Atmospheric corrosion in the Canary Islands

Corrosion is a process that occurs naturally and irreversibly. It is defined as the deterioration of a material (usually a metal) due to its interaction with the surrounding environment. Economic losses related to corrosive processes account for about 5% of the Gross National Product (GNP) of Western countries, China and India. Only in the United States, the costs related to metal corrosion are estimated at app. $1,000 annual per capita, and responsible for a substantial portion of this cost is atmospheric corrosion. Within the various types of corrosive processes, atmospheric corrosion attracts great interest since it affects the entirety of metal materials exposed to air, including urban and industrial infrastructures. It is a widelystudied process, and there are national and international standardized norms for its characterization classifying the aggressiveness of a given environment for a specific metal type (usually those most widely used by the industry). However, major discrepancies between the results of direct exposure and those obtained from the application of standardized norms and predictive models occur for fragmented geographical areas, as in the case of archipelagos. In the Canary Islands, due to their characteristic orography and the regime of winds that affects the archipelago, a multitude of microclimates is generated in a very small geographical area. This variability of atmospheric environments in different islands means, even for the same metal, that the extent of the atmospheric attack may vary substantially between two locations separated only a few miles away. This fact imposes the need for the development of specific prediction models to characterize the corrosion rate for different metals. Investigations carried out in the Canary Islands allowed the characterization of the atmospheric corrosion for metals of wide industrial use (namely mild steel, galvanized steel, zinc, copper, and aluminium), and to obtain maps of atmospheric corrosivity for all the islands. Specific mathematical models have been developed for the prediction of the corrosion rates for these metals exposed on the various islands that make up the archipelag

Characterization of the corrosion products formed on zinc in archipelagic subtropical environments

The atmospheric corrosion of zinc samples exposed at 25 test sites with different climatic and pollution conditions was investigated during a two-year exposure program carried out in three of the Canary Islands (Spain) as to cover the typical range of subtropical environmental conditions. The composition and distribution of the corrosion products of zinc were analyzed qualitatively by X-ray diffraction (XRD). Simonkolleite (Zn5(OH)8Cl2) and hydrozincite (Zn4CO3(OH)6·H2O) were the corrosion products more frequently observed, revealing that chloride and carbon dioxide are the most aggressive pollutants present in the atmosphere. Sulphate-containing species, namely Zinc oxysulfate (Zn3O(SO4)2), Zinc hydroxysulfate (Zn4SO4(OH)6), Zinc diamminehydroxynitrate (Zn5(OH)8(NO3)2·2NH3) and zinc chlorohydroxysulfate (NaZn4Cl(OH)6SO4·6H2O), were also found though in smaller amounts

Development of new mathematical models for the estimation of atmospheric corrosion rates in subtropical environments

In this communication we report an investigation on the mathematical modelling of atmospheric corrosion rates in archipelagic subtropical environments based on the variability of environmental parameters related to both weather factors and pollutant distributions. Experimental data describing the degradation of carbon steel were collected over 3 years from 74 test sites distributed along the seven islands that form the Canary Islands (Spain). The main parameters introduced in the models were the deposition rates for chloride and sulphur dioxide, time of wetness and exposure time. A set of qualitative variables was introduced to account for the variations occurring at different sites at early exposures as to characterize their initial local characteristics. The impact of the new parameters was evaluated from the models, and good fitting correlations between experimental and estimated data have been achieve

A novel approach to the mathematical modelling of atmospheric corrosion rates from fragmented subtropical environments

A new mathematical model for the estimation of atmospheric corrosion rates that satisfactorily describes the behaviour of carbon steel F111 in a fragmented subtropical region has been developed. It is a semi-empirical equation that includes a set of qualitative coefficients established from collections at short exposures (typically one year), in addition to environmental parameters, namely duration of exposure, time of wetness, and deposition rate for chloride ions and sulphur dioxide. The validity of the proposed model has been tested by comparing the estimates obtained using this equation with the experimental data collected from 35 outdoor test sites during 3 years. Satisfactory estimates of the corrosion rates matching the majority of the experimental observations for longer exposures were obtaine

Development of mathematical models to predict the atmospheric corrosion rate of carbon steel in fragmented subtropical environments

Mathematical modelling of atmospheric corrosion based on the aggressiveness categories defined by standard ISO 9223 greatly fail to predict the actual corrosion rates of metals in subtropical environments. Therefore, new concepts for modelling are required as to adequately predict corrosion rates from environmental factors such as the deposition rate of chemical agents (namely chloride and sulphur dioxide), climate effects (such as moisture and time of wetness), and the duration of metal exposure. The novel methodology is based on the definition of a set of qualitative variables to distribute locations exhibiting distinctive initial characteristics towards metal corrosion. The validity of the method was checked by using data obtained during three years of exposure of carbon steel in 74 stations distributed along the seven main islands of the Canary Islands (Spain). A definite evaluation of the impact of environmental factors on the extent of corrosion was achieved, and good results were defined in terms of fitting quality

Beliefs and traditions related to a child´s first year of life : a study of the Northwest of Portugal

