The moisture effect on 223Ra and 224Ra measurements using Mn-cartridges

Important processes in the ocean can be evaluated with radioactive nuclides, including radium isotopes. An approach for quantifying radium isotopes in seawater with in-situ pumps has been developed in advance of the GEOTRACES program [1]. Precise measurements of 223Ra and 224Ra by means of the delayed coincidence counting system (RaDeCC) [2] are dependent on the moisture content of the medium [3]. In order to verify the optimum moisture content for this new approach, a set of measurements of the Mn-cartridge standards under different moisture conditions was conducted, as this was done previously for acrylic fiber. At a time, an amount of water equivalent to 5% of the cartridges weight was added, and the activities were determined. The variation of 224Ra activity occurs mainly between 0 to 15% of humidity. Under moisture conditions higher than 15%, the emanation efficiency reaches an optimum plateau until 100% of moisture. This result differs slightly from those found for 224Ra measurements using the acrylic fiber (plateau from 30 to 100 %) [3]. The 223Ra Mn-cartridge standard reaches the plateau under 5% of humidity, and above 50% moisture the activity seems to decrease. Considering the counting error (7%), it is hard to state that the effect of the moisture is critical. However, this decrease can be related to the shorter half-life of the 219Rn compared to the time needed to its diffusion through the water film, which could be a reason for the frequently observed lower efficiency of the 223Ra channel of the RaDeCC system [4]. [1] Henderson et al. (2013) J. Radioanal. Nucl. Chem. 296, 357–362. [2] Moore and Arnold (1996) J. Geophys. Res. 101, 321–1329. [3] Sun and Torgersen (1998) Mar. Chem. 61, 163–171. [4] Charette et al. (2012) Limnol. Oceanogr. 10, 451–463

Radon (222Rn) as tracer for submarine groundwater discharge investigation—limitations of the approach at shallow wind‐exposed coastal settings

Mapping radon (222Rn) distribution pat- terns in the coastal sea is a widely applied method for localizing and quantifying submarine groundwater discharge (SGD). While the literature reports a wide range of successful case studies, methodical problems that might occur in shallow wind-exposed coastal settings are generally neglected. This paper evalu- ates causes and effects that resulted in a failure of the radon approach at a distinct shallow wind-exposed location in the Baltic Sea. Based on a simple radon mass balance model, we discuss the effect of both wind speed and wind direction as causal for this fail- ure. We show that at coastal settings, which are domi- nated by gentle submarine slopes and shallow waters, both parameters have severe impact on coastal radon distribution patterns, thus impeding their use for SGD investigation. In such cases, the radon approach needs necessarily to allow for the impact of wind speed and wind direction not only during but also prior to the field campaign

Radon (222Rn) as Tracer for Submarine Groundwater Discharge Investigation—Limitations of the Approach at Shallow Wind-Exposed Coastal Settings

Mapping radon (222Rn) distribution patterns in the coastal sea is a widely applied method for localizing and quantifying submarine groundwater discharge (SGD). While the literature reports a wide range of successful case studies, methodical problems that might occur in shallow wind-exposed coastal settings are generally neglected. This paper evaluates causes and effects that resulted in a failure of the radon approach at a distinct shallow wind-exposed location in the Baltic Sea. Based on a simple radon mass balance model, we discuss the effect of both wind speed and wind direction as causal for this failure. We show that at coastal settings, which are dominated by gentle submarine slopes and shallow waters, both parameters have severe impact on coastal radon distribution patterns, thus impeding their use for SGD investigation. In such cases, the radon approach needs necessarily to allow for the impact of wind speed and wind direction not only during but also prior to the field campaign

A extensão universitária atuando na avaliação e na melhoria da qualidade da água subterrânea consumida por comunidade carente de água potável.

ResumoA Ilha dos Marinheiros (1400 hab.) pertence à cidade do Rio Grande (RS). Nela não há suprimento de água potável, sendo consumida a água subterrânea. Em 2013 foi aí desenvolvido o projeto de extensão "A água do seu poço é ferruginosa? o conhecimento acadêmico a serviço da comunidade". Foram analisados os níveis de ferro na água consumida em cada uma das 309 casas habitadas, usando-se um kit analítico. Foi constatado que em 41,75% das casas há consumo de água ferruginosa (ferro>0,3mg/L). Em cada casa foi entregue um laudo do resultado com informações sobre tratamentos caseiros de remoção do ferro da água. A partir da conscientização dos ilhéus, eles agiram na busca de consumirem água de qualidade

Kit analítico simplificado: uma ferramenta para avaliação massiva da qualidade da água subterrânea

