Teresa Diamantino - Academia.edu (original) (raw)

Papers by Teresa Diamantino

Environmental Toxicology and Chemistry, 1997

Continuous‐flow systems in toxicity testing are advantageous because they introduce constant toxi... more Continuous‐flow systems in toxicity testing are advantageous because they introduce constant toxicant concentrations and constant food to the test organisms and continuously purge wastes. Therefore, continuous‐flow systems are particularly useful in hazard assessment of substances that may readily be lost from test chambers (i.e., poorly water soluble, volatile, readily biodegradable or photodegradable, hydrolitically unstable compounds). Within METIER (Modular ecotoxicity tests incorporating ecological relevance), a European Union‐funded project, a basic design for a standard flow‐through exposure system was developed. This paper addresses the adaptation of the flow‐through system for use with cladocerans, which involved designing a suitable test chamber and appropriate operation procedures. The sublethal toxicity of a reference compound (3,4‐dichloroaniline) to Daphnia magna Straus was evaluated under both flow‐through and semi‐static conditions. Tests conducted under flow‐through conditions provided a less sensitive measure of toxicity than under semi‐static conditions. This result is probably a function of the higher food availability within the flow‐through system. The no‐observed‐effect concentration for reproduction was the most sensitive endpoint and was 5 μg/L in the flow‐through system and 2.5 μg/L in semi‐static conditions.

Influence of atmospheric corrosivity on solar thermal collector's degradation was studied by expo... more Influence of atmospheric corrosivity on solar thermal collector's degradation was studied by exposure of flat plate collectors to two different corrosivity environments, one urban Outdoor Exposure Testing (OET) site with medium corrosivity (C2-C3) and a very high/extreme corrosivity (industrial and marine) (C5-CX) atmosphere highly polluted and simultaneously with highly airborne salinity. Results of thermal performance measurements after two years of exposure in the two OET sites are presented, as well as the evaluation of the corrosion rate inside the collectors, with zinc as reference material, atmospheric contaminants, temperature and relative humidity. For the measurement of temperature and relative humidity inside the collectors, in house produced data acquisition system and sensors were used and are shortly described. Collectors were dismantled and optical properties of the absorbers were measured.

Corrosão e Protecção de Materiais, 2007

Neste trabalho, os autores apresentam uma panorâmica geral sobre as tintas antivegetativas. Após ... more Neste trabalho, os autores apresentam uma panorâmica geral sobre as tintas antivegetativas. Após a conveniente localização destas tintas no esquema de protecção anticorrosiva das obras vivas dos navios e/ ou outras estruturas móveis, fazem uma síntese dos principais tipos de produtos antivegetativos usados ao longo dos tempos, até aos nossos dias. Complementarmente, sistematizam as principais tipologias dos organismos vivos que se fixam nas obras vivas das embarcações e referem alguns tipos de fauna e flora predominantes em duas regiões da Ibero-América. Abordam também, ainda que sumariamente, os principais mecanismos básicos de funcionamento dos diferentes tipos de tintas antivegetativas. Finalmente, referem algumas das principais linhas de investigação actualmente em curso, no domínio da luta contra a fixação dos organismos marinhos nos cascos dos navios.

Surface & Coatings Technology, Jul 1, 1998

Surface treatment of zinc galvanised steel, using chromate based baths, was extensively used in o... more Surface treatment of zinc galvanised steel, using chromate based baths, was extensively used in order to both improve the corrosion resistance and enhance the chemical adhesion of organic coatings. Although the detailed formation mechanism of chromium conversion coatings ...

