Nuclear physics Radioactivity

Nuclear-physical methods ai e the basic ones in controlling environmental pollution which results from nucleai -power complexes and power plants work. Oil and gas production leads to the extraction of radio nuclides of natural origin in considerable amounts, which later spread from oil-slimes and water wastes in the neighborhoods of oil and gas producing entei prises. Similaidy, toxic and radioactive elements can pollute environment in case of mineral deposits extraction. 

In the discussion that follows we refer to nuclear activation detection reactions in lieu of analysis reactions since the signals that are measured are not necessarily always from a radioactive product. Again, we will use standard nuclear physics notation in specifying nuclear reactions, namely ... 

The important phenomenon of exponential decay is the prototype first-order reaction and provides an informative introduction to first-order kinetic principles. Consider an important example from nuclear physics the decay of the radioactive isotope of carbon, carbon-14 (or C). This form of carbon is unstable and decays over time to form nitrogen-14 ( N) plus an electron (e ) the reaction can be written as... 

Cork, James M., Radioactivity and Nuclear Physics, Third Edition, D. Van Nostrand Company, Inc. 

In short, with sublime irony, Duchamp has employed a modernist visual vocabularly to camouflage an underlying, deliciously anachronistic, allegorical content. Hence, his playful physics is neo-Alchemy, a strictly contemporary, modernist solution. Like some contemporary writers, Duchamp validates the heavily pictorialized fossil science by inserting it into the modernist, pseudoscientific context of radioactivity, electricity, automobiles, X rays, and nuclear physics. According to Duchamp s later recollection to Tomkins,... 

SODDY, FREDERICK (1877-1965). A British physicist who won the Nobel pnze in chemistry in 1921. His work was concerned with radioactive elements and atomic energy. His concept of isotopes and the displacement law of radioactive change is basic to nuclear physics. His education was at Oxford and Glasgow. He later worked in Canada and Australia. 

In 1934, nuclear physics was young and the neutron had only just been discovered, yet the transuranium project was approached with a remarkable degree of confidence. The concepts from chemistry and nuclear physics that framed and guided the investigation were never seriously questioned, even though the synthesis and identification of new elements was, by definition, a leap into the unknown. Similarly, researchers were relatively unconcerned about the limitations of their small-scale experiments, even though the experiments themselves were notoriously difficult due to the tiny quantities of radioactive material. 

The development of nuclear physics began with the discovery of radioactivity by the French scientist Henri Becquerel in 1896, and associated fundamental works by Pierre and Marie Curie who all received the Nobel Prize in physics in 1903. 

The simplest substances are the elements. They cannot be broken down into simpler constituents by chemical reactions. Ninety-two elements exist in nature although some additional ones can be created experimentally by the techniques of nuclear physics, they exist only for very short periods of time before decaying radioactively. The elements can be arranged in basic groupings based on their properties a fundamental division is into metals (e.g. iron, copper, gold, sodium) and nonmetals (e.g. carbon, oxygen, hydrogen, sulfur). 

E. Segre (Ed.), Radioactive Decay, in Experimental Nuclear Physics, Vol. Ill, Wiley, New York, 1959... 

E. Segre (Kd.), Experimental Nuclear Physics, Vol. 1, Wiley, New York, 1953 A. H. Compton, S. K. Allison, X-rays in Theory and Experiment, Van Nostrand, London, 1935 I. G. Draganic, Z. D. Draganic, J. P. Adloff, Radiation and Radioactivity on Earth and Beyond, CRC Press, Boca Raton, FL, 1990... 

J. M. Cork, Radioactivity and Nuclear Physics, Ann Arbor, Michigan, 1946. 

Rutherford s work has made him known as the father of nuclear physics with his research on radioactivity (alpha and beta particles and protons, which he named), and he was the first to describe the concepts of half-life and decay constant. He showed that elements such as uranium transmute (become different elements) through radioactive decay, and he was the first to observe nuclear reactions (split the atom in 1917). In 1908 he received the Nobel Prize in chemistry for his investigations into the disintegration of the elements, and the chemistry of radioactive substances. He was president of the Royal Society (1926-30) and of the Institute of Physics (1931-33) and was decorated with the Order of Merit (1925). He became Lord Rutherford in 1931. 

Although, in hindsight, the 1932 model of Z protons and N = A — Z) neutrons became obsolete in 1964 (as seen below), it is still the colloquial way of thinking in nuclear physics, and it served to describe the stellar and the major part of the prestellar (primordial) nucleosynthesis. Since geologists pointed out their dissatisfaction with the maximum life-time of 50 million years for our Sun, if powered by gravitational contraction, as first calculated by Lord Kelvin [William Thomson (1824-1907)] one had looked to something like radioactivity, but it was found that the only viable reaction is... 

E. Browne and R. B. Firestone, V. S. Shirley (Ed.), Table of Radioactive Isotopes, 1. Wiley Sons, 1986. K. S. Krane, Introductory Nuclear Physics, J. Wiley Sons, 1988. 

Nuclear reactors are designed for production of heat, mechanical and electric power, radioactive nuclides, weapons material, research in nuclear physics and chemistry, etc. The design depends on the purposes, e.g. in the case of electric power production the design is chosen to provide the cheapest electricity taking long term reliability in consideration. This may be modified by the availability and economy of national resources such as raw material, manpower and skill, safety reasons, etc. Also the risk for proliferation of reactor materials for weapons use may influence the choice of reactor type. Many dozois of varying reactor concepts have been formulated, so we must limit the discussion in this chapter to a summary of the main variables, and the most common research and power reactors. Fast reactors and some other designs are discussed in Chapter 20. 

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