Η παρούσα διπλωματική εργασία πραγματεύεται την αυτοματοποίηση του βιολογικού σταθμού καθαρισμού της εταιρείας «Αλουμίνιον της Ελλάδος», από τη μελέτη του αυτοματισμού μέχρι και την υλοποίησή του. Η εργασία αυτή εκπονήθηκε στην εταιρεία «Αλουμίνιον της Ελλάδος» στα Άσπρα Σπίτια Βοιωτίας. Σκοπός είναι ο εκσυγχρονισμός του βιολογικού σταθμού της εταιρείας, ώστε η λειτουργία του σταθμού να είναι πλήρως αυτοματοποιημένη και ελεγχόμενη από το σύστημα του αυτοματισμού πέρα από τον ανθρώπινο έλεγχο. Αρχικά μελετήθηκε ο τρόπος λειτουργίας του βιολογικού σταθμού ώστε να γίνει ο προγραμματισμός του αυτοματισμού που θα ελέγχει τη λειτουργία του. Στη συνέχεια δημιουργήθηκε ένας βασικός προγραμματισμός ώστε όλος ο αυτοματισμός να ακολουθεί ένα μοτίβο για πιο εύκολη κατανόηση και έλεγχο του προγράμματος του αυτοματισμού. Επιπρόσθετα καταγράφηκε το υλικό προς αυτοματοποίηση του σταθμού και οι είσοδοι και έξοδοι του προγράμματος. Σε αυτό το βήμα το τελικό στάδιο περιλάμβανε την κατάρτιση του προγράμματος λειτουργίας του αυτοματισμού. Το επόμενο βήμα ήταν να εγκατασταθεί ο εξοπλισμός του υλικού και να γίνουν οι κατάλληλες συνδέσεις των συσκευών στην κεντρική μονάδα επεξεργασίας του ελεγκτή(PLC). Τέλος σχεδιάστηκε η απεικόνιση της εγκατάστασης σε σύστημα SCADA και έγιναν οι απαραίτητες συνδέσεις του συστήματος αυτοματισμού με το πρόγραμμα SCADA ώστε να είναι δυνατή η απεικόνιση της λειτουργίας του βιολογικού σταθμού σε πραγματικό χρόνο καθώς και ο έλεγχος ή τροποποίησή της. / The following dimploma thesis deals with the automation of the biological purification station of the company “Aluminium of Greece”, starting from the study of the automation to its implementation. This thesis was developed at the facilities of “Aluminium of Greece”, in Aspra Spitia Voiotias. Its purpose is the modernization of the biological purification station, in order of a fully automated function as well as controlled by the automation system beyond the human control. Initially, the function of the biological purification station was analyzed to help programming the automation system, that controls its function. The next step was the creation of a basic program to be used as a pattern for the whole automation. The result was to be easier to understand, control and fix any problem of the automation program. Subsequently, all the devices to be connected to the automation system were recorded and a list of inputs and outputs was created. The final stage of this step consisted of creating the full program of the automation.. Thereafter the required equipment was installed and all the devices to be automated were connected to the programmable logic controller (PLC). Finally, the display of the installation was designed in a SCADA system and all the necessary connections of the SCADA system with the facility were made. With the completion of this step the engineer is now able to watch the function of the biological purification station in real time, control it and make all the necessary modifications if required.

