Photomultipliers are constructed from a glass envelope with a high vacuum inside, which houses a photocathode, several dynodes, and an anode.

Photomultipliers with large distances between the photocathode and the first dynode are especially sensitive to magnetic fields.

* Photomultipliers are used in conjunction with scintillators to detect Ionizing radiation by means of hand held and fixed radiation protection instruments, and particle radiation in physics experiments.

* Photomultipliers are used in research laboratories to measure the intensity and spectrum of light-emitting materials such as compound semiconductors and quantum dots.

* Photomultipliers are used as the detector in many spectrophotometers.

* Photomultipliers are used in numerous medical equipment designs.

* Photomultipliers are typically used as the detectors in Flying-spot scanners.

* Photomultipliers were the first electric eye devices, being used to measure interruptions in beams of light.

Photomultipliers offer the best possible opportunity to exceed the Johnson noise for many configurations.

An earlier but still influential school of painting, surrealism, had suggested the way of dealing with the dream experience, that event in which seemingly incongruous objects are linked together through the curious associations of the subconscious.

We are desperately in the need of such invention, for man is still very much at the mercy of man.

Our collective policies, group and national, are similarly based on voodoo, but here we often lack even the empirically successful rituals and are still engaged in determing them.

Even in domains where detailed and predictive understanding is still lacking, but where some explanations are possible, as with lightning and weather and earthquakes, the appropriate kind of human action has been more adequately indicated.

These my grandmother left in their places ( they are still there, more persistent and longer-lived than the generations of man ) and planted others like them, that flourished without careful tending.

`` I care not how soon we reach Calcutta, and are placed in a still room, with a bowl of milk and a loaf of Indian bread.

You are still in France ''.

The curving benches are broken, chipped, tumbled, but still in place, as are the marble chairs, the seats of honor for the legislators.

To the extent that our sampling of the orientations of American college students in the years 1950 and 1952 may be representative of our culture -- and still valid in 1959 -- we are disposed to question the summary characterization of the current generation as silent, beat, apathetic, or as a mass of other-directed conformists who are guided solely by social radar without benefit of inner gyroscopes.

And although they were, as I have indicated, under increasing strain at the time of Racine, they are still alive in his theatre.

But in ways more fundamental than specific political opinions they are still what they always were: passionate, sure without a shadow of doubt of whatever it is that they are sure of, capable of seeing black and white only and, therefore, committed to the logical extreme of whatever it is they are temporarily committed to.

If we are to believe the list of titles printed in Malraux's latest book, La Metamorphose Des Dieux, Vol. 1 ( ( 1957 ), he is still engaged in writing a large novel under his original title.

But while war still serves as a catalyst for the values that Malraux wishes to express, these values are no longer linked with the triumph or defeat of any cause -- whether that of an individual assertion of the will-to-power, or a collective attempt to escape from the humiliation of oppression -- as their necessary condition.

But in so many other areas we still are dragging.

( Significantly, bitter echoes of the 1960 power struggle that saw Mosk moving into the national committee post over Ziffren are still audible in party circles.

However, there are still several types of calls that necessitate the use of telephone operators.

How can we old-fashioned parents, who still feel that adults are due some respect from children, battle the new type of advertising that appears on TV without denying the children the use of television entirely??

structurally, the U.N. is still fluid, vulnerable to the pressures that its new and enlarged membership are bringing to bear upon it.

As Critic Walter Kerr points out: `` Adaptations, so long as they are good, still qualify as creative ''.

and it is still very far from certain how valid the party's claim is that in `` a growing number of kolkhozes '' the peasants are finding it more profitable, to surrender their private plots to the kolkhoz and to let the latter be turned into something increasingly like a state farm.

Often, therefore, there are a number of rules having the same effect, and commonly other sets of rules as well, having the opposite effect.

Since they commonly translate thoughts and feelings into deeds, hands naturally represent action, and since nearly half the characters in Great Expectations are of the underworld or closely allied to it, the linking of hands with crime or violence is not to be wondered at.

Can the church risk assuming that the `` folly '' of men is as dear to God as their `` wisdom '', or, as is also commonly implied, that `` the foolishness of God '' and `` the foolishness of men '' are simply two ways of talking about the same thing??

They dwell, in short, in the doltish twilight in which peasants and serfs of the past are commonly reported to have lived.

Members of this order with smooth skins are commonly referred to as frogs while those with warted skins are known as toads.

Though the prokaryotic cyanobacteria ( commonly referred to as blue-green algae ) were traditionally included as " algae " in older textbooks, many modern sources regard this as outdated as they are now considered to be bacteria.

Comparisons, which are most commonly planned, can be either simple or compound.

An adapted abacus, invented by Tim Cranmer, called a Cranmer abacus is still commonly used by individuals who are blind.

Most commonly, tones are indicated with diacritics, the way vowels are treated in abugidas.

The footing and stem wall are commonly 24 and 14 inches, much larger than a frame house because of the weight of the walls.

Ornamental annual perennials commonly grown as annuals are impatiens, wax begonia, snapdragon, Pelargonium, coleus and petunia.

They are commonly called " Christmas Bells ", because of the shape of their flowers and their flowering time, which coincides with Christmas in Australia.

Collectively they are commonly known as " water plantain ".

( In less formal treatments, all three systems are commonly called alphabets.

Solvent extraction and ion chromatography are commonly used for the separation.

Asteraceae or Compositae ( commonly referred to as the aster, daisy, or sunflower family ), are an exceedingly large and widespread family of Angiospermae.

The most commonly used physical therapy interventions for cerebellar ataxia are vestibular habituation, proprioceptive neurofaciliation, Frenkel exercises, and balance training ; however, therapy is often highly individualized and gait and coordination training are large components of therapy.

For example, automobile wheels made of an aluminium alloy are commonly referred to as simply " alloy wheels ", although in point of fact steels and most other metals in practical use are also alloys.

Because of their biological significance, amino acids are important in nutrition and are commonly used in nutritional supplements, fertilizers, and food technology.

Though the are has fallen out of use, the hectare is still commonly used to measure land: