Kārtot: Augošā secībā
sarashkins 06.10.2011 22:59

Sviestnesis rakstīja: ...

Juglas Kanālāmetējs. = Provincionālais Vārtrūmēmetējs.

sarashkins 06.10.2011 21:22
Metējs. Vārtrūmē.
sarashkins 05.10.2011 14:07
Man ta vienalga, katik reitungs ceļas!
sarashkins 05.10.2011 13:02

Japnis rakstīja:

sarashkins rakstīja:

Japnis rakstīja:

SEA rakstīja: Es varētu tikai iespert, ja tas der...

Tas Pirmajam patiktos...

A jūs bieži tā abi izklaidējaties?

Regulāri

regulārs

Svešvārdu vārdnīca. Jumava

- Izcelsme - latīņu regularis.

- 1. Tāds, kas atkārtojas ar noteiktiem starplaikiem; vienmērīgs; pastāvīgs.

Tad jau jūs pēc pulksteņa TO darat?

Vai pēc kalendāra tomēr?

sarashkins 04.10.2011 21:57

Japnis rakstīja:

SEA rakstīja: Es varētu tikai iespert, ja tas der...

Tas Pirmajam patiktos...

A jūs bieži tā abi izklaidējaties?

sarashkins 04.10.2011 21:56

Japnis rakstīja:

SEA rakstīja: Pēdējoreiz viņš lāga apmierināts neizskatījās, ...

Tas tapēc, ka tu nespēri vēl un vēl un vēl...

Iesper divreiz! Divreiz!

sarashkins 04.10.2011 21:55

Japnis rakstīja:

SEA rakstīja: Pēdējoreiz viņš lāga apmierināts neizskatījās, ...

Tas tapēc, ka tu nespēri vēl un vēl un vēl...

Iesper divreiz! Divreiz!

sarashkins 04.10.2011 20:34
Tos rezistorus var izvilkt līdz pečkas radiatoram un sildīt salonu, kad vajag.
sarashkins 04.10.2011 17:57

muttabor rakstīja: Ieliekot pagriezienam diožu lampu, samazinās pretestība uz releju, un pagrieziens mirgo ātrāk. It kā vajadzētu strāvas vadā ielikt pretestību, bet nezinu cik omi tai jābūt. Cik man zināms, tie omi, apzīmējas ar krāsām. Var būt kāds zina konkrēti, cik omu pretestībai jābūt, (vai ar kādām krāsām tā ir marķēta) lai atrisinātu šo bēdu?

P.S.

Apcirst līkus nagus, ja nav paredzēts, nelien, jau esmu lasījis. Bet nu laikam tāds cirvis vēl nav nokalts......nesanāk.

6 ômi, bet 50 vatti!!!

www.ebay.co.uk/...

sarashkins 03.10.2011 21:10

sarashkins 03.10.2011 21:10

sarashkins 03.10.2011 21:10

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:05

sarashkins 03.10.2011 21:04

sarashkins 03.10.2011 21:03
Te visi laikam pārvākušies uz šo vietu? www.draugiem.lv/...

sarashkins 03.10.2011 21:01

sarashkins 03.10.2011 20:57

sarashkins 03.10.2011 20:53

SEA rakstīja: ....

sarashkins 30.09.2011 23:45

sarashkins rakstīja: Paņēmu no plaukta ķīmijas mācību grāmatas un apskatījos attiecīgās nodaļas par spirtiem - nekur nekas par alkoholu nav rakstīts, vienīgi par spirtiem- gan 1988. gadā Zvaigznes izdotajā "Organiskajā ķīmijā", gan 1985. gada "Ķīmija augstskolu reflektantiem", gan 1994. gada "Ķīmija rokasgrāmata skolēniem". Pirmajā vienīgais, kas saistībā ar alkoholu ir minēts - par alkoholisko rūgšanu, kas notiek vīna raudzēšanas procesā. Pēdējā pie vienvērtīgajiem piesātinātajiem spirtiem iekavās minēts nosaukums "alkanoli".

