Academic literature on the topic 'Metallic/trace'
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Journal articles on the topic "Metallic/trace"
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Magdalena Richter and Henryk Matusiewicz. "Review of the local tissue reaction to metallic spinal implant debris: Ions and nanoparticles." World Journal of Advanced Research and Reviews 9, no. 3 (March 30, 2021): 167–87. http://dx.doi.org/10.30574/wjarr.2021.9.3.0085.
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Biologic reactivity to implant debris is the primary determinant of long-term clinical performance. The metallic implants placed in human bodies can exhibit electrochemical or mechanical corrosion that yields in the liberation of metallic products. Such implants-derived metal wear products can be present in the form of metal ions and particulate metal debris with still unknown effects on human health. In situ generation of metallic wear particles, corrosion products and in vivo trace metal ions release from metal and metallic alloys implanted into the body in spine surgery is becoming a major cause for concern regarding the health and safety of patients. In vivo clinical studies addressing the adverse local tissue reaction effects of metallic wear products on surrounding soft tissues and bodily fluids are less numerous. Although numerous studies have focused on the clinical significance of corrosion and wear of hip and knee replacements, research involving spine instrumentation is not well documented. This review explores how migration of metallic wear nanoparticles and trace metal ions in the area of metallic spinal implants influences the surrounding tissues and bodily fluids, and what the clinical consequences of this process may be.
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Sastry, M. D. "Atomic Spectroscopy for Trace Metallic Assay of Nuclear Fuels." Materials Science Forum 48-49 (January 1991): 381–92. http://dx.doi.org/10.4028/www.scientific.net/msf.48-49.381.
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Kato, Takahiro, Hirokazu Okawa, Katsuyasu Sugawara, Risehiro Nonaka, and Masashi Tsuda. "Separation of Trace Magnesium from Metallic Bismuth by Chlorination." JOURNAL OF CHEMICAL ENGINEERING OF JAPAN 53, no. 7 (July 20, 2020): 366–74. http://dx.doi.org/10.1252/jcej.20we023.
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Ashino, Tetsuya, Naofumi Ohtsu, and Kazuaki Wagatsuma. "Trace Analysis of Released Metallic Ions in Static Immersion Test for Characterization of Metallic Biomaterials." Journal of the Japan Institute of Metals 73, no. 9 (2009): 728–31. http://dx.doi.org/10.2320/jinstmet.73.728.
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Ashino, Tetsuya, Naofumi Ohtsu, and Kazuaki Wagatsuma. "Trace Analysis of Released Metallic Ions in Static Immersion Test for Characterization of Metallic Biomaterials." MATERIALS TRANSACTIONS 49, no. 6 (2008): 1342–45. http://dx.doi.org/10.2320/matertrans.mra2007325.
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Cheng, Hao, Yangjun Mao, Yunhao Lu, Peng Zhang, Jian Xie, and Xinbing Zhao. "Trace fluorinated-carbon-nanotube-induced lithium dendrite elimination for high-performance lithium–oxygen cells." Nanoscale 12, no. 5 (2020): 3424–34. http://dx.doi.org/10.1039/c9nr09749j.
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Muszyńska, Ewa, and Mateusz Labudda. "Dual Role of Metallic Trace Elements in Stress Biology—From Negative to Beneficial Impact on Plants." International Journal of Molecular Sciences 20, no. 13 (June 26, 2019): 3117. http://dx.doi.org/10.3390/ijms20133117.
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Heavy metals are an interesting group of trace elements (TEs). Some of them are minutely required for normal plant growth and development, while others have unknown biological actions. They may cause injury when they are applied in an elevated concentration, regardless of the importance for the plant functioning. On the other hand, their application may help to alleviate various abiotic stresses. In this review, both the deleterious and beneficial effects of metallic trace elements from their uptake by roots and leaves, through toxicity, up to the regulation of physiological and molecular mechanisms that are associated with plant protection against stress conditions have been briefly discussed. We have highlighted the involvement of metallic ions in mitigating oxidative stress by the activation of various antioxidant enzymes and emphasized the phenomenon of low-dose stimulation that is caused by non-essential, potentially poisonous elements called hormesis, which is recently one of the most studied issues. Finally, we have described the evolutionary consequences of long-term exposure to metallic elements, resulting in the development of unique assemblages of vegetation, classified as metallophytes, which constitute excellent model systems for research on metal accumulation and tolerance. Taken together, the paper can provide a novel insight into the toxicity concept, since both dose- and genotype-dependent response to the presence of metallic trace elements has been comprehensively explained.
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ONO, Hiroshi. "Simultaneous determination of trace amounts of multielements in metallic materials." BUNSEKI KAGAKU 49, no. 3 (2000): 209–10. http://dx.doi.org/10.2116/bunsekikagaku.49.209.
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Chizzola, R. "METALLIC TRACE ELEMENTS IN HERBS AND SPICES GROWN IN AUSTRIA." Acta Horticulturae, no. 249 (September 1989): 89–96. http://dx.doi.org/10.17660/actahortic.1989.249.10.
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Kl�ck, W., H. Palme, and H. J. Tobschall. "Trace elements in natural metallic iron from Disko Island, Greenland." Contributions to Mineralogy and Petrology 93, no. 3 (July 1986): 273–82. http://dx.doi.org/10.1007/bf00389387.
Full textDissertations / Theses on the topic "Metallic/trace"
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Abraham, C. J. "Trace-element analysis of metallic and organic matrix materials exploiting RIMS." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635842.
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Sputter initiated Resonance Ionisation Spectroscopy (SIRIS) was used to perform trace analysis for a number of elements in various matrices. The system consisted of a reflection time of flight (ToF) mass spectrometer combined with a duoplasmatron primary ion source which was coupled to a Nd:YAG pumped dye laser. External electronics were constructed to synchronise precisely the timing of the laser pulse, primary ion source and dual channel plate detector. The present set-up allowed the utilisation of the simplest of all ionisation routes, namely the one-colour, two-photon RIS schemes. The elements titanium, chromium, nickel, molybdenum, iron and tin were photo-ionised in the 290-300 nm and 280-290 nm range. Various resonances for these elements were obtained providing valuable information on efficient RIS routes, which could be used in trace analysis. The sensitivity of the RIMS technique was demonstrated by the detection of 15 ppm of iron in a nickel host, with an ultimate detection limit of less than 5ppb. Trace detection of potentially toxic elements such as iron and aluminium in brain homogenate tissue was demonstrated for samples, with concentrations of 100 ppm of aluminium and 400 ppm of iron: detection was possible without isobaric interferences. These elements have been linked to the neurological disorders of Alzheimer's disease and Parkinsonian dementia. In a separate application, the detection of 480 ppm of tin in an insulator of silicone gum is shown, demonstrating the diverse range of samples which can be analysed using RIMS. A brief review of the theoretical modelling for ion sputtering and the process of resonance ionisation is given, including the benefits and limitations of the various methods.
