2,613 research outputs found
FTIR, a powerful technique in organic coatings failure diagnosis
FTIR spectrometry (Fourier Transform Infrared) is an instrumental technique of analysis that presents significant advantages on the dispersive traditional system, such as the increase of the relation signal-noise, the capacity of getting absorption spectra of low energy and therefore, bands of absorption of weak intensity. This technique is widely used in the study of resin characterization and evaluation of polymeric materials as well as degradation when polymers and coatings are exposed to various conditions of service, or still in the analysis and diagnosis of defects that occur during the application or production process. Techniques connected to the FTIR have appeared such as the photoacoustic (PAS-FTIR), the microscopy (MCT-FTIR) and the attenuated total reflectance (ATR), which allows to analysis of weekly transparent and dark samples without removal of coatings from the substrates. The choice of the technique to use depends on the morphology of the surfaces to analyze and the type of failure (lack of adhesion, contamination, aging degradation, etc). This work illustrates the application of FTIR and associated techniques to identify causes of diverse types of defects in applied organic coatings on polymeric materials
FTIR, a powerful technique in organic coatings failure diagnosis
FTIR spectrometry (Fourier Transform Infrared) is an instrumental technique of analysis that presents
significant advantages on the dispersive traditional system, such as the increase of the relation signalnoise,
the capacity of getting absorption spectra of low energy and therefore, bands of absorption of weak
intensity. This technique is widely used in study, resin characterization and evaluation of polymeric
materials as well as of its degradation when exposed to the most varied conditions of service, or still in
the analysis and diagnosis of defects that occur during the application or production process. Techniques
connected to the FTIR had more recently appeared as the photoacoustic (PAS-FTIR), the microscopy
(MCT-FTIR) and the attenuated total reflectance (ATR), which allow to analyze weekly transparent and
dark samples without removal of coatings from the substrates. The choice of the technique to use depends
on the morphology of the surfaces to analyze and the type of failure in cause (lack of adhesion,
contamination, aging degradation, etc). In this work the application of FTIR and techniques associates to
the identification of the causes that had originated diverse types of defect in applied organic coatings on
polymeric materials is presented. Key words: FTIR, Organic Coatings, Failure Diagnosi
Geography and the built environment: spatial trends in urban growth induced by a core-periphery model
This article intends to use a traditional core-periphery scenario to model urban growth as a function of peripherality. This latter variable is itself a function of timedistances and resident population. Hence, it may be decomposed in order to better understand observed patterns. The ultimate goal of this research is to understand general urban growth patterns in Continental Portugal, a territory characterized by strong polarization of activity towards two urban nodes, Lisbon and Oporto. It is also intended to understand differences between population growth and urban sprawl as this may help understanding different planning policies which were adopted in the country.Peer Reviewe
Rasmussen, Chenery and Watanabe, and labour-based multiplier analysis and sensitivity analysis of input coefficients for Spain in 2009
In this paper we identify the key sectors of the Spanish economy with the last input-output available data following the approaches by Rasmussen and by Chenery and Watanabe. We also calculate labour-based multipliers and sensitivity of input coefficients and we compare the results in order to present useful advice for sector policiesEn este trabajo analizamos cuáles son los sectores claves en España con los últimos datos publicados del marco input-output. Seguimos las metodologÃas de Rasmussen y de Chenery y Watanabe. También hacemos uso de los multiplicadores de remuneraciones, trabajadores y asalariados asà como de la técnica de sensibilidad de coeficientes. En las conclusiones se presentan los principales hallazgos que permiten diseñar una polÃtica sectorial eficaz para Españ
Modification of polyamide 6.6 dyeing properties by grafting with poly(acrylic acid)
978-972-8063-67-2The wet chemical surface modification continues to be a growing area of research interest. This study describes preparation and characterization of poly (acrylic acid)-grafted polyamide 6.6 fabric. Poly(acrylic acid) has been grafted onto polyamide backbone using benzoyl peroxide (BPO) as catalyst in aqueous medium.
The benzoyl peroxide initiator optimum concentration was 0.03 M. The best conditions for optimum grafting reaction were reaction time 120 min, grafting temperature 85°C, monomer concentration 0.5 M and BPO concentration 0.03 M.
The grafting rate was evaluated gravimetrically. The maximum grafting percentage obtained was 13.3%.
All samples were characterized by Fourier–transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR).
The influence of acrylic acid grafting onto polyamide 6.6 was studied in terms of dye uptake using a basic dye, Rouge Maxilon GRL. Mechanical properties were also analysed
modelling the combined use of bicycles and train in Lisbon, Portugal
UIDB/04647/2020
UIDP/04647/2020
UIDB/03127/2020Many capital cities are expanding bicycle lanes or investing in public bike-sharing systems to make cycling mobility a viable transport solution within urban areas. While bicycles are fit for short-distance trips (publishersversionepub_ahead_of_prin
Application of FTIR-ATR spectroscopy on the bee pollen characterization
Bee pollen contains almost all nutrients required by the human organism as well as diverse health-promoting substances. However, its composition and nutritional value greatly depend on the botanical origin. As such, it is important to develop a rapid and non-expensive methodology that allows studying its characteristics, making labelling more objective and easier. The FTIR-ATR technique was used to predict some nutritional parameters in 126 bee pollen samples. FTIR-ATR spectrum obtained in the region between 4000 and 400 cm -1 with PLS Regression models were used to correlate spectral information with the data obtained using reference methods. In this first approach with pollen samples, good correlation models with appropriate accuracy were obtained for the evaluated parameters with r 2 varying from 74.8 to 97% and residual prediction deviation between 2.0 and 5.8. These results suggest that FTIR-ATR may be a useful technique for assessing bee pollen’s composition.Centro de Estudos Florestais is a research unit funded by
FCT (PEst-OE/AGR/UI0239-2014). Centre of Molecular and
Environmental Biology is a research unit funded by FCT, UID/
BIA/04050/2013 (POCI-01-0145-FEDER-007569) and by the
ERDF through the COMPETE2020 – Programa Operacional
Competitividade e Internacionalizac¸a˜o (POCI).info:eu-repo/semantics/publishedVersio
Characterisation of Technological Innovation Management Journals
This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have.This paper seeks to characterise the publications of the technological innovation management forum. With this aim, it analyses four aspects: orientation, style, originality and readability. The information used for this study was obtained from the Emerald Management Reviews database (Emerald Group Publishing). The time period considered ran from 1996 to 2003. From the analysis, the work concludes an increasingly clear research orientation over the period. Research-Technology Management is the journal most oriented to practice. The work also finds a clear predominance of the academic style, with some room provided for the professional-journalistic style, and a certain loss of originality and readability in the publications over the period. Finally, the journals declare a more varied readership than they actually seem to have
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