acid deposition (A type of pollution which washes out of the atmosphere as dilute sulphuric and nitric acids. It tends to be a regional rather than a global phenomenon, linked to particular industrial activities and meteorological conditions. It includes rain, more than normally acidic snow, mist, sleet, fog, gas and dry particles. It upsets the balance of nature, disrupting ecosystems, and destroys forests and woodlands, plants and crops; kills aquatic life by altering the chemical balance of lakes and rivers and corrodes building materials and fabrics. The pollutants are caused principally by discharges from power station chimneys of sulphur dioxide and nitrogen oxides released by burning fossil fuels, coal and oil) |
deposició àcida |
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acid rain (Rain having a pH less than 5.6. The acidity results from chemical reactions occurring when water, sulphur dioxide, and nitrogen oxides, generally released by industrial processes, are chemically transformed into sulphuric and nitric acids) |
pluja àcida |
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acidification (Addition of an acid to a solution until the pH falls below 7) |
acidificació |
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acidity (The state of being acid that is of being capable of transferring a hydrogen ion in solution) |
acidesa |
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acidity degree (The amount of acid present in a solution, often expressed in terms of pH) |
grau d'acidesa |
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acoustic comfort |
confort acústic |
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acoustic filter (A device employed to reject sound in a particular range of frequencies while passing sound in another range of frequencies) |
filtre acústic |
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acoustic insulation (The process of preventing the transmission of sound by surrounding with a nonconducting material) |
aïllament acústic |
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acoustic level (Physical quantity of sound measured, usually expressed in decibels) |
nivell acústic |
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acoustic property (The characteristics found within a structure that determine the quality of sound in its relevance to hearing) |
propietat acústica |
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acoustical quality (The characteristics of a confined space that determines its ability to enable music and speech to be heard clearly within it) |
qualitat acústica |
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acoustics (The science of the production, transmission and effects of sound) |
acústica |
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act (1. Something done voluntarily by a person, and of such a nature that certain legal consequences attach to it. 2. Documents, decrees, edicts, laws, judgments, etc.) |
actes |
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actinide (A group of 15 radioactive elements some of which occur naturally while others are produced in nuclear reactions. They include plutonium, americium and neptunium. The health hazard presented by the actinides, if they are released into the environment, comes from the potency of their radioactive characteristics. They are alpha-emitters, and therefore can cause intense localized damage in tissues if absorbed into the body) |
actínid |
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actinium (A radioactive element of the actinide series, occurring as a decay product of uranium. It is used as an alpha particle source and in neutron production) |
actini |
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action group (A collection of persons united to address specific sociopolitical or socioeconomic concerns) |
grup d'acció |
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activated carbon (A powdered, granular or pelleted form of amorphous carbon characterized by a very large surface area per unit volume because of an enormous number of fine pores) |
carbó actiu |
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activated sludge (Sludge that has been aerated and subjected to bacterial action; used to speed breakdown of organism matter in raw sewage during secondary waste treatment) |
llots activats |
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active participation (The involvement, either by an individual or a group of individuals, in their own governance or other activities, with the purpose of exerting influence) |
participació activa |
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active population (The number of people available and eligible for employment within a given enterprise, region or nation) |
població activa |
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