550 resultados para radon daughters
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The main concern of this paper is to present some improvements to results on the existence or non-existence of countably additive Borel measures that are not Radon measures on Banach spaces taken with their weak topologies, on the standard axioms (ZFC) of set-theory. However, to put the results in perspective we shall need to say something about consistency results concerning measurable cardinals.
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Mathematics Subject Classification 2010: 42C40, 44A12.
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Purpose: Early onset of sexual activity has been linked to later substance abuse. Our study aimed to further describe the associations between Latina mothers’ and daughters’ early sexual activity and adult substance abuse. Methods: A survey was conducted with 92 Latina mother–daughter dyads whose members never experienced sexual abuse. Childhood sexual experience was defined as the occurrence of a consensual sexual encounter at the age of 15 years or younger. Substance abusers were identified by the extent of substance use during the 12 months prior to the interview. Path analysis was used to fit our conceptual models to the data. Main findings: Daughters’ current, adult substance abuse was associated independently with: their own childhood sexual experience (odds ratio [OR] = 6.0) and mothers’ current, adult substance abuse (OR = 2.0). Compared with daughters who first experienced sex after the age of 19, the odds of using substances were 17.7 times higher among daughters who had childhood sexual experience and 3.8 times higher among daughters who first experienced sex between the age of 16–19 years. Explicitly, sexual experiences between the ages of 16–19 years were also risk factors for later adult substance abuse. Mothers’ childhood sexual experience (OR = 7.3) was a strong predictor for daughters’ childhood sexual experience. Conclusions: Our study supported a link between mother and daughter childhood sexual experience among Latinas, and indicated it is a correlate of adult substance abuse. Family based substance abuse prevention efforts and future longitudinal studies should consider maternal childhood sexual experience as a potential indication of risk for Latina daughters.
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General note: Title and date provided by Bettye Lane.
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Air-sea gas exchange plays a key role in the cycling of greenhouse and other biogeochemically important gases. Although air-sea gas transfer is expected to change as a consequence of the rapid decline in summer Arctic sea ice cover, little is known about the effect of sea ice cover on gas exchange fluxes, especially in the marginal ice zone. During the Polarstern expedition ARK-XXVI/3 (TransArc, August/September 2011) to the central Arctic Ocean, we compared 222Rn/226Ra ratios in the upper 50 m of 14 ice-covered and 4 ice-free stations. At three of the ice-free stations, we find 222Rn-based gas transfer coefficients in good agreement with expectation based on published relationships between gas transfer and wind speed over open water when accounting for wind history from wind reanalysis data. We hypothesize that the low gas transfer rate at the fourth station results from reduced fetch due to the proximity of the ice edge, or lateral exchange across the front at the ice edge by restratification. No significant radon deficit could be observed at the ice-covered stations. At these stations, the average gas transfer velocity was less than 0.1 m/d (97.5% confidence), compared to 0.5-2.2 m/d expected for open water. Our results show that air-sea gas exchange in an ice-covered ocean is reduced by at least an order of magnitude compared to open water. In contrast to previous studies, we show that in partially ice-covered regions, gas exchange is lower than expected based on a linear scaling to percent ice cover.
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The reuse of industrial by-products is important for members of numerous industrial sectors. However, though the benefits of reuse are evident from an economical point of view, some compounds in these materials can have a negative effect on users' health.In this study, the radon emanation and exhalation features of red mud were surveyed using heat-treatment (100-1200 °C). As a result of the 1200°C-treated samples, massic radon exhalation capacity reduced from 75 ± 10 mBq kg-1 h-1 to 7 ± 4 mBq kg-1 h-1, approximately 10% of the initial exhalation rate.To find an explanation for internal structural changes, the porosity features of the heat-treated samples were also investigated. It was found that the cumulative pore volume reduced significantly in less than 100 nm, which can explain the reduced massic exhalation capacity in the high temperature treated range mentioned above.SEM snapshots were taken of the surfaces of the samples as visual evidence for superficial morphological changes. It was found that the surface of the high temperature treated samples had changed, proving the decrement of open pores on the surface.
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Radon Affected Area potential in Northern Ireland was estimated using a joint mapping method. This method allows variation of radon potential both between and within geological units. The estimates are based on the results of radon measurements and geological information for more than 23,000 homes. Elevated radon potential is presented here as indicative maps based on the highest radon potential for each 1 kilometre square of the Irish grid. The full definitive detail is published as a digital dataset for geographical information systems, which can be licensed. The estimated radon potential for an individual home can be obtained through the Public Health England (PHE) UKradon website. The work was partially funded by the Northern Ireland Environment Agency and was prepared jointly by PHE and the British Geological Survey. This report replaces the 2009 review and atlas (HPA-RPD-061).
