O anfibolito Cafelândia faz parte da Sequência Serra da Malacacheta, Complexo Barro Alto, GO. Por ser rocha com bandamento composicional bem definido, o anfibolito tem sido interpretado como produto de metamorfismo de gabro acamadado. Entretando, uma das feições que esse bandamento composicional apresenta é a presença de veios de leucossoma paralelos à foliação da rocha. O contato transicional entre o anfibolito e alguns dos veios de leucossoma indicam que os veios foram formados por fusão in situ. O objetivo do presente trabalho é investigar o processo de fusão que afetou a rocha, utilizando descrições macroscópicas, microscópicas e análises químicas de minerais em diversos contextos texturais. O bandamento composicional é definido pela variação na proporção modal de hornblenda, plagioclásio, titanita, clinopiroxênio, granada e quartzo. Veios de leucossoma com porfiroblastos de hornblenda, concordantes ou discordantes da foliação são observados reforçando o bandamento. No topo estrutural do anfibolito ocorrem camadas com mais de 70% de hornblenda e outras dominadas por clinopiroxênio e granada. Ortopiroxênio é raro e não é possível ter certeza se os grãos presentes são reliquiares do protolito ígneo ou se são metamórficos. As camadas ricas em granada e clinopiroxênio não ultrapassam espessuras maiores que 5 a 10 cm. Na porção basal do anfibolito a proporção de hornblenda é menor e a proporção de clinopiroxênio e granada maior, ocorrendo ortopiroxênio em alguns afloramentos. Os porfiroblastos de hornblenda do leucossoma são substituídos por clinopiroxênio e rara granada. Diferenças sutis nas composições dos grãos de hornblenda e clinopiroxênio do anfibolito Cafelândia e do leucossoma ocorrem, mas são mascaradas pela influência da composição da banda na composição dos minerais. De modo geral, a hornblenda no leucossoma é mais rica em Si e Mg do que os grãos da matriz, enquanto o clinopiroxênio do leucossoma é mais rico em Al. Micro-exsoluções no clinopiroxênio do leucossoma também impedem a comparação da sua composição real com os grãos da matriz da rocha. Cálculos termobarométricos foram feitos em amostras do topo e da base estrutural do anfibolito utilizando o termômetro granada-clinopiroxênio e o barômetro granada-clinopiroxênio-plagioclásio-quartzo, além do programa THERMOCALC. A termobarometria convencional fornece valores P-T menores para temperatura e similares de pressão aqueles calculados com o THERMOCALC e não são muito diferentes dos que já foram calculados previamente, com valores para o topo de 870 ºC e 10,9 kbar e para a base de 881 ºC e 9,8 kbar. Se quartzo não é usado nos cálculos P-T, acréscimo de 2 a 3 kbar ocorre nos resultados. Os dados P-T calculados são compatíveis ou algo inferiores aos resultados experimentais de fusão de rochas máficas contendo hornblenda, produção de líquido tonalítico e resíduo contendo clinopiroxênio e granada. A presença de hornblenda dentro do leucossoma do topo da unidade pode estar associada com influxo de H2O no sistema durante a fusão, diferente do que ocorre na base do corpo. É possível que o líquido que se encontrava na porção basal esvai em direção as porções superiores do anfibolito, reidratando a rocha e formando porfiroblastos de hornblenda dentro do leucossoma do topo. Uma conclusão importante tirada aqui é que o protolito do anfibolito Cafelândia pode ser o anfibolito da base da sequência Juscelândia, sobreposta, e que o bandamento composicional foi gerado por metamorfismo, fusão e segregação/perda do liquido e não por metamorfismo de gabro acamadado. / The Cafelândia amphibolite is part of the Serra da Malacacheta sequence, Barro Alto Complex, GO. As it is a rock with well-defined compositional banding, the amphibolite has been interpreted as a product of metamorphism of layered gabbro. However, a feature that reinforces the banding is the presence of leucosome veins, which are mainly parallel to the rock foliation. The transitional contact between amphibolite and some of the veins of leucosome indicate that the veins were formed by in situ melting. The purpose of this study is to investigate the melting process that affected the rock using macroscopic and microscopic descriptions, as well as chemical analysis of minerals in various textural contexts. The compositional banding is defined by variation in modal proportion of hornblende, plagioclase, titanite, clinopyroxene, garnet and quartz. Veins of leucosome with porphyroblasts of hornblende, concordant or discordant to foliation are observed, reinforcing the banding. At the structural top, layers of amphibolite occur with more than 70% of hornblende and others are dominated by clinopyroxene and garnet. Orthopyroxene is rare and its metamorphic origin cannot be assured, being possible that these grains are relicts of the igneous protolith. The garnet and clinopyroxene rich layers do not exceeding thicknesses greater than 5 to 10 cm. In the basal portion hornblende proportion is much smaller, but clinopyroxene and garnet are larger. Orthopyroxene occurs in some outcrops. The porphyroblasts of hornblende from the leucosome are replaced by clinopyroxene and rare garnet. Subtle differences in the composition of the of hornblende and clinopyroxene grains in the Cafelândia amphibolite and leucosome occur, but are masked by the influence of the bulk composition of each band in the composition of minerals. In general, the hornblende in the leucosome is richer