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Jadhav, Raja A. "Multifunctional sorbents for gas phase trace metallic capture : kinetic and mechanistic studies /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488195633518351.
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Jones, O. R. "Resonance ionisation mass spectrometry of trace elements in metallic and organic host matrices." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637710.
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In this work, sputter initiated resonance ionisation mass spectrometry has been used for quantitative analysis of trace amounts of elements in both metallic and organic host matrices. In parallel with the experimental work, theoretical methods have been developed to describe both the interaction of the laser radiation with the plume of sputtered particles and the processes involved in resonance ionisation. On the experimental side, general one-colour, two-step resonance ionisation schemes were demonstrated, using a reflectron type time-of-flight mass spectrometer combined with a duoplasmatron primary sputter ion source and a Nd:YAG pumped dye laser system. Timing electronics were developed to precisely synchronise the pulsed laser system to the sputter process and the mass spectrometric analysis. For metal matrices, the elements titanium, chromium, iron, nickel and molybdenum were probed in the 290-300nm wavelength range. The detection of an enhanced molybdenum signal at 294.421nm is believed to be the first resonance ionisation signal to have been obtained for this element. Aluminium was probed in the 305-310nm wavelength range. For organic matrices, the feasibility of using spatially resolved resonance ionisation mass spectrometry for the analysis of potentially toxic element accumulation in neural tissue was investigated. In particular it was shown that aluminium, which is linked to brain disorders such as Alzheimer's disease, could be detected in brain tissue at concentrations of around 100ppm, with a detection limit of about 3ppm using the current set-up. On the theoretical side, the use of a quantum mechanical density matrix approach in describing the process of resonance ionisation was shown to be more generally applicable than a simple rate-equation or Schrödinger equation approach. In particular, the saturation of the resonant and ionisation steps, and the power broadening of the resonant transition at high laser fluences were investigated, with satisfactory agreement found between theory and experiment in both cases.
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Amarachintha, Surya P. "Optimal Growth Conditions for Tracheal Epithelial Stem Cells." Bowling Green State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1187395530.
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Omrane, Fatma. "Human health risk assessment of occupational exposure to trace metallic elements mixtures in metalworking industries in the Sfax metropolis (Tunisia)." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0097/document.
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Les éléments trace métalliques (ETM) sont des polluants qui sont sources de préoccupations majeures à cause de leurs toxicités et de leurs propriétés cumulatives. Certains d’eux peuvent être cancérogènes. La métropole de Sfax, située au sud de la Tunisie, a été touchée par des rejets et émissions d’ETM depuis des décennies. Plusieurs études ont confirmé que la pollution métallique est principalement d’origine anthropique, liée en particulier aux activités industrielles. Cela présente un risque sur la santé des habitants, particulièrement pour ceux qui sont également exposés par leur métier dans des procédés industriels. L’objectif de cette étude est d’évaluer les risques sanitaires associés à l’exposition professionnelle dans les industries qui manipulent des ETM dans leurs processus de production, en suivant l’approche de l’évaluation des risques sanitaires. Dans ce but, cinq entreprises qui utilisent des métaux comme matière première pour produire une variété de produits métalliques, ont accepté d’adhérer à notre étude. Les métaux qui étaient explorés sont Al, Cr, Ni, Cu, Zn and Pb. Des modèles mathématiques de prédiction des expositions professionnelles aux agents chimiques ont été utilisés pour estimer les concentrations des ETM dans l’air intérieur pour 15 postes différents. Des prélèvements atmosphériques ont été effectués afin de comparer les concentrations prédites à celles mesurées, en utilisant des prélèvements individuels ou sur postes fixes. Finalement, des prélèvements urinaires ont été collectés chez 61 travailleurs afin d’évaluer le lien entre l’excrétion des ETM et les niveaux atmosphériques. Globalement, les estimations des concentrations atmosphériques avaient une bonne concordance avec les valeurs mesurées sur l’ensemble des postes de travail. Des meilleures prédictions ont été trouvées pour certaines activités, en particulier pour des processus de découpage des tôles et de soudures. Les valeurs qui correspondent au 90ème percentile de la distribution de l’exposition ont été utilisées pour le calcul du « interaction-based hazard index HIint » pour évaluer les risques associés aux mélanges d’ETM. Un excès de risque total de cancer a été aussi calculé. Les résultats ont montré des expositions élevées qui peuvent provoquer des pathologies respiratoires, avec un HIint allant jusqu’à 93,6. Les niveaux les plus élevés sont attribués à la soudure à l'arc à l'électrode enrobée et au débitage et cisaillage des tôles. Ces risques augmentent à cause de l’effet synergique qui existe entre Cr, Ni et Cu. Des risques élevés de cancer du poumon et du rein ont été encore démontrés (risque total vie entière de cancer pour les ouvriers exposés : 3.7×10-4). Ce travail montre que les modèles mathématiques peuvent prédire correctement les niveaux d’exposition des ETM dans l’air intérieur pour plusieurs processus de la métallurgie. Ce résultat est intéressant pour aider les différents acteurs pour piloter de manière efficiente les systèmes de surveillance et la réduction des expositions dans ce secteur économique. Des progrès en matière d’hygiène industrielle sont nécessaires dans ce secteur industriel pour minimiser le risque sanitaire élevé auquel sont actuellement exposés les travailleurs concernésTrace metallic elements (TMEs) are pollutants of great concern even in trace amounts because of their toxicity and cumulative property. Some of them can be carcinogenic. The Sfax metropolis, located in the southern region of Tunisia, has been affected by releases of TMEs for decades. Several studies confirmed that this pollution is predominantly originated from anthropogenic sources, mainly from industrial activities. It represents a threat to the health of residents, particularly for those also exposed during occupational activities in industrial processes. The present study aims to assess health risks associated with occupational exposure in industries handling TMEs in their production processes, following the human health risk assessment approach. To this end, five companies using raw material containing TMEs to produce a variety of metallic products accepted to participate to the study. The metals that were investigated are Al, Cr, Ni, Cu, Zn and Pb. Mathematical models for estimating occupational exposure to chemicals were used to predict indoor air TME exposure levels in 15 different job tasks. Air monitoring was conducted in order to compare the predicted workplace air concentrations versus the direct measured ones, using both workplace-fixed monitors and personal samplers. And finally, urine samples were collected from 61 workers to assess whether TMEs excretion correlate with job exposure levels. Globally, the predicted air estimates relate well with measured concentrations over the whole set of job tasks. Better predictions were found for certain activities, in particular for steel cutting and welding processes. The values that correspond to the 90th percentile of the exposure distribution were then used in the interaction-based hazard index HIint to assess health risks associated with the mixtures of TMEs. Total cancer risk was also investigated. Results showed high exposures for metals that may elicit respiratory conditions, with a HIint reaching 93.6, the highest levels being for the shielded metal arc welding and metal shearing and slitting tasks. The risk is enhanced by a synergetic effect between Cr, Ni and Cu. High risks of lung and kidney cancers were demonstrated (the predicted life-long total cancer risk for exposed workers is 3.7×10-4). This work shows that mathematical models can be accurate in predicting TME airborne exposure levels for several processes in the metallurgic industry, a result that is of interest to help the different stakeholders to monitor efficiently exposure surveillance and abatement. Progress in industrial hygiene is needed in this industrial sector to reduce the high level of health risks currently experienced by the metalworking workers
