The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit w...

... Abstract : The effects of electron radiation on Ultem, a ... were studied for total absorbed doses from 1.0 kGy to 100 MGy at absorbed dose rates from ...

... dose, Q is the quality factor, and N is the product of any other modifying factors such as those accounting for effects due to dose rate, dose ...

A technique is presented for calculating the dose or energy absorbed in a material from a knowledge of the ..gamma.. radiation field and the composition of the material. The absorbed dose per unit exposure for various elements and the absorbed dose as a function of material ...

The introduction of a biophysical quantity, the biological dose, is proposed, which is defined in terms of the absorbed dose and the relative biological effectiveness. The unit of the biological dose is the rem, while the unit of the absorbed ...

The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total ...

The absorbed dose in a material near a boundary with a dissimilar material may differ considerably from the dose in the bulk material. The peak dose near the interface can be more than a factor of ten greater than the bulk dose. The dose distribution is d...

The effects of various factors that can affect the effective absorbed dose of the tissues in radiotherapy with radiocolloids are studied. Radiocolloids of Au/sup 198/, P/sup 32/, and Y/sup 90/ are used. A mathematical evaluation is made of the dose absorbed by the ...

While in orbit, Astronauts are exposed to a much higher dose of ionizing radiation than when on the ground. It is important to model how shielding designs on spacecraft reduce radiation effective dose pre-flight, and determine whether or not a danger to h...

The biological effect taking place in the medium as the result of irradiation is determined by the absorbed irradiated energy and its micro and macro distribution in the tissue under irradiation. The quantitative evaluation of irradiation is effected by the measured dose contained in the air and expressed ...

... effects of external reflectors by absorbing and scattering thermal neu- ... moderating experiments) broaden the pulse and reduce the dose rates ...

With the development of the water calorimeter direct measurement of absorbed dose in water becomes possible. This could lead to the establishment of an absorbed dose rather than an exposure related standard for ionization chambers for high energy electrons and photons. In changing to an ...

5 Sievert-Equivalent dose determined by multiplying the absorbed dose at each energy desposition value (Linear Energy Transfer (LET)) by the corresponding ...

Measurements of the absorbed radiation dose fractions were made in a representation of an adult human. The primary purpose of this research was to investigate the effect of source organ size on the absorbed fractions in many target organs in the body. For...

The effects of high absorbed dose on the reusability of CaF{sub 2}:Mn thermoluminescence dosimeters (TLDs) are investigated to determine a recommended upper limit on absorbed dose for TLDs that are to be reused. This investigation examines degradation in the uniformity of response and changes ...

We describe here the use of computational methods for evaluation of the low dose effects on human fibroblasts after irradiation with Technetium-99m ((99m)Tc) Auger electrons. The results suggest a parabolic relationship between the irradiation of fibroblasts with (99m)Tc Auger electrons and the total absorbed dose. ...

In the past decade, a large amount of effort has gone into the development of hit size effectiveness functions (HSEFs), with the ultimate aim of replacing the present absorbed dose-RBE-Q system. However, the absorbed dose determined at the tissue level is...

The problem of estimating the absorbed dose to organs and tissues of the human body due to the presence of a radiopharmaceutical in one or more organs is discussed. Complications are introduced by the fact that the body is not homogeneous and in many case...

...purpose. (b) Effective dose equivalent means the...products of the absorbed dose and appropriate effectiveness...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

...purpose. (b) Effective dose equivalent means the...products of the absorbed dose and appropriate effectiveness...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

... Accession Number : AD0672563. Title : A CALORIMETER WITH INTERCHANGEABLE ABSORBERS FOR ABSORBED DOSE ...

or deterministic effects): injury to a population of cells which only occurs if a given threshold of absorbed dose is the absorbed dose, D. When particles other than photons and electrons (low-LET radiation) are involved, is a function of dose without threshold. � Lethal ...

... Title : MODELS FOR ESTIMATING THE ABSORBED DOSE FROM ASSIMILATION OF RADIONUCLIDES IN BODY ORGANS OF HUMANS,. ...

