Patricia Sanmartín

Bio: Patricia Sanmartín is an academic researcher from University of Santiago de Compostela. The author has contributed to research in topics: Graffiti & Medicine. The author has an hindex of 18, co-authored 61 publications receiving 1058 citations. Previous affiliations of Patricia Sanmartín include University of Oxford & Harvard University.

Measuring the color of granite rocks: A proposed procedure

Abstract: In spite of color being one of the physicochemical parameters most commonly used to characterize ornamental stone, there is yet no standardized protocol for measuring this parameter. Such a protocol is of particular importance for characterizing the color of heterogeneous surfaces, as in the case of granite. The aim of the present study was to determine the minimum area and the number of measurements required to characterize the color of granite rocks. A spectrophotometer and a tristimulus colorimeter, were used to measure the color of granite samples, and the measurements were expressed in CIE L*a*b* color system units. Three parameters were considered as variable factors: the type of rock (Labrador Claro, Grissal, Rosa Porrino, and Blanco Cristal), surface finish (polished, honed, sawn, and flamed), and target area (circular apertures of diameter 5, 8, 10, and 50 mm). The results of the application of multivariate analysis of variance and of the classical CIELAB formula and CIE L*a*b*-based color-difference formulae (i.e., CIE94 and CIEDE2000) to the data revealed that, although all considered factors affected the minimal area and the number of measurements required, the different circular apertures of both the instruments can be disregarded if the number of measurements and area recommended in this study are used. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010

Melding the Old with the New: Trends in Methods Used to Identify, Monitor, and Control Microorganisms on Cultural Heritage Materials.

Abstract: Microbial activity has an important impact on the maintenance of cultural heritage materials, owing to the key role of microorganisms in many deterioration processes. In order to minimize such deleterious effects, there is a need to fine-tune methods that detect and characterize microorganisms. Trends in microbiology indicate that this need can be met by incorporating modern techniques. All of the methods considered in this review paper are employed in the identification, surveillance, and control of microorganisms, and they have two points in common: They are currently used in microbial ecology (only literature from 2009 to 2015 is included), and they are often applied in the cultural heritage sector. More than 75 peer-reviewed journal articles addressing three different approaches were considered: molecular, sensory and morphological, and biocontrol methods. The goal of this review is to highlight the usefulness of the traditional as well as the modern methods. The general theme in the literature cited suggests using an integrated approach.

Spectrophotometric color measurement for early detection and monitoring of greening on granite buildings.

Abstract: This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite facade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Δb*: +0.59 CIELAB units that correspond, in the present study, to 6.3 μg of biomass dry weight cm(-2) and (8.43 ± 0.24) × 10(-3) μg of extracted chlorophyll a cm(-2).

The Design and Analysis of Experiments

Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

Simple Strategy for Producing Superhydrophobic Nanocomposite Coatings In Situ on a Building Substrate

Abstract: Numerous superhydrophobic materials have been developed in recent years by using a combination of two strategies: reducing the surface free energy and roughening the surface. Most of these procedures have the serious drawback of involving tedious multistage processes, which prevent their large-scale application, such as on the external stone and similar material surfaces of buildings exposed to the weather. This paper describes an innovative synthesis route for producing superhydrophobic surface coatings. The coating can even be produced, outdoors, on the building by a low-cost process. We demonstrate that the addition of silica nanoparticles to a mixture of organic and inorganic silica oligomers in the presence of a surfactant produces a coating of closely packed particles. The effect of this is to trap air beneath the water droplets, thus significantly minimizing the contact area between droplet and surface. The organic component reduces the surface free energy of the material, resulting in a high stati...