Resumo: A cultura do arroz no Brasil apresenta baixa produtividade de grãos tendo entre as várias causas, o cultivo em solos de baixas fertilidades com altos níveis de alumínio tóxico na solução e o baixo uso de insumos agrícolas, sendo incipiente os estudos sobre o desenvolvimento do sistema radicular de cultivares de arroz associados aos grupos comerciais moderno, intermediário e tradicional. Em função do exposto, o presente trabalho objetivou estudar as respostas de cultivares de arroz, quanto ao crescimento radicular, desenvolvimento da parte aérea e a nutrição das plantas sob diferentes níveis de alumínio em solução nutritiva. O experimento foi conduzido em solução nutritiva em condições de casa-devegetação, no Departamento de Produção Vegetal da FCA/UNESP, Câmpus de Botucatu, no ano de 2005. O delineamento experimental utilizado foi inteiramente casualizado com quatro repetições, seguindo um modelo fatorial 3x4, com três cultivares de arroz (BRS Talento, Caiapó e Primavera) e quatro níveis de alumínio na solução nutritiva (0,0; 10,0; 20,0 e 40, 0 mg L-1). Pelos resultados obtidos concluiu-se que, a cultivar Primavera é mais tolerante á toxidez de Al3+, enquanto BRS Talento e Caiapó são mais sensíveis à toxicidade de Al3+, o sistema radicular, a massa seca das raízes, da parte aérea e total são bons indicadores de tolerância ao Al3+, níveis tóxicos de Al3+, interferem no transporte de P, K, Ca, Mg e Mn para a parte aérea, o P, Mg e Mn são os nutrientes menos acumulados pelo arroz sob estresse de Al3+, a eficiência de absorção do sistema radicular fica comprometida pelo estresse de Al3+, principalmente para o P e Mg. / Abstract: The rice field in Brasil show low yields having many factors affecting as planting in soil with low fertility with high levels of toxic aluminum and low use of tecnology and fertilizer, being incipient the studies about the development of radicular system of rice cultivars to the modern, intermediate and tradicional groups. This work objected to study rice cultivars response for root growth, vegetative parts development and nutrition of plants submitted to different levels of aluminum in nutritive solution.The experimente was conduct in nutritive solution inside the greenhouse at the Departament of Vegetal Production on FCA/UNESP , Botucatu Campus, in 2005.The experimental design used was completelly randomized with four replications, 3x4 factorial design, with three rice cultivars(BRS Talento, Caiapó and Primaera) and four aluminum levels on nutritive solution (0,0, 10,0, 20,0 e 40,0 mg L-1. Results showed that the cultivar Primavera is more tolerant to Al+3 toxicity, while BRS Talendo and Caiapó are more sensitive. Root system development, root dry matter and vegetative part development are good indicators of Al+3 tolerance. High levels of aluminum interfere P, K, Ca, Mg e Mn transportation to vegetative parts, and P, Mg e Mn are the less acumulative nutrients for rice under Al+3 stress. Absorption of P and Mg by the root system is damage under Al+3 stress. / Orientador: Leandro Borges Lemos / Coorientador: Carlos Alexandre Costa Crusciol / Banca: Maurício Dutra Zanotto / Banca: José Salvador Simoneti Foloni / Banca: José Carlos Feltran / Banca: Sandro Roberto Brancalião / Doutor

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Resumo: Este trabalho está basicamente dividido em duas partes. A primeira está relacionada à limpeza da superfície da liga de alumínio AA6063T5 e sua influência na proteção contra a corrosão. A segunda parte se refere à preparação de revestimentos híbridos orgânicoinorgânico pelo processo sol-gel e deposição sobre a superfície da liga de alumínio por dipcoating. Três amostras de liga AA6063T5 foram investigadas: como recebida, debastada e polida mecanicamente e tratada quimicamente. O tratamento mecânico foi realizado utilizando lixas SiC de granulometria 320 a 4000 e o químico foi realizado utilizando uma solução aquosa contendo uma mistura de hidróxido, sulfato e cloreto de sódio. Todas as amostras foram caracterizadas fisicamente por difratometria de raios X (XRD), medidas de dureza, microscopia eletrônica de varredura (SEM) e microscopia óptica (MO), e por medidas de potencial de circuito aberto (OCP) e espectroscopia de impedância eletroquímica (EIS) em solução 3,5% NaCl. As imagens SEM mostraram que a presença de partícula intermetálicas na superfície da liga diminui após o tratamento químico comparado ao tratamento mecânico. Os resultados de EIS mostraram que o tratamento químico oferece maior resistência à corrosão do que as submetidas aos outros tratamentos, porque o ataque alcalino utilizado dissolveu a maioria dos precipitados contendo Fe ou Cu, elementos responsáveis por sítios catódicos. A lavagem com HNO3 pela qual passou a amostra tratada quimicamente provavelmente reforçou a camada de óxido, tornando a superfície da liga mais resistente ao ataque por cloreto. Os revestimentos híbridos foram somente depositados na liga que recebeu tratamento químico. Esses filmes híbridos foram preparados com tetraetoxi-silano (TEOS) e 3-metacriloxipropril trimetoxi silano (MPTS), pela hidrólise e policondensação em meio ácido seguido por... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work is basically divided in two parts: the first one is related to the surface treatment of AA6063T5 aluminum alloy and its influence on the protection against corrosion. The second concerns to the preparation of organic-inorganic hybrid coatings by the sol-gel process that were deposited on the aluminum alloys by dip-coating. Three samples of AA6063T5 aluminum alloys were investigated, the as-received one, after mechanical and chemical treatment, respectively. The mechanical treatment was realized using SiC paper grades 320 to 4000 and the chemical one was done by an aqueous solution containing a mixture of sodium hydroxide, chloride and sulfate. All samples were physically characterized by X-ray diffractometry (XRD), hardness measurements, scanning electron microscopy (SEM) and optical microscopy (OM), and electrochemically by open circuit measurements (OCP) and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. The SEM images depicted that the presence of intermetallic particles on the alloy surface decreased after the chemical treatment compared to the mechanical one. The EIS results showed that the sample chemically treated possesses a higher corrosion resistance than those obtained using other procedures. EIS results showed that the chemically treated sample presented higher corrosion resistance than the ones submitted to other procedures. The alkaline treatment dissolves the great part of precipitates containing iron or copper, which are responsible by the cathodic sites formation. The washing of the sample with nitric acid solution after the alkaline treatment removes impurities from the surface and can give to the oxide layer higher resistance against the action of the chloride ion. The hybrid coatings were only deposited on the alloy that received the chemical treatment. Hybrid films containing tetraethoxysilane (TEOS) and 3-methacryloxypropyltrimetho... (Complete abstract click electronic access below) / Orientador: Assis Vicente Benedetti / Coorientador: Cecílio Sadao Fugivara / Banca: Celso Valentim Santilli / Banca: Patrícia Hatsue Suegama / Banca: Roberto Garcia / Banca: Adalgisa Rodrigues de Andrade / Doutor

Impact damage resistance is an essential requirement of lightweight structural components for high-performance applications. The aim of this thesis is to study the impact damage and perforation behaviour of lightweight materials including thin aluminium alloy plates and carbon fibre reinforced epoxy composites. The focus of this investigation is on the stress state and strain rate dependence of failure, and the effect of microstructural modifications on indentation and impact response. The thesis is divided into three parts. In the first part (Chapter 2) the impact response of thin monolithic ductile aluminium alloy plates is investigated. Impact perforation experiments are performed using different projectile nose shapes to span a wide range of stress states at the onset of ductile fracture. Impact perforation behaviour, ballistic limit velocity, energy absorption capability and sensitivity to projectile tip geometry are evaluated. Modes of deformation and failure during impact are assessed experimentally. It is shown that modelling the stress state and strain rate dependence of plasticity and failure is crucial to accurately predict ductile fracture initiation in thin metal plates. In the second part (Chapters 3 and 4), the stress state and strain rate dependent yield and failure behaviour of epoxy resin is investigated. An iterative numerical-experimental approach is shown to be essential to develop a material model capable of predicting the failure behaviour of epoxy for a wide range of stress triaxialities across different regimes of failure. The influence of microstructural modifications in epoxy, through two different toughening strategies, on its failure behaviour is investigated. The effect of increasing the applied strain rate on the stress state dependent response of epoxy is investigated to provide an insight into the impact damage resistance of carbon fibre reinforced epoxy composites. In the third part (Chapter 5), experimental studies are conducted on the quasi-static indentation and impact perforation response of plain weave carbon fibre reinforced epoxy composites to investigate the effect of toughening the epoxy matrix to improve resistance to indentation and impact. The nose shape sensitivity of failure initiation in carbon/epoxy composite targets is assessed by considering indenters with different tip geometries. Conclusions and suggestions for future work are presented in Chapter 6.

