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1.
Prev Chronic Dis ; 16: E156, 2019 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-31775009

RESUMEN

Gardens provide access to healthy food, increase access to nutrition and physical activity opportunities, and are a focal point for community interventions. We used a gardening intervention to improve local access to and consumption of fruits and vegetables and as an integral part of overall efforts of local wellness coalitions. Seasonal garden coordinators were hired, and action plans included goals for nutrition and physical activity education programs and youth and adult engagement. The characteristics of each garden (size, items planted, number of volunteers) and pre- and post-intervention surveys were used to understand how the gardens affected communities. Thirteen gardens were planted, and volunteers provided 18,136 hours; adults from the community reported an increased awareness of garden benefits. The community garden intervention provided opportunities for collaboration with a variety of schools, community organizations, and city and tribal organizations, thereby increasing the sustainability of the intervention.


Asunto(s)
Participación de la Comunidad , Jardinería , Población Rural , Instituciones Académicas , Voluntarios , Abastecimiento de Alimentos , Frutas , Educación en Salud , Promoción de la Salud , Humanos , Estados Unidos , Verduras
2.
J Environ Radioact ; 195: 9-19, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30237079

RESUMEN

When post-irradiation materials from the nuclear fuel cycle are released to the environment, certain isotopes of actinides and fission products carry signatures of irradiation history that can potentially aid a nuclear forensic investigation into the material's provenance. In this study, combinations of Pu, Cs, and Ba isotope ratios that produce position (in the reactor core) independent monitors of irradiation history in spent light water reactor fuel are identified and explored. These position independent monitors (PIMs) are modeled for various irradiation scenarios using automated depletion codes as well as ordinary differential equation solutions to approximate nuclear physics models. Experimental validation was performed using irradiated low enriched uranium oxide fuel from a light water reactor, which was sampled at 8 axial positions from a single rod. Plutonium, barium and cesium were chemically separated and isotope ratio measurements of the separated solutions were made by quadrupole and multi-collector inductively coupled mass spectrometry (Cs and Pu, respectively) and thermal ionization mass spectrometry (Ba). The effect of axial variations in neutron fluence and energy spectrum are evident in the measured isotope ratios. Two versions of a combined Pu and Cs based PIM are developed. A linear PIM model, which can be used to solve for irradiation time is found to work well for natural U fuel with <10% 240Pu and known or short cooling times. A non-linear PIM model, which cannot be solved explicitly for irradiation time without additional information, can nonetheless still group samples by irradiation history, including high burnup LEU fuel with unknown cooling time. 137Ba/138Ba is also observed to act as a position independent monitor; it is nearly single valued across the sampled fuel rod, indicating that samples sharing an irradiation history (same irradiation time and cooling time) in a reactor despite experiencing different neutron fluxes will have a common 137Ba/138Ba ratio. Modeling of this Ba PIM shows it increases monotonically with irradiation and cooling time, and a confirmatory first order analytical solution is also presented.


Asunto(s)
Radioisótopos de Bario/análisis , Radioisótopos de Cesio/análisis , Reactores Nucleares , Plutonio/análisis , Monitoreo de Radiación/instrumentación , Espectrometría de Masas
3.
Forensic Sci Int ; 240: 111-21, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24836840

RESUMEN

Early in 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. During the search of the laboratory, a small glass jar labelled "Gamma Source" and containing a green powder was discovered. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterise and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive range of parameters were measured, the key 'nuclear forensic signatures' used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine.

4.
Appl Spectrosc ; 67(9): 1049-56, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24067636

RESUMEN

Uranium ore concentrates (UOCs) are produced at mining facilities from the various types of uranium-bearing ores using several processes that can include different reagents, separation procedures, and drying conditions. The final UOC products can consist of different uranium species, which are important to identify to trace interdicted samples back to their origins. Color has been used as a simple indicator; however, visual determination is subjective and no chemical information is provided. In this work, we report the application of near-infrared (NIR) spectroscopy as a non-contact, non-destructive method to rapidly analyze UOC materials for species and/or process information. Diffuse reflectance spectra from 350 to 2500 nm were measured from a number UOC samples that were also characterized by X-ray diffraction. Combination and overtone bands were used to identify the amine and hydroxyl-containing species, such as ammonium uranates or ammonium uranyl carbonate, while other uranium oxide species (e.g., uranium trioxide [UO3] and triuranium octoxide [U3O8]) exhibit absorption bands arising from crystal field effects and electronic transitions. Principal component analysis was used to classify the different UOC materials.

5.
Sci Total Environ ; 437: 373-83, 2012 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-22960112

RESUMEN

Beryllium has been historically machined, handled and stored in facilities at Lawrence Livermore National Laboratory (LLNL) since the 1950s. Additionally, outdoor testing of beryllium-containing components has been performed at LLNL's Site 300 facility. Beryllium levels in local soils and atmospheric particulates have been measured over three decades and are comparable to those found elsewhere in the natural environment. While localized areas of beryllium contamination have been identified, laboratory operations do not appear to have increased the concentration of beryllium in local air or water. Variation in airborne beryllium correlates to local weather patterns, PM10 levels, normal sources (such as resuspension of soil and emissions from coal power stations) but not to LLNL activities. Regional and national atmospheric beryllium levels have decreased since the implementation of the EPA's 1990 Clean-Air-Act. Multi-element analysis of local soil and air samples allowed for the determination of comparative ratios for beryllium with over 50 other metals to distinguish between natural beryllium and process-induced contamination. Ten comparative elemental markers (Al, Cs, Eu, Gd, La, Nd, Pr, Sm, Th and Tl) that were selected to ensure background variations in other metals did not collectively interfere with the determination of beryllium sources in work-place samples at LLNL. Multi-element analysis and comparative evaluation are recommended for all workplace and environmental samples suspected of beryllium contamination. The multi-element analyses of soils and surface dusts were helpful in differentiating between beryllium of environmental origin and beryllium from laboratory operations. Some surfaces can act as "sinks" for particulate matter, including carpet, which retains entrained insoluble material even after liquid based cleaning. At LLNL, most facility carpets had beryllium concentrations at or below the upper tolerance limit determined by sampling facilities with no history of beryllium work. Some facility carpets had beryllium concentrations above the upper tolerance limits but can be attributed to tracking of local soils, while other facilities showed process-induced contamination from adjacent operations. In selected cases, distinctions were made as to the source of beryllium in carpets. Guidance on the determination of facility beryllium sources is given.


Asunto(s)
Berilio/análisis , Material Particulado/análisis , Suelo/análisis , Filtros de Aire/historia , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/historia , Contaminantes Ocupacionales del Aire/análisis , Contaminantes Ocupacionales del Aire/historia , Berilio/historia , Monitoreo del Ambiente/historia , Pisos y Cubiertas de Piso/historia , Historia del Siglo XX , Historia del Siglo XXI , Metales Pesados/análisis , Metales Pesados/historia , Material Particulado/historia , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/historia
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