No description available.

No description available.

Offshore solutions for container infrastructure such as Sea Technologies' floating container terminal can bring both environmental benefits and transport efficiencies for shipping.Large investment costs and requirements for long-term operational reliability for such structures entail the need for long technical service life. Several factors affect and limit the service life of marine structures, including fatigue and corrosion. The container terminal in question is in this context, marine structures, exceptionally large. This means that conventional maintenance of marine structures is not directly applicable and thus noticeable affect complexity of maintenance of the structure. In this work, factors that affect the technical service life and approaches to remedy these factors are investigated for marine structures in general and Sea Technologies' floating container terminal in particular. The purpose of the work has been to investigate possible approaches and technical solutions to meet a technical lifespan of 60 years. This has been done according to methodology from systems engineering with information and facts from studies of technical literature, industry publications and meetings and conversations with industry experts. The work has been limited to a literature study and conversations with experts within the time frames for a master's thesis. Areas affected by the work are corrosion, fatigue and underwater fouling. Lifelimiting factors have been identified in relation to its potential service life impact and maintenance complexity. Furthermore, requirements from stakeholders have been identified in accordance with the engineering of the system. Based on this, possible methods for meeting a life expectancy of 60 years have been investigated. The methods examined can be divided into three categories. These are, design measures, construction measures and maintenance measures. The possible measures examined have been compiled into a collection of recommended measures based on its technical functionality, estimated cost and fulfilment of stakeholder requirements. In summary, the report demonstrates that corrosion and corrosion protection are the most important factor in enabling long service life for this marine structure, both in terms of structural integrity and reliability of operations. Methods for corrosion protection and corrosion control recommended in the report are generally coating systems with extraordinarily long lifespans. Furthermore, a long technical life, also places demands for efficient and functional maintenance. The work therefore also presents recommendations on procedures for efficient maintenance, including the implementation of risk-based inspections and maintenance as well as technical solutions for systematisation and automation of inspections. / Offshore lösningar för containerinfrastruktur såsom Sea Technologies flytande containerterminal kan medföra både miljövinster och transporteffektiviseringar för sjöfarten. Stora investeringskostnader och krav på lång operativ pålitlighet för sådana strukturer innebär behovet för lång teknisk livslängd. Flera faktorer påverkar och begränsar livslängden för marina konstruktioner, däribland utmattning och korrosion. Containerterminalen som avses är i sammanhanget marina konstruktioner, exceptionellt stor. Detta innebär att konventionellt underhåll av marina strukturer inte är direkt tillämpbart och därmed påtaglig komplexitet i underhåll av strukturen. I detta arbete utreds faktorer som påverkar teknisk livslängd tillvägagångssätt för avhjälpning av dessa faktorer för marina strukturer i allmänhet och Sea Technologies flytande containerterminal i synnerhet. Syftet med arbetet har varit att undersöka möjliga tillvägagångsätt och tekniska lösningar för att tillgodose en teknisk livslängd på 60 år. Detta har gjorts enligt metodik från systems engineering med information och fakta från studier av teknisk litteratur, branschpublikationer och moten och samtal med branschexperter. Arbetet har avgränsats till en litteraturstudie och samtal med experter inom tidsramarna för ett examensarbete på masternivå. Områden som berörs i arbetet är korrosion, utmattning och undervattensbeväxning.  Livslängdsbegränsande har faktorer angivits i förhållande till dess potentiella livslängdspåverkan och underhållskomplexitet. Vidare har krav från intressenter identifierats i enlighet med sytems enginnering. Baserat på detta har därefter möjliga metoder för att tillgodose en livslängd på 60 år undersökts. Metoderna som undersöks kan delas in i tre kategorier. Dessa är, designåtgärder, konstruktionsåtgärder och underhållsåtgärder. De möjliga åtgärder som undersökts har sammanställts till en samling rekommenderade åtgärder baserat på dess tekniska funktionalitet, uppskattade kostnad och uppfyllande av intressenters krav.  Sammanfattningsvis påvisas det i rapporten att korrosion och korrosionsskydd är den viktigaste faktorn för att möjliggöra lång livslängd både med avseende på strukturell integritet och pålitlighet i verksamhets drift. Metoder för korrosionsskydd och korrosionskontroll som rekommenderas i rapporten är generellt färgsystem med extraordinärt långa livslängder. Vidare ställer även lång teknisk livslängd, krav på effektivt och funktionellt underhåll. I presentationen presenteras därför även rekommendationer på tillvägagångssätt för effektivt underhåll, bland annat implementering av risk baserade inspektioner och underhåll samt tekniska lösningar för systematisering och automation av inspektioner.