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Yedomon, Brice. "Travail informel au Bénin : Expositions professionnelles et conséquences sanitaires chez les forgerons-ferblantiers à Cotonou." Thesis, Limoges, 2016. http://www.theses.fr/2016LIMO0108/document.
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Contexte et objectifs : Au Bénin, le « secteur informel » représente près de 80 % des travailleurs avec une prédominance d’acteurs dans l’artisanat, suivi par le secteur privé moderne (11 %) et la fonction publique (9 %). La situation socio-professionnelle des artisans est caractérisée par l’absence d’équipements de protection, par l’exposition à des nuisances physiques et chimiques et par l’absence de sécurité sociale. L’objectif principal de ce travail de thèse était d’étudier l’impact des conditions de travail sur la santé des forgerons-ferblantiers exerçant dans le cadre de l’économie informelle, à Cotonou au Bénin. Ce travail a permis également d’évaluer l’imprégnation sanguine en éléments traces métalliques chez les ferblantiers par comparaison avec les concentrations observées dans la population masculine de Cotonou, non exposée professionnellement. Cette partie de l’étude a nécessité la mise en place d’une première enquête en population générale, chez 70 donneurs de sang à Cotonou afin de proposer des valeurs de référence pour 29 éléments traces métalliques.Méthode : Une étude transversale a été réalisée à Midombô sur le site des artisans ferblantiers dans le 3ème arrondissement de Cotonou au Bénin. Au total, 84 responsables d’atelier sur 102 ont donné leur accord de participation pour l’étude des postes et conditions de travail, soit un taux de participation de 82,4 %. Parmi les 251 personnes travaillant dans les 102 ateliers investigués, 135 ferblantiers ont accepté de venir au centre de santé Erasme (53,8 %) pour bénéficier d’un entretien médical gratuit. Dans cette population, 31 personnes étaient des apprentis (23,0 %) et 104 étaient des artisans ou maitres-artisans (77,0 %). Résultats : Il a été observé des niveaux de bruit supérieurs à 85 décibels dans 58,3 % des ateliers, avec une durée du travail en moyenne de 10 h par jour pouvant être à l’origine des déficits auditifs (légers à sévères) observés dans 99,3% des cas. L’exposition directe aux fumées et poussières métalliques (38,52 %) et la consommation d’aliments au poste de travail seraient à l’origine d’une imprégnation métallique. Pour 6 éléments traces, plus de 20 % des ferblantiers présentaient des concentrations sanguines supérieures aux valeurs de référence de la population générale. Par ordre croissant de niveau d’imprégnation, il s’agissait du molybdène, du cuivre, du strontium, de l’étain, de l’antimoine, et du plomb. Environ 71 % des ferblantiers présentaient des plombémies supérieures au 95ème percentile des concentrations retrouvées en population non exposée à Cotonou. Pour les moins de 18 ans, la prévalence des travailleurs ayant une plombémie ≥ 100 μg/L était de 83 %. Une baisse de l’acuité visuelle non corrigée (> 20 %) et une hypertension artérielle non traitée (27,4 %) ont été dépistées chez les ferblantiers participants. Conclusion : Les travailleurs informels sont dans une situation de grande vulnérabilité du fait d’une faible couverture en matière de protection sociale et d’un niveau élevé d’exposition aux risques professionnels. Compte tenu du grand nombre de travailleurs dans l’économie informelle, l’amélioration de la santé et de la sécurité au travail des acteurs de ce secteur, devrait permettre un renforcement du capital humain et la réduction des maladies professionnelles encore mal documentéesContext and objectives: In Benin, the "informal sector" represents almost 80% of workers with a predominance of craftsmen, followed by the modern private sector (11%) and the civil service (9%). The socio-professional situation of craftsmen is characterized by the lack of personal or collective protective equipment, exposure to physical and harmful chemical substances and a lack of social security. The main objective of this thesis was to study the impact of working conditions on the health of tinsmiths in the informal economy in Cotonou, Benin. This research also allowed us to evaluate the blood impregnation of trace elements in tinsmiths compared to the background levels of the non-occupationally exposed male population of Cotonou. This part of the study required a first survey of 70 blood donors in Cotonou, in order to propose reference values for 29 trace elements. Method: A cross-sectional study was carried out in Midombô on the site of the tinsmiths in the 3rd district of Cotonou in Benin. Study population: A total of 84 workshop managers out of 102 gave their agreement to participate in the study of work places and conditions (participation rate of 82.4 %). Among the 251 tinsmiths working in the 102 workshops investigated, 135 agreed to go to the “Erasmus” health center (53.8%) for free medical care. In this population, there were 31 apprentices (23.0 %) and 104 craftsmen or master craftsmen (77.0 %). Results: Noise levels greater than 85 decibels were observed in 58.3% of the workshops, with an average working time of 10 hours per day. This exposure can be the cause of hearing impairment (mild to severe) observed in 99, 3% of the cases. Direct exposure to metal fumes and dust (38.52 %) and the consumption of food at the workplace are the cause of metallic impregnation. For 6 trace elements, more than 20 % of the tinsmiths had blood concentrations above the reference values of the general population. These elements, classified from the lowest to the highest level of impregnation were molybdenum, copper, strontium, tin, antimony, and lead, respectively. Approximately 71% of the tinsmiths had lead levels above the 95th percentile of concentrations found in unexposed populations in Cotonou. 83% of the workers who were under 18 years of age had blood lead levels ≥ 100 μg / L. Uncorrected visual acuity (> 20%) and untreated arterial hypertension (27.4 %) were detected in the participating tinsmiths. Conclusion: Informal workers are in a very vulnerable situation due to poor social protection and a high level of exposure to occupational risks. Given the large number of employees in the informal sector, improving the occupational health and safety of these workers should help to strengthen human capital and reduce the incidence of occupational diseases that are still poorly documented
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Feniou, Romain. "Etude du transfert d’un composé trace dans un gaz de stockage vers un aquifère. Mesures et Modélisation. Cas du mercure." Thesis, Pau, 2012. http://www.theses.fr/2012PAUU3039.
