920 resultados para In Situ Hybidization


Relevância:

100.00% 100.00%

Publicador:

Resumo:

An in situ experiment in a full scale timber frame test building was carried out to compare the hygrothermal performance of Hemp and Stone Wool insulations of identical thermal conductivity. Hemp and Stone Wool insulations were installed in timber frame wall panels without vapour barrier. The comparison was made in terms of heat transfer properties, likelihood of mould growth and condensation. Step changes in internal relative humidity were performed to explore the effect of high and normal internal moisture load on the wall panels. No significant difference between the average equivalent thermal transmittance (U-values) of the panels incorporating Hemp and Stone Wool insulations was observed. The average equivalent U-values of the panels were closer to the calculated U-values of the panels based on the manufacturers declared thermal conductivity of Hemp and Stone Wool insulations. It was observed that the placement of heat flux sensor along the depth of the insulation had significant influence on the measured equivalent U-value of the panels during high internal moisture load. The frequency and likelihood of condensation was higher in the interface of Stone Wool and Oriented Strand Board (OSB). In terms of the parametric assessment of mould germination potential, relative humidity, temperature and exposure conditions in the insulation-OSB interfaces were found to be favourable to germination of mould spore. However, when the insulations were dismantled, no mould was visually detected.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This work describes the electrochemical methodology for the determination of the Donnan potential from diffusion-limited steady-state voltammograms of acrylamide gels. The technique is based upon the measurement of gelsol systems that have reached Donnan equilibrium and contain Cd2+ as a probe ion. Au-amalgam microelectrodes are used to measure the Cd concentration in the gel phase relative to the solution phase, thus permitting comparison of the Cd voltammograms obtained in both phases. This approach yields two independent measures of the Donnan potential resulting from (i) the potential shift relative to the reference electrode, and (ii) the enhancement of the Cd2+ wave. Two suites of acrylamide gels containing 0.2% and 0.5% Na-acrylate were studied as a function of ionic strength by varying [NaNO3] and maintaining a constant concentration of the electroactive probe ion, [Cd2+] = 1 10 5 mol/L in the equilibrating solutions. Independent model predictions of the Donnan potential as a function of ionic strength that consider the effects of differential swelling on the charge density, the influence of a mixed electrolyte on the potential developed in the gel at the limit of low ionic strength and the effects of incomplete dissociation of the carboxylic functional groups were in agreement with the Donnan potentials independently measured by the twofold steady-state voltammetric approach.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the marine environment, phytoplankton and bacterioplankton can be physically associated. Such association has recently been hypothesized to be involved in the toxicity of the dinoflagellate genus Alexandrium. However, the methods, which have been used so far to identify, localize, and quantify bacteria associated with phytoplankton, are either destructive, time consuming, or lack precision. In the present study we combined tyramide signal amplificationfluorescent in situ hybridization (TSA-FISH) with confocal microscopy to determine the physical association of dinoflagellate cells with bacteria. Dinoflagellate attached microflora was successfully identified with TSA-FISH, whereas FISH using monolabeled probes failed to detect bacteria, because of the dinoflagellate autofluorescence. Bacteria attached to entire dinoflagellates were further localized and distinguished from those attached to empty theca, by using calcofluor and DAPI, two fluorochromes that stain dinoflagellate theca and DNA, respectively. The contribution of specific bacterial taxa of attached microflora was assessed by double hybridization. Endocytoplasmic and endonuclear bacteria were successfully identified in the nonthecate dinoflagellate Gyrodinium instriatum. In contrast, intracellular bacteria were not observed in either toxic or nontoxic strains of Alexandrium spp. Finally, the method was successfully tested on natural phytoplankton assemblages, suggesting that this combination of techniques could prove a useful tool for the simultaneous identification, localization, and quantification of bacteria physically associated with dinoflagellates and more generally with phytoplankton.