3,045 research outputs found

    Suspended-core fibers for sensing applications

    Get PDF
    A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.info:eu-repo/semantics/publishedVersio

    Development of a method using image analysis for the measurement of cellulose-binding domains adsorbed onto cellulose fibers

    Get PDF
    The surface concentration of CBD-FITC conjugates, adsorbed on cellulose fibers, was determined by image analysis. The program consists of two scripts, the first dedicated to the elaboration of the calibration curve. The emission of fluorescent light, detected by image analysis, is correlated with the concentration of CBD solutions. This calibration is then used (second script) to determine the concentration of CBDs adsorbed on cellulosic fibers. This method allows the direct estimation of the surface concentration of adsorbed CBDs, which usually is not accurately calculated from depletion studies, since the surface area is hardly known. By observing different spots in the surface of the fibers, site-specific information is obtained. It was verified that the physically heterogeneous fibers exhibit different amounts of adsorbed CBDs.Fundação para a Ciência e a Tecnologia (FCT

    LES validation of lock-exchange density currents interacting with an emergent bluff obstacle

    Get PDF
    Publisher Copyright: © 2022, The Author(s), under exclusive licence to Springer Nature B.V.We address the capability of large eddy simulation (LES) to predict the physics of density currents interacting with bluff obstacles. Most density currents of interest in engineering and geophysical applications interact with obstacles or topographic features. Validating LES solutions in these contexts is crucial to establish it as a trusted tool. We thus propose a validation effort based on simple geometries that nonetheless pose challenges common to more complex systems, including boundary layer separation and convective instabilities. We focus on lock-exchange gravity currents in the slumping phase interacting with an emergent vertical circular cylinder. Our main investment was in ensuring that the comparison of experimental data and numerical results include, at least, the velocity and the density fields , and derived quantities (e.g., second order moments). Measurements of both density and velocity fields were performed in the side and plan views for cylinder Reynolds numbers, Red, in the range 1300 to 3475. It was found that the LES accurately predicts the temporal evolution of the current front position. The computed front velocity exhibits a maximum relative error less than 8%. A good agreement between the LES and the experimental size and shape of the current head, and billows was found. The overall features upstream the cylinder, including a reflected wave, adverse pressure gradient and backflow, and downstream the cylinder, including the backflow, wake and the formation of a new head are well reproduced by LES. The agreement between the LES and the experimental time-space evolution of current spanwise- and depth-averaged density contours and the instantaneous velocity fields are not affected by Red.publishersversionpublishe

    Quantification of the CBD-FITC conjugates surface coating on cellulose fibres

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Cellulose Binding Domains (CBD) were conjugated with fluorescein isothiocyanate (FITC). The surface concentration of the Binding Domains adsorbed on cellulose fibres was determined by fluorescence image analysis.</p> <p>Results</p> <p>For a CBD-FITC concentration of 60 mg/L, a coating fraction of 78% and 110% was estimated for <it>Portucel </it>and Whatman fibres, respectively. For a saturating CBD concentration, using Whatman CF11 fibres, a surface concentration of 25.2 × 10<sup>-13 </sup>mol/mm<sup>2 </sup>was estimated, the equivalent to 4 protein monolayers. This result does not imply the existence of several adsorbed protein layers.</p> <p>Conclusion</p> <p>It was verified that CBDs were able to penetrate the fibres, according to confocal microscopy and TEM-immunolabelling analysis. The surface concentration of adsorbed CBDs was greater on amorphous fibres (phosphoric acid swollen) than on more crystalline ones (Whatman CF11 and Sigmacell 20).</p