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Depuis près de 55 ans, TIGF exploite, dans le sud-ouest de la France deux stockages de gaz naturel en aquifère. Le gaz stocké est essentiellement composé de méthane (CH4 à plus de 90 %), mais il contient également d’autres hydrocarbures légers (< C4H10), du diazote (N2), du dioxyde de carbone (CO2), de produits soufrés (H2S, mercaptans) et des composés métalliques présents sous formes de traces ou ultra-traces. L’objectif de la thèse est l’étude du transfert de ces composés vers l’aquifère avec comme cas d’étude : le mercure. Un dispositif expérimental a donc été conçu et développé pour (i) mesurer la solubilité dans l’eau du mercure gazeux présent dans le gaz stocké, ainsi que (ii) pour étudier les phénomènes d’adsorption sur la roche dans les conditions de pression (60 bar) et de température (45°C) du réservoir naturel. Les résultats expérimentaux obtenus en laboratoire ont été utilisés dans un modèle numérique afin de simuler le comportement du réservoir et évaluer notamment les quantités de mercure susceptibles de rester en son sein lors de l’exploitation du stockageFor nearly 55 years, TIGF operates two gas storages in an aquifer in the southwest of France. The stored gas is mainly composed of methane (CH4 over 90%) but it also contains other light hydrocarbons (
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Menana, Zahra. "Étude de faisabilité de la valorisation en bioraffinerie de biomasses issues de phytotechnologies : cas d’une plante hyperaccumulatrice (noccaea caerulescens) et d’un ligneux (salix viminalis)." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0225/document.
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La phytoremédiation est un concept pour la dépollution et de réhabilitation des sols et/ou de friches industrielles contaminés par des éléments traces métalliques (ETMs), utilisant les végétaux pour absorber ou immobiliser les contaminants en présence des organismes microbiens de la rhizosphère. Cette technique a pour conséquence une production de biomasse plus ou moins contaminée qu’il est nécessaire de traiter et également de valoriser. Cependant, la présence d’ETMs peut être problématique dans une approche de conversion en bioraffinerie. Pour répondre à cette question, deux espèces ont été étudiées : une plante herbacée hyperaccumulatrice (Noccaea caerulescens) et un ligneux (Salix viminalis). Deux prétraitements ont été sélectionnés pour cette étude : les prétraitements par explosion vapeur et organosolv, en appliquant différentes conditions opératoires, afin (1) de suivre la distribution des ETMs au cours du traitement, (2) de purifier la matière lignocellulosique et (3) d’évaluer l’effet des ETMs sur les étapes ultérieures d’hydrolyse enzymatique et de fermentation. Pour le prétraitement organosolv la majeure partie des ETMs est récupérée dans le résidu solide cellulosique alors que par explosion à la vapeur, les ETMs sont extraits en grande partie dans les effluents aqueux du traitement. La présence d’ETMs dans les pâtes cellulosiques et les hydrolysats ne montre pas d’effet significatif sur la cinétique d’hydrolyse enzymatique et de fermentation. Concernant spécifiquement Noccaea caerulescens des teneurs relativement importantes en pectines ont été observées, ce qui ouvre des perspectives intéressantes pour la valorisation de cette plante par la production d’un biopolymère d’intérêt industriel. Finalement, les résultats obtenus montrent qu’il serait possible de combiner réhabilitation des sols et valorisation en bioraffinerie de biomasses issues de phytotechnologies soit pour la production du bioéthanol ou la production de molécules plateformePhytoremediation is a concept for the depollution and rehabilitation of soils and/or industrial wastelands contaminated by metal trace elements (MTEs), using plants to absorb or immobilize contaminants in the presence of microbial organisms in the rhizosphere. This technique results in a more or less contaminated biomass production that must be treated and also recovered. However, the presence of MTEs can be an issue in a biorefinery conversion approach. To address this question, two species were studied: an hyperaccumulator herbaceous plant (Noccaea caerulescens) and a woody plant (Salix viminalis). Two pre-treatments were selected for this study: steam explosion and organosolv pre-treatments, applying different operating conditions, in order to (1) monitor the distribution of MTEs during the process, (2) purify lignocellulosic material and (3) evaluate the effect of MTEs on subsequent enzymatic hydrolysis and fermentation steps. For organosolv pretreatment, most of the MTEs are recovered in the solid cellulosic residue while by steam explosion, MTEs are mostly extracted in the aqueous effluents of the treatment. The presence of MTEs in cellulosic pastes and hydrolysates does not show a significant effect on the kinetics of enzymatic hydrolysis and fermentation. Concerning specifically Noccaea caerulescens, the plant contains relatively high levels of pectins, which opens up interesting prospects for the valorization of this plant through the production of a biopolymer of industrial interest. Finally, the results obtained show that it would be possible to combine soil rehabilitation and biorefinery valorization of biomasses from phytotechnologies for either bioethanol production or the production of platform molecules
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Mallmann, Fábio Joel Kochem. "Simulação do transporte vertical de zinco, chumbo e cobre em solos contaminados." Universidade Federal de Santa Maria, 2009. http://repositorio.ufsm.br/handle/1/5490.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe environmental contamination by metallic trace elements is a problem that is getting worse around the world due to the growth and the technologic development of the humanity. Among the main sources of this kind of contamination are the atmospheric deposition of particles in soils located around industrial complexes and the prolonged and concentrated application of organic wastes in the soil. When present at the soil surface, these elements will migrate in depth and may reach the subsurface water bodies, causing their contamination. This study aimed to use the software Hydrus-2D to simulate the vertical redistribution of zinc, lead and copper in soil profiles contaminated by air pollution or by the application of swine liquid manure as well the transfer of these metallic trace elements into the groundwater. Chemical models were used under different hypotheses of reactivity of these elements with the soil particles and the physical, hidric and chemical characteristics of each soil profile. In the attempt to validate these models, it was simulated the vertical transports of zinc and lead, between 1900 and 2000, at three uses of a soil in northern France and of zinc and copper, between 2000 and 2008, at a soil profile located in Santa Maria RS, Brazil. Using a two sites chemical model with the kinetic constant decreased to 1% of the value measured in the laboratory, the simulations of the vertical transport of the metallic trace elements were validated in all soil profiles. This model was able to redistribute efficiently these elements in the profile, according their concentrations determined in situ. It was also predicted that the transfer of these contaminants do not represent, until now, any risk of pollution of the groundwater. Even with the continued application of high doses of swine liquid manure until 2058, the predicted increasing of zinc and copper concentrations in soil solution will not represent a risk of subsurface waters pollution. However, the model estimated that copper will be accumulated on the surface of this profile in greater quantities than zinc, increasing its concentration to levels above the value of intervention to agricultural areas. It was concluded that Hydrus-2D was a useful tool in detecting and/or forecasting environmental problems arising from the accumulation of metallic trace elements in soil and its leaching to the subsurface water bodies.