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recently, the development of highly inspired biomaterials with multi-functional characteristics has gained considerable attention, especially in biomedical, and other health-related areas of the modern world. It is well-known that the lack of antibacterial potential has signicantly limited biomaterials for many challenging applications such as infection free wound healing and/or tissue engineering etc. In this perspective, herein, a series of novel bio-composites with natural phenols as functional entities and keratin-EC as a base material were synthesised by laccase-assisted grafting. Subsequently, the resulting composites were removed from their respective casting surfaces, critically evaluated for their antibacterial and biocompatibility features and information is also given on their soil burial degradation profile. In-situ synthesised phenol-g-keratin-EC bio-composites possess strong anti-bacterial activity against Gram-positive and Gram-negative bacterial strains i.e., B. subtilis NCTC 3610, P. aeruginosa NCTC 10662, E. coli NTCT 10418 and S. aureus NCTC 6571. More specifically, 10HBA-g-keratin-EC and 20T-g-keratin-EC composites were 100% resistant to colonisation against all of the aforementioned bacterial strains, whereas, 15CA-g-keratin-EC and 15GA-g-keratin-EC showed almost negligible colonisation up to a variable extent. Moreover, at various phenolic concentrations used, the newly synthesised composites remained cytocompatible with human keratinocyte-like HaCaT, as an obvious cell ingrowth tendency was observed and indicated by the neutral red dye uptake assay. From the degradation point of view, an increase in the degradation rate was recorded during their soil burial analyses. Our investigations could encourage greater utilisation of natural materials to develop bio-composites with novel and sophisticated characteristics for potential applications.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Naturally occurring radioactive materials (NORM) under certain conditions can reach hazardous radiological levels contributing to an additional exposure dose to ionizing radiation. Most environmental concerns are associated with uranium mining and milling sites, but the same concerns should be addressed to natural near surface occurrences of uranium as well as man-made sources such as technologically enhanced naturally occurring radioactive materials (TENORM) resulting from phosphates industry, ceramic industry and energy production activities, in particular from coal-fired power plants which is one of the major sources of increased exposure to man from enhanced naturally occurring materials. This work describes the methodology developed to assess the environmental radiation by in situ gamma spectrometry in the vicinity of a Portuguese coal fired power plant. The current investigation is part of a research project that is undergoing in the vicinity of Sines Coal-Fired Power Plant (south of Portugal) until the end of 2013.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper refers to the assessment on site by semi-destructive testing (SDT) methods of the consolidation efficiency of a conservation process developed by Henriques (2011) for structural and non-structural pine wood elements in service. This study was applied on scots pine wood (Pinus sylvestris L.) degraded by fungi after treatment with a biocidal product followed by consolidation with a polymeric product. This solution avoids substitutions of wood moderately degraded by fungi, improving its physical and mechanical characteristics. The consolidation efficiency was assessed on site by methods of drill resistance and penetration resistance. The SDT methods used showed good sensitivity to the conservation process and could evaluate their effectiveness. (C) 2015 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Using low cost portable devices that enable a single analytical step for screening environmental contaminants is today a demanding issue. This concept is here tried out by recycling screen-printed electrodes that were to be disposed of and by choosing as sensory element a low cost material offering specific response for an environmental contaminant. Microcystins (MCs) were used as target analyte, for being dangerous toxins produced by cyanobacteria released into water bodies. The sensory element was a plastic antibody designed by surface imprinting with carefully selected monomers to ensure a specific response. These were designed on the wall of carbon nanotubes, taking advantage of their exceptional electrical properties. The stereochemical ability of the sensory material to detect MCs was checked by preparing blank materials where the imprinting stage was made without the template molecule. The novel sensory material for MCs was introduced in a polymeric matrix and evaluated against potentiometric measurements. Nernstian response was observed from 7.24 1010 to 1.28 109 M in buffer solution (10 mM HEPES, 150 mM NaCl, pH 6.6), with average slopes of 62 mVdecade1 and detection capabilities below 1 nM. The blank materials were unable to provide a linear response against log(concentration), showing only a slight potential change towards more positive potentials with increasing concentrations (while that ofthe plastic antibodies moved to more negative values), with a maximum rate of +33 mVdecade1. The sensors presented good