In this paper we propose an approach to investigate, in the North-west of Portugal, the parents’ behaviour at birth and during the first year of life of their children. We compare the heritage, specifically the beliefs and traditions, with the changes that resulted from the recent and deep cultural transformations that have taken place in Portugal in the last few decades. In parallel, we tried to determine if the parents’ behaviours, based on beliefs and traditions, can affect the children’s health. We based our investigation on standardized interviews with 76 mothers of one-year-old children (born between January and December 2001) who lived in two parishes of Vizela city. This is a territory where a more traditional way of life prevails than in other territories of the centre and south of the country, where there is a strong attachment for religious and social values and where the influence of the ancestral traditions is still alive. The paper concludes that cultural heritage can have important impact on individual health. Health professionals, who work in primary care and in hospitals, must be aware of the responsibility they have to change this scenario.(undefined

A Predictive Model of Postnatal Surgical Intervention in Children With Prenatally Detected Congenital Anomalies of the Kidney and Urinary Tract

The aim of this study was to identify predictive factors and develop a model to assess individualized risk of postnatal surgical intervention in patients with antenatal hydronephrosis. This is a retrospective cohort study of 694 infants with prenatally detected congenital anomalies of kidney and urinary tract with a median follow-up time of 37 months. The main event of interest was postnatal surgical intervention. A predictive model was developed using Cox model with internal validation by bootstrap technique. Of 694 patients, 164 (24%) infants underwent surgical intervention in a median age of 7.8 months. Predictors of the surgical intervention in the model were: baseline glomerular filtration rate, associated hydronephrosis, presence of renal damage and the severity of renal pelvic dilatation. The optimism corrected c statistic for the model was 0.84 (95%CI, 0.82–0.87). The predictive model may contribute to identify infants at high risk for surgical intervention. Further studies are necessary to validate the model in patients from other settings

Predicting the Proteins of Angomonas deanei, Strigomonas culicis and Their Respective Endosymbionts Reveals New Aspects of the Trypanosomatidae Family

Endosymbiont-bearing trypanosomatids have been considered excellent models for the study of cell evolution because the host protozoan co-evolves with an intracellular bacterium in a mutualistic relationship. Such protozoa inhabit a single invertebrate host during their entire life cycle and exhibit special characteristics that group them in a particular phylogenetic cluster of the Trypanosomatidae family, thus classified as monoxenics. in an effort to better understand such symbiotic association, we used DNA pyrosequencing and a reference-guided assembly to generate reads that predicted 16,960 and 12,162 open reading frames (ORFs) in two symbiont-bearing trypanosomatids, Angomonas deanei (previously named as Crithidia deanei) and Strigomonas culicis (first known as Blastocrithidia culicis), respectively. Identification of each ORF was based primarily on TriTrypDB using tblastn, and each ORF was confirmed by employing getorf from EMBOSS and Newbler 2.6 when necessary. the monoxenic organisms revealed conserved housekeeping functions when compared to other trypanosomatids, especially compared with Leishmania major. However, major differences were found in ORFs corresponding to the cytoskeleton, the kinetoplast, and the paraflagellar structure. the monoxenic organisms also contain a large number of genes for cytosolic calpain-like and surface gp63 metalloproteases and a reduced number of compartmentalized cysteine proteases in comparison to other TriTryp organisms, reflecting adaptations to the presence of the symbiont. the assembled bacterial endosymbiont sequences exhibit a high A+T content with a total of 787 and 769 ORFs for the Angomonas deanei and Strigomonas culicis endosymbionts, respectively, and indicate that these organisms hold a common ancestor related to the Alcaligenaceae family. Importantly, both symbionts contain enzymes that complement essential host cell biosynthetic pathways, such as those for amino acid, lipid and purine/pyrimidine metabolism. These findings increase our understanding of the intricate symbiotic relationship between the bacterium and the trypanosomatid host and provide clues to better understand eukaryotic cell evolution.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)ERC AdG SISYPHEUniv Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, Lab Ultraestrutura Celular Hertha Meyer, BR-21941 Rio de Janeiro, BrazilUniv Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, Lab Metab Macromol Firmino Torres de Castro, BR-21941 Rio de Janeiro, BrazilLab Bioinformat, Lab Nacl Computacao Cient, Rio de Janeiro, BrazilINRIA Grenoble Rhone Alpes, BAMBOO Team, Villeurbanne, FranceUniv Lyon 1, CNRS, UMR5558, Lab Biometrie & Biol Evolut, F-69622 Villeurbanne, FranceUniv Estadual Campinas, Inst Biol, Dept Genet Evolucao & Bioagentes, São Paulo, BrazilUniv São Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Ciencias Farmaceut, São Paulo, BrazilLab Nacl Ciencia & Tecnol Bioetano, São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, Belo Horizonte, MG, BrazilUniv Fed Goias, Inst Ciencias Biol, Mol Biol Lab, Goiania, Go, BrazilFundacao Oswaldo Cruz, Inst Carlos Chagas, Lab Biol Mol Tripanossomatideos, Curitiba, Parana, BrazilFundacao Oswaldo Cruz, Inst Carlos Chagas, Lab Genom Func, Curitiba, Parana, BrazilUniv Estadual Campinas, Ctr Pluridisciplinar Pesquisas Quim Biol & Agr, São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Parasitol, Belo Horizonte, MG, BrazilUniv Fed Santa Catarina, Dept Microbiol Imunol & Parasitol, Ctr Ciencias Biol, Lab Protozool & Bioinformat, Florianopolis, SC, BrazilUniv Fed Vicosa, Dept Bioquim & Biol Mol, Ctr Ciencias Biol & Saude, Vicosa, MG, BrazilInst Butantan, Lab Especial Ciclo Celular, São Paulo, BrazilUniv São Paulo, Dept Biol, Fac Filosofia Ciencias & Letras Ribeirao Preto, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc