12 research outputs found

    Hydrothermal waves and corotating rolls in laterally heated convection in simple liquids

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    The stability of a liquid layer with an undeformable interface open to the atmosphere, subjected to a horizontal temperature gradient, is theoretically analysed. Buoyancy and surface tension forces give rise to a basic flow for any temperature difference applied on the system. Depending on the liquid depth, this basic flow is destabilised either by an oscillatory instability, giving rise to the so-called hydrothermal waves, or by a stationary instability leading to corotating rolls. Oscillatory perturbations are driven by the basic flow and therefore one must distinguish between convective and absolute thresholds. The instability mechanisms as well as the di¤erent regimes observed in experiments are discussed. The calculations are performed for a fluid used in recent experiments, namely silicone oil of 0.65 cSt ðPr ¼ 10Þ. In particular,it is shown that two branches of absolute instability exist, which may be related to the two types of hydrothermal waves observed experimentally

    Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography

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    [EN] Historic buildings have a great cultural and architectural value. It is necessary to analyze their state of conservation, but sometimes it is difficult to perform laboratory tests without damaging this heritage. In the field of architecture, infrared thermography is usually used to provide descriptive information about the surface temperature of building materials. This current research presents a methodology widely applicable to historic buildings. As an example of application, the study is focused in the Seminary-School of Corpus Christi of Valencia (Spain), a very outstanding building from the 16th Century. This research presents an analytical study to be able to differentiate the temperature distribution of all pixels of a thermographic image. Thermal images are a matrix of data and their study helps us in decision-making based on objective data.Lerma Elvira, C.; Mas Tomas, MDLA.; Gil Benso, E.; Vercher Sanchis, JM.; Torner-Feltrer, MEM. (2018). Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography. Russian Journal of Nondestructive Testing. 54(8):601-609. https://doi.org/10.1134/S1061830918080065S601609548Avdelidis, N.P. and Moropoulou, A., Applications of infrared thermography for the investigation of historic structures, J. Cult. Heritage, 2004, no. 5, pp. 119–127. doi 10.1016/j.culher.2003.07.002Barreira, E. and Freitas, V., Evaluation of building materials using infrared thermography, Constr. Build. Mater., 2007, vol. 21, pp. 218–224. doi 10.1016/j.conbuildmat.2005.06.049Bauer, E., Pavón, E., Barreira, E., and Kraus, E., Analysis of building façade defects using infrared thermography: Laboratory studies, J. Build. Eng., 2016, no. 6, pp. 93–104. doi /doi 10.1016/j.jobe.2016.02.012Binda, L., Cardani, G., and Zanzi, L., Nondestructive testing evaluation of drying process in flooded full-scale masonry walls, J. Perform. Constr. Facil., 2010, pp. 473–483. doi 10.1061/(ASCE)CF.1943-5509.0000097Cañas, I., Martín, S., and González, I., Thermal-physical aspects of materials used for the construction of rural buildings in Soria (Spain), Construct. Build. Mater., 2005, vol. 19, pp. 197–211. doi 10.1016/j.conbuildmat. 2004.05.016Carlomagno, G.M., Maio, R., Fedi, M., Meola, C., Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys, J. Geophys. Eng., 2011, vol. 8, pp. 93–105. doi 10.1088/1742-2132/8/3/S09Cerdeira, F., Vázquez, ME, Collado, J., and Granada, E., Applicability of infrared thermography to the study of the behavior of Stone panels as building envelopes, Energy Build., 2011, vol. 43, pp. 1845–1851. doi 10.1016/j.enbuild.2011.03.029EN 13187:1998. Thermal performance of buildings. Qualitative detection of thermal irregularities in building envelopes. Infrared method (ISO 6781:1983 modified).Galarza Tortajada, M., La tapia valenciana: una técnica constructiva poco conocida, Proc. First Natl. Congr. Construct. Hist., Madrid, 1996.Grinzato, E., Bison, P.G., and Marinetti, S., Monitoring of ancient buildings by the thermal method, J. Cult. Heritage, 2002, vol. 3, pp. 21–29. doi 10.1016/S1296-2074(02)01159-7Ibarra-Castanedo C., Sfarra, S., Ambrosini, D., Paoletti, D., Bendada, A, and Maldague, X., Diagnostics of panel paintings using holographic interferometry and pulsed thermography, Quant. Infrared Thermogr. J., 2010, vol. 7, no. 1. doi 10.3166/qirt.7.85-114Lagüela, S., Martínez, J., Armesto, J., and Arias, P., Energy efficiency studies through 3D laser scanning and thermographic technologies, Energy Build., 2011, vol. 43, pp. 1216–1221. doi 10.1016/j.enbuild.2010.12.031Lerma, C., Mas, Á., Gil, E., and Galiana, M., An analytical procedure for the study of the documented construction process of the Seminary-School of Corpus Christi in Valencia (Spain), Inf. Constr., 2014, vol. 66 (533), e007. doi 10.3989/ic.12.117Lerma, C., Mas, A., Gil, E., Vercher, J., and Penalver, M.J., Pathology of building materials in historic buildings. Relationship between laboratory testing and infrared thermography, Mater. Constr., 2014, vol. 64 (313), e009. doi 10.3989/mc.2013.06612Lerma, J.L., Cabrelles, M., and Portalés, C., Multitemporal thermal analysis to detect moisture on a building façade, Construct. Build. Mater., 2011, vol. 25, pp. 2190–2197. doi 10.1016/j.conbuildmat.2010.10.007Madruga, F.J., Ibarra-Castanedo, C., Conde, O., López-Higuera, J.M., and Maldague, X., Infrared thermography processing based on higher-order statistics, NDT&E Int., 2010, vol. 43, pp. 661–666. doi 10.1016/j.ndteint.2010.07.002Meola, C., Infrared thermography of masonry structures, Infrared Phys. Technol., 2007, vol. 49, no. 3, pp. 228–33. doi 10.1016/j.infraredPosta, J., Dolejs, J., Non-destructive assessment of timber elements with an emphasis on radiometry., Intern. J. Arch. Herit., 2015, vol. 9, no.6.Válek, J., Kruschwitz, S., Wöstmann, J., Kind, T., Valach, J., Köpp, C., and Lesák, J., Nondestructive investigation of wet building material: Multimethodological approach, J. of performance of Constructed Facilities, pp. 462–472. doi 10.1061/(ASCE)CF.1943-5509.000005

