Extractions involve many expensive steps such as roasting and smelting, which require sufficient concentrations of elements in ores and are environmentally unfriendly.

Panzer forces were dispersed among the three German concentrations without strong emphasis on independent use, being used to create or destroy close pockets of Polish forces and seize operational-depth terrain in support of the largely un-motorized infantry which followed.

In a chemical reaction, chemical equilibrium is the state in which both reactants and products are present at concentrations which have no further tendency to change with time.

They can also be affected by high concentrations of other macromolecules, which causes macromolecular crowding.

However, this value is only approximate, as reaction quotient is defined in terms of ion activities which can be approximated with the concentrations as calculated here.

Other reasons include: a ) changes in plant canopy caused by shifts in plant biomass production associated with moisture regime ; b ) changes in litter cover on the ground caused by changes in both plant residue decomposition rates driven by temperature and moisture dependent soil microbial activity as well as plant biomass production rates ; c ) changes in soil moisture due to shifting precipitation regimes and evapo-transpiration rates, which changes infiltration and runoff ratios ; d ) soil erodibility changes due to decrease in soil organic matter concentrations in soils that lead to a soil structure that is more susceptible to erosion and increased runoff due to increased soil surface sealing and crusting ; e ) a shift of winter precipitation from non-erosive snow to erosive rainfall due to increasing winter temperatures ; f ) melting of permafrost, which induces an erodible soil state from a previously non-erodible one ; and g ) shifts in land use made necessary to accommodate new climatic regimes.

This radiogenic helium is trapped with natural gas in concentrations up to 7 % by volume, from which it is extracted commercially by a low-temperature separation process called fractional distillation.

However, HDL carries many lipid and protein species, several of which have very low concentrations but are biologically very active.

The simple formula for the Hall coefficient given above becomes more complex in semiconductors where the carriers are generally both electrons and holes which may be present in different concentrations and have different mobilities.

Electrical breakdown occurs when the electric field in the material is strong enough to accelerate free charge carriers ( electrons and ions, which are always present at low concentrations ) to a high enough velocity to knock electrons from atoms when they strike them, ionizing the atoms.

This targets the 3 ' ( sib ) end of the mRNA for RNAaseIII degradation, which results in a lower effective concentration of int mRNA than xis mRNA ( as the int cistron is nearer to the sib sequence than the xis cistron is to the sib sequence ), so a higher concentrations of xis than int is observed.

The largest concentrations of population are in North P ' yŏngan and South P ' yŏngan provinces, in the municipal district of P ' yongyang, and in South Hamgyŏng Province, which includes the Hamhŭng-Hŭngnam urban area.

Analysis of the relative concentrations of various uranium, thorium and protactinium isotopes in water and minerals is used in radiometric dating of sediments which are up to 175, 000 years old and in modeling of various geological processes.

The fact that how fast reactions occur can often be specified with just a few concentrations and a temperature, instead of needing to know all the positions and speeds of every molecule in a mixture, is a special case of another key concept in physical chemistry, which is that to the extent an engineer needs to know, everything going on in a mixture of millions of billions of billions of particles can often be described by just a few variables like pressure, temperature, and concentration.

Red tide is a common name for a phenomenon also known as an algal bloom ( large concentrations of aquatic microorganisms ), an event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and results in discoloration of the surface water.

Since the cytosol contains high concentrations of glutathione and is, therefore, a reducing environment, proteins containing disulfide bonds, which are formed from oxidized cysteine residues, cannot be produced in this compartment.

Excess sodium in the soil limits the uptake of water due to decreased water potential, which may result in wilting ; similar concentrations in the cytoplasm can lead to enzyme inhibition, which in turn causes necrosis and chlorosis.

Even in the narrow range of concentrations which make up steel, mixtures of carbon and iron can form a number of different structures, with very different properties.

Rigid restrictions are observed for the concentrations of certain chemical substances which can affect the taste and quality of sake.

In this example, which reaction takes place is controlled in part by the relative concentrations of the reactants.

The majority of the TCAs act primarily as serotonin-norepinephrine reuptake inhibitors ( SNRIs ) by blocking the serotonin transporter ( SERT ) and the norepinephrine transporter ( NET ), respectively, which results in an elevation of the synaptic concentrations of these neurotransmitters, and therefore an enhancement of neurotransmission.

By studying how quickly the reagent species disappears in the presence of differing concentrations of a ( usually stable ) co-reagent species the reaction rate constant at the low temperature of the CRESU flow can be determined.

Stable carbamazepine concentrations occur usually within 2 – 3 weeks after initiation of therapy.

By repeatedly evaluating their course, and adjusting if they are moving in the wrong direction, bacteria can direct their motion to find favorable locations with high concentrations of attractants ( usually food ) and avoid repellents ( usually poisons ).

When separating proteins or small nucleic acids ( DNA, RNA, or oligonucleotides ) the gel is usually composed of different concentrations of acrylamide and a cross-linker, producing different sized mesh networks of polyacrylamide.

can be used to derive hydrogen ion concentrations from experimental measurements of E. The slope factor, f, is usually slightly less than one.

The quasispecies equations are usually expressed in terms of concentrations where

Clay minerals are typically formed over long periods of time by the gradual chemical weathering of rocks, usually silicate-bearing, by low concentrations of carbonic acid and other diluted solvents.

However, the ozone hole is most usually measured not in terms of ozone concentrations at these levels ( which are typically of a few parts per million ) but by reduction in the total column ozone, above a point on the Earth's surface, which is normally expressed in Dobson units, abbreviated as " DU ".

* Root pressure: If the water potential of the root cells is more negative than that of the soil, usually due to high concentrations of solute, water can move by osmosis into the root from the soil.

* Dehydration – loss of fluid in the body ( usually water ) resulting in abnormal concentrations of substances in the blood and fluids.

The dissociation constant is usually written as a quotient of the equilibrium concentrations ( in mol / L ), denoted by, and:

However, use of activities is very inconvenient, so the equilibrium constant is usually divided by the quotient of activity coefficients, to become a quotient of concentrations.

They usually have higher sugar concentrations, and the texture may be chewy, hard, or brittle.

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, chlorapatite and bromapatite, named for high concentrations of OH < sup >−</ sup >, F < sup >−</ sup >, Cl < sup >−</ sup > or Br < sup >−</ sup > ions, respectively, in the crystal.

An entire control system involving high pressure pumps ( usually called the charging and letdown system ) is required to remove water from the high pressure primary loop and re-inject the water back in with differing concentrations of boric acid.

In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids.

Such products with concentrations of 30 parts per million ( ppm ) or less are typically manufactured using an electrolysis process, whereas those with higher concentrations of 50 ppm or more are usually silver compounds that have been bound with a protein.

Classic protein hormones circulate in nanomolar ( 10 ) concentrations that usually vary by less than one order of magnitude.

Blood or plasma citalopram concentrations are usually in a range of 50-400 μg / L in persons receiving the drug therapeutically, 1000-3000 μg / L in patients who survive acute overdosage and 3 – 30 mg / L in those who do not survive.

Blood or plasma concentrations are usually in a range of 10-300 ug / l in persons either receiving the drug therapeutically or in those arrested for impaired driving.

* Parts per million, a way of quantifying small concentrations, usually mass

None of these devices prevent future episodes of anaphylaxis, but patients who experience severe or life-threatening reactions may be treated with a series of allergy injections composed of increasing concentrations of naturally occurring substances such as venom to provide excellent and usually lifelong protections against adverse effects of future insect stings: the initial injections have a very low concentration, usually 1 ppb or less.