1,410 research outputs found

    Development of a flow through photo-reactor to study degradation of organic compounds by Sequential Injection Analysis (SIA)

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    This work describes a photo-reactor to perform in line degradation of organic compounds by photo-Fenton reaction using Sequential Injection Analysis (SIA) system. A copper phthalocyanine-3,4',4<FONT FACE=Symbol><FONT FACE=Symbol>²</FONT></FONT>,4<FONT FACE=Symbol><FONT FACE=Symbol>²¢</FONT></FONT>-tetrasulfonic acid tetrasodium salt dye solution was used as a model compound for the phthalocyanine family, whose pigments have a large use in automotive coatings industry. Based on preliminary tests, 97% of color removal was obtained from a solution containing 20 µmol L-1 of this dye.Este trabalho descreve um foto-reator para a execução "in line" da degradação de compostos orgânicos através da reação de foto-Fenton, utilizando-se de um sistema de Análise por Injeção Sequencial (SIA). Uma solução do corante do sal tetrassódico de ácido 3,4',4<FONT FACE=Symbol><FONT FACE=Symbol>²</FONT></FONT>,4<FONT FACE=Symbol><FONT FACE=Symbol>²¢</FONT></FONT>-tetrassulfônico de ftalocianina de cobre foi empregada como modelo da família das ftalocianinas, cujos pigmentos apresentam grande utilização na indústria de tintas automotivas. Baseando-se em testes preliminares, uma remoção de cor de 97% foi obtida em uma solução contendo 20 µmol L-1 deste corante.FAPESPCNP

    Validity and reliability of the Structured Clinical Interview for Depersonalization-Derealization Spectrum (SCI-DER).

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    This study evaluates the validity and reliability of a new instrument developed to assess symptoms of depresonalization: the Structured Clinical Interview for the Depersonalization-Derealization Spectrum (SCI-DER). The instrument is based on a spectrum model that emphasizes soft-signs, sub-threshold syndromes as well as clinical and subsyndromal manifestations. Items of the interview include, in addition to DSM-IV criteria for depersonalization, a number of features derived from clinical experience and from a review of phenomenological descriptions. Study participants included 258 consecutive patients with mood and anxiety disorders, 16.7% bipolar I disorder, 18.6% bipolar II disorder, 32.9% major depression, 22.1% panic disorder, 4.7% obsessive compulsive disorder, and 1.5% generalized anxiety disorder; 2.7% patients were also diagnosed with depersonalization disorder. A comparison group of 42 unselected controls was enrolled at the same site. The SCI-DER showed excellent reliability and good concurrent validity with the Dissociative Experiences Scale. It significantly discriminated subjects with any diagnosis of mood and anxiety disorders from controls and subjects with depersonalization disorder from controls. The hypothesized structure of the instrument was confirmed empirically

    Determination of picloram in waters by sequential injection chromatography with UV detection

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    This paper describes a sequential injection chromatography procedure for determination of picloram in waters exploring the low backpressure of a 2.5 cm long monolithic C18 column. Separation of the analyte from the matrix was achieved in less than 60 s using a mobile phase composed by 20:80 (v v-1) acetonitrile:5.0 mmol L-1 H3PO4 and flow rate of 30 &#956;L s-1. Detection was made at 223 nm with a 40 mm optical path length cell. The limits of detection and quantification were 33 and 137 &#956;g L-1, respectively. The proposed method is sensitive enough to monitor the maximum concentration level for picloram in drinking water (500 &#956;g L-1). The sampling frequency is 60 analyses per hour, consuming only 300 &#956;L of acetonitrile per analysis. The proposed methodology was applied to spiked river water samples and no statistically significant differences were observed in comparison to a conventional HPLC-UV method.Este trabalho descreve um procedimento de cromatografia por injeção seqüencial para a determinação de picloram em águas explorando a baixa pressão de uma coluna monolítica C18 de 2,5 cm de comprimento. A separação do analito da matriz foi obtida em menos de 60 s usando como fase móvel uma mistura de acetonitrila e H3PO4 5,0 mmol L-1 na proporção 20:80 (v v-1) e vazão de 30 &#956;L s-1. Detecção foi feita a 223 nm com uma cela de 40 mm de caminho óptico. O limite de detecção do método é adequado para monitorar o nível de concentração máximo permitido para picloram em água potável (500 &#956;g L-1). A frequência de amostragem é de 60 análises por hora, consumindo 300 &#956;L de acetonitrila por análise. A metodologia foi aplicada a águas de rio fortificadas, não sendo observadas diferenças estatisticamente significativas em comparação com a metodologia convencional de HPLC-UV.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Perceptions of and Satisfaction with Sexual and Reproductive Health Interventions in Pre-Adolescent and Adolescent Students in UE/EEA Countries: A Systematic Review

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    : The objective of this review is to investigate perceptions of and satisfaction with sexual and reproductive health (SRH) interventions among pre-adolescents and adolescents of all genders and ethnicities in EU/EEA countries. This systematic review was conducted in accordance with PRISMA recommendations. A systematic literature search was conducted on MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (Central), CINAHL (EBSCO), and PsycINFO (EBSCO) up to March 2022 to identify all published articles that included information on perceptions and levels of satisfaction with SRH interventions. The selected studies were independently and blindly evaluated for risk of bias. Finally, only five papers were included in our review, divided according to the implemented intervention design: conducted by research groups (health or non-health professionals) or structured entirely in a peer-to-peer approach. Both types of program designs analyzed in the included studies were well accepted by students, even though satisfaction assessment methods were not standardized. Peer-to-peer conducted SRH programs or interventions with practical components (e.g., exercises, discussion) were more appreciated. We also found higher levels of satisfaction among younger participants. Future SRH educational programs should consider an assessment of participants' perceptions and satisfaction, possibly adopting standardized tools. Following a peer-to-peer structure and delivering programs early could lead to greater participant satisfaction

    Google earth engine as multi-sensor open-source tool for supporting the preservation of archaeological areas: The case study of flood and fire mapping in metaponto, italy

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    In recent years, the impact of Climate change, anthropogenic and natural hazards (such as earthquakes, landslides, floods, tsunamis, fires) has dramatically increased and adversely affected modern and past human buildings including outstanding cultural properties and UNESCO heritage sites. Research about protection/monitoring of cultural heritage is crucial to preserve our cultural properties and (with them also) our history and identity. This paper is focused on the use of the open-source Google Earth Engine tool herein used to analyze flood and fire events which affected the area of Metaponto (southern Italy), near the homonymous Greek-Roman archaeological site. The use of the Google Earth Engine has allowed the supervised and unsupervised classification of areas affected by flooding (2013–2020) and fire (2017) in the past years, obtaining remarkable results and useful information for setting up strategies to mitigate damage and support the preservation of areas and landscape rich in cultural and natural heritage

    Water adsorption on amorphous silica surfaces: A Car-Parrinello simulation study

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    A combination of classical molecular dynamics (MD) and ab initio Car-Parrinello molecular dynamics (CPMD) simulations is used to investigate the adsorption of water on a free amorphous silica surface. From the classical MD SiO_2 configurations with a free surface are generated which are then used as starting configurations for the CPMD.We study the reaction of a water molecule with a two-membered ring at the temperature T=300K. We show that the result of this reaction is the formation of two silanol groups on the surface. The activation energy of the reaction is estimated and it is shown that the reaction is exothermic.Comment: 12 pages, 6 figures, to be published in J. Phys.: Condens. Matte
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