    Long term follow-up and patterns of response of ALT in patients with chronic hepatitis NANB/C treated with recombinant interferon-alpha

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    The response to interferon treatment in chronic hepatitis NANB/C has usually been classified as complete, partial or absent, according to the behavior of serum alanine aminotransferase (ALT). However, a more detailed observation of the enzymatic activity has shown that the patterns may be more complex. The aim of this study was to describe the long term follow-up and patterns of ALT response in patients with chronic hepatitis NANB/C treated with recombinant interferon-alpha. A follow-up of 6 months or more after interferon-a was achieved in 44 patients. We have classified the serum ALT responses into six patterns and the observed frequencies were as follows: I. Long term response = 9 (20.5%); II. Normalization followed by persistent relapse after IFN = 7 (15.9%); III. Normalization with transient relapse = 5 (11.9%); IV. Temporary normalization and relapse during IFN = 4 (9.1%); V. Partial response (more than 50% of ALT decrease) = 7 (15.9%); VI. No response = 12 (27.3%). In conclusion, ALT patterns vary widely during and after IFN treatment and can be classified in at least 6 types.A resposta ao tratamento com interferon em pacientes com hepatite crônica NANB/C tem sido classificada como completa, parcial ou ausente, de acordo com o comportamento da alanino aminotransferase sérica (ALT). Entretanto, uma observação mais detalhada da atividade enzimática tem mostrado que os padrões podem ser mais complexos. O objetivo deste estudo foi descrever o seguimento tardio e os padrões de resposta da ALT em pacientes com hepatite crônica NANB/C tratados com interferon alfa recombinante. Classificamos os tipos de resposta da ALT em 6 padrões e as freqüências observadas foram:I. Resposta completa e persistente = 9 (20,5%); II. Resposta completa com recaída persistente após o IFN = 7 (15,9%); III. Resposta completa com recaída temporária = 5 (11,9%); IV. Normalização temporária e recaída durante o tratamento com IFN = 4 (9,1%); V. Resposta parcial (queda dos níveis iniciais da ALT maior que 50%) = 7 (15,9%); VI. Não resposta = 12 (27,3%). Em conclusão, os padrões de ALT variam durante e após o tratamento e podem ser classificados em pelo menos 6 tipos

    Seguimento tardio e padrões de resposta da ALT em pacientes com hepatite crônica NANB/C tratados com interferon-a

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    The response to interferon treatment in chronic hepatitis NANB/C has usually been classified as complete, partial or absent, according to the behavior of serum alanine aminotransferase (ALT). However, a more detailed observation of the enzymatic activity has shown that the patterns may be more complex. The aim of this study was to describe the long term follow-up and patterns of ALT response in patients with chronic hepatitis NANB/C treated with recombinant interferon-a. A follow-up of 6 months or more after interferon-a was achieved in 44 patients. We have classified the serum ALT responses into six patterns and the observed frequencies were as follows: I. Long term response = 9 (20.5%); II. Normalization followed by persistent relapse after IFN = 7 (15.9%); III. Normalization with transient relapse = 5 (11.9%); IV. Temporary normalization and relapse during IFN = 4 (9.1%); V. Partial response (more than 50% of ALT decrease) = 7 (15.9%); VI. No response = 12 (27.3%). In conclusion, ALT patterns vary widely during and after IFN treatment and can be classified in at least 6 types. _________________________________________________________________________________________ ABSTRACT: A resposta ao tratamento com interferon em pacientes com hepatite crônica NANB/C tem sido classificada como completa, parcial ou ausente, de acordo com o comportamento da alanino aminotransferase sérica (ALT). Entretanto, uma observação mais detalhada da atividade enzimática tem mostrado que os padrões podem ser mais complexos. O objetivo deste estudo foi descrever o seguimento tardio e os padrões de resposta da ALT em pacientes com hepatite crônica NANB/C tratados com interferon alfa recombinante. Classificamos os tipos de resposta da ALT em 6 padrões e as freqüências observadas foram:I. Resposta completa e persistente = 9 (20,5%); II. Resposta completa com recaída persistente após o IFN = 7 (15,9%); III. Resposta completa com recaída temporária = 5 (11,9%); IV. Normalização temporária e recaída durante o tratamento com IFN = 4 (9,1%); V. Resposta parcial (queda dos níveis iniciais da ALT maior que 50%) = 7 (15,9%); VI. Não resposta = 12 (27,3%). Em conclusão, os padrões de ALT variam durante e após o tratamento e podem ser classificados em pelo menos 6 tipos
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