    Protein Supplementation Is Vital for Beef Cattle Fed with Tropical Pasture

    Get PDF
    The production of beef on pasture is one of the potentials of Brazilian agriculture, mainly due to the territorial extension and climatic conditions. Therefore, the production of beef on tropical pastures mainly consists of the use of tropical forages; when correctly handled, forage plants show good productivity and improvement in the nutritive value. Among main factors that affect the performance of beef cattle fed on pastures, the availability and quality of the pasture stand first. In tropical regions, during the dry period of the year, the production of forage as well as its nutritive value is diminished. Hence, it is necessary to use protein supplements as a feed strategy to promote increased intake and improved nutrient utilization efficiency by animals. In view of this, by-products of biodiesel from oilseeds, such as peanuts, cottonseed and sunflower seeds, with high nutritional values can be used as an animal feed alternative to the protein sources commonly used for the formulation of supplements. Protein supplementation contributes to an increase in live weight gain as well as improvement in ruminal microbiota activity and, consequently, potentiates nutrient utilization efficiency in beef cattle fed with tropical pasture

    Analysis of the quality of hospital information systems Audit Trails.

    Get PDF
    BACKGROUND: Audit Trails (AT) are fundamental to information security in order to guarantee access traceability but can also be used to improve Health information System's (HIS) quality namely to assess how they are used or misused. This paper aims at analysing the existence and quality of AT, describing scenarios in hospitals and making some recommendations to improve the quality of information. METHODS: The responsibles of HIS for eight Portuguese hospitals were contacted in order to arrange an interview about the importance of AT and to collect audit trail data from their HIS. Five institutions agreed to participate in this study; four of them accepted to be interviewed, and four sent AT data. The interviews were performed in 2011 and audit trail data sent in 2011 and 2012. Each AT was evaluated and compared in relation to data quality standards, namely for completeness, comprehensibility, traceability among others. Only one of the AT had enough information for us to apply a consistency evaluation by modelling user behaviour. RESULTS: The interviewees in these hospitals only knew a few AT (average of 1 AT per hospital in an estimate of 21 existing HIS), although they all recognize some advantages of analysing AT. Four hospitals sent a total of 7 AT - 2 from Radiology Information System (RIS), 2 from Picture Archiving and Communication System (PACS), 3 from Patient Records. Three of the AT were understandable and three of the AT were complete. The AT from the patient records are better structured and more complete than the RIS/PACS. CONCLUSIONS: Existing AT do not have enough quality to guarantee traceability or be used in HIS improvement. Its quality reflects the importance given to them by the CIO of healthcare institutions. Existing standards (e.g. ASTM:E2147, ISO/TS 18308:2004, ISO/IEC 27001:2006) are still not broadly used in Portugal.publishersversionpublishe

    Structural and functional characteristics of rat hearts with and without myocardial infarct. Initial experience with doppler echocardiography

    Get PDF
    OBJECTIVE: To assess by Doppler echocardiography the structural and functional alterations of rat heart with surgical induced extensive myocardial infarction. METHODS: Five weeks after surgical ligature of the left coronary artery, 38 Wistar-EPM rats of both sexes, 10 of them with extensive infarction, undergone anatomical and functional evaluation by Doppler echocardiography and then euthanized for anatomopathological analysis. RESULTS: Echocardiography was 100% sensible and specific to anatomopathological confirmed extensive miocardial infarction. Extensive infarction lead to dilatation of left ventricle (diastolic diameter: 0.89cm vs.0.64cm; systolic: 0.72cm vs. 0.33cm) and left atrium (0.55cm vs. 0.33cm); thinning of left ventricular anterior wall (systolic: 0.14cm vs. 0.23cm, diastolic: 0.11cm vs. 0.14cm); increased mitral E/ A wave relation (6.45 vs. 1.95). Signals of increased end diastolic ventricle pressure, B point in mitral valve tracing in 62.5% and signs of pulmonary hypertension straightening of pulmonary valve (90%) and notching of pulmonary systolic flow (60%) were observed in animals with extensive infarction. CONCLUSION: Doppler echocardiography has a high sensitivity and specificity for detection of chronic extensive infarction. Extensive infarction caused dilatation of left cardiac chambers and showed in Doppler signals of increased end diastolic left ventricular pressure and pulmonary artery pressure.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL
    corecore