A contaminação do ambiente por elementos traços metálicos é um problema que vem se agravando em todo o mundo. Ela é decorrente do crescimento e do desenvolvimento tecnológico da humanidade, que apresenta, entre as principais fontes, as contaminações oriundas da deposição atmosférica de partículas aos solos localizados no entorno de complexos industriais e da aplicação concentrada e prolongada de resíduos orgânicos. Uma vez presentes na superfície do solo, esses elementos migrarão em profundidade, podendo atingir os corpos de água subsuperficiais e contaminá-los. Este trabalho teve por objetivo principal usar o programa computacional Hydrus-2D para simular a redistribuição vertical de zinco, chumbo e cobre no perfil de solos contaminados por poluição atmosférica ou pela aplicação de dejeto líquido de suínos e a transferência desses elementos traços metálicos rumo ao lençol freático. Para tal, foram usados modelos químicos sob diferentes premissas de reatividade dos elementos com as partículas do solo e as características físico-hídricas e químicas de cada perfil de solo. Buscou-se validar estes modelos, simulando os transportes verticais de zinco e chumbo, entre 1900 e 2000, em três usos de um solo do norte da França e de zinco e cobre, entre 2000 e 2008, num perfil de solo localizado em Santa Maria RS, Brasil. Utilizando um modelo químico de dois sítios com a constante cinética diminuída a 1% do valor medido em laboratório, as simulações do transporte vertical dos elementos traços metálicos foram validadas em todos os perfis de solo. Esse modelo foi capaz de redistribuir eficientemente estes elementos no perfil, conforme suas concentrações determinadas in situ. Ele também previu que a transferência destes contaminantes não representou, até o momento, nenhum risco de poluição da água do lençol freático. Mesmo com a manutenção da aplicação de altas doses de dejeto líquido de suínos até 2058, o aumento na concentração de zinco e cobre na solução do solo previsto não representará risco à poluição das águas subsuperficiais. Porém, o modelo estimou que o cobre se acumulará na superfície deste perfil em maior quantidade que o zinco, elevando sua concentração para níveis acima do valor de intervenção para áreas agrícolas. Dessa forma, o Hydrus-2D apresentou-se como uma ferramenta muito útil na detecção e/ou previsão de problemas ambientais decorrentes do acúmulo de elementos traços metálicos no solo e da sua lixiviação para os corpos de água subsuperficiais.
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Biscéré, Tom. "Effets des métaux et des changements climatiques sur les coraux." Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS382.
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Les récifs coralliens se sont largement dégradés au cours de ces dernières décennies sous l’influence des activités anthropiques. Parmi ces perturbations, l’augmentation des concentrations métalliques concerne de nombreux récifs à travers le monde (e.g. grande barrière australienne, Costa Rica, Mer Rouge, Nouvelle-Calédonie). A ces stress locaux vient s’ajouter le changement climatique, et plus particulièrement l’élévation des températures et l’acidification des océans, auxquelles les coraux doivent désormais faire face. Dans ce contexte particulier, les objectifs de cette thèse ont donc été (1) de déterminer l’effet sur la physiologie corallienne, des principaux métaux présents dans les sédiments latéritiques (fer, manganèse, nickel et cobalt), à des concentrations représentatives de celles mesurées sur le littoral calédonien, et (2) de définir leurs rôles potentiels dans ce contexte de changement climatique. Les résultats obtenus ont montré que les métaux ont des effets très différents sur le métabolisme corallien. Alors qu’à température ambiante un apport en nickel ou en manganèse stimule le métabolisme de l’hôte et la photosynthèse des symbiotes, à l’inverse, un enrichissement en cobalt inhibe la calcification et devient même toxique dès 1.0 μg L-1 pour les symbiotes et l’hôte. De même, malgré son importance dans les processus photosynthétiques, un apport en fer diminue la densité en Symbiodinium des tissus et inhibe la calcification. En période de stress thermique, le manganèse augmente la tolérance des coraux à cette hausse de température, probablement en stimulant leurs défenses antioxydantes, tandis que le nickel aggrave ces effets en diminuant encore davantage leur croissance. Ces travaux constituent une étape importante vers une meilleure compréhension de la réaction des coraux aux enrichissements métalliques et permettraient d’expliquer, dans une certaine mesure, la sensibilité des espèces coralliennes aux changements climatiquesCoral reefs have largely degraded in recent decades under the influence of human activities. Among those disturbances, the increase in metal concentrations affects many reefs worldwide (e.g. Australian Great Barrier Reef, Costa Rica, Red Sea, New Caledonia). Furthermore, reefs have now to face climate change, and more particularly temperature increase and ocean acidification. In this context, the aims of my thesis were to (1) determine the effects of the main metals present in lateritic sediments (iron, manganese, nickel and cobalt) on coral physiology using concentrations representative of those measured along the New Caledonian coastline, and to (2) define their potential roles in this context of climate change. My results showed that metals affect coral metabolism in different ways. While at ambient temperature, a nickel or manganese enrichment stimulates host metabolism and symbiont photosynthesis, conversely a cobalt enrichment inhibits calcification and becomes even toxic for the host and symbionts, from 1 μg L-1. Despite its importance in photosynthetic processes, an iron enrichment induces a decrease in Symbiodinium densities and an inhibition of calcification rates. Under thermal stress, manganese enhances coral tolerance to temperature increase, likely by stimulating their antioxidant defenses, while nickel worsens its effects by decreasing even more their growth. These works represent an important step towards a better understanding of coral responses to metal enrichment and would explain, to some extent, species susceptibility to climate change
Books on the topic "Metallic/trace"
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Angebranndt, Martin John. Surface enhanced raman spectroscopy on metallic colloids for the purpose of trace analysis. 1991.
