* Calcium tungstate ( CaWO < sub > 4 </ sub >) is used in luminous paints, fluorescent lights and in X-ray studies.

Terbium is used to dope calcium fluoride, calcium tungstate and strontium molybdate, materials that are used in solid-state devices, and as a crystal stabilizer of fuel cells which operate at elevated temperatures.

The most common formal oxidation state of tungsten is + 6, but it exhibits all oxidation states from − 2 to + 6 .< ref > Tungsten typically combines with oxygen to form the yellow tungstic oxide, WO < sub > 3 </ sub >, which dissolves in aqueous alkaline solutions to form tungstate ions,.

Tungsten is found in the minerals wolframite ( iron-manganese tungstate, ( Fe, Mn ) WO < sub > 4 </ sub >), scheelite ( calcium tungstate, ( CaWO < sub > 4 </ sub >), ferberite ( FeWO < sub > 4 </ sub >) and hübnerite ( MnWO < sub > 4 </ sub >).

Sodium tungstate is used in Folin-Ciocalteu's reagent, a mixture of different chemicals used in the " Lowry Assay " for protein content analysis.

Wolframite, ( Fe, Mn ) WO < sub > 4 </ sub >, is an iron manganese tungstate mineral that is the intermediate between ferberite ( Fe < sup > 2 +</ sup > rich ) and huebernite ( Mn < sup > 2 +</ sup > rich ).

Thomas Edison quickly discovered that calcium tungstate screens produced brighter images and is credited with designing and producing the first commercially available fluoroscope.

* PbWO < sub > 4 </ sub > or Lead tungstate: due to its high-Z, PbWO < sub > 4 </ sub > is suitable for applications where a high stopping power is required ( e. g. γ ray detection ).

Ferberite is a black monoclinic mineral composed of iron ( II ) tungstate, FeWO < sub > 4 </ sub >.

In chemistry a tungstate is a compound that contains an oxoanion of tungsten or is a mixed oxide containing tungsten.

The simplest tungstate ion is WO < sub > 4 </ sub >< sup > 2 −</ sup >, " orthotungstate ".

Powellite is a mineral form of calcium molybdate containing a small amount of tungstate, and scheelite is a mineral form of calcium tungstate containing a small amount of molybdate.

Wolframite is manganese and iron tungstate, and all these are valuable sources of tungsten.

Unlike chromate, tungstate is not a good oxidizer, but like chromate, it polymerizes in acid and depolymerizes back to tungstates in alkaline solutions.

Lead tungstate is extremely dense ( denser than iron ), stopping most photons that reach it.

* CdWO < sub > 4 </ sub > or cadmium tungstate: a high density, high atomic number scintillator with a very long decay time ( 14 μs ), and relatively high light output ( about 1 / 3 of that of NaI ( Tl )).

Predominance diagrams can become very complicated when many polymeric species can be formed as, for example, with vanadate, molybdate and tungstate.

It forms a solid solution series with scheelite ( calcium tungstate, CaWO < sub > 4 </ sub >).

There are many other tungstate ions that contain more than one tungsten atom and belong to a large group of polyatomic ions that are termed polyoxometalates, (" POMs "), and specifically termed isopolyoxometalates as they contain, along with oxygen and maybe hydrogen, only one other element.

Powellite ( calcium molybdate ) and scheelite ( calcium tungstate ) fluoresce intrinsically in yellow and blue, respectively.

Until Edison discovered that calcium tungstate fluoroscopy screens produced brighter images than the barium platinocyanide screens originally used by Wilhelm Röntgen, the technology was capable of producing only very faint images.

In aqueous solution, tungstate gives the heteropoly acids and polyoxometalate anions under neutral and acidic conditions.

He invented a fluorescent lamp in 1896 that used a coating of calcium tungstate as the fluorescing substance, excited by X-rays, but although it received a patent in 1907, it was not put into production.

See tungstate for info.