Jautājums - kur un ko iedgars ir mācījies?

Vārdu sakot, gaidām no i_edgara konkrētas ķīmijas mācību grāmatas nosaukumu, izdevniecību un gadu, kur tāds "alkohols", kā pats apgalvo, ir definēts.

sarashkins 30.09.2011 23:43
Savukārt, Britannica 2001 ir šāds ieraksts:

alcohol

any of a class of organic compounds characterized by one or more hydroxyl (OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain). Alcohols may be considered as derivatives of water (H2O) in which one of the hydrogen atoms has been replaced by an alkyl group. Alcohols are among the most common organic compounds and are valuable intermediates in the synthesis of other compounds.

Alcohols may be classified according to which carbon of the alkyl group is bonded to the hydroxyl group. In primary alcohols (RCH2OH), the oxygen of the hydroxyl group is bonded to a carbon atom bearing at least two hydrogen atoms. In secondary alcohols (R2CHOH), the hydroxyl group is bonded to a carbon attached to two other carbons, while in tertiary alcohols (R3COH) it is bonded to a carbon attached to three other carbon atoms.

Most alcohols are colourless liquids or solids at room temperature: primary alcohols with fewer than 12 carbon atoms are liquid; those with 12 or more carbon atoms are solid. Polyhydric alcohols (those with more than one hydroxyl group) usually have the consistency of syrup. Alcohols with complex arrangements of carbon atoms, such as sterols, are usually solids. Alcohols of low molecular weight are highly soluble in water. With increasing molecular weight, alcohols become less soluble in water and their boiling points, vapour pressures, densities, and viscosities increase.

Primary alcohols may be oxidized to aldehydes or further to carboxylic acids, and secondary alcohols may be oxidized to ketones. When tertiary alcohols are oxidized, they decompose, breaking carbon-carbon bonds. Alcohols generally react with carboxylic acids to produce esters--neutral organic compounds found in fats and oils. Alcohols can also be converted to ethers and olefinic hydrocarbons.

Adding hydroxyl groups to an alcohol without increasing the number of carbon atoms changes many of its properties. In some cases, it may enhance sweetness, and the resultant alcohols are used as sweeteners. Alcohols with 8 to 12 carbon atoms have a characteristic roselike or lilylike odour and are used in making perfumes. In general, the most important industrial use of alcohols is as chemical intermediates, chiefly because alcohols can readily be converted into a large number of other compounds. This is done by simple chemical reactions to yield products such as fats and waxes--surface active agents used in detergents, plasticizers, emulsifiers, lubricants, emollients, and foaming agents.

Alcohols are among the more abundantly produced organic chemicals in industry. Some, such as ethanol and methanol, are utilized in great quantities. Ethanol, CH3CH2OH, also called ethyl alcohol, or grain alcohol, can be made by fermentation from the carbohydrates found in fruits, molasses, grains, and other agricultural products. It is also made industrially from ethylene, CH2CH2. Ethanol is used in toiletries and pharmaceuticals and to sterilize hospital instruments. It is, moreover, the alcohol in alcoholic beverages. The anesthetic ether is also made from ethanol.

Methanol, also known as methyl alcohol, wood alcohol, or carbinol, can be manufactured from hardwood or from hydrogen and carbon monoxide (CO). It is used as a solvent, as a raw material for the manufacture of formaldehyde and special resins, in special fuels, in antifreeze, and for cleaning metals.

Methanol and ethanol are good fuels for automobile engines because they have high octane ratings and low pollution emission, though their solvent properties can cause problems by dissolving certain materials used in modern fuel systems. Gasohol, a solution of 10 percent ethanol in gasoline, is an alternative fuel that can be used in most automobiles without the solvency problem.

Copyright © 1994-2001 Encyclop¿dia Britannica, Inc.

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