No description available.

Microbial fuel cells (MFCs) are potentially advantageous as an energy-efficient approach for wastewater treatment. Integrating membrane filtration with MFCs could be a viable option for advanced wastewater treatment with a low energy input. Such an integration is termed as membrane bioelectrochemical reactors (MBERs). Comparing to the conventional membrane bioreactors or anaerobic membrane bioreactors, MBER could be a competitive technology, due to the its advantages on energy consumption and nutrients removal. By installing the membrane in the cathodic compartment or applying granular activated carbon as fluidized bed materials, membrane fouling issue could be alleviated significantly. In order to drive MBER technology to become a more versatile platform, applying anion exchange membrane (AEM) could be an option for nutrients removal in MBERs. Wastewater can be reclaimed and reused for subsequent fermentation use after a series MFC-MBR treatment process. Such a synergistic configuration not only provide a solution for sustainable wastewater treatment, but also save water and chemical usage from other non-renewable resource. Integrating membrane process with microbial fuel cells through an external configuration provides another solution on sustainable wastewater treatment through a minimal maintenance requirement. / Ph. D.

Membrane technology has been used in water purification for decades. However, membrane fouling remains a limiting factor. One way to control fouling is through surface modification. Several studies report that increasing surface hydrophilicity can reduce membrane fouling. Surface modification via physical coating (i.e., thin-film composite membrane) was explored in this research to prevent membrane fouling. Before making thin-film composite membranes, it was important to study structure/property relations in a series of potential coating materials. This research aims to contribute to a better fundamental understanding of the structure/property relations which govern water transport, rejection of model foulants (i.e., emulsified oil droplet or protein), and fouling characteristics in hydrogels based on poly(ethylene glycol) diacrylate (PEGDA) and N-vinyl-2-pyrrolidone (NVP). Crosslinked poly(ethylene glycol) (PEG) free-standing films were prepared by UV-induced photopolymerization of PEGDA crosslinker in the presence of varying amounts of water or monofunctional poly(ethylene glycol) acrylate (PEGA). The crosslinked PEGDA films exhibited polymerization induced phase separation (PIPS) when the water content of the prepolymerization mixture was greater than 60 wt%. Visible light absorbance measurements, water uptake, water permeability, and salt kinetic desorption experiments were used to characterize the structure of these phase-separated, crosslinked hydrogels. The films with PIPS exhibited a porous morphology in cryogenic scanning electron microscope (CryoSEM) studies. Dead-end filtration experiments using deionized water and bovine serum albumin (BSA) solutions were performed to explore the fundamental transport and fouling properties of these materials. The total flux of pure water through the films after prior exposure to BSA solution was nearly equal to that of the as-prepared material, indicating that these PEGDA films resist fouling by BSA under the conditions studied. Crosslinked NVP free-standing films were prepared by UV-induced photopolymerization in the presence of water, with NVP as the monomer and N,N’-methylenebisacrylamide (MBAA) as the crosslinker. A series of crosslinked films were polymerized at various prepolymerization water contents, NVP/MBAA ratios and at various levels of UV light intensity in the polymerization. Like PEGDA, the NVP films also underwent phase-separation during polymerization. The influence of monomer/ crosslinker ratio, prepolymerization water content, and UV intensities on membrane morphology and water transport was characterized with CryoSEM, bio-atomic force microscope (Bio-AFM) and dead-end filtration. Molecular weight cutoff (MWCO) measurements were used to characterize the sieving property of crosslinked NVP films polymerized at different UV intensities. UV intensity was found to have an impact on the interconnectivity of crosslinked membranes. Finally, tests of fouling resistance to protein solution (bovine serum albumin) and oily water emulsion were performed. The NVP crosslinked films had good protein and oily water fouling resistance. Overall, both crosslinked PEGDA and NVP films exhibit fouling resistance to oily water emulsions or protein solution. NVP films had more porous structure and higher water permeability than did PEGDA films, while the more compact structure of PEGDA films led to better rejection of model foulants (e.g., protein) than in NVP films. Based on different applications (e.g., oil/water separation, protein filtration), different coating materials must be chosen according to the membrane morphology, transport property, and rejection of model foulants to achieve the highest water flux and foulant rejection in membranes used for water purification. / text