Groundwater resources constitute an important alternative supply. However, the physic - chemical conditions in the subterranean environment favoring the dissolution of some compounds, including iron. This element, when present in excess in the water for residential use can lead to poor quality of life and health. In this context, this paper presents a method for the preparation and handling of a simplified water test kit, optimized for the qualitative determination of dissolved iron in the water. The method principle is based on visual colorimetry, wherein the sample becomes colored by the addition of reactants, allowing the comparison with a color chart and its associated iron levels. The use of this tool can facilitate, for example, making diagnoses of water quality by a massive evaluation of the water used in communities without access to safe water. This water test kit was applied as a diagnostic tool in an area where there is no supply of drinking water, in Rio Grande city - RS. Of the 309 households assessed, on average 47 ± 23% is supplied by rusty water. These results enabled the awareness and mobilization of the residents, as well as the performance of public agencies to develop strategies for improving the quality of water consumed by the population.Os recursos hídricos subterrâneos configuram uma importante alternativa de abastecimento. Porém, as condições físico-químicas no ambiente subterrâneo favorecem a dissolução de alguns compostos, entre eles o ferro. Esse elemento, quando presente em excesso na água para consumo residencial, pode acarretar problemas de qualidade de vida e de saúde. Nesse contexto, o presente trabalho apresenta um método para a elaboração e manuseio de um kit analítico simplificado, otimizado para a determinação qualitativa do ferro dissolvido na água. Esse instrumento é fundamentado na colorimetria visual, na qual a adição de reagentes confere cor à amostra, permitindo sua comparação com uma cartela de cores contendo níveis de contaminação associados aos diferentes tons da cor laranja. A utilização desta ferramenta pode facilitar a elaboração de diagnósticos da qualidade da água, através da avalia- ção massiva da água subterrânea consumida em comunidades desprovidas de água potável canalizada. Este kit analí- tico foi aplicado como ferramenta de diagnóstico em uma área sem suprimento de água potável em Rio Grande - RS. Das 309 residências avaliadas, em média 47±23 % são abastecidas por água ferruginosa. Esses resultados possibilitaram a conscientização e mobilização dos moradores da área, bem como a atuação dos órgãos públicos na elabora- ção de estratégias para a melhoria na qualidade da água consumida pela população

Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil)

This study optimized and validated a method to perform chemical speciation of inorganic arsenic in water samples collected under the Monitoring Program of the Port of Rio Grande-RS in July and October 2010 from the Laguna dos Patos Estuary (RS, Brazil). The flow injection hydride generation atomic absorption spectrometry technique was employed, allowing quantification of As3+ and As5+ present in estuarine water samples. Data interpretation for results generated using the improved method for analyzing water samples collected from Laguna dos Patos Estuary was done by main components analysis

CHEMICAL SPECIATION OF INORGANIC ARSENIC IN LAGUNA DOS PATOS ESTUARY (RS, BRAZIL)

Submitted by Paula Gautério ([email protected]) on 2014-05-31T15:19:53Z No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5)Approved for entry into archive by cristiane soares ([email protected]) on 2014-08-22T17:21:37Z (GMT) No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5)Made available in DSpace on 2014-08-22T17:21:37Z (GMT). No. of bitstreams: 1 Especiação química de arsênio inorgânico no estuário da Laguna dos Patos (RS, Brasil).pdf: 268780 bytes, checksum: 868015eaf618029b34109b4e868ce420 (MD5) Previous issue date: 2012This study optimized and validated a method to perform chemical speciation of inorganic arsenic in water samples collected under the Monitoring Program of the Port of Rio Grande-RS in July and October 2010 from the Laguna dos Patos Estuary (RS, Brazil). The flow injection hydride generation atomic absorption spectrometry technique was employed, allowing quantification of As3+ and As5+ present in estuarine water samples. Data interpretation for results generated using the improved method for analyzing water samples collected from Laguna dos Patos Estuary was done by main components analysis

Cardiac remodeling induced by 13-cis retinoic acid treatment in acne patients

Background: Currently, 13-cis-retinoic acid (13-cis-RA) is the most effective therapy for acne. Isotretinoin, a first-generation synthetic 13-cis-RA compound, is associated with numerous adverse effects. To investigate the cardiac effects of 13-cis-RA, acne patients receiving 13-cis-RA were studied. Methods: Twenty male patients with acne were enrolled in the study. Patients were treated with a dose of 0.5 mg/kg/d of isotretinoin. All participants were assessed prior to treatment and after 10 weeks of therapy with Doppler-echocardiogram. Results: Patients showed reductions in right atrium vertical diameter, left atrium longitudinal diameter, left atrium volume and left ventricular diastolic diameter over the course of treatment. Significant increases in interventricular septum diastolic thickness, posterior wall diastolic thickness, relative wall relative thickness and left ventricle (LV) mass were observed. The LV mass index showed an increase in ventricular mass and a decrease in the cavity size. Examining LV systolic function, a decrease was observed for the cardiac index. Conclusion: In this study, 10 weeks of 13-cis-RA therapy at a dose of 0.5 mg/kg/d was found to promote concentric-type heart remodeling due to the occurrence of two associated events: heart hypertrophy and hypovolemia. © 2011 Elsevier B.V. All rights reserved