scholarly journals Natural radioactive isotopes in glacier meltwater studies

2011 ◽  
Vol 45 (6) ◽  
pp. 423-429 ◽  
Author(s):  
A. KIES ◽  
A. NAWROT ◽  
Z. TOSHEVA ◽  
J. JANIA
Keyword(s):  
Radioactive Isotopes ◽  
Glacier Meltwater

Bioavailability of Vitamin B12

2010 ◽  
Vol 80 (45) ◽  
pp. 330-335 ◽  
Author(s):  
Lindsay Helen Allen
Keyword(s):  
Vitamin B12 ◽  
Vitamin B12 Deficiency ◽  
The Elderly ◽  
Radioactive Isotopes ◽  
Animal Source Foods ◽  
Dietary Requirements ◽  
In Vivo Labeling ◽  
B12 Deficiency ◽  
Vitamin B12 Malabsorption

Vitamin B12 deficiency is common in people of all ages who consume a low intake of animal-source foods, including populations in developing countries. It is also prevalent among the elderly, even in wealthier countries, due to their malabsorption of B12 from food. Several methods have been applied to diagnose vitamin B12 malabsorption, including Schilling’s test, which is now used rarely, but these do not quantify percent bioavailability. Most of the information on B12 bioavailability from foods was collected 40 to 50 years ago, using radioactive isotopes of cobalt to label the corrinoid ring. The data are sparse, and the level of radioactivity required for in vivo labeling of animal tissues can be prohibitive. A newer method under development uses a low dose of radioactivity as 14C-labeled B12, with measurement of the isotope excreted in urine and feces by accelerator mass spectrometry. This test has revealed that the unabsorbed vitamin is degraded in the intestine. The percent bioavailability is inversely proportional to the dose consumed due to saturation of the active absorption process, even within the range of usual intake from foods. This has important implications for the assessment and interpretation of bioavailability values, setting dietary requirements, and interpreting relationships between intake and status of the vitamin.

EVALUATION OF NATURAL ION EXCHANGERS FOR THE REMOVAL OF RADIOACTIVE ISOTOPES FROM LIQUID EFFLUENTS

2002 ◽  
Vol 1 (4) ◽  
pp. 577-588
Author(s):  
Eveline Popovici ◽  
Igor Cretescu ◽  
Elena Botezatu ◽  
Gabriela Soreanu ◽  
Alina Mihaela Hanu ◽  
...  
Keyword(s):  
Radioactive Isotopes ◽  
Ion Exchangers

Superposition of Potential Chemical Polluants and Radioisotopes and Their Influence Upon the Environment and Living Organisms

2017 ◽  
Vol 68 (9) ◽  
pp. 2189-2195
Author(s):  
Valeriu V. Jinescu ◽  
Simona Eugenia Manea ◽  
George Jinescu ◽  
Vali Ifigenia Nicolof
Keyword(s):  
Solid Waste ◽  
Critical Energy ◽  
Radioactive Isotopes ◽  
Nuclear Facility ◽  
Chemical Pollutants ◽  
Living Organisms

Following the activities developed in a nuclear facility result gaseous and liquid radioactive effluents and radioactive solid waste. All these waste contain radioactive isotopes which are potentially pollutants for the environment. In the same time chemicals are, also, pollutants. According to the legislation, discharging of chemicals and radioactive liquid and gaseous effluents into the environment, should meet the requirements of the unrestricted discharge. However, what happens when several pollutants superpose: only chemical pollutants, or only radioactive pollutants, or chemical and radioactive pollutants? Such problems have been solved in this paper on the basis of the principle of critical energy.

scholarly journals On the Measures to Solve Environmental Problems of the Territory with Intensive Open Pit Coal Mining

2019 ◽  
Vol 105 ◽  
pp. 02006
Author(s):  
Tatiana Gvozdkova ◽  
Pawel Stefanek ◽  
Michaela Koščová
Keyword(s):  
Soil Cover ◽  
Mineral Resources ◽  
Radioactive Isotopes ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Coal Deposits ◽  
Disturbed Land ◽  
Ecological Problems ◽  
Suitable Form

Ecological problems in the open pit mining of coal deposits are extremely hard, since mining operations are accompanied by disturbed land to a large depth with significant changes in the landscape, hydrometeorological conditions, mixing of rocks and removal of infertile or even harmful rocks with radioactive isotopes to the surface. Disturbed lands are unusable if they are not repaired. All man-made disturbances of the environment caused by open pit mining are divided into landscape (changes in terrain, vegetation and soil cover) and environmental (violation of living conditions within the allotment and adjacent lands: changes in water regime, pollution of the soil, air and water basins) onesOne of the most important areas in the field of environmental protection is the reclamation (restoration) of the earth’s surface. In accordance with the requirements of the protection of the subsoil, enterprises engaged in the development of mineral deposits are obliged at their own expense to bring disturbed lands into a state suitable form for their further use. Reclamation of ought to be carried out during open pit mining operations and must be completed after mining of mineral resources in the terms established by the authorities that provide land for use.

scholarly journals Yttrium Oxide Freeze-Casts: Target Materials for Radioactive Ion Beams

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2864
Author(s):  
Eva Kröll ◽  
Miriana Vadalà ◽  
Juliana Schell ◽  
Simon Stegemann ◽  
Jochen Ballof ◽  
...  
Keyword(s):  
Pore Structure ◽  
Yttrium Oxide ◽  
Ion Beam ◽  
Isotope Separation ◽  
Target Material ◽  
Ion Beams ◽  
Radioactive Isotopes ◽  
Solid Loading ◽  
Radioactive Ion Beams ◽  
Freeze Casting

Highly porous yttrium oxide is fabricated as ion beam target material in order to produce radioactive ion beams via the Isotope Separation On Line (ISOL) method. Freeze casting allows the formation of an aligned pore structure in these target materials to improve the isotope release. Aqueous suspensions containing a solid loading of 10, 15, and 20 vol% were solidified with a unidirectional freeze-casting setup. The pore size and pore structure of the yttrium oxide freeze-casts are highly affected by the amount of solid loading. The porosity ranges from 72 to 84% and the crosslinking between the aligned channels increases with increasing solid loading. Thermal aging of the final target materials shows that an operation temperature of 1400 °C for 96 h has no significant effect on the microstructure. Thermo-mechanical calculation results, based on a FLUKA simulation, are compared to measured compressive strength and forecast the mechanical integrity of the target materials during operation. Even though they were developed for the particular purpose of the production of short-lived radioactive isotopes, the yttria freeze-cast scaffolds can serve multiple other purposes, such as catalyst support frameworks or high-temperature fume filters.

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