This PhD thesis is focused on the development of novel catalysis with low-oxidation main group species, mainly based on the group 13 element gallium, a relatively abundant, inexpensive, and low-toxic metal. Gallium in its stable high-oxidation state ‘+III’ is a commonly used Lewis acid catalyst in organic synthesis. In contrast, gallium in its less stable low-oxidation state ‘+I’ is under-explored, but may display both acceptor and donor properties at a single site (ambiphilicity). Based on the hypothesis that potentially ambiphilic gallium(I) –oxidatively generated in situ from gallium(0) using a silver salt– may activate both basic and acidic reagents, various gallium(I)-catalyzed carbon–carbon bond formations have been developed. These include catalytic C–O and C–B bond activations of electrophiles (acetals and aminals) and pro-nucleophiles (allyl and allenyl boronates), respectively. Gallium(III) and other metal Lewis acids have proved to be ineffective. These results represent the first catalytic use of gallium(0) in organic synthesis and a rare example of gallium(I) catalysis. The identity of the gallium(I) catalyst and its regeneration have been confirmed by 71Ga NMR analysis, and a reactive allyl–Ga(I) intermediate has been detected for the first time. In combination with 11B NMR and HRMS analyses, an SN1 reaction mechanism has been proposed. Importantly, the potential for asymmetric gallium(I) catalysis has been demonstrated using a chiral silver co-catalyst (40% ee). This gallium(I) chemistry has proved to be applicable to the catalytic activation of other electrophiles, including ethers or aldehydes, and pro-nucleophiles such as boranes, silanes, or tin-based reagents. Finally, the potential of a related low-oxidation aluminium catalyst has been explored for C–C bond formation.

Organically modified sol-gel coatings have been investigated as potential replacements for chromate conversion coating of AA1050 and AA2024 aluminium alloys. The coatings were prepared by a combination of a completely hydrolysable precursor of tetra-n-propoxyzirconium (TPOZ), with a partially hydrolysable precursor of glycidoxypropyltrimethoxysilane (GPTMS). GPTMS contains organic functional groups, which are retained in the sol-gel coatings after the hydrolysis-condensation process. Different process parameters, e.g. GPTMS/TPOZ ratios, withdrawal speeds, solvent water concentrations, and curing temperatures were studied. Coatings produced using a low GPTMS/TPOZ ratio and a high withdrawal speed generated significant cracks due to the shrinkage of the coatings. It was found that increase of organic moieties reduced the shrinkage of the coatings and the tendency for crack formation. By controlling process parameters and ratios of organic and inorganic moieties, crack-free sol-gel coatings from 0.1 μm to 9 μm thick can be achieved. The sol-gel coatings formed are amorphous and contain organic epoxy-ether retained silicon oxide, silicon hydroxide, zirconium oxide, zirconium hydroxide, and zirconium acetate. The Si/Zr ratios of resultant sol-gel coatings are proportional to the initial GPTMS/TPOZ ratio. Cerium oxide nanoparticles were successfully incorporated into sol-gel coatings with a single layer and double layer sol-gel process. Through the dip coating process, crack-free sol-gel coatings, of varied thickness, were developed on different aluminium substrate, including electropolished superpure aluminium, magnetron sputtered aluminium with varied copper contents from 0 to 30 wt.%, and commercial AA1050 and 2024 aluminium alloys. Sol-gel coatings formed on commercial AA1050 and 2024 aluminium alloys revealed a significant passivation in 3.5 wt.% sodium chloride solution during anodic polarisation when the sol-gel coating is more than 1 µm thick and proper surface pretreatments of the alloys were used. Corrosion tests by immersion in 3.5 wt% sodium chloride solution and by salt spray in 5 wt.% sodium chloride solution revealed that sol-gel coatings successfully protected AA2024 aluminium alloy against the aggressive environment and have the potential to replace chromate containing coating systems.