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Lo scopo di questa tesi si articola in tre punti. In primo luogo, ci proponiamo di definire, sia in ambito analitico che in un contesto più algebrico e geometrico, la trasformata di Radon, di discutere la possibilità di un'eventuale generalizzazione a spazi non euclidei, e di presentare le sue proprietà più caratteristiche. In secondo luogo vogliamo dimostrare, sfruttando un collegamento di questa con la trasformata di Fourier, che la trasformata di Radon è un'applicazione iniettiva tra spazi funzionali e che è dunque invertibile, per poi descrivere uno dei possibili metodi formali di inversione. Accenneremo anche alle problematiche che insorgono nell'utilizzare l'antitrasformata di Radon in situazioni reali, e alle relative soluzioni. Infine, concluderemo la trattazione con una breve ma, ottimisticamente, delucidatrice, introduzione ad alcuni esempi di applicazione della trasformata di Radon a vari ambiti fisici e matematici.
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[EN]Rn has been detected in 28 groundwater samples from the northeast of Gran Canaria (Canary Islands, Spain) utilizing a closed loop system consisting of an AlphaGUARD monitor that measures radon activity concentration in the air by means of an ionization chamber, and an AquaKIT set that transfers dissolved radon in the water samples to the air within the circuit. Radon concentration in the water samples studied varies between 0.3 and 76.9 Bq/L. Spanish radiological protection regulations limit the concentration of 222Rn for drinking water to 100 Bq/L, therefore the values obtained for all the analyzed samples are below this threshold. The hydrogeological study reveals a significant correspondence between the radon activity concentration and the material characteristics of the aquifer.
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Natural radioactive tracer-based assessments of basin-scale submarine groundwater discharge (SGD) are well developed. However, SGD takes place in different modes and the flow and discharge mechanisms involved occur over a wide range of spatial and temporal scales. Quantifying SGD while discriminating its source functions therefore remains a major challenge. However, correctly identifying both the fluid source and composition is critical. When multiple sources of the tracer of interest are present, failure to adequately discriminate between them leads to inaccurate attribution and the resulting uncertainties will affect the reliability of SGD solute loading estimates. This lack of reliability then extends to the closure of local biogeochemical budgets, confusing measures aiming to mitigate pollution. Here, we report a multi-tracer study to identify the sources of SGD, distinguish its component parts and elucidate the mechanisms of their dispersion throughout the Ria Formosa – a seasonally hypersaline lagoon in Portugal. We combine radon budgets that determine the total SGD (meteoric + recirculated seawater) in the system with stable isotopes in water (δ2H, δ18O), to specifically identify SGD source functions and characterize active hydrological pathways in the catchment. Using this approach, SGD in the Ria Formosa could be separated into two modes, a net meteoric water input and another involving no net water transfer, i.e., originating in lagoon water re-circulated through permeable sediments. The former SGD mode is present occasionally on a multi-annual timescale, while the latter is a dominant feature of the system. In the absence of meteoric SGD inputs, seawater recirculation through beach sediments occurs at a rate of ∼ 1.4 × 106 m3 day−1. This implies that the entire tidal-averaged volume of the lagoon is filtered through local sandy sediments within 100 days ( ∼ 3.5 times a year), driving an estimated nitrogen (N) load of ∼ 350 Ton N yr−1 into the system as NO3−. Land-borne SGD could add a further ∼ 61 Ton N yr−1 to the lagoon. The former source is autochthonous, continuous and responsible for a large fraction (59 %) of the estimated total N inputs into the system via non-point sources, while the latter is an occasional allochthonous source capable of driving new production in the system.
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This brochure discusses these topics concerning radon: What Is Radon?, Health Effects Of Radon, Radon Action Level, How Much Radon In A Home Is Safe?, What Do I Do If I Have A Radon Problem?, Major Radon Entry Routes, How Do I Know If I Have A Radon Problem?, Where Should I Test?, Retesting For Radon and Radon in Water.
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This chart gives the long term effects of radon on smokers and non-smokers.
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This is a list of some basic installation requirements and recommendations that your contractor should meet when installing a radon reduction system in your home.
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Questa tesi analizza il problema della variazione delle misurazioni della concentrazione del Radon in presenza di anidride carbonica e fornisce varie soluzioni al problema.