Consumers, primary

Primary consumers for ferrous scrap are the iron and steel mills and foundries. Minor consumers iaclude ferroalloy producers, copper producers for use ia copper precipitation (see Recycling, nonferrous metals), and the chemical iadustry. The steel iadustry consumes about three-fourths of the total. Scrap consumption for ferroalloy production, copper precipitation, and the chemical iadustry total less than one million t. The United States is the leading exporter of ferrous scrap, exporting almost nine million t ia 1994, valued at about 1.3 biUioa. Total value of domestic scrap purchases and exports ia 1994 was 8 biUioa (2). 

Nickel. Around 56,000 t of nickel were recycled from scrap in 1994. This is just over one-third of the consumption of the metal. The only mining and smelter in the United States was idle in 1994, although INMETCO (EUwood City, Peimsylvania) was a primary consumer of recyclable metal in the production of stainless steel. Almost one-half of all nickel went into the production of stainless steels with an additional 29% in superaHoys and... 

Hill WR, Stewart AJ, Napolitano GE. 1996. Mercury speciation and bioaccumulation in lotic primary producers and primary consumers. Can J Fish Aquat Sci 53 812-819. 

Enhanced nutrient cycling in both the rhizosphere and bulk soil may depend on the bacterial grazing by protozoa or nematodes with release of inorganic N. Nematodes appear to be the primary consumers of bacteria in the rhizosphere, whereas protozoa are equally prevalent in rhizosphere and bulk soil (41,97). Estimated C-to-N ratios of bacterial-feeding nematodes range from 5 1 to 10 1 (98,99) and are generally higher than those of their bacterial food source thus the excess N is excreted as ammonia (100,101) by nematodes. The estimated... 

Most of those involved in health care administration agree that elderly patients are the primary consumers of drug products. The actual extent to which this occurs is shown quite clearly in Fig. 1, which lists by age group the distribution in the United States of the drug mentions those medications that have been prescribed, recommended or given in any medical setting... 

As 6 actions continue, such "cascade effects" as the PCB situation will be seen the first stages impacted will be the manufacturer whose product line will be modified. The next level of effect will be the user industries who are the primary consumers the final economic impact will fall on the consumer of the product or service. 

The primary consumer (grazers) are size specialized. The smallest phytoplankton (1 to 20 (Jim) are consumed by the smallest members of the zooplankton, called the... 

Tobin, J. E. (1994). Ants as primary consumers diet and abundance in the Formicidae. In Nourishment and Evolution in Insect Societies, vol. 9, eds. J. H. Hunt and C. A. Nalepa, pp. 279-307. Boulder, CO Westview Press. 

Producers support all other trophic levels, collectively called consumers. Organisms that consume producers are primary consumers. These are herbivores ( grass-eaters ), such as grazing mammals, most insects, and most birds. The primary consumers in aquatic environments are the many microscopic organ-... 

We humans eat at all trophic levels. When we eat such things as fruits, vegetables, or the grains shown in Figure 15-2, we are primary consumers when we eat beef or other meat from herbivores, we are secondary consumers. When we eat fish like trout or salmon, which eat insects and other small animals, we are tertiary or quaternary consumers. Our great and growing numbers, however, are possible only because of our ability to ear as primary consumers. 

Most people are primary consumers, with a diet consisting primarily of grains. 

Was this youT answeT Sharks feed on fish and marine mammals, which makes them secondary, tertiary, or quaternary consumers. Phytoplanktonfeeding gray whales, however, are primary consumers. When an orca feeds on a shark, it is eating at a higher trophic level than when it feeds on a gray... 

The higher the trophic level, the less biochemical energy is available to sustain a population. Our great and growing numbers are possible only because of our ability to eat as primary consumers. 

Primary consumer Cladoceran testb Ceriodaphnia dubia assay Acute motility inhibition (after a 48-h exposure) Environment Canada, 1990... 

Primary consumer Cladoceran test Daphnia magna Acute lethality (after a 48-h exposure), LC50 Dutka, 1989b... 

Owing to possible future restrictions that could preclude the testing of samples with all five toxicity tests, we evaluated the index response with a reduced battery of toxicity tests. The basic rule for the selection of tests in a reduced battery was to maintain one primary producer, one primary consumer and a secondary consumer. The test combinations of two selected reduced batteries were Hydra, Daphnia and Lactuca tests (H-D-L) and Hydra, Daphnia and S. capricornutum (H-D-S) tests... 

Heterotrophic organisms which consume other organisms and/or particulate organic matter. Primary consumers are herbivores (e.g., daphnids eating micro-algae) whereas secondary consumers are carnivores (e.g., hydras eating daphnids). Volume 2(1). 

According to Mannsville Chemical Products Corporation (1999), production of DEHP is expected to grow at a rate less than the gross domestic product over the next few years due to limited growth in polyvinyl chicride (PYC) markets -which have been the primary consumers of DEHP. In addition,... 

Extrapolating toxicant effects among media may differ according to the trophic status of the species under consideration. Whether a species is a primary producer, primary consumer, or secondary consumer will influence which environmental compartments and media, and hence which routes of uptake, need to be considered. 

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