Nuclear-based Techniques Research Articles

Isotope signature and elemental characteristics of subsurface formations around deep-laying coal seams probed by means of atomic and nuclear-based techniques.

A systematic investigation on the isotopic and elemental signature, for both stable and radioactive elements, and mineral contents was performed to examine the characteristics of subsurface formations collected at different depths between 3.962km and 4.115km around deep-laying coal seams located under the Marmarica plateau in Egypt. Concentrations of major and minor oxides (Na2O, MgO, Al2O3, SiO2, SO3, K2O, CaO, TiO2, MnO, ΣFeO+Fe2O3, SrO, ZrO2, and BaO) were determined by X-ray fluorescence and dependencies among these concentrations revealed the type and sort of the formations. Organic contents were determined by Fourier Transform infrared spectroscopy to investigate the variation of the CO/CC bonding ratio with depth. Rare earth elements (REE), specifically Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu were determined by inductively coupled plasma mass spectrometry while actinoids were detected by the radioactive decay of its daughter nuclei. The results showed a high trapping of REE elements and actinoids in layers above the coal seams which indicates the occurrence of aqueous flow followed by possible sorption in these layers. The mobility of the fluid was investigated using the process radioactive decay series between Ra226 and Ac228 from one side and their daughters from the other side.

Myocardial metabolic imaging: Viability and beyond

Because of the high metabolic cost of maintaining an adequate cardiac output, the heart possesses the ability to utilize a wide variety of metabolic substrates, including fatty acids, glucose, lactate, amino acids, and ketone bodies. The relative contribution of each of these substrates is regulated by multiple factors, including substrate concentration, presence of adequate blood flow and oxygen, the action of a variety of hormones, and the influences of disease states that can alter the metabolic machinery of the heart. This review summarizes the biochemical and cellular basis of myocardial substrate selection, as well as the changes in the metabolic phenotype of the heart in response to cardiac diseases. Based on this background, this review also illustrates the nuclear-based imaging techniques that can be used to assess myocardial metabolism and their current and future applications to patient care.

Multivariant analyses of trace element patterns for environmental tracking

Nuclear-based analytical techniques: INAA, PIXE and photon activation permit simultaneous multielemental determination of concentrations in environmental materials, which data are often found sufficiently precise and free of uncontrolled, random errors among the various elements such that the data sets can yield valuable information on elemental communality through multi-variant statistical ‘factor’ analysis. Characteristic factor patterns obtained in this way can provide clues to the likely sources in the environment of various components. Recent studies in three different environmental situations: solid waste incinerators, Chinese soils, and iron and steel industry, involving measurements of 30–35 elements, have yielded distinct elemental patterns or, environmental signatures, with factor loading coefficients ranging mostly in the ranges: 0.7–0.96.

Nuclear techniques for finding chemical explosives in airport luggage

Chemical explosives are composed of concentrated densities of nitrogen and oxygen. High values of the nitrogen alert the presence of a bomb; high values of both nitrogen and oxygen densities certify the bomb's presence uniquely. More than a dozen nuclear-based techniques have been proposed for rapidly scanning airport luggage to find hidden explosives by measuring these elemental distributions. In almost every scheme, the technological challenge is the accelerator, which must be small, well-shielded, cost-effective, and be operable in busy airports by nominally-trained personnel, with minimum unscheduled downtime for repairs or service. This paper will summarize, within the limits imposed by security, four of the imaging schemes.

Explosive detection system based on thermal neutron activation

Nuclear-based techniques for the detection of bulk explosives are described. These techniques are shown to provide the only feasible approach for meeting the operational criteria of high throughput of screening luggage and cargo against concealed explosives in air transportation. The nuclear-based techniques are characterized by probing the screened object (e.g. luggage) with highly penetrating radiation, i.e. neutrons or energetic gamma rays. High-energy gamma rays produced by the probing radiation are characteristic to the elemental composition of the objects. The gamma rays are detected by an array of detectors placed near the object. The intensity, energy, and spatial distribution of the detected radiation and their relationship to the primary radiation allow a computer to determine the presence or absence of explosives. The nature of neutron interactions, the gamma detectors used, and the data analysis on which the decision is based are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Nuclear-based techniques for explosive detection

Abstract The status of bulk explosive detection techniques based on nuclear interrogation methods is reviewed. The desirable characteristics of an operational system capable of meeting the requirements for civil aviation security are compared with what can be expected from nuclear-based techniques. The comparison is limited to those techniques that utilize penetrating neutron and photon probes on the target elements of explosives most likely to be encountered in the airport scenario. The physical properties of a relevant group of explosives are surveyed for unique characteristics that could provide detectable signatures to nuclear-based techniques. A survey of the accessible reactions and their relative detection sensitivities are tabulated for a selection of practical interrogating probes. Some results obtained with systems currently under development are reported.

Nuclear-based techniques for the in vivo study of human body composition. Report of an Advisory Group of the International Atomic Energy Agency.

A variety of nuclear-based techniques for the in vivo study of human body decomposition is now available for clinical diagnosis and research, and the number of centres where such work is performed is likely to grow substantially in the next few years. Their most important applications at present are in the measurement of bone mineral mass (calcium), body protein (nitrogen) and organ contents of cadmium and lead. Although still mainly used as research tools, they are already at a stage where routine applications can be justified in clinical diagnosis and occupational health monitoring. The radiation doses delivered to the subject vary according to the sensitivity and precision required, but are generally low compared with many common radiological examinations and diagnostic tests.

Techniques for pollution measurement

Report on the Development of nuclear-based techniques for the measurement, detection and control of environmental pollutants (IAEA), 15-19 March 1976 in Vienna.

International Symposium on the Development of Nuclear-Based Techniques for the Measurement, Detection, and Control of Environmental Pollutants

International Symposium on the Development of Nuclear-Based Techniques for the Measurement, Detection, and Control of Environmental Pollutants