|
| |
| | Radiometric Dating |
 | | Electron capture decay of light atoms--those having the fewest electrons--can be very slightly affected by extremely high pressures or certain chemical bonds, so as to change their half-lives by a fraction of a percent. | | | Decay The change from one element or isotope to another. | | | During the change, or decay, energy is released either in the form of light or energetic particles. |
|
http://www.asa3.org/ASA/resources/Wiens.html
(16626 words)
|
|
| |
| | Theory: Decays |
| | Nuclear stability and radioactive decays can all be explained from the same set of conservation laws and underlying interaction types as those for isolated particles. | | | If the half-life were any shorter, proton decays would have been observed in experiments searching for them, yet they have not been seen. | | | In contrast, the experimental lower limit on the half-life for the proton decay is 100,000,000,000,000,000,000,000,000,000,000 or 10 |
|
http://www2.slac.stanford.edu/vvc/theory/decays.html
(507 words)
|
|
| |
| | Decay Heat in Nuclear Reactors |
| | Some radioactive atoms will decay while the reactor is operating and the energy released by their decay will be removed from the core along with the heat produced by the fission process. | | | Activation of light elements in structural materials plays a role only in special circumstances, and is usually excluded from decay heat analyses. | | | Decay heat will continue to decrease, but it will decrease at a much slower rate. |
|
http://www.ontronic-efi.com/decay_heat.htm
(2463 words)
|
|
| |
| | Beta decay - Wikipedia, the free encyclopedia |
| | In nuclear physics, beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted. | | | Beta decay does not change the number of nucleons A in the nucleus but changes only its charge Z. | | | Historically, the study of beta decay provided the first physical evidence of the neutrino. |
|
http://en.wikipedia.org/wiki/Beta_decay
(759 words)
|
|
| |
| | Short Primer on U238 Radioactive Decay |
| | As it undergoes radioactive decay, a chain of products is formed as a result of one by-product itself decaying to another element, which in turn decays further until finally reaching an element that is stable. | | | The half-life is the time taken for half of the atoms of a radioactive substance to decay. | | | Atoms in a radioactive substance decay in a random fashion but at a characteristic rate. |
|
http://www.atral.com/U2381.html
(308 words)
|
|
| |
| | Radioactive decay - Wikipedia, the free encyclopedia |
| | Radioactive decay has been put to use in the technique of radioisotopic labelling, used to track the passage of a chemical substance through a complex system (such as a living organism). | | | Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). | | | On the premise that radioactive decay is truly random (rather than merely chaotic), it has been used in hardware random-number generators and is an invaluable tool in estimating the absolute ages of geological materials and young organic matter. |
|
http://en.wikipedia.org/wiki/Radioactive_decay
(1739 words)
|
|
| |
| | decay |
| | Not surprisingly, the earliest radioactive substances studied were ones that decayed fairly rapidly. | | | There are several quantitative aspects of radioactivity that are important for managing nuclear waste materials, including how much radioactivity a given substance emits, how concentrated the substance is in its surrounding medium, how dangerous its emissions are to human and other biological populations, and how long the substance goes on being radioactive. | | | Why do we expect a model function for the amount (or concentration) of a radioactive substance to be an exponential function? |
|
http://www.math.jmu.edu/~liu/decay.htm
(1137 words)
|
|
| |
| | What are the Radioactive Byproducts of Depleted Uranium (Uranium-238)? |
| | When uranium ore is extracted from the earth, most of the uranium is removed from the crushed rock during the milling process, but the radioactive decay products are left in the tailings. | | | The half-life of a radioactive element is the time it takes for half of its atoms to decay into something else. | | | The horizontal bar beside the name of each decay product indicates the "half life" of that particular substance, measured on a logarithmic scale (each half-inch to the right represents multiplication by a factor of one thousand). |
|
http://www.ccnr.org/decay_U238.html
(403 words)
|
|
| |
| | SDA Vol 4, Num 3: Radfacts |
| | However, practices using X-rays, radium, and radon (a radioactive decay product of uranium-238) for supposed medical treatment which amounted to quackery and which flew in the face of the well-established evidence of the dangers of radiation, persisted well into the twentieth century. | | | Energetic helium nuclei (two protons and two neutrons) emitted from the nucleus of a heavier element in the process of radioactive decay of the element. | | | Number of medical tests and studies using radioactive materials in 1987: 7 690 000 |
|
http://www.ieer.org/sdafiles/vol_4/4-3/radfact.html
(1210 words)
|
|
| |
| | Plate Rotation |
