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In pyrometry measurements, the unknown target emissivity is a critical source of uncertainty, especially when the emissivity is low. Aiming to overcome this problem, various multi-spectral pyrometry systems and processing techniques have been proposed in the literature. Basically, all multi-spectral systems are based on the same principle: the radiation emitted by the target is measured at different channels having different spectral characteristics, and the emissivity is modelled as a function of wavelength with adjustable parameters to be obtained empirically, resulting in a system of equations whose solution is the target temperature and the parameters of the emissivity function. The present work reviews the most important multi-spectral developments. Concerning the spectral width of the measurement channels, multi-spectral systems are divided into multi-wavelength (monochromatic channels) and multi-band (wide-band channels) systems. Regarding the number of unknowns and equations (one equation per channel), pyrometry systems can either be determined (same number of unknowns and equations, having a unique solution) or overdetermined (more equations than unknowns, to be solved by least-squares). Generally, higher-order multi-spectral systems are overdetermined, since the uncertainty of the solutions obtained from determined systems increases as the number of channels increases, so that determined systems normally have less than four channels. In terms of the spectral characteristics of the measurement channels, narrow bands, far apart from each other and shifted towards lower wavelengths, seem to provide more accurate solutions. Many processing techniques have been proposed, but they strongly rely on the relationship between emissivity and wavelength, which is, in turn, strongly dependent on the characteristics of a particular target. Several accurate temperature and/or emissivity results have been reported, but no universally accepted multi-spectral technique has yet been developed.

a b s t r a c tThis paper addresses the study of the pre-experimental planning phase of the Design of Experiments (DoE) in order to improve the final product quality. The pre-experimental planning phase includes a clear identification of the problem statement, selection of control factors and their respective levels and ranges. To improve production quality based on the DoE a new approach for the pre-experimental planning phase, called Non-Conformity Matrix (NCM), is presented. This article also addresses the key steps of the pre-experimental runs considering a consumer goods manufacturing process. Results of the application for an industrial case show that this methodology can support a clear definition of the problem and also a correct identification of the factor ranges in particular situations. The proposed new approach allows modeling the entire manufacturing system holistically and correctly defining the factor ranges and respective levels for a more effective application of DoE. This new approach can be a useful resource for both research and industrial practitioners who are dedicated to large DoE projects with unknown factor interactions, when the operational levels and ranges are not completely defined. Códigos JEL: L660Palabras clave: Series pre-experimentales Matriz de no conformidades Diseño de Experimentos r e s u m e n El presente ensayo aborda el estudio de la fase pre-experimental de planificación del Diseño de Experimentos (DoE) con el fin de mejorar la calidad del producto final. En dicha fase pre-experimental de planificación se incluye una identificación clara del planteamiento del problema, de la selección de los factores de control y de sus correspondientes niveles y rangos. Para mejorar la calidad de producción basada en el DoE se presenta un nuevo enfoque para la fase pre-experimental de planificación llamado Matriz de No Conformidades (NCM). Este ensayo aborda también los pasos clave de las series experimentales teniendo en cuenta el proceso de fabricación de artículos de consumo. Los resultados de la puesta en marcha para un caso industrial demuestran que esta metodología puede respaldar una definición clara del problema y también la correcta identificación de los rangos de factores para situaciones concretas. Este nuevo enfoque propuesto permite modelar todo el sistema de fabricación de manera holística y definir correctamente los rangos de factores y niveles correspondientes para una puesta en marcha eficaz del DoE. Dicho enfoque puede ser un recurso útil tanto para profesionales de la investigación como de la industria que se dedican a grandes proyectos de DoE cuyas interacciones de factores son desconocidas, cuando los niveles y rangos operativos no están definidos del todo.

Purpose High concentration of suspended solids (SS)-fine fraction of eroded soil particles-reaching lotic environments and remaining in suspension by turbulence can be a significant stressor affecting the biodiversity of these aquatic systems. However, a method to assess the potential effects caused by SS on freshwater species in the life cycle impact assessment (LCIA) phase still remains a gap. This study develops a method to derive endpoint characterisation factors, based on a fate and effect model, addressing the direct potential effects of SS in the potential loss of aquatic invertebrate or algae and macrophyte species. Methods Characterisation factors for the assessment of the direct effects of SS in the potential disappearance of macroinvertebrates, algae and macrophytes in 22 different European river sections were derived by combining both fate and effect factors. Fate factors reflect the environmental residence time of SS in river sections per unit of water volume in this same section. Effect factors were calculated from an empirical relationship between the potentially disappeared fraction (PDF) of aquatic species and the concentration of SS. These factors were determined based on a concentration-response function, on gross soil erosion data and detrimental concentrations of SS for different taxa in river sections. Results and discussion The product of fate with effect factors constitutes the characterisation factors for both macroinvertebrates, algae and macrophytes. The estimated EFs are higher for macroinvertebrates in almost all river sections under study, showing that the potential effects caused by SS throughout the water column are higher for macroinvertebrates than for algae and macrophytes. For macroinvertebrates, characterisation factors range between 2.8 × 10 − 7 and 3.1 × 10 − 3 PDF m 3 day mg −1 , whereas for algae and macrophytes, they range between 1.6×10 −7 and 4.7×10 −4 PDF m 3 day mg −1 . Conclusions The developed method and the derived characterisation factors enable a consistent assessment and comparison of the potential detrimental effects of SS on aquatic invertebrate and macrophyte communities at different locations. Long-term, on-site monitoring of SS levels in the water column should be performed to understand the magnitude of the effects of SS on aquatic biota and to determine the taxa that are more sensitive to the SS stressor. This monitoring will improve the robustness of the proposed LCA method, the reliability of the characterisation factors, as well as the development of characterisation factors for a wider range of rivers.

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