Bulletin of Environmental Contamination and Toxicology, Oct 1, 1998

The standardization of ecotoxicity tests has been an important topic for ecotoxicologists (Soares... more The standardization of ecotoxicity tests has been an important topic for ecotoxicologists (Soares and Calow 1993). In the last few decades, there was an effort to develop protocols for standardizing the experimental conditions, mainly by running ‘ring tests’ (‘round robin tests’) (Bradley et al. 1993) with the cladoceran Daphnia magna. It is a suitable test species as it is easily cultured in the laboratory and is very sensitive to chemical stress (Adema 1978). Ecotoxicity tests using cladocerans are usually static and semi-static, which are simple, inexpensive, and require minimum space. The main disadvantages of these two systems are: 1) possible toxicant loss, oxygen depletion, and waste accumulation; 2) they can only be used with organisms adapted to lenthic environments. The objectives of a flow-through system are to submit test organisms to constant and continuous concentration of toxicant and to improve the assessment and standardization of ecological risks of toxic compounds. The flow-through system previously developed within the METIER project is flexible enough to meet the requirements necessary for testing difficult substances and yet sufficiently simple and cost-effective to operate using a wide range of aquatic organisms (Ribeiro et al. 1995; Diamantino et al. 1997).

Solar Energy Materials and Solar Cells, Jul 1, 2017

The degradation and durability of different selective solar absorbers surfaces in outdoor exposur... more The degradation and durability of different selective solar absorbers surfaces in outdoor exposure testing (OET) sites with different atmospheric corrosivity (maritime/industrial and urban atmospheres) were investigated for the optimization of accelerated aging tests to the qualification in terms of durability of selective solar absorber coatings in different environments. Two Outdoor Exposure Testing (OET) sites were constructed, the climate was characterized and the atmospheric corrosivity categories were determined by corrosion rate measurements of standard specimens (carbon steel, zinc, copper and aluminium) during 12 months, according to ISO 9223, ISO 9225 and ISO 9226:2012. Two Physical Vapour Deposition (PVD) coatings (commercially available) and three paint coatings (commercially available) were also exposed in the two OET sites with evaluation of degradation after 1, 2, 4, 6, 9 and 12 months of exposure in terms of optical properties (solar absorptance and thermal emittance), morphology and chemical evaluation (SEM/EDS and XRD). The selective solar absorber surfaces submitted to OET sites for one year were ranked according to their performance in terms of optical properties and corrosion over time. The results obtained show the relevance of outdoor exposure testing sites, namely in places with high corrosivity as in marine and/or industrial areas as a reliable way to verify the corrosion resistance of new materials and products and the evolution of optical properties degradation of absorber surfaces in the presence of high concentration of contaminants.

Progress in Organic Coatings, Apr 1, 2007

The authors present a general overview of marine paints, paying particular attention to the case ... more The authors present a general overview of marine paints, paying particular attention to the case of antifouling paints. After locating these paints in the anticorrosive protection systems used on the underwater parts of ships and/or other moving structures, a summary is made of the main types of antifouling products used through history up to the present time. This is complemented by a systematic assessment of the main types of living organisms that fix themselves to the underwater parts of ships. Consideration is also briefly made of the main basic mechanisms by which the different types of antifouling paints work. Finally a number of current research lines on antifouling technologies are mentioned.

Nucleation and Atmospheric Aerosols, 2019

Realistic lifetime prediction and testing procedures for solar mirrors have been demanded by inve... more Realistic lifetime prediction and testing procedures for solar mirrors have been demanded by investors, plant developers and material manufacturers during the last years. It has been proven that most of the commonly used accelerated aging tests, which were adopted from other industries, cannot be correlated to outdoor exposure. This work studies different accelerated aging test sequences and analyzes the produced degradation. The results made it possible to discover the most demanding environmental conditions for the three tested mirror types. The degradation of the mirrors was strongly affected by the share of the Copper Accelerated Salt Spray (CASS, ISO9227) testing time in the cycle. The CASS test was combined with several other aging tests and it was concluded that especially the combination with the UV/humidity test according to ISO16474-3 was harmful for the protective coatings of the tested silvered-glass mirrors. The conclusions from the testing campaign presented in this paper are helpful to design suited comparative accelerated aging testing procedures.