Find full textBook chapters on the topic "Metallic/trace"
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El Hajjami, S., S. Souabi, M. El Alami, and A. Taleb. "Spatio-Temporal Evaluation of the Contamination by Metallic Trace Elements of the Surface Waters of Oued Sebou, Morocco." In Advances in Intelligent Systems and Computing, 630–42. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36671-1_56.
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Laznicka, Peter. "From trace metals to giant deposits." In Giant Metallic Deposits, 59–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12405-1_3.
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Benessam, Sihem, Taha-Hocine Debieche, Souad Amiour, Amal Chine, and Smaïl Khelili. "Mobility of Metallic Trace Elements in Surface Waters and Sediments: Case of the Nil Wadi (Jijel, North-East Algeria)." In Advances in Sustainable and Environmental Hydrology, Hydrogeology, Hydrochemistry and Water Resources, 69–71. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-01572-5_17.
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Silió, F., A. Santos, and B. Ribas. "The Metallic Component of the Glucose Tolerance Factor, G.T.F." In Trace Elements in Man and Animals 10, 540–41. New York, NY: Springer US, 2002. http://dx.doi.org/10.1007/0-306-47466-2_173.
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Ashraf, Muhammad Aqeel, Maliha Sarfraz, Rizwana Naureen, and Mohamedreza Gharibreza. "Modelling the Trace Metal Speciation of Labile Chemical Species in Natural Waters by Electrochemical Methods." In Environmental Impacts of Metallic Elements, 229–50. Singapore: Springer Singapore, 2015. http://dx.doi.org/10.1007/978-981-287-293-7_8.
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"Root Responses to Trace Metallic Elements." In Plant Roots, 572–601. CRC Press, 2013. http://dx.doi.org/10.1201/b14550-43.
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Anhichem, Mimouna, and Samir Benbrahim. "Study of Water and Sediment Quality in the Bay of Dakhla, Morocco: Physico-Chemical Quality and Metallic Contamination." In Sediment Transport - Recent Advances [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.95108.
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The present study contributes to the evaluation of the impact of the various activities developed around the Bay of Dakhla in Morocco through the study of the physico-chemical quality of the waters and sediments of the Bay. For this purpose, a spatial and temporal monitoring of the physicochemical and metallic pollution indicator parameters was conducted between May 2014 and March 2015. The main physicochemical descriptors of water quality were monitored, namely: temperature, salinity, pH, dissolved O2, nutrients (ammonium, nitrites, nitrates, phosphates) and chlorophyll (a). A qualification of the waters of the Bay was drawn up based on water quality assessment grids. The quality of the sediments was assessed through the determination of granulometry, the total organic carbon content and the contents of the main metallic trace elements (cadmium, lead, mercury, chromium, copper and zinc). The results of the present study show the beginning of nutrient enrichment of the water bodies of the bay, especially the stations located near the urban area, where 1.83 mg l−1 of nitrates, 0.37 mg l−1 of phosphate and 7.42 μg l−1 of chlorophyll (a) were recorded. For the sediment, the maximum concentrations of metallic trace elements were recorded in the station near the harbour basin. These results allowed to establish a quality grid for the waters of the bay, generally qualified as “Good”, except for the sites located near the urban area for which the quality is qualified as “Average”. The sediment quality of the bay was assessed according to the criteria established by the Canadian Council of Ministers of the Environment. The levels of metallic trace elements remain below the toxicity thresholds, except for the sediments taken from the harbour basin.
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Verhaverbeke, Steven. "Cleaning of Trace Metallic Impurities from Solid Substrates Using Liquid Media." In Handbook for Cleaning/Decontamination of Surfaces, 485–538. Elsevier, 2007. http://dx.doi.org/10.1016/b978-044451664-0/50015-2.
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Radi, Mohamed, Abdelilah Meddich, Elmehdi Ouatiki, Lahcen Ouahmane, Mohamed Hafidi, and Abdelkrim Ben Salem. "Effects of Urbanization on the Degradation of the Palm Grove Around the City of Marrakech." In Handbook of Research on Environmental Education Strategies for Addressing Climate Change and Sustainability, 323–37. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-7512-3.ch016.
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The city of Marrakech is experiencing a very significant development in terms of urbanization which leads to a significant reduction of the agricultural activity and increase of the rate of metallic pollution in soils. The impact of this metallic pollution on the microbial activity in these soils can negatively affect the growth and the development of the date palm (Phoenix dactylifera L). In addition, the urbanization has direct effects on the degradation of palm groves in the Marrakech region, following a decrease in agricultural and forestry productivity after anthropogenic activities which are at the origin of high metallic trace element (MTE) contents in soils. In order to assess the impacts of this pollution, the authors carried out a study in the rhizospheric soils of the date palm (Phoenix dactylifera L) monitoring the levels of heavy metals (Pb, Zn). Eight sites were chosen: five urban sites (three gardens, two boulevards) and two peri-urban sites (palm groves).
