Red verticals are five-minute intervals, the wiggly black horizontal line is the radioactivity level.
Telt made readings, he had other records of radioactivity in this same magter keep--proof that something is there.
So far he's found no trace of a jump-space generator, or excess radioactivity that might indicate a bomb.
School children were examined in a project to determine possible pathways by which radioactivity may enter the human body.
In contrast to devices that disclose concentrations of radioactivity in a small area or a particular organ, whole body counters usually are used to total up the burden of radioactivity in all parts of a human body.
The need for an instrument that would measure whole body radioactivity was first felt in the 1920s when the hazardous nature of radium was recognized.
Radioactivity in Man: Whole Body Counting and the Effects of Internal Gamma Ray-Emitting Radioisotopes, George R.
Furthermore, steel produced since the war may contain unwanted radioactivity originating in fallout from nuclear tests and make it undesirable for shielding.
Instruments record the body radioactivityvisibly at timed intervals as the crystal moves along the patient’s body.
Although normal radioactive decay progressively reduced the total amount of radioactivity in the area, the Marshallese still were carrying this nuclide in their bodies after several years.
Medicines such as “Radithor” and “Radium Water” were manufactured and sold before it was known that overexposure to radioactivity was harmful.
Illustration: Figure 12 Using a whole body counter to determine radioactivity in milk.
Similar studies have been conducted by scientists of the Pacific Northwest Laboratory at Richland, Washington, who since 1959 have been measuring radioactivity of plants and animals in Alaska.
Natural radioactivity in the rocks thereabouts is greater than normal and Prof.
It may be that the relatively slight increases of heat found as one goes deeper in existing mines are due to radioactivity in the rocks instead of to outward seepage from the internal fires.
Their method of measuring the radioactivityis as follows (48): A wire not exceeding 1 mm.
It requires a radium salt of high radioactivity to be at all comparable in effectiveness with a good water-dropper.
The radioactivity is denoted by A, and A=1 signifies that the potential of the dissipation apparatus fell 1 volt in an hour per metre of wire introduced.
Any fool could have seen that radioactivity would be the only thing to cause an instrument disturbance like that!
Three to five years had to pass before the radioactivity would be harmless.
It could only have been the result of radioactivity in a large mass.
If so, he is called a radiologist and is an expert in the use of radiation beams, injection of radioisotopes, and implantation of radioactivity into the body, as well as in the use of the more familiar radium and X-ray devices.
Biology Biology deals with the structure and behavior of plants and animals: the botanist studies plants, the zoologist studies animals, and they both can use radioactivity widely in their research.
He may analyze various materials for use in atomic reactors, nuclear submarines, or medical treatment rooms where radioactivity is used.
Botanists useradioactivity to learn more about plants, and zoologists use it to study animals.
The many, and sometimes seemingly strange, effects of radioactivity on plants and growing conditions provide a wide and fascinating field for the botanist.
Alpha particles, remember, have very little penetrating power, so all the energy of the alpha radioactivity is expended within the individual tumor cells.
The advantages of chromium over iodine-131, which has also been used, are that smaller doses are required, and that there is no transfer of radioactivity to the fetal circulation.
Then theradioactivity of the cells is measured, just before injection into the patient.
Radioactivity is a process that is practically uninfluenced by any of the factors, such as temperature and pressure, that are used to control the rate of chemical reactions.
Note dark ring of radioactivity surrounding the lighter area of decreased activity at the central portion of spleen.
Through a tedious series of chemical separations, she obtained from pitchblende (a uranium ore) small amounts of two new elements, polonium and radium, and showed that they possessed far greater radioactivity than uranium itself.
A sample of labeled red blood cells is introduced into a vein, and the recording device counts the radioactivity appearing in the aorta as a function of time.
The simplest is to give the B₁₂ by mouth, and after about 8 hours study the level of cobalt radioactivity in the blood.
After a suitable time to permit thorough mixing of the added material throughout the blood stream, a new blood sample is taken and its radioactivity is measured.
The total volume of red blood cells then can be calculated by dividing the total radioactivity of the injected sample by the activity per milliliter of the second sample.
The distribution of residual radioactivity in the sea a month after the close of a nuclear testing program could be determined by counting radioactivity in plankton samples.
Or radioactivity actually may be transported "uphill", from water to land, as when birds that feed on fish containing radioactivity leave their excretions at nesting areas.
The scientists found in the Bikini ecosystem, in low but perceptible amounts, residual traces of radioactivity deposited by the tests.
Radioactivity introduced into any community may be "taken up" by the biological system, becoming subject to cycling in food chains or to accumulation in plant or animal tissues.
Scientists will study movement of the radioactivity into insects and their predators.
The addition of radioactivity makes possible broad-gauged studies to trace the movement and concentration of radionuclides in the environment.
The presence of radioactivity permits study of the workings of a system as large as an ocean, perhaps, or of one no larger than a tree.