Environmental Toxicology and Chemistry, Jun 1, 1997

Solar Energy Materials and Solar Cells, Feb 1, 2017

The selective solar absorber surface is a fundamental part of a solar thermal collector, as it is... more The selective solar absorber surface is a fundamental part of a solar thermal collector, as it is responsible for the solar radiation absorption and for reduction of radiation heat losses. The most common absorbers are nowadays produced by vacuum deposition, presenting disadvantages, such as lower durability, lower resistance to corrosion, higher cost and complex production techniques. Spectrally selective paints are a potential alternative for absorbing surfaces in low temperature applications, with attractive features such as ease of processing, durability and commercial availability with low cost. Thus, two PVD coatings and three organic coatings obtained by projection on aluminium substrates were studied. Electrochemical impedance spectroscopy (EIS) allows for the assessment of mechanistic information on the degradation processes, especially if equivalent circuits are used, providing quantitative data that can easily relate to the kinetic parameters of the system. EIS measures were carried out in NaCl and Na 2 SO 4 solutions at different immersion times up to 4 weeks. The performance of the coatings, based on coupons as-received and exposed to atmosphere, is discussed and a ranking is proposed.

Proceedings of EuroSun 2018, 2018

The need of a higher role of solar energy within the energy mix in the coming decades obliges the... more The need of a higher role of solar energy within the energy mix in the coming decades obliges the systems to increase their performance and reliability. It is demanded that the solar absorbers, as the key component of solar thermal systems, should be low cost with high efficiency for extended lifetimes under different kinds of environments. Commercially, there are two different types of solutions as selective solar absorbers coatings: coatings obtained by physical vapor deposition (PVD) and by paint coatings (PC). These coatings present different physical and chemical characteristics. Therefore, it is important to know how these coatings degrade over time in different environments. Results obtained with two different PVD coatings and three PC, under different accelerated aging tests, are presented. The aging tests performed included different environmental stress corrosion conditions: temperature, humidity, chlorides, sulphur dioxide and nitrogen oxides. Cyclic variation of corrosion promoting gases (sulfur dioxide and nitrogen dioxide), higher humidity, salt spraying and drying seem to be an aging test that reflects the different environments where the solar thermal collectors are exposed. In addition to the contaminants, drying / wetting cycles also play an important role in degradation mechanisms of absorber coatings.

Corrosão e Protecção de Materiais, Mar 1, 2016

Solar Energy, 2019

The corrosion rates of AISI 316L and AISI 321H austenitic stainless steel, immersed in a stagnant... more The corrosion rates of AISI 316L and AISI 321H austenitic stainless steel, immersed in a stagnant isothermal mixture of 60% NaNO 3 and 40% KNO 3 molten salt at 550°C in atmospheric air are 8.6 and 9.0 µm/yr, respectively. The corrosion mechanism was proposed by recording the weight changes of the steel coupons at different time intervals up to 3000 h, and by the characterization of multilayer oxide scales formed on the steel surface. Multilayers made of different oxides, mainly Fe 2 O 3 and Fe 3 O 4 , are the principal scale products. At 3000 h, the thickness of the scale layer formed on AISI 321H (7.5 ± 2.9 µm) is slightly higher than the one formed at the AISI 316L (6.9 ± 2.1 µm). This small difference might reflect the partial spallation of the corrosion layer on AISI 321H, which is seen for times longer than 1000 h. A minimal change of the composition of the molten nitrate salt is observed in time and is predominantly due to the appearance of soluble chromate products and nitrite compounds (0.004 wt% and 1.4 wt% at 3000 h, respectively). The observed corrosion behaviour of these alloys shows that they are good candidate for usage as containers of molten nitrate salts in the thermal energy storage (TES) system for a CSP plant.

The main driving forces concerning the use of pre-primed automotive sheet are corrosion protectio... more The main driving forces concerning the use of pre-primed automotive sheet are corrosion protection increase and cost reduction during vehicle manufacturing. In this work, the behaviour of two conductive primers, codified by 1 and 2, was studied and compared with that of a conventional electrophoretic primer. Primer 1 is an organic zinc rich silicate with a low thickness (near 4 µm) and primer 2 is a very thin (near 2 µm) water based primer filled with graphite. These primers were applied on electrogalvanized, hot dip galvanized and galvannealed steel sheets.