Measurement of Radiation

A sensitive photographic strip is worn by regular users of isotopes to monitor the radiation dose to which they have been exposed, when the strip is developed. Generally counting a- or p-particles or y rays depends on their energy and the physical state of the source. Either gas ionisation, scintillation or semiconductor counters are used. 

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Curie measure of radiation activity equal to 3.7 X 10 ° disintegrations per second Cyclic arrangement of molecule in which carbons are bonded together in a ring-pattern... 

To compare doses resulting from different types of radiation it is necessary to formulate a measure of radiation effects on the crystal structure doses can be recalculated to the number of displacements per atom (dpa). A dose of 0.1 dpa, for example, means that one of ten atoms was displaced from its initial position. Equivalent values in dpa units may be calculated for different types of radiation from the effects of its interaction with the crystal lattice. To recalculate a-dose to dpa the following formula is used ... 

B 4. Several spectroscopic techniques were studied in this chapter. Which experimental techniques involve an actual measurement of radiation absorbed ... 

There are several geometrical arrangements for the measurement of radiation by these techniques. The TLC plate may pass over, under or between the components of the detector. The speed of the recorder can be adjusted to match that of the plate so that the location of the spots or zones on the chromatogram can be accurately determined. However, for two-dimensional separations, it is necessary to form colored derivatives or to use adsorbents which contain fluorescent pigments in order to locate the spots prior to scanning. The advantage of these scanning techniques is that they are simple and rapid. 

Dizdaroglu M (1992) Measurement of radiation-induced damage to DNA at the molecular level. Int J Radiat Biol 61 175-183... 

Fuciarelli AF, Wegher BJ, Gajewski E, Dizdaroglu M, Blakely WF (1989) Quantitative measurement of radiation-induced base products in DNA using gas chromatography-mass spectroscopy. Radiat Res 119 219-231... 

Measures of Radiation-Induced Responses. This Section discusses the measures of response from radiation exposure generally used in radiation protection and assessments of radiation risk in general terms. 

An important limitation that is sometimes encountered is due to the particulate nature of electricity (electrons, ions) and of radiation (photons). The measurement of radiation intensities is in certain cases (e.g., X rays) performed by counting particles or photons one at a time. The number A counted in a time interval of given magnitude is subject to statistical fluctuations a count of A is subject to an estimated standard error given by... 

Rochette, P, Desjardin, R.L., Pattey, E., and Lessard, R. 1996. Instantaneous measurement of radiation and water-use efficiencies of a maize crop. Agron. J. 88 627-635. 

Neutron activation analysis (NAA) is a sensitive multielement analytical technique used for both qualitative and quantitative analyses of major, minor, trace, and rare elements. The NAA method is based on the transformation of stable nuclides into radioactive nuclides by bombarding the sample with neutrons, followed by measurement of radiation, particularly gamma radiation. Today, artificial radionuclides in samples can be measured in two ways [15, 16] ... 

Frelon S, Douki T, Ravanat J-L, Pouget J-P, Tornabene C, Cadet J. (2000) High performance Kquid chromatography-tandem mass spectrometry for the measurement of radiation-induced base damage to isolated and cellular DNA. Chem Res Toxicol 13 1002-1010. 

Frank R, Gaugbtz G. Measurement of radiation intensities by chemical actinometers. CAV 1978 19-22. 

Environmental monitoring means the measurement of radiation and radioactivity outside the boundaries of installations operating nuclear power plants, research reactors, fuel reprocessing plant, accelerators or handling radioactivity materials including nuclear fuels or radioactive sources. 

The intermediate phase covers the period which starts from the first few hours after the commencement of the release and could extend for several days or weeks. During this phase, environmental measurements of radiation levels from deposited radioactive materials, as well as levels of radioactive contaminants in food, water and air, will become available. It is also during the intermediate phase that the plant is expected to be restored to a safe condition and the protective measures, based on the environmental measurements, will be implemented. In this phase the results of the prediction calculations by ESR will be very important to design and check the environmental monitoring plans and to carry out the appropriate evaluations of environmental consequences in conjunction with environmental monitoring activities. 

The measurement of radiations emitted during the activating collision is a method that has been applied in a number of cases where the sensitivity of neutron activation analysis is otherwise poor. 

One of the earliest devices for the measurement of radiation dosage, the Fricke dosimeter, is based on the oxidation of the ferrous ion by OH radicals produced in the radiolysis of a dilute aqueous solution of ferrous sulfate ... 

Discuss the interactions of radiation with various kinds of matter and the measurement of radiation dosage (Section 19.4, Problems 33-36). 

Class 3-Methods Based on Direct Mechanical Effects. These include the use of acoustical probes [57-71], acoustic impedance measurements [72—75], acoustic fluxmeter [76], the measurement of radiation forces [17,21,77—112], the distortion of liquid surface [ 113-115], surface cleaning, dispersive effects, emulsification [ 116-118], erosion [ 19,22,119-125], mass transfer measurements (electrochemical probe) [26,129], absorption methods [93,132], particle velocity measurements [132], and optical methods [133-141],... 

Figure 20. Different configurations for the measurements of radiation force.

Figure 2 DNA damage induced by ionizing radiation. A) DNA damage and repair. All the constitutive elements of DNA (sugar-phosphate backbone and bases) are possibly modified by ionizing radiation. Single strand breaks (SSB), oxidized bases and abasic site are processed by base excision repair (BER), double strand breaks (DSB) by homologous recombination and non homologous end joining (HR and NHEJ) and DNA-protein crosslinks by nucleotide excision repair (NER). B) Quantitative measurement of radiation-induced and spontaneous DNA damage.

Dosimetry. The calculation or measurement of radiation absorbed doses. 

Two approaches to the measurement of radiation (with emphasis on the ultraviolet wavelength range) are commonly used. The first is to use a physical standard (e.g., chemical actinometer), which is a reference material (substance) that shows a change in property proportional to the dose of incident radiation (UV or other specific... 

In this section we will examine briefly the effects of radiation on biological systems. Bnt first let us define quantitative measures of radiation. The fundamental unit of radioactivity is the curie (Ci) 1 Ci corresponds to exactly 3.70 X 10 ° nuclear disintegrations per second. This decay rate is equivalent to that of 1 g of radium. A millicurie (mCi) is one-thousandth of a curie. Thus, 10 mCi of a carbon-14 sample is the quantity that undergoes... 

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