Anodiseringsanläggningar förbrukar stora mängder elektricitet som omsätts i värme. Samtidigt kräver processen en konstant temperatur på cirka 20 °C för att ytskiktet som bildas ska hålla en jämn kvalitét. Nedkylningen av baden är därför kritisk och där finns möjligheter att effektivisera ur ett energi och tillförlitlighetsperspektiv. Genom att få bättre kännedom om processen kan kostsamma produktionsavbrott undvikas samtidigt som möjligheten att optimera parametrarna för energiåtervinningen kan undersökas. En viktig utmaning är att det med tiden byggs upp beläggningar på plattvärmeväxlarnas ytor, så kallad fouling, som minskar värmeväxlarnas kyleffekt. Studien har därför fokuserat på att mäta och beräkna foulingnivåer för att kunna förutsäga nödvändiga serviceintervaller samt öka tillförlitligheten. Metoden i den här rapporten grundar sig på datainsamling från mätinstrument som registrerar temperaturer och flöden ur produktionssystemet. Den information som samlats in har därefter att analyseras statistiskt och matematiskt. Resultatet visar att det går att följa systemets utveckling antingen med hjälp av filtrerade medelvärden och styrdiagram, eller genom att anpassa matematiska funktioner härledda ur teorin. Fördelen med att anpassa funktioner är att dessa kan användas för att extrapolera systemets k-värden i framtiden. Vidare föreslås möjliga åtgärder för att förebygga fouling i framtiden.

The marine surface-associated bacterium Pseudoaltermonas tunicata, produces a range of compounds that inhibit fouling organisms, including invertebrate larvae, bacteria, algal spores and fungi. In addition to these antifouling compounds P. tunicata cells produce both a yellow and a purple pigment. The aim of this study was to further characterise the antifouling activities, their regulation and relationship with pigmentation, and the ecological significance of P. tunicata and related organisms. It was discovered that the anti-algal compound was extracellular, heat sensitive, polar and between 3 and 10 kDa in size. The anti-fungal compound was found to be the yellow pigment and active against a wide range of fungal and yeast isolates. Chemical analysis suggests that this compound consists of a carbon ring bound to a fatty-acid side chain. Genetic analysis supports the chemical data for the active compound as a mutant in a gene encoding for a long-chain fatty-acid CoA ligase was deficient for anti-fungal activity. To address the regulation of antifouling compounds and their relationship to pigmentation transposon mutagenesis of P. tunicata was performed. Mutants lacking the yellow pigment displayed a reduced ability to inhibit fouling organisms. Further analysis of these mutants identified genes involved with the synthesis and regulation of synthesis of pigment and antifouling compounds. One of these mutants was disrupted in a gene (wmpR) with similarity to the transcriptional regulators ToxR from Vibrio cholerae and CadC from Escherichia coli. Analysis of global protein expression using two-dimensional gel electrophoresis showed that WmpR is essential for the expression of at least fifteen proteins important for the synthesis of fouling inhibitors. The ecological significance of antifouling bacteria was addressed by assessing the antifouling capabilities of a collection of bacteria isolated from different marine surfaces. Overall, isolates from living surfaces displayed more antifouling traits then strains isolated from non-living surfaces. Five dark-pigmented strains originating from the alga Ulva lactuca were further studied. Phylogenetic and phenotypic analysis revealed that they were all members of the genus Pseudoalteromonas and were closely related to P. tunicata. Two strains represented a novel species within the genus and were taxonomically defined as P. ulvae sp. nov.

