second metal

1) металл || покрывать металлом || металлический

2) рудоносная порода

3) щебень || мостить щебнем

4) ж.-д. балласт || балластировать

5) мн. ч. англ. рельсы

6) стекломасса

இரண்டாம்புரிவெட்டும் திருகாணி

இரண்டாங்கொத்தரம் (பருமனரம்)

இரண்டாங்கொத்தரம் (பருமனரம்)

இரு கொத்து அரம்

இருகொத்து அரம்

இடையான அல்லது இரண்டாந்திருகலுட் புரிவெடி

செக்கனுக்கடி (செ. அ.)

SUBJECT AREA: Electricity, Electronics and information technology, Telecommunications

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At the age of 17 Hertz entered the Gelehrtenschule of the Johaneums in Hamburg, but he left the following year to obtain practical experience for a year with a firm of engineers in Frankfurt am Main. He then spent six months at the Dresden Technical High School, followed by year of military service in Berlin. At this point he decided to switch from engineering to physics, and after a year in Munich he studied physics under Helmholtz at the University of Berlin, gaining his PhD with high honours in 1880. From 1883 to 1885 he was a privat-dozent at Kiel, during which time he studied the electromagnetic theory of James Clerk Maxwell. In 1885 he succeeded to the Chair in Physics at Karlsruhe Technical High School. There, in 1887, he constructed a rudimentary transmitter consisting of two 30 cm (12 in.) rods with metal balls separated by a 7.5 mm (0.3 in.) gap at the inner ends and metallic plates at the outer ends, the whole assembly being mounted at the focus of a large parabolic metal mirror and the two rods being connected to an induction coil. At the other side of his laboratory he placed a 70 cm (27½ in.) diameter wire loop with a similar air gap at the focus of a second metal mirror. When the induction coil was made to create a spark across the transmitter air gap, he found that a spark also occurred at the "receiver". By a series of experiments he was not only able to show that the invisible waves travelled in straight lines and were reflected by the parabolic mirrors, but also that the vibrations could be refracted like visible light and had a similar wavelength. By this first transmission and reception of radio waves he thus confirmed the theoretical predictions made by Maxwell some twenty years earlier. It was probably in his experiments with this apparatus in 1887 that Hertz also observed that the voltage at which a spark was able to jump a gap was significantly reduced by the presence of ultraviolet light. This so-called photoelectric effect was subsequently placed on a theoretical basis by Albert Einstein in 1905. In 1889 he became Professor of Physics at the University of Bonn, where he continued to investigate the nature of electric discharges in gases at low pressure until his death after a long and painful illness. In recognition of his measurement of radio and other waves, the international unit of frequency of an oscillatory wave, the cycle per second, is now universally known as the Hertz.

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See also: Heaviside, Oliver

1) Engineering: bimetallic corrosion, corrosion at contact, corrosion at contact with a second metal, direct attack, galvanic corrosion, two-metal corrosion

2) Metallurgy: crevice corrosion (обычно с неметаллом)

3) Oil: meeting corrosion, contact corrosion

4) Polymers: mating corrosion

5) Electrochemistry: bi-metallic corrosion

இடையான குழாய் வாயில் (இரண்டாங்குழாய் வாயில்)

1 scrap (metal) (metal).

2 junk (objetos, piezas).

3 cheap and nasty jewelry (informal) (joyas).

4 small change (informal) (monedas).

5 scrap metal, waste iron, scrap iron, old iron.

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► nombre femenino

1 (escoria) slag

2 (hierro viejo) scrap iron, scrap

3 familiar peyorativo (calderilla) small change

4 familiar peyorativo (joyas) junk jewellery (US jewelry)

5 familiar figurado (trasto) piece of junk

■ este máquina es una chatarra this machine is a piece of junk

\

parque de chatarra scrap yard

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* * *

SF scrap, scrap iron

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adjetivo invariable (Méx)

1) (Metal) scrap (metal)

2) (fam) ( calderilla) change, small o loose change

* * *

= scrap, scrap metal, lemon, jalopy, cruft.

Ex. The demand for the old faces came to an abrupt end and the founders withdrew them from sale, some even destroying the old punches and matrices as so much scrap.

Ex. It may look like junk, but to thieves scrap metal has become as good as gold.

Ex. The California Lemon Law act applies not only to defective cars (or ' lemons') but recreational vehicles as well.

Ex. For all Havana's crumbling structures, its disintegrating roads and toxin-belching jalopies, it attracts over a million tourists each year.

Ex. This cruft doesn't harm the system, it merely takes up some space.

* * *

adjetivo invariable (Méx)

1) (Metal) scrap (metal)

2) (fam) ( calderilla) change, small o loose change

* * *

* * *

( Méx): comida chatarra junk food

productos chatarra cheap o shoddy goods

empresas chatarra second-rate companies

A ( Metal) scrap, scrap metal

el coche es pura chatarra the car is just a heap of scrap

B ( fam) (calderilla) change, small o loose change

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◊ comida chatarra junk food;

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chatarra nf

1. [metal] scrap (metal)

2. [objetos, piezas] junk

3. Fam [joyas] cheap and nasty jewellery;

este anillo es pura chatarra this ring is a piece of tat

4. Fam [condecoraciones] brass, medals;

un general cargado de chatarra a general weighed down with medals

5. Fam [monedas] small change

6. Méx Fam [comida] junk food

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f scrap

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chatarra nf

: scrap metal

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chatarra n

1. (metal) scrap

2. (monedas) small change

- overhead way machine