Cadmium electroplating is widely used in the aerospace industry for the corrosion protection of aircraft components like fasteners manufactured from non corrosion resisting high strength steels. However, environmental and safety concerns over the high toxicity of cadmium and its compounds have led to the investigation of suitable replacements. Alternatives to cadmium should offer effective corrosion protection and have no detrimental effects on the steel substrate. Hydrogen is known to be absorbed during processes like electroplating, thus causing hydrogen embrittlement on high strength steel fasteners. Another source of hydrogen is the water reduction occuring in parallel with the corrosion of the coating, and thus causing re–embrittlement of the steel substrate. This study has investigated the effect of the application of two aluminium–based coatings, SermeTel CR984–LT and Galvano–Aluminium Alcotec, on the hydrogen re–embrittlement of high strength steels used for aerospace applications. Slow strain rate testing has been performed to study the effect of hydrogen on the re–embrittlement of the steel substrate as a result of the corrosion of the aluminium–based coatings in a variety of environments, such as NaCl solution, salt spray and marine atmosphere. Permeation measurements have been used to measure hydrogen uptake by unplated steel membranes potentiostatically charged at the potentials of the aluminium–based coatings, so as to simulate the amount of absorbed hydrogen due to their corrosion. Corrosion tests have been utilised to evaluate the performance of SermeTel CR984–LT and Galvano–Aluminium Alcotec.

The combination of chemotherapy and photodynamic therapy was investigated by synthesis and characterization of octacarboxy phthalocyanine covalent conjugates with platinum complexes. This work presents the synthesis, characterization and photophysicochemical properties of aluminium (diaquaplatinum) octacarboxyphthalocyanine and aluminium (diammine) octacarboxyphthalocyanine. The conjugates were prepared by conjugating aluminium octacarboxy phthalocyanine with potassium tetrachloro platinate to yield aluminium tetrakis and trikis (diaquaplatinum) octacarboxy phthalocyanine. The aluminium octacarboxy phthalocyanine was also conjugated with cis-diamminedichloroplatinum to yield aluminium bis and tris (diaquaplatinum) octacarboxy phthalocyanine. From the characterization of the conjugates it was discovered that the aluminium (diaquaplatinum) octacarboxy phthalocyanine had formed platinum nanoparticles with the Pc acting as a capping agent. The triplet lifetimes decreased with the increasing number of platinum complexesconjugated to the Pc. The heavy atom effect improved the overall photophysicochemical properties.

abstract: The study of response of various materials to intense dynamic loading events, such as shock loading due to high-velocity impacts, is extremely important in a wide variety of military and industrial applications. Shock loading triggers extreme states, leading to high pressures and strain rates, and neglecting strength is a typical approximation under such conditions. However, recent results have shown that strength effects are larger than expected, so they must be taken into account. Recently, hydrodynamic instabilities, the most common being the Rayleigh-Taylor (RTI) and Richtmyer-Meshkov (RMI) instabilities, have been used to infer the dynamic strength of materials at high pressure conditions. In our experiments and simulations, a novel RMI approach is used, in which periodic surface perturbations are made on high purity aluminium target, which was laser ablated to create a rippled shock front. Due to the slow linear growth rate of RMI, the evolution of the perturbations on the back surface of the sample as a result of the rippled shock can be measured via Transient Imaging Displacement Interferometry (TIDI). The velocity history at the free surface was recorded by spatially resolved laser velocimetry. These measurements were compared with the results from the simulations, which were implemented using rate independent and rate dependent material models, to characterize the dynamic strength of the material. Simulations using the elastic-perfectly plastic model, which is rate independent, failed to provide a value of dynamic yield strength that would match experimental measurements of perturbation amplitudes. The Preston-Tonks-Wallace (PTW) model, which is rate dependent model, worked well for aluminium. This model was, in turn, used as a reference for calibrating the rate dependent Steinberg-Lund model and the results from simulations using the calibration models were also compared to experimental measurements. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2017