magnetic drum, the earliest magnetic storage devices. Drums registered information as magnetic pulses in tracks around a metal cylinder. Read/write heads both recorded and recovered the data. Drums eventually stored as many as 4,000 words and retrieved any one of them in as little as five-thousandths of a second. 1951 The UNIVAC I delivered to the U.S. Census Bureau was the first commercial computer to attract widespread public attention. Although manufactured by Remington Rand, the machine often was mistakenly referred to as the "IBM UNIVAC." Remington Rand eventually sold 46 machines at more than $1 million each. SPEED: 1,905 operations per second INPUT/OUTPUT: magnetic tape, unityper, printer MEMORY SIZE: 1,000 12-digit words in delay lines MEMORY TYPE: delay lines, magnetic tape
annaabi.ee 