selectivity towards sulphate, iron and ammonium ions, and also chloroform and tetrachloroethylene (TCE) and fast response (<20 s). This concept was successfully tested on the analysis of spiked environmental water samples. The sensors were further applied onto recycled chips, comprehending one site for the reference electrode and two sites for different selective membranes, in a biparametric approach for in situ analysis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A conjuntura econmica da construo no se encontra numa fase de prosperidade, existindo a necessidade de criar solues construtivas que permitam a reduo de custos dos materiais a nvel de obra. As lajes de beto armado, devido sua grande rea de implantao, possuem uma parcela importante no oramento final de qualquer obra de edifcios correntes. Sabendo das possibilidades de aligeiramento de lajes, torna-se necessria a realizao de um estudo pormenorizado e comparativo entre solues de aligeiramento. O desenvolvimento deste relatrio reflete todo o trabalho efetuado durante a realizao de um estgio curricular desenvolvido na empresa FercaNorte Estruturas, Lajes e Cofragens, Lda. e foca-se num dimensionamento e estudo comparativo de solues de lajes fungiformes aligeiradas, aplicadas a dois casos de estudo e tambm num dimensionamento e estudo comparativo de solues de lajes aligeiradas unidirecionais mas apenas aplicadas a um caso de estudo. No primeiro caso de estudo, laje fungiforme com um vo de 6 metros nas duas direes, so dimensionadas e comparadas quatro solues: laje fungiforme macia; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos de forma ortogonal e envolvidos totalmente por beto; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos em formato de favo de mel e envolvidos totalmente por beto; e laje fungiforme nervurada com moldes recuperveis. No segundo caso de estudo, laje fungiforme com um vo de 7,04 metros nas duas direes, so dimensionadas e comparadas cinco solues: laje fungiforme macia, laje fungiforme aligeirada com blocos cbicos perdidos dispostos de forma ortogonal e envolvidos totalmente por beto; laje fungiforme aligeirada, com blocos elipsoides perdidos dispostos de forma ortogonal e envolvidos totalmente por beto; laje fungiforme aligeirada com blocos elipsoides perdidos dispostos em formato de favo de mel e envolvidos totalmente por beto; e laje fungiforme nervurada com moldes recuperveis. No terceiro caso de estudo, laje unidirecional com um vo de 8 metros apoiada em vigas com vo de 5 metros, so dimensionadas e comparadas trs solues: laje macia; laje aligeirada com perfis tubulares com seco transversal reta oval; e laje nervurada com moldes recuperveis. No final apresentada uma estimativa oramental para cada soluo analisada nos trs casos de estudo abordados.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Raman spectroscopy has been applied to characterize fiber dyes and determine the discriminating ability of the method. Black, blue, and red acrylic, cotton, and wool samples were analyzed. Four excitation sources were used to obtain complementary responses in the case of fluorescent samples. Fibers that did not provide informative spectra using a given laser were usually detected using another wavelength. For any colored acrylic, the 633-nm laser did not provide Raman information. The 514-nm laser provided the highest discrimination for blue and black cotton, but half of the blue cottons produced noninformative spectra. The 830-nm laser exhibited the highest discrimination for red cotton. Both visible lasers provided the highest discrimination for black and blue wool, and NIR lasers produced remarkable separation for red and black wool. This study shows that the discriminating ability of Raman spectroscopy depends on the fiber type, color, and the laser wavelength.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Mont Collon mafic complex is one of the best preserved examples of the Early Permian magmatism in the Central Alps, related to the intra-continental collapse of the Variscan belt. It mostly consists (&gt; 95 vol.%) of ol+hy-nonnative plagioclase-wehrlites, olivine- and cpx-gabbros with cumulitic structures, crosscut by acid dikes. Pegmatitic gabbros, troctolites and anorthosites outcrop locally. A well-preserved cumulative, sequence is exposed in the Dents de Bertol area (center of intrusion). PT-calculations indicate that this layered magma chamber emplaced at mid-crustal levels at about 0.5 GPa and 1100 degrees C. The Mont Collon cumulitic rocks record little magmatic differentiation, as illustrated by the restricted range of clinopyroxene mg-number (Mg#(cpx)=83-89). Whole-rock incompatible trace-element contents (e.g. Nb, Zr, Ba) vary largely and without correlation with major-element composition. These features are characteristic of an in-situ crystallization process with variable amounts of interstitial liquid L trapped between the cumulus mineral phases. LA-ICPMS measurements show that trace-element distribution in the latter is homogeneous, pointing to subsolidus re-equilibration between crystals and interstitial melts. A