Comparing tungsten to the other group 6 elements, the large tungstate ions generally contain 6 coordinate metal atoms similar to molybdenum ( molybdates ) and contrast to chromium ( chromates ) where 4 coordination predominates.

Solutions of tungstates, like those of molybdates, give intensely blue solutions of complex tungstate ( V, VI ) analoguous to the molybdenum blues when reduced by most organic materials.

The tungstate can be constantly regenerated through the presence of hydrogen peroxide.

It will be made of lead tungstate crystals.

When high energy photons strike lead tungstate, they make it glow, or scintillate, and this glow can be measured.

This is an important step because any misalignment would cause progressively worse misalignment in the hull as you advance in construction.

In practice an analog signal is subject to electronic noise and distortion introduced by communication channels and signal processing operations, which can progressively degrade the signal-to-noise ratio.

** In a process that can take weeks to months, saline solution is injected to progressively expand the overlaying tissue.

The character of God in the story is progressively revealed through the use of irony.

All the layers are stacked, one above the next, in any desired order ; and the bottom layer is usually rendered as a base in the resultant image, with each higher layer being progressively rendered on top of the previously composited of layers, moving upward until all layers have been rendered into the final composite.

Equipment from the Soviet Union is being progressively replaced by more modern U. S., French, and British equipment, a significant portion of which is built under license in Egypt, such as the M1 Abrams tank.

Equipment from the Soviet Union is being progressively replaced by more modern U. S., French, and British equipment, a significant portion of which is built under license in Egypt, such as the M1A1 Abrams tank which makes Egypt the owner of the second largest number of latest generation main battle tanks in the region after Israel, and the second after Syria in case of the older generations.

Forward chaining is the questioning of an expert who has no idea of the solution and investigates progressively ( e. g. fault diagnosis ).

Coalescence is another form of instability-small droplets bump into each other within the media volume and continuously combine to form progressively larger droplets.

Each covenant is mediated by a great leader ( Noah, Abraham, Moses ), and at each stage God progressively reveals himself by his name ( Elohim with Noah, El Shaddai with Abraham, Yahweh with Moses ).

However, the SGML concept of generalized markup is based on elements ( nested annotated ranges with attributes ) rather than merely print effects, with also the separation of structure and processing ; HTML has been progressively moved in this direction with CSS.

An often-repeated mathematical joke is that topologists can't tell their coffee cup from their donut, since a sufficiently pliable donut could be reshaped to the form of a coffee cup by creating a dimple and progressively enlarging it, while shrinking the hole into a handle.

When CD4 < SUP >+</ SUP > T cell numbers decline below a critical level, cell-mediated immunity is lost, and the body becomes progressively more susceptible to opportunistic infections.

Fresh hashish considered to be good quality is soft and pliable and becomes progressively harder and less potent over weeks and months as its THC content oxidizes to other cannabinoids and as essential oils evaporate.

His election needs a wide majority that is progressively reduced from two-thirds to one-half plus one of the votes as the ballots progress.

In three places in the Torah, there are lists of family members between whom it is prohibited to have sexual relations ; each of these lists is progressively shorter.

This is the main reason for absorption of HF radio waves, particularly at 10 MHz and below, with progressively smaller absorption as the frequency gets higher.

During the course of the illness, the patient's mobility is progressively restricted as it becomes hard for him or her to bend down, reach for things, walk quickly and so on.

The different versions of the photo of the dog at the right demonstrate how much data can be dispensed with, and how the images become progressively coarser as the data that made up the original one is discarded ( lost ).

Also, as the fiber tip pen is used, the tip slowly wears away on the plotting medium, producing a progressively wider, smudged line.

* Progressive revelation ( Bahá ' í ), a core teaching of Bahá ' í that suggests that religious truth is revealed by God progressively and cyclically over time

Likewise, a Prime Minister is no longer just " first amongst equals " in HM Government ; although theoretically his Cabinet might still outvote him, in practice he progressively entrenches his position by retaining only personal supporters in the Cabinet.