648 research outputs found
Idade Média: Tempo do mundo, tempo dos homens, tempo de Deus. [Reseña]
Reseña de: José Antônio DE CAMARGO RODRIGUES DE
SOUZA (org.), Idade Média: Tempo do mundo,
tempo dos homens, tempo de Deus, EST
Edições, Porto Alegre 2006, 535 pp
Wasted sardine oil as a co-substrate for biogas production - pilot experiment of decentralized organic waste management in a pig farm
RAMIRAN International ConferenceThe purpose of this work was to demonstrate in a commercial pig farm with a biogas plant and in real conditions,
the possibilities to co-digest WSO and PS at farm level. Anaerobic digestion is one of the most adequate
technologies to manage this type of industrial organic waste streams (Chowdhury et al., 2009), and the decentralized
operations of organic waste management for biogas production have many advantages but also a number of
uncertainties that must be evaluated (Weiland, 2006; Raven et al., 2007).
Since it was the first time that in Portugal such an experience was done, the production of technical
information to the veterinary authorities was a secondary goal
Seismic characterization of fluid migration and Pockmarks formation in the Estremadura Spur, Western Iberian Margin
: A field with more than 30 pockmarks was recently discovered in the Estremadura Spur outer shelf (Lourinhã Monocline). The processing of high-resolution seismic lines permitted the characterization of this pockmark field and of the seismic sequence of the Plio-Quaternary basin where they occur. Results show that this region has been affected by several episodes of fluid migration and fluid escape during the Plio-Quaternary, expressed by the presence of the pockmarks that at the present-time seem to be mainly inactive
Determination of 2,4,6-trichloroanisole by cyclic voltammetry
The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia
Perception of sleep duration in adult patients with suspected obstructive sleep apnea
PURPOSE: Discrepancies between subjective and objective measures of total sleep time (TST) are frequent among insomnia patients, but this issue remains scarcely investigated in obstructive sleep apnea (OSA). We aimed to evaluate if sleep perception is affected by the severity of OSA. METHODS: We performed a 3-month cross-sectional study of Brazilian adults undergoing overnight polysomnography (PSG). TST was objectively assessed from PSG and by a self-reported questionnaire (subjective measurement). Sleep perception index (SPI) was defined by the ratio of subjective and objective values. Diagnosis of OSA was based on an apnea/hypopnea index (AHI) ≥ 5.0/h, being its severity classified according to AHI thresholds: 5.0-14.9/h (mild OSA), 15.0-29.9/h (moderate OSA), and ≥ 30.0/h (severe OSA). RESULTS: Overall, 727 patients were included (58.0% males). A significant difference was found in SPI between non-OSA and OSA groups (p = 0.014). Mean SPI values significantly decreased as the OSA severity increased: without OSA (100.1 ± 40.9%), mild OSA (95.1 ± 24.6%), moderate OSA (93.5 ± 25.2%), and severe OSA (90.6 ± 28.2%), p = 0.036. Using logistic regression, increasing SPI was associated with a reduction in the likelihood of presenting any OSA (p = 0.018), moderate/severe OSA (p = 0.019), and severe OSA (p = 0.028). However, insomnia was not considered as an independent variable for the presence of any OSA, moderate/severe OSA, and severe OSA (all p-values > 0.05). CONCLUSION: In a clinical referral cohort, SPI significantly decreases with increasing OSA severity, but is not modified by the presence of insomnia symptoms.publishersversionpublishe
XPS characterization of Au (core)/SiO2 (shell) nanoparticles
Core-shell nanoparticles with ca. 15-nm gold core and 6-nm silica shell were prepared and characterized by XPS. The Au/Si atomic ratio determined by XPS is independent of the electron takeoff angle because of the concentric spherical shape of the nanoparticles. The formula given by Wertheim and DiCenzo (Phys. Rev. B 1988, 37, 844) for spherical nanoparticles and the modified one by Yang et al. (J. Appl. Phys. 2005, 97, 024303) for core-shell nanoparticles are used to correlate the XPS-derived composition with the geometry of the nanoparticles only after significantly modifying either the bulk density of the silica shell or the attenuation length of the photoelectrons. © 2005 American Chemical Society
Development, validation and comparative study with no-apnea, STOP-bang, and NoSAS