So long as radioactivity remained in the biological cycles there were possibilities of future developments.
But radioactivity sometimes results in the expulsion of a [beta]-particle from the nucleus.
The study of radioactivity was pursued with great ability not only by the Curies and A.
The energy of radioactivity is millions of times as intense as the energy released by chemical reactions.
If all the energy delivered by a gram of uranium in the course of its radioactivity over many billions of years was totalled, it was enormously greater than the energy produced by the burning of a candle with a mass equal to that of uranium.
The Energy of Radioactivity It eventually became clear that radioactivity involved the giving off of energy.
Was the stable lead that had no connection with radioactivitymade up of atoms of still another isotope, one with a fractional atomic weight?
Then, the investigations into radioactivity had shown that atoms of uranium and thorium spontaneously broke up into smaller particles, including electrons and alpha particles.
What is involved then in radioactivity and in the sun is “nuclear energy”.
Radioactivity Was there a connection between these two sets of particles—atoms and electrons?
The amount of energy liberated by a gram of uranium in 1 second of radioactivity was an insignificant fraction of the energy released by a burning candle.
In 1899 Thomson showed that certain perfectly normal metals with no trace of radioactivity gave off electrons when exposed to ultraviolet light.
Second, a neutron source—some material with the type of radioactivitythat produced neutrons—to start the reaction.
Back on the asteroid, a pit that glowed with radioactivity marked the site of the first blast.
By then theradioactivity from the blasts would have died down considerably.
If there's any radioactivity there, it's not very much.
But the dial indicated an increase in radioactivity as newly created neutrons spread their poison like a cancer.
He explained what had happened, told her the radioactivity had not quite reached critical point--which was a lie.
They neither knew nor cared what went on in the world outside; what cities were reported destroyed, what forces triumphed or went down into defeat, what activity or radioactivity prevailed.
Use of thermo-nucs had been limited, fortunately, so radioactivity did not linger, and the vast craters hollowed out by ordinary warheads had been partially filled by rubble and debris.
Afterwards the stable element could probably be separated out of the mixture and the trace of radioactivity would, it was hoped, be carried along with it.
Slowly, it began to seem to Hahn that the failure to separate the barium and the radioactivity meant that the isotopes to which the radioactivity belonged had to be so much like barium as to be nothing else but barium.
The radioactivityliberated spreads over the world and may do slow but cumulative damage.
They found that a considerable quantity of the radioactivity did indeed accompany the barium when they separated that element out of the system.
A natural conclusion was that the isotopes producing the radioactivity belonged to an element that was chemically very similar to barium.
Two of them sent the needle surging clear off the scale; three were as untainted by radioactivity as Benedetto himself.
It's standard medical practice in cases like his to put them in suspension for a while, until the level of radioactivity dies down and they can safely be revived.
There is a high level of radioactivity all up and down the mountain.
If the radioactivity keeps them out, why shouldn't they put a cordon around the entire old city?
Deep in the old city, in a place where the radioactivityis negligible," the man answered as the doctor took his pulse.
In the field of surgery the X-ray is in daily use, and radium and radioactivity may yet be great aids to medicine.
Madame Curie developed the radioactivity as a great contribution to the evolution of science.
They were unable to venture into his old one because of the radioactivity and micro-organisms.
But the Ambassador stayed invisible for five hours, until some of the radioactivity had abated.
I even hooked a gadget to the water pipe so their Holy Waters would have the usual refreshing radioactivity when they started flowing again.
The radioactivityin the water didn't hurt the natives.
Telt made readings, he had other records of radioactivity in this same magter keep.
Twenty minutes after the irradiation period, the radioactivity of the calcium standards is measured by the same instrument.
Remove them and measure the radioactivity produced from the sample.
The promptness with which we can begin measuring radioactivity and the efficiency of this measurement.
The elements labeled β yield radioisotopes that emit few or no gamma rays and can only be analyzed by neutron activation using appropriate chemical separation procedures followed by beta radioactivity measurements.
About 4 hours after the samples are removed from the reactor, he begins the radioactivity measurements.
Thus, each factor of two in radioactivity occupies the same distance along the vertical axis.
The patient is scanned from head to foot in approximately 12½ minutes at a rate that is varied to compensate for the gradual decay of the calcium-49 radioactivity during this period.
Later on, radioactivity from silver (silver-110m) can be measured using a longer counting time.
In this case, after 2 days it takes approximately ten times as much sodium to yield the same radioactivity as it would if the sample were measured when it was fresh out of the reactor.
Becquerel, and those associated with them were influenced by the hypothesis that radioactivity is an atomic property of radioactive substances.
They concurred in the view held by all the most prominent workers in this subject, namely, that radioactivity is an atomic phenomenon.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "radioactivity" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: activity; decontamination; fallout; radioactivity