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Hernandez-Avila, Juan, Edgar Omar Serrano-Mejía, Eleazar Salinas-Rodríguez, Eduardo Cerecedo-Sáenz, María Isabel Reyes-Valderrama, María del Pilar Gutiérrez-Amador, and Ventura Rodríguez-Lugo. "Use of Porous no Metallic Minerals to Remove Heavy Metals, Precious Metals and Rare Earths, by Cationic Exchange." In Trace Metals in the Environment - New Approaches and Recent Advances. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.88742.
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This chapter is related with the preliminary study of some non-metallic minerals to evaluate their cationic exchange capacity, to remove heavy and precious metals, as well as rare earths elements. The minerals and materials used to execute the ion metals removal were bentonite, phosphorite, and diatomite. The chapter shows the physicochemical behavior of all these minerals, which were used to remove the mentioned elements from solutions coming from ore leaching. It was found that in all cases, the removal of heavy and precious metals, as well as rare earths elements reached over 90%. Although, there were minimal differences in efficiency for all minerals used (bentonite, phosphorite, and diatomite), it could be pointed that the phosphorite has the best results going from 99.43% of removal of Gd, to 99.95–100% for the case of Ce, Nd, La, Yb, Eu, Er, Sm, Tb, Ge, Pd, Pt, and Au.
Conference papers on the topic "Metallic/trace"
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Lee, Aaron, Bernice Zee, and Fang Jie Foo. "Metallic Trace Contaminant Detection Using SEM/EDX." In 2019 IEEE 26th International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA). IEEE, 2019. http://dx.doi.org/10.1109/ipfa47161.2019.8984856.
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Lee, Hyung Woo, Soo Hyun Kim, Yoon Keun Kwak, and Chang Soo Han. "A New Method for a Single Semi-Conducting Nanotube Device." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61602.
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We report a new technology for the selective deposition of a semi-conducting single-walled carbon nanotube(SWNT) between two electrodes. This technology consists of two processes. First, to separate the most of metallic nanotubes from semi-conducting ones and align the nanotubes, we applied dc and ac voltage to the electrodes respectively. But, in spite of the separation of the metallic nanotubes from semi-conducting nanotubes, some of metallic nanotubes and semi-conducting nanotubes are still deposited together. The second process is to burn the metallic and semi-conducting nanotubes by applying the voltage between two electrodes which enable to obtain a single semi-conducting nanotube structure. We verified the trace of the burning by SEM images or AFM images, and checked the characteristic of semi-conducting nanotubes through the I-V characteristic graph.
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Liang, Xingyu, Yu Chen, Lihui Dong, and Chonglin Song. "Investigation on Amorphous Particles Evolution of the Diesel Engine." In ASME 2012 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ices2012-81054.
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Analysis of the changes in mass and size of particles formed during the diesel combustion process, the morphological characteristics, and the trace elements within these amorphous particles was carried out using a total cylinder sampling system installed on a direct injection diesel engine. Utilizing field emission transmission electron microscope technology, the results showed that the amorphous particles formed during the combustion process were abundant in metallic and non-metallic elements mainly derived from the lubrication oil, which was found to have entered the combustion process, oxidized and combusted, further increasing the absorbed carbon particles during the later stages of combustion.
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Vu, Trinh, Highqueen Sarpomah, Michael Kamen, Tolessa Deksissa, and Jiajun Xu. "Nanoparticles Infused Mesoporous Material for Water Treatment Processes." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-70475.
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In current study, a hybrid mesoporous material infused with metallic oxide nanoparticles, MCM-48 with TiO2 nanoparticles, has been developed for potential application in water treatment. Using this unique hybrid structure, it can combine the advantages of the effective pollutants removal capability of metallic oxide nanoparticles, and the strong yet high permeable structure of mesoporous material. A modified hydrothermal method has been developed to synthesize three hybrid samples with TiO2 nanoparticles of three assorted sizes (15, 50 and 300nm), and their structure have also been characterized. The synthesized samples are tested for its capability of removing organic dye and trace metals using ICP-MS. The results have shown that while all three hybrid materials have shown over 80% adsorption rate for organic dye, the sample synthesized using 300nm TiO2 nanoparticle has shown the highest adsorption rate. Similarly, the highest adsorption rate for most trace metals test here also occurs in the sample made with 300nm TiO2 nanoparticle. Coincidentally, the sample prepared with 300nm TiO2 nanoparticle has a much larger internal surface area and smaller average pore size compared to the two other samples, which may lead to the higher adsorption rate of trace metals and organic dye tested here. This study has presented a hybrid mesoporous material that can be potentially used for pollutants removal of water treatment. Future studies are still needed to fully explore this hybrid material and its capability in water treatment.
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Adams, Sarah M., and Regina Ragan. "Gold Nanoparticle Self Assembly on Diblock Copolymers for Application as Biomolecular Sensors." In ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13126.
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Current efforts in medical diagnostic technology focus toward developing biological sensors with the capacity for detecting trace quantities of specified organic molecules. In this study, metallic nanoparticles were investigated for the development of field-enhanced chemical and biological detection devices with the capacity to achieve single-molecule level detection resulting from surface enhanced Raman scattering (SERS) associated with closely spaced noble metal nanostructures.[1, 2] Localized surface plasmon resonance (LSPR) sensors likewise benefit from the incorporation of ordered metal nanoparticles on surfaces, providing increased shift in minimum of reflectivity with biological binding event (figure 1).[3]
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Xu, Jiajun. "Assessment and Characterization of Hybrid Mesoporous Material MCM With Titanium Dioxide for Water Treatment." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-12272.
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Abstract In the current study, a new method was developed to synthesize the hybrid mesoporous material with metallic oxides, MCM-48 with TiO2, at an improved efficiency and reduced cost. The results have shown an over 95% adsorption efficiency for trace metals for the hybrid MCM-48 with TiO2 materials, and a significantly improved maximum adsorption capacity compared to pure MCM-48. Its unique hybrid structured allows the polluted water to pass through the strong yet highly permeable structure of mesoporous material, while gives enough time for the pollutants to react with the TiO2 infused on the porous structure so that the polluted water can be treated without introducing secondary pollutants. The microstructures of the MCM-48 with and without TiO2 are characterized using SEM with EDS and Porosimiter. The effectiveness of wastewater treatment is measured using Inductively Couple Plasma-Mass Spectrometer (ICP-MS). The significant improvements observed here is likely due to the infused TiO2 to the base MCM-48 structure, which also agree with the authors’ previous finding. It is noticed that, while the higher concentration of TiO2 has a positive impact on the adsorption of trace metals, the higher concentration of Ti source does not necessarily yield significantly higher concentration of TiO2 in the final product. Future study is needed to further explore this hybrid mesoporous material for other pollutants treatment, and to obtain a further understanding of its mechanisms.