Background: Obstructive sleep apnea (OSA) is a very prevalent disorder. Here, we aimed to develop and validate a practical questionnaire with yes-or-no answers, and to compare its performance with other well-validated instruments: No-Apnea, STOP-Bang, and NoSAS. Methods: A cross-sectional study containing consecutively selected sleep-lab subjects underwent full polysomnography. A 4-item model, named GOAL questionnaire (gender, obesity, age, and loud snoring), was developed and subsequently validated, with item-scoring of 0–4 points (≥2 points indicating high risk for OSA). Discrimination was assessed by area under the curve (AUC), while predictive parameters were calculated using contingency tables. OSA severity was classified based on conventionally accepted apnea/hypopnea index thresholds: ≥5.0/h (OSA≥5), ≥15.0/h (OSA≥15), and ≥30.0/h (OSA≥30). Results: Overall, 7377 adults were grouped into two large and independent cohorts: derivation (n = 3771) and validation (n = 3606). In the derivation cohort, screening of OSA≥5, OSA≥15, and OSA≥30 revealed that GOAL questionnaire achieved sensitivity ranging from 83.3% to 94.0% and specificity ranging from 62.4% to 38.5%. In the validation cohort, screening of OSA≥5, OSA≥15, and OSA≥30, corroborated validation steps with sensitivity ranging from 83.7% to 94.2% and specificity from 63.4% to 37.7%. In both cohorts, discriminatory ability of GOAL questionnaire for screening of OSA≥5, OSA≥15, and OSA≥30 was similar to No-Apnea, STOP-Bang or NoSAS. Conclusion: All four instruments had similar performance, leading to a possible greater practical implementation of the GOAL questionnaire, a simple instrument with only four parameters easily obtained during clinical evaluation.publishersversionpublishe
II Ciclo de Conferências : Conselho Técnico-Científico: temas atuais em investigação
A obra é constituída pelos resumos das comunicações apresentadas pelos docentes da Escola Superior Agrária do Instituto Politécnico de Castelo Branco e são referentes aos projetos de investigação nos quais estão envolvidos.O atual Conselho Técnico-Científico (CTC) da Escola Superior Agrária de Castelo Branco (ESACB) tomou posse em fevereiro de 2012, tendo decidido dar continuidade ao ciclo de conferências iniciado pelo CTC anterior. Os trabalhos de Investigação, Inovação e Experimentação que foram apresentados demonstram não só o dinamismo e a ligação com a comunidade, como também a preocupação na identificação e resolução de problemas, que acrescentem valor aos produtos e processos que se situam no âmbito das competências desta Escola. Sendo este um objetivo prioritário da missão do IPCB/ESA, a divulgação destas conferências permite chegar a um público mais alargado e abrir caminhos para a concretização de novos projetos, que contribuam de forma efetiva para o desenvolvimento e aumento da competitividade da região e do país
Optical response of Ag-Au bimetallic nanoparticles to electron storage in aqueous medium
Composition and structure dependence of the shift in the position of the surface plasmon resonance band upon introduction of NaBH 4 to aqueous solutions of gold and silver nanoparticles are presented. Silver and gold nanoalloys in different compositions were prepared by co-reduction of the corresponding salt mixtures using sodium citrate as the reducing agent. After addition of NaBH 4 to the resultant nanoalloys, the maximum of their surface plasmon resonance band, ranging between that of pure silver (ca. 400 nm) and of pure gold (ca. 530 nm), is blue-shifted as a result of electron storage on the particles. The extent of this blue shift increases non-linearly with the mole fraction of silver in the nanoparticle, parallel to the trends reported previously for both the frequency and the extinction coefficient of the plasmon band shifts. Gold(core)@silver(shell) nanoparticles were prepared by sequential reduction of gold and silver, where addition of NaBH 4 results in relatively large spectral shift in the plasmon resonance band when compared with the nanoalloys having a similar overall composition. The origin of the large plasmon band shift in the core-shell is related with a higher silver surface concentration on these particles. Hence, the chemical nature of the nanoparticle emerges as the dominating factor contributing to the extent of the spectral shift as a result of electron storage in bimetallic systems. Copyright © 2008 American Scientific Publishers All rights reserved
- …