...meanings: (a) Effective dose equivalent means the...the products of absorbed dose and appropriate factors...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

...meanings: (a) Effective dose equivalent means the...the products of absorbed dose and appropriate factors...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

...meanings: (a) Effective dose equivalent means the...the products of absorbed dose and appropriate factors...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

...meanings: (a) Effective dose equivalent means the...the products of absorbed dose and appropriate factors...due to the quality of radiation and its distribution in...of reference man. The unit of the effective dose equivalent is the...

Phantom measurements of red bone marrow (RBM) doses, integral absorbed doses, and somatically effective dose equivalent (SEDE) from four different maxillary occlusal projections are presented. For each projection, different combinations of focus-skin distances and tube potentials were compared ...

A method to obtain the absorbed dose in Drosophila melanogaster irradiated in the thermal column facility of the Triga Mark III Reactor has been developed. The method is based on the measurements of neutron activation of gold foils produced by neutron capture to obtain the neutron fluxes. These fluxes, combined with the calculations of kinetic energy ...

...relevant to safety and effectiveness. FDA's determination of the safety and effectiveness of a diagnostic...radiopharmaceutical), and (c) The estimated absorbed radiation dose of the diagnostic...

The estimate of absorbed dose to individual organs of a space crewmember is affected by the geometry

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The problem of estimating the absorbed dose to organs and tissues of the human body due to the presence of a radiopharmaceutical in one or more organs is discussed. Complications are introduced by the fact that the body is not homogeneous and in many cases the organ shapes are not regular. Publications of the MIRD Committee have provided a direct means of ...

Aug 20, 2010 ... Mathematically, RBE is the ratio of the absorbed dose of low-LET ... Non- stochastic, or deterministic effects, are threshold effects the ...

For ionizing radiation, absorbed dose is defined as the energy imparted per unit mass of an infinitesimal volume. While straightforward to define, absorbed dose is somewhat more difficult to measure or infer. There is growing attention to the uncertainty in values of absorbed ...

The absorbed dose in the liver, spleen and bone marrow of Thorotrast patients was estimated for 71 autopsy cases. 232Th amounts in tissues were determined from measurements of 228Ac gamma-rays and the activity ratio of 228Ac to 232Th. In calculating the absorbed dose, Kaul's data were used as values of the steady ...

The probability of detrimental effects (R), such as cancer induction in irradiated multicellular tissue, from low-dose exposure to ionizing radiation is conventionally related to absorbed dose (D) to tissue by the proportionality constant {alpha} for a given type of radiation: R = {alpha}{center_dot}D This ...

The various aspects of the problem of the evaluation of the dose of radiations absorbed for medical reasons before additional medical exposure are examined. At present, it cannot be excluded that, in the case of certain harmful effects, such as the production of leukemia, the absorbed ...

The recommended practice presents a technique for calculating the dose of energy absorbed in a material from knowledge of the gamma radiation field and the composition of the material. The procedure is also applicable for x-radiation and electrons provided the effective energy of the beam is known and falls within the range from 0.10 ...

Estimation of dose absorbed in the human body is important from the point of view of health physics as well as because of the increased utilization of nuclear radiation in clinical and diagnostic medicine or therapy. An idealized mathematical model of the human body was developed and Monte Carlo calculation was applied to evaluate the photon ...

A comparison was made between the effect of absorbed dose from /sup 210/ Po in tissues of rats treated and untreated with sodium 2-(2,3-dimercaptopropoxi) ethansulfonate (oxathiol). The rats were subcutaneously injected with 0.1 mu Ci of /sup 210/Po in the form of polonium nitrate. The oxathiol treatment led to considerable ...

A study on the effect of gamma radiation dose and dose rate on the yield of copper nanoparticles produced had been done. Its objective is to show the relationship between the absorbed doses with the yield of production. The copper sulphate solution is prepared with addition of ethanol as ...

Dose calculations for neutron therapy irradiations should be based on the dosimetrically best accessible parameters "total absorbed Dose Dt" and "gamma ray absorbed dose Dgamma". By adequate standardization it should be possible, that only one single reference parameter contains all deviations ...

Patient irradiation in diagnostic radiology was estimated from measurements of absorbed doses in different organs, assessment of the energy imparted and retrospective calculations based on literature data. Possible late biological effects, with special as...

Effects of the presence of inhomogeneities in tissue irradiated by negative pion beams are investigated. Soft-tissue targets are considered with embedded regions of bone and cavities of air. The absorbed dose is calculated as a function of position in the...