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

Photomultipliers are still commonly used wherever low levels of light must be detected.

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

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

At first they were only feathers and dark indistinguishable faces and bodies, hunched over their horses' heads.

Two of the new hands, a Mexican named Jose Amado and a kid known only as Laredo, were picked for the first trick of riding night herd.

After the first two murders, the warning notes were rarely ignored.

Even the knowledge that she was losing another boy, as a mother always does when a marriage is made, did not prevent her from having the first carefree, dreamless sleep that she had known since they dropped down the canyon and into Bear Valley, way, way back there when they were crossing those other mountains.

Out of compulsion to say something cheery, Ben Prime blurted, `` Well, we were lucky to be on soft ground when the first floodheads hit.

His political opponent and lifetime friend, Thomas Jefferson, achieved immortality through his authorship of the Declaration of Independence, but equally notable were the legal and constitutional reforms he instituted in his native Virginia, his role as father of our territorial system, and his acquisition of the Louisiana Territory during his first term as President.

This is the primary function of the imagination operating in the absence of the original experiential stimulus by which the images were first appropriated.

Before being daughter, wife, or mother, before being cultured ( a word now bereft both socially and politically of the sheen you children of frontiersmen bestowed on it ), before being sorry for the poor, progressive about public health, and prettily if somewhat imprecisely humanitarian, indeed first and foremost, you were a lady.

Even the first wave of homesickness had passed, although there were moments when Captain Heard pointed out on his compass the direction of Bradford that she felt a little twinge at her heart.

When they were first written, there was evidently no thought of their being published, and those which refer to the writer's love for Mrs. Meynell particularly have the ring of truth.

The evening of our first day we drove with Christopher and Judy Sakellariadis, who were friends and patients of Norton, to dine at a restaurant on the shores of the Aegean.

So persistent were these attacks that in March of the following year, Woodruff was finally moved to action, and Pike was to learn his first lesson in frontier politics, the subtle art of diversion.

In the next few months of comparative silence, Pike waited patiently until conditions were perfect for a new attack, and then, displaying a remarkable grasp of the subtleties of political infighting, gained from his first bout with Woodruff, he used these changed conditions to excellent advantage.

Although this kind of wholesale objection came at first from some men who were not technically Puritans, still, once the Puritans gained power, they climaxed the affair by passing the infamous ordinance of 1642 which decreed that all `` public stage-plays shall cease and be forborne ''.

Our first impression of the data was that the students were surprisingly orthodox and religiously involved.

But all the reports of this first embassy show that the two Savoyards were the heads of it, for they were the only ones who were empowered to swear for the king that he would abide by the pope's decision and who were allowed to appoint deputies in the event that one was unavoidably absent.

the Low Countries, where the Middle Ages were to last for another two centuries and die out only when Charles the Bold of Burgundy met his first defeat in the fields and forests below the walls of Grandson.

It was the first American war in which the death rate from disease was lower than that from battle, due to the provision of trained medical personnel ( of the 200,000 officers, 42,000 were physicians ), compulsory vaccination, rigorous camp sanitation, and adequate hospital facilities.

There were several men of ninety or more whom I knew first or last, all of whom were still productive and most of whom knew one another as if they had naturally come together at the apex of their lives.

It met a serious rebuff in New Orleans, where the two schools selected for the first moves toward integration were boycotted by white parents.

These microfossils indicate the swamp was `` formed during the Lower Cretaceous period when dinosaurs were at their heyday and when the first flowering plants were just appearing.

It poured out of him like an electric current, a feeling that the muscles and nerves of his fine-drawn body were coiling for action, and that that action would be all that he anticipated.

The giant electric signs and marquees were lit up for the first time since blackout regulations had been instituted, and the atmosphere was alive with the feeling that victory was just around the corner.

Experiments were made on an electric arc applying a porous graphite anode cooled by a transpiring gas ( Argon ).

Many patent contests were waged over automobile components and accessories, among them tires, detachable rims, ball bearings, license brackets, and electric horns.

Electric street lighting was introduced in 1900 and electric trams were transporting passengers in 1909.

By the late 19th century, improved instruments were designed which could be mounted in any position and allowed accurate measurements in electric power systems.

Field ion microscopy techniques were initially construed as a modification of field emission, a technique which allows for a stream of electrons to be emitted from a sharp needle when subjected to a sufficiently high electric field (~ 3-6 V / nm ).

Horse drawn buses were used from the 1820s, followed by steam buses in the 1830s, and electric trolleybuses in 1882.

Several different computer printers were simply computer-controllable versions of existing electric typewriters.

These were an essential part of printing telegraphs such as teleprinter page printers, as well as electric typewriters, notably the IBM Selectric.

These mechanisms were found in some types of synchronous-motor-driven electric clocks.

In the early cold cathode vacuum tubes, called Crookes tubes, this was done by using a high electrical potential between the anode and the cathode to ionize the residual gas in the tube ; the ions were accelerated by the electric field and released electrons when they collided with the cathode.

German scientists Eilhard Wiedemann, Heinrich Hertz and Goldstein believed they were " aether waves ", some new form of electromagnetic radiation, and were separate from what carried the electric current through the tube.

This evidence that the beams were composed of particles was strong because scientists knew it was impossible to deflect electromagnetic waves with an electric field.

His engines were used to power pipelines, electric and water plants, automobiles and trucks, and marine craft.

They were forced to compete with louder horn instruments ( and later amplified electric guitars ), making bass parts difficult to hear.

Whereas Sergei Eisenstein viewed his montage of attractions as a propaganda tool through which the film-viewing masses could be subjected to “ emotional and psychological influence ” and therefore able to perceive “ the ideological aspect ” of the films they were being shown, Vertov believed the Kino-Eye would influence the actual evolution of man, “ from a bumbling citizen through the poetry of the machine to the perfect electric man .”

Long before any knowledge of electricity existed people were aware of shocks from electric fish.

Patients suffering from ailments such as gout or headache were directed to touch electric fish in the hope that the powerful jolt might cure them.

Ørsted's slightly obscure words were that " the electric conflict acts in a revolving manner.

Electric motors of increasing efficiency were constructed throughout the 19th century, but commercial exploitation of electric motors on a large scale required efficient electrical generators and electrical distribution networks.

Other European pioneers were Robert Boyle, who in 1675 stated that electric attraction and repulsion can act across a vacuum ; Stephen Gray, who in 1729 classified materials as conductors and insulators ; and C. F. du Fay, who proposed in 1733 that electricity comes in two varieties that cancel each other, and expressed this in terms of a two-fluid theory.

The first electric guitars used in jazz were hollow archtop acoustic guitar bodies with electromagnetic transducers.

The first recordings using the electric guitar were by Hawaiian style players, in 1933.