quantitative modeling based on Langmuir's in-situ crystallization equation successfully duplicated the REE concentrations in cumulitic minerals of all rock facies of the intrusion. The calculated amounts of interstitial liquid L vary between 0 and 35% for degrees of differentiation F of 0 to 20%, relative to the least evolved facies of the intrusion. L values are well correlated with the modal proportions of interstitial amphibole and whole-rock incompatible trace-element concentrations (e.g. Zr, Nb) of the tested samples. However, the in-situ crystallization model reaches its limitations with rock containing high modal content of REE-bearing minerals (i.e. zircon), such as pegmatitic gabbros. Dikes of anorthositic composition, locally crosscutting the layered lithologies, evidence that the Mont Collon rocks evolved in open system with mixing of intercumulus liquids of different origins and possibly contrasting compositions. The proposed model is not able to resolve these complex open systems, but migrating liquids could be partly responsible for the observed dispersion of points in some correlation diagrams. Absence of significant differentiation with recurrent lithologies in the cumulitic pile of Dents de Bertol points to an efficiently convective magma chamber, with possible periodic replenishment, (c) 2005 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We present a new method for lysis of single cells in continuous flow, where cells are sequentially trapped, lysed and released in an automatic process. Using optimized frequencies, dielectrophoretic trapping allows exposing cells in a reproducible way to high electrical fields for long durations, thereby giving good control on the lysis parameters. In situ evaluation of cytosol extraction on single cells has been studied for Chinese hamster ovary (CHO) cells through out-diffusion of fluorescent molecules for different voltage amplitudes. A diffusion model is proposed to correlate this out-diffusion to the total area of the created pores, which is dependent on the potential drop across the cell membrane and enables evaluation of the total pore area in the membrane. The dielectrophoretic trapping is no longer effective after lysis because of the reduced conductivity inside the cells, leading to cell release. The trapping time is linked to the time required for cytosol extraction and can thus provide additional validation of the effective cytosol extraction for non-fluorescent cells. Furthermore, the application of one single voltage for both trapping and lysis provides a fully automatic process including cell trapping, lysis, and release, allowing operating the device in continuous flow without human intervention.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Se han utilizado los resultados de 144 lances ejecutados en el transcurso del Crucero 9803-05. Se compararon los histogramas de TS y los de tallas en bsqueda de correlacin entre ambas a fin de determinar el factor b20 de la Ecuacin de Fuerza de Blanco (20 log (LT,cm) + b20). Se han determinado nuevas ecuaciones de TS para anchoveta (38 y 120 kHz), sardina (120 kHz), jurel (38 kHz) y caballa (38 y 120 kHz). Se deber continuar con estas mediciones puesto que un cambio en las propuestas reflectivas de los peces puede afectar la correcta obtencin de los estimados de biomasa.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Se efectuaron mediciones de TS (Fuerza de Blanco, Target Strenght) durante los 108 lances de comprobacin de ecotrazos realizados por el BIC Humboldt en el marco del Crucero 9808-09 de Evaluacin Hidroacstica de Recursos Pelgicos. Se consideran para el anlisis nicamente aquellos lances donde ms del 90% de la captura perteneci a una sola especie. Los factores b20 de la ecuacin de TS (TS=20 log L - b20) que han sido determinados, las cuales debern ser considerados como provisionales, son las siguientes: Pez cinta (Trichiurus lepturus) = 70,95 (120 kHz); Vinciguerria o pez linterna (Vinciguerria lucetia pacifici) = 83,29 (120 kHz); Samasa (Anchoa nasus) = 86,57 (120 kHz); Caballa (Scomber japonicus) = 83,09 (120 kHz); Pez cinta (Trichiurus lepturus) = 71,41 (38 kHz); y Vinciguerria o pez linterna (Vinciguerria lucetia pacifici)= 82,04 (38kHz).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Se realizaron mediciones de la Fuerza de Blanco (TS) del krill (Euphausia superba) durante los 29 lances efectuados en el Crucero de Evaluacin Hidroacstica utilizando la ecosonda SIMRAD EK 500 a bordo del BIC Humboldt entre los das 12 y 24 de enero de 1998 a lo largo del Estrecho de Bransfield y alrededores de la Isla Elefante. Se derivaron los valores de b20 a partir de le ecuacin de TS de FOOTE (1990), de las longitudes promedios de los individuos capturados durante cada uno de los lances y de las tablas de TS generadas por la ecosonda, determinndose una ecuacin de TS para el krill en un rango de longitud comprendido entre 2,1 y 5,3 cm de la siguiente forma: TS = 20 log L - 89,26. Se discute el posible sesgo de la ecuacin debido, entre otros aspectos a que no se consideraron los estados sexuales del krill.