Title: Thin films of plasma polymers as stable supports for biomedical applications Author: Ivan Gordeev Institute: Charles University in Prague, Department of Macromolecular Physics Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, Ph.D, Charles University in Prague, Department of Macromolecular Physics. Abstract: Plasma polymers have been widely considered for use as bio-active coatings. In biomedicine, the surfaces that withstand accumulation of biofilms are of particular importance. This thesis is focused on development of new plasma-based methods for deposition of bio-resistant (non-fouling) plasma polymers. Poly(ethylene oxide) was the subject material. R.f. magnetron sputtering, plasma-assisted thermal vapour deposition and amplitude modulated atmospheric pressure surface dielectric barrier discharge were the methods adapted to fabricate thin films with tunable chemical composition, cross-link density and biological response. A new insight was gained into the processes of plasma polymerization as well as into composition/structure relationship and its effect on biological properties of resultant films. Keywords: plasma polymerization, PEO, 'non-fouling' properties, protein adsorption, cell adhesion

Terminais portuÃrios adicionam estruturas artificiais ao ambiente marinho propiciando o estabelecimento de organismos epibÃnticos nativos e espÃcies exÃticas devido à intensa circulaÃÃo de navios. O presente estudo caracterizou e comparou a composiÃÃo especÃfica e a distribuiÃÃo batimÃtrica da malacofauna associada aos pilares dos terminais portuÃrios do PecÃm e do Mucuripe - CearÃ, Brasil, a fim de verificar a ocorrÃncia de espÃcies exÃticas. Foi avaliada tambÃm a estrutura populacional do bivalve invasor Isognomon bicolor em ambos os portos. As coletas da malacofauna foram realizadas por meio de mergulho autÃnomo e mÃtodo destrutivo. A amostragem foi feita entre 0-5 metros de profundidade, espaÃadas em 1 metro. Foram coletadas 41 espÃcies de moluscos sendo 35 nativas, cinco criptogÃnicas e uma exÃtica. As maiores densidades foram registradas para Petaloconchus aff. varians, Isognomon bicolor, Lithophaga bisulcata, Crassostrea rhizophorae e Sphenia antillensis. Em ambos os portos, houve maior densidade mÃdia de moluscos no primeiro metro, bem como de I. bicolor. Nenhum dos portos demonstrou diferenÃa significativa dos descritores de comunidade em relaÃÃo à orientaÃÃo das faces nos pilares (interna e externa). No primeiro metro, foram observados os indivÃduos de I. bicolor de menor tamanho da concha. Esta distribuiÃÃo dos organismos pode provavelmente ser determinada pelo assentamento larval diferencial ao longo dos pilares e tambÃm a faixa em que I. bicolor està mais adaptado fisiologicamente. Estudos sobre estas comunidades sÃo de grande importÃncia para o monitoramento de regiÃes portuÃrias e o diagnÃstico precoce de espÃcies potencialmente invasoras. / Ports add artificial structures to the marine environment giving the establishments of natives epibenthics organisms and exotics species due to intense ship traffic. The present study classifies and compared the specific composition and bathimetric distribution of molluscs faune associated to the ports pillars of PecÃm and Mucuripe â CearÃ, Brasil, wanting to check the ocorrence of exotic species. It was also evaluated the population structure of the bivalves Isognomon bicolor invaders on both ports. The gathering of mollusc faune was possible through the autonomous diving and destructive method. The sample was made between 0-5 meters of depth, with space of 1 meter. 41 species of molluscs were gathered, being 35 natives, 5 criptogenic and 1 exotic. The highest densities were registered to Petaloconchus aff. Varians, Isognomon bicolor, Lithophaga bisulcata, Crassostrea rhizophorae and Sphenia antillensis. On both ports, there was a medium density of molluscs in the first meter. Neither of the Ports showed significant difference from communities descriptors related to the orientation of the pillarâs faces. Considering the bathimetric of I. bicolor on PecÃm Port, it was verified a predominance of these bivalves in the first meter of pillars. This organismâs distribution might be determinate on pillars by differential larval settlement on pillars length and also the range in which I. bicolor is more physiologically adapted. Studies about these communities are of great importance to the monitoring of portuaries regions and the early diagnoses of potentially invasive species.