Strontium source

Inside the main cavity of the sensor is a strontium source contained in silver foil. The surface layer on the foil that contained the radioactive material must be very thin or the 3 particles will not be able to leave the surface. This tenuous layer protecting the radioactive material is rather vulnerable to mechanical abrasion, which could result in radioactive contamination. The radioactive strength of the... 

No studies were located regarding health effects in humans or animals after dermal exposure to stable strontium. Studies in which solid radioactive strontium sources were placed near or against the skin are described in Section 3. 2.4 External Exposure, since the exposure method provided no opportunity for absorption of radiostrontium through the skin. 

No studies were located regarding health effects in humans or animals after external exposure to stable strontium. Cardiovascular, dermal, ocular, and cancer effects have been reported following acute- or intermediate-duration external exposure to beta radiation from a solid radioactive strontium source apposed to the skin or eye. In these studies, 90Sr was considered to be in equilibrium with90Y that is, following decay of 90Sr, some radiation emissions could be expected from decay of its daughter radionuclide, 90Y. 

In vivo counting systems are calibrated using tissue-equivalent phantoms. These phantoms have shapes similar to the human torso and are made of polystyrene or other tissue equivalent material. Standard radioactive strontium sources of known activity are inserted at locations where strontium would be expected to accumulate in a human body. Relationships are determined between the radioactive strontium activity measured by the detection system and the known activity in the phantom (Kozheurov 1994). 

Argonne National Laboratory. Strontium Human Health Fact Sheet. Available online. URL www.ead.anl.gov/pub/doc/ strontium.pdf. Accessed on June 23, 2009. Human health fact sheet contains details on strontium sources, uses, and human health risks. 

Table 8.1. Strontium sources and typical 87Sr/86Sr values...

Deposits of celestite in Gloucestershire, the United Kingdom, represented the main source of the world supply from 1884 to 1941 and provided up to 90% of the world strontium supply (4). During World War II, shipments to the United States and Western Europe from the United Kingdom were dismpted, and celestite deposits in Mexico and Spain were developed. 

Strontium Oxide, Hydroxide, and Peroxide. Strontium oxide, SrO, is a white powder that has a specific gravity of 4.7 and a melting point of 2430°C. It is made by heating strontium carbonate with carbon in an electric furnace, or by heating celestite with carbon and treating the sulfide formed with caustic soda and then calcining the product (10). It reacts with water to form strontium hydroxide [18480-07-4] and is used as the source of strontium peroxide [1314-18-7],... 

Because normal radioisotopic decay lowers the thermal output by about 2.5%/yr in these units, they are purposefully overdesigned for beginning of life conditions. Several of these generators have successfully operated for as long as 28 years. This is approximately equal to the half-life of the strontium-90 isotope used in the heat sources. The original SNAP-7 series immobilized the strontium-90 as the titanate, but the more recent ones have used it in the form of the fluoride, which is also very stable. A number of tiny nuclear-powered cardiac pacemaker batteries were developed, which have electrical power outputs of 33—600 p.W and have been proven in use (17). 

Hardness Calcium, magnesium, barium and strontium salts expressed as CaCOa Chief source of scale in heat exchange equipment, boilers, pipe lines, etc. forms curds with soap interferes wKh dyeing, etc. Softening, distillation, internal boiler water treatment, surface active agents, reverse osmosis, electrodialysis... 

The hydrolysis of dimethyl sulphate also provides a source of sulphate ion, and the reaction has been used for the precipitation of barium, strontium, and calcium as well as lead ... 

Gale, N. (1981), Mediterranean obsidian source characterization by strontium isotope analysis, Archaeometry 23, 41-51. 

Negrel Ph, Allegre CJ, Dupre B, Lewin E (1993) Erosion sources determined by inversion of major and trace element ratios and strontium isotopic ratios in river water the Congo Basin case. Earth Planet Sci Lett 120 59-76... 

English, N. B., Betancourt, J. L., Dean, J. S., and Quade, J. (2001). Strontium isotopes reveal distant sources of architectural timber in Chaco Canyon, New Mexico. Proceedings of the National Academy of Sciences of the United States of America 98 11891-11896. 

Tomascak PB, Hemming NG, Pedone VA(2001) Lithium, boron, and strontium isotope constraints on solute sources for the Great Salt Lake, Utah. Eleventh VM Goldschmidt Conf Abst, LPI Contribution 1088, Lunar Planetary Institute, 3758... 

The atomic absorption characteristics of technetium have been investigated with a technetium hollow-cathode lamp as a spectral line source. The sensitivity for technetium in aqueous solution is 3.0 /ig/ml in a fuel-rich acetylene-air flame for the unresolved 2614.23-2615.87 A doublet under the optimum operating conditions. Only calcium, strontium, and barium cause severe technetium absorption suppression. Cationic interferences are eliminated by adding aluminum to the test solutions. The atomic absorption spectroscopy can be applied to the determination of technetium in uranium and its alloys and also successfully to the analysis of multicomponent samples. 

Radiotherapy is a local treatment aiming to achieve local control or cure of locally confined tumours. It cannot treat metastases. Radiotherapy may be administered as external beam radiotherapy with X-rays or gamma rays, in sealed radioactive sources (e.g. prostate brachytherapy), or unsealed sources (e.g. orally administered radioiodine for thyroid cancer, intravenous strontium-89 for bone metastases). In external beam radiotherapy, the X-ray or gamma ray beams are targeted at the tumour to damage and kill the tumour cells. Inevitably, surrounding normal tissues are also affected resulting in the early and late side effects of radiotherapy. 

Davy also discovered several other elements (potassium, barium, calcium, and strontium) by isolating the metals from their compounds through electrolysis. His work led to the development of electrochemistry, which is the use of electricity as the energy source to break up the oxides of these alkali and alkali earth elements. 

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