| | Radioactive decay is an exponential process such that half of the parent element will decay to the daughter element in a set amount of time (known as the half-life). | | | Elements such as uranium, thorium, and plutonium are observed to emit particles and thereby undergo radioactive decay. | | | You may change the time step parameter any time during the decay process. |
|
http://www.mines.utah.edu/~ggapps/radiation/radiation.html
(425 words)
|
|
| |
| | Theory: Radioactive Decay |
| | It is produced as a step in a radioactive decay chain when a massive nucleus produced by fission relaxes from the excited state in which it first formed towards its lowest energy or ground-state configuration. | | | Beta decay and gamma decay often occur as steps in a chain of radioactive decays that begins with the fission of some heavy element. | | | A nucleus will decay if there is a set of particles with lower total mass that can be reached by any of the above types of decay process or simply by fission, a process in which a massive nucleus splits into two less massive ones. |
|
http://www2.slac.stanford.edu/vvc/theory/nuclearstability.html
(694 words)
|
|
| |
| | Beta Decay |
| | There are several ways in which radioactive atoms can decay. | | | I'm going to illustrate how radioactive decay works with the help of an isotope table applet, which should now be open in a separate window. | | | This process is known as beta decay, and the electron is called a beta particle in this context. |
|
http://www.colorado.edu/physics/2000/isotopes/radioactive_decay.html
(262 words)
|
|
| |
| | C-decay - EvoWiki |
| | This effect should be plainly evident in observations of radioactive decay curves in supernovas, but in fact, all the radioactive decay curves yet observed exhibit no such effect. | | | Specifically: Light emitted from Point P at time T should get here more quickly than light emitted from Point P at a later time (T + 1), which in turn should get here more quickly than light emitted from Point P at a still later time (T + 2), and so on. | | | As well, there are pulsars -- the astronomical equivalent of metronomes -- the fastest of which (PSR1937+21) emits signals at a rate of one every 1.5 milliseconds, or 640 Hertz. |
|
http://wiki.cotch.net/index.php/C-decay
(616 words)
|
|
| |
| | Radioactive Decay Data |
| | Energy-ordered list of the most intense decay gamma rays from radioactive sources with half-lives greater than 1 day. | | | This page is dedicated to providing access to radioactive decay from the Table of Isotopes and other sources. | | | Mass-ordered list of decay parent nuclei properties including level energy, decay mode(s), spin-parity, half-life, decay Q-value. |
|
http://ie.lbl.gov/decay.html
(324 words)
|
|
| |
| | A Quantum of Common Sense |
| | Therefore one possible argument against the "consciousness" interpretation is that the wavefunction collapses the moment the decaying radioactive material emits a particle or photon that interacts with the trigger apparatus. | | | The idea was that the radioactive decay was only predictable by wavefunction since it is a quantum problem. | | | If someone makes a specific testable claim about some well known scientific area, it is easy to simply put it to the test and show whether it actually does what it says or not. |
|
http://www.skepticreport.com/tools/quantum.htm
(9338 words)
|
|
| |
| | Confessions of a Quackbuster: Polite request to creationists |
| | Do not suggest that the rates of radioactive decay may have been millions of times greater in the past unless you are prepared to offer evidence, because wishful thinking is not evidence that the Earth was created in six literal days about 6,000 years ago. | | | I confess to being a skeptic (I have a naturalistic world view) who is concerned about healthcare consumer protection, and therefore about quackery, healthfraud, chiropractic quackery, and other forms of so-Called "Alternative" Medicine (sCAM). | | | An opinion poll about how many people believe in special creation is irrelevant, because that is not evidence that the Earth was created in six literal days about 6,000 years ago. |
|
http://quackfiles.blogspot.com/2005/06/polite-request-to-creationists.html
(1095 words)
|
|
| |
| | LP: Fuel suspected deep inside Earth |
| | One point about methane production deep in the earth that has not been pointed out is that Hydrogen produced by normal radioactive decay (Helium is also a product) is at least one source. | | | Your statement may or may not be true. | | | But questions of feasabilty of action and possibility of harm do not equate to a proper label of quackery for the theororists. |
|
http://www.libertypost.org/cgi-bin/readart.cgi?ArtNum=66536&Disp=0
(3380 words)
|
|
| |
| | EPA - Decay Chains (EPA's Radiation Protection Program: Understanding Radiation) |
| | As radioactive decay progresses, the concentration of the original radionuclides decreases, while the concentration of their decay products increases and then decreases as they undergo transformation. | | | For example, uranium-238 decays through a series of steps to become a stable form of lead. | | | However, close examination of the uranium-238 decay chain identified radon-222 as the most likely culprit. |
|
http://www.epa.gov/radiation/understand/chain.htm
(781 words)
|
|
| |
| | Some notes on Skepticism |
| | Neutrinos are ghostlike particles that were introduced by Pauli as an ad-hoc hypothesis to save the relativistic law of energy conservation (which fails to correctly describe radioactive beta decay otherwise). | | | Why not similarly list the dangers of improperly performed surgery and then denounce the whole field as quackery? | | | Another example of established science that should not be so established is the neutrino. |
|
http://www.suppressedscience.net/skepticism.html
(11599 words)
|
|
| |
| | Indoor Radon and Radon Decay Product Measurement Device Protocols - Glossary |
| | Equilibrium, radioactive: A state in which the formation of atoms by decay of a parent radioactive isotope is equal to its rate of disintegration by radioactive decay. | | | Beta decay is radioactive decay in which an electron is emitted from a nucleus. | | | Equilibrium ratio, radioactive: The total concentration of radon decay products (RDPs) present divided by the concentration that would exist if the RDPs were in radioactive equilibrium with the radon gas concentration which is present. |
|
http://www.radon.com/pubs/devprot5.html
(10 words)
|
|
| |
| | Medcyclopaedia - Radioactive decay |
| | Another type of decay is the so-called electron capture EC Many radioactive isotopes, particularly heavy ones such as uranium, disintegrate by a series of radioactive decays (radioactive series) until they have been transformed into stable atoms. | | | Radioactive decay obeys the radioactive decay law: an exponential decay. | | | There are several types of radioactive decay, classified as alpha decay, beta decay and gamma decay. |
|
http://medcyclopaedia.com/library/topics/volume_i/r/RADIOACTIVE_DECAY.aspx
(241 words)
|
|
| |
| | Radioactive Half-Life |
| | The radioactive half-life for a given radioisotope is a measure of the tendency of the nucleus to "decay" or "disintegrate" and as such is based purely upon that probability. | | | Radioactive decay is a statistical process which depends upon the instability of the particular radioisotope, but which for any given nucleus in a sample is completely unpredictable. | | | The rate of radioactive decay is typically expressed in terms of either the radioactive half-life, or the radioactive decay constant. |
|
http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli2.html
(450 words)
|
|
| |
| | Radioactive Half-Life |
| | The rate of radioactive decay is typically expressed in terms of either the radioactive half-life, or the radioactive decay constant. | | | The radioactive half-life for a given radioisotope is a measure of the tendency of the nucleus to "decay" or "disintegrate" and as such is based purely upon that probability. | | | Radioactive decay is a statistical process which depends upon the instability of the particular radioisotope, but which for any given nucleus in a sample is completely unpredictable. |
|
http://hyperphysics.phy-astr.gsu.edu/HBASE/nuclear/halfli2.html
(450 words)
|
|
| |
| | Radioisotopes Terms and Definitions at www.MedicalGlossary.org |
| | Isotopes that exhibit radioactivity and undergo radioactive decay. | | | Thallium Radioisotopes - Unstable isotopes of thallium that decay or disintegrate emitting radiation. | | | Sr 80-83, 85, and 89-95 are radioactive strontium isotopes. |
|
http://www.medicalglossary.org/isotopes_radioisotopes_definitions.html
(740 words)
|
|
| |
| | Decay chain - Wikipedia, the free encyclopedia |
| | Nearly all the decay products of radioactive decay are themselves radioactive. | | | Because of this, most radioactive substances do not decay directly to a stable state, but rather undergo a series of decays until eventually a stable isotope is reached. | | | In practice there are only three common modes of radioactive decay: alpha decay, beta minus decay, and beta plus decay. |
|
http://en.wikipedia.org/wiki/Decay_chain
(740 words)
|
|
| |
| | Decay product - Wikipedia, the free encyclopedia |
| | In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. | | | Decay products are extremely important in understanding radioactive decay and the management of radioactive waste. | | | Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. |
|
http://en.wikipedia.org/wiki/Decay_product
(740 words)
|
|
| |
| | NTU Info Centre: Decay product |
| | In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. | | | Decay products are extremely important in understanding radioactive decay and the management of radioactive waste. | | | Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. |
|
http://www.nowtryus.com/article:Decay_product
(740 words)
|
|
| |
| | Decay product |
| | In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. | | | Decay products are extremely important in understanding radioactive decay and the management of radioactive waste. | | | Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. |
|
http://www.sciencedaily.com/encyclopedia/decay_product
(740 words)
|
|
| |
| | Articles - Decay product |
| | In nuclear physics, a decay product, also known as a daughter product, is a nuclide resulting from the radioactive decay of a parent or precursor nuclide. | | | Decay products are extremely important in understanding radioactive decay and the management of radioactive waste. | | | Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. |
|
http://www.lastring.com/articles/Decay_product?mySession=3294ebdfd63954d556e60ef7070a5480
(740 words)
|
|
|