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Robertson, Daniel, Stephen Burnley, and Rod Barratt. "The Immobilisation of Flue Gas Treatment Residues Through the Use of a Single Staged Wash and Crystalline Matrix Encapsulation (CME) Treatment Process." In 11th North American Waste-to-Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/nawtec11-1679.
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All incineration and other thermal treatment technologies produce flue gas treatment residues (FGTR) that require specialised treatment and disposal. In the United Kingdom the FGTR arising from municipal solid waste incineration is classified as a hazardous (special) waste. This is primarily due to the irritant properties of chloride, but also due to the content of heavy metals. These wastes must be handled, transported & disposed of in accordance with the Special Waste Regulations 1996 and are disposed into highly engineered landfill sites, which isolate the material from the environment. The low levels of trace elements in the FGTR mean that the recycling of the metallic elements is not economic. Control through stabilisation and encapsulation in a crystalline matrix converts the FGTR primary form from a powder into solid block form. The use of a novel metal matrix encapsulation (MME) process allows low level engineering processes to be employed, increasing a range of reuse options combined with long-term improved storage.
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Wei, Hsiu-Ping, Ming-Chih Yew, Chao-Jen Huang, and Kuo-Ning Chiang. "Failure Mode and Thermal Performance Analysis of Stacked Panel Level Package (PLP)." In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33368.
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In this paper, a new packaging technology, chip-on-metal (COM) panel level package (PLP), with stacking and fan-out capabilities is proposed. Moreover, the concept of the COM PLP and the process of its fabrication are described. During the manufacturing process, the trench around the chip is filled with the filler polymer material. Therefore, the solder bumps could be located on both the filler polymer and the chip surfaces by the redistribution lines, and the pitch of the chip side is fanned-out. In our previous research, it was shown that the physical behavior of the COM PLP is different from that of the conventional wafer level package (WLP). To assess the thermal performance and thermo-mechanical characteristic of the proposed PLP, the finite element analysis (FEA) in board level is carried out. The junction temperature and thermal resistance of the COM PLP and the stacked PLP are discussed to study the thermal performance. At the same time, the mean cycle to failure of the solder joints is predicted, and the result shows that the reliability of solder joints can be highly improved by the proposed packaging technology. However, the new failure mode may occur at the metallic traces so the reliability assessment of the signal trace is also investigated. In addition, the parametric analysis of the COM PLP is studied to enhance the thermal performance and reliability characteristic. Thus, the PLP technology will have high potential for various applications in the near future.
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Arafat, Haider N., Ali H. Nayfeh, and Char-Ming Chin. "Nonlinear Nonplanar Dynamics of Parametrically Excited Cantilever Beams." In ASME 1997 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/detc97/vib-4028.
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Abstract The nonlinear nonplanar response of cantilever inextensional metallic beams to a principal parametric excitation of two of its “exural modes, one in each plane, is investigated. The lowest torsional frequencies of the beams considered are much larger than the frequencies of the excited modes so that the torsional inertia can be neglected. Using this condition as well as the inextensionality condition, we develop a Lagrangian whose variation leads to the two integro-partial-differential equations of Crespo da Silva and Glynn. The method of time-averaged Lagrangian is used to derive four first-order nonlinear ordinary-differential equations governing the modulation of the amplitudes and phases of the two interacting modes. The modulation equations exhibit the symmetry property found by Feng and Leal by analytically manipulating the interaction coefficients in the modulation equations obtained by Nayfeh and Pai by applying the method of multiple scales to the governing integro-partial-differential equations. A pseudo arclength scheme is used to trace the branches of the equilibrium solutions and an investigation of the eigenvalues of the Jacobian matrix is used to assess their stability. The equilibrium solutions experience pitchfork, saddle-node, and Hopf bifurcations. A detailed bifurcation of the dynamic solutions of the modulation equations is presented. Five branches of dynamic (periodic and chaotic) solutions were found. Two of these branches emerge from two Hopf bifurcations and the other three are isolated. The limit cycles undergo symmetry-breaking, cyclic-fold, and period-doubling bifurcations, whereas the chaotic attractors undergo attractor-merging and boundary crises.
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Zhou, Qixin, and Yechun Wang. "Flow Accelerated Degradation of Corrosion Protective Organic Coatings." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63727.
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Water percolation into coating-metal interface is usually the main cause for the deterioration of corrosion protective property of organic coatings, which leads to coating delamination and under film corrosion. Recently, flowing fluid has received attention due to its capability to accelerate the degradation of materials. A plethora of works have focused on the corrosion of metallic materials accelerated by the flow of working fluids, while few studies have investigated the flow accelerated degrading behavior of organic coatings. For organic coatings, flowing fluid above the coating surface affects corrosion by enhancing the water percolation and by abrading the surface due to wall shear stress. Hence, it is of great importance to understand the influence of flowing fluids on the degradation of corrosion protective organic coatings. In this study, a commercially available epoxy based clear coating and pigmented marine coating were exposed to the laminar flow as well as stationary immersion. The laminar flow was pressure driven and confined in a newly designed flow channel. A 3.5 wt% sodium chloride solution was employed as the working fluid with a variety of flow rates. The corrosion protective properties of organic coatings were monitored inline by Electrochemical Impedance Spectroscopy (EIS) measurement. Equivalent circuit models were employed to interpret the EIS spectra. The time evolution of coating resistance and capacitance obtained from the model was studied to demonstrate the coating degradation. Thickness, gloss, and other topography characterizations were conducted to facilitate the assessment of the corrosion. The immersing solutions were measured by pH and conductivity meters as well as Fourier Transform Infrared Spectrometer (FTIR) to trace coating degradation products as they leached out from the coating. Initial attempts to acquire acceleration factors and predict service lifetime of organic coatings were also conducted.