Emittance measurement study

Directional spectral emittance of black body cavitie

A review of test protocols for assessing coating performance of water ballast tank coatings

Concerns on corrosion and effective coating protection of double hull tankers and bulk carriers in service have been raised especially in water ballast tanks (WBTs). Test protocols/methodologies specifically that which is incorporated in the International Maritime Organisation (IMO), Performance Standard for Protective Coatings for Dedicated Sea Water ballast tanks (PSPC) are being used to assess and evaluate the performance of the coatings for type approval prior to their application in WBTs. However, some of the type approved coatings may be applied as very thick films to less than ideally prepared steel substrates in the WBT. As such films experience hygrothermal cycling from operating and environmental conditions, they become embrittled which may ultimately result in cracking. This embrittlement of the coatings is identified as an undesirable feature in the PSPC but is not mentioned in the test protocols within it. There is therefore renewed industrial research aimed at understanding this issue in order to eliminate cracking and achieve the intended coating lifespan of 15 years in good condition. This paper will critically review test protocols currently used for assessing and evaluating coating performance, particularly the IMO PSPC

Probing the chemistry of CdS paints in The Scream by in situ noninvasive spectroscopies and synchrotron radiation x-ray techniques

The degradation of cadmium sulfide (CdS)-based oil paints is a phenomenon potentially threatening the iconic painting The Scream (ca. 1910) by Edvard Munch (Munch Museum, Oslo) that is still poorly understood. Here, we provide evidence for the presence of cadmium sulfate and sulfites as alteration products of the original CdS-based paint and explore the external circumstances and internal factors causing this transformation. Macroscale in situ noninvasive spectroscopy studies of the painting in combination with synchrotron-radiation x-ray microspectroscopy investigations of a microsample and artificially aged mock-ups show that moisture and mobile chlorine compounds are key factors for promoting the oxidation of CdS, while light (photodegradation) plays a less important role. Furthermore, under exposure to humidity, parallel/secondary reactions involving dissolution, migration through the paint, and recrystallization of water-soluble phases of the paint are associated with the formation of cadmium sulfates

How Can Ozone and Relative Humidity Affect Artists’ Alkyd Paints? A FT-IR and Py-GC/MS Systematic Study

Knowledge of the chemical–physical reactions that determine the main degradation behaviour of artists’ alkyd paints represents one of the main problems within the museum exhibitions. The collection and interpretation of these data on degradation phenomena, especially after ozone exposure at different relative humidity values, can be useful for their conservation needs. Therefore, a systematic investigation of these materials may help achieve this goal. Firstly, surface-level identification of the main functional groups of ad hoc created and aged alkyd paints was performed using attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR). Subsequently, these paints were investigated by pyrolysis–gas chromatography and mass spectrometry (Py–GC/MS), allowing for precise bulk identification of the organic compounds before and after accelerated ageing. A first successful attempt to provide quantitative Py–GC/MS data on alkyd-based paints is here presented and discussed. Comparing the results, it was possible to obtain new insights into the degradation behaviour of alkyd paints when exposed to ozone, allowing us to devise specific preventive and conservation strategies for these artistic materials

A Comprehensive and Systematic Diagnostic Campaign for a New Acquisition of Contemporary Art—The Case of Natura Morta by Andreina Rosa (1924–2019) at the International Gallery of Modern Art Ca’ Pesaro, Venice

A multi-analytical approach has been employed to investigate the painting Natura Morta (1954–1955) by Andreina Rosa (1924–2019) to assess the state of conservation and to understand more about the painting materials and techniques of this artwork, which was recently donated by the painter’s heirs to the International Gallery of Modern Art Ca’ Pesaro (Venice-Italy). A comprehensive and systematic diagnostic campaign was carried out, mainly adopting non-invasive imaging and spectroscopic methods, such as technical photography, optical microscopy, Hyperspectral Imaging Spectroscopy (HIS), fiber optics reflectance spectroscopy (FORS), External Reflectance Fourier Transform Infrared (ER-FTIR), and Raman spectroscopies. Microsamples, collected from the edges of the canvas in areas partially detached, were studied by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and Gas Chromatography-Mass Spectrometry (GC-MS). By crossing the information gained, it was possible to make inferences about the composition of the groundings and the painted layers, the state of conservation of the artwork, and the presence of degradation phenomena. Hence, the present study may be of interest for conservation purposes as well as for enhancing the artistic activity of Andreina Rosa. The final aim was to provide useful information for the Gallery which recently included this painting in its permanent collection

AN INVESTIGATION OF IMAGE PROCESSING TECHNIQUES FOR PAINT DEFECT DETECTION USING A MACHINE VISION SYSTEM

Detection and inspection of metal surface corrosion in the ballast tanks of U.S. Navy ships has been a long time problem. The adverse climatic conditions to which the ballast tanks are exposed and the uneven geometry of ballast tanks makes the visual inspection process of surface coatings a difficult job. Thousands of tanks are inspected yearly, with the average cost of an individual tank inspection at approximately $8-15 thousand/each. To aid the visual inspection process, this research is conducted to develop a new technique to automate the visual task of metal surface inspection by image acquisition and post processing. The best results of image processing are achieved by the enhanced contrast between the paint defect and the background using a newly developed optically active additive (OAA) used in paints. Thorough investigation of image processing algorithms has been carried out and a background of imaging theory and experiments is illustrated in this work

Stable White Coatings

In a previous research program for the Jet Propulsion- Laboratory, extensive studies led to the development and specifications of three zinc oxide-pigmented thermal-control coatings. The principal objectives of this program are: improvement of the three paints (as engineering materials), determination of the validity of our accelerated space-simulation testing, and continuation of the zinc oxide photolysis studies begun in the preceding program. Specific tasks that are discussed include: improvement of potassium silicate coatings as engineering materials and elucidation of their storage and handling problems; improvement of methyl silicone coatings as engineering materials; studies of zinc oxide photolysis to establish reasons for the observed stability of zinc oxide; and determination of space-simulation parameters such as long-term stability (to 8000 ESH), effect of coating surface temperature on the rate of degradation, and validity of accelerated testing (by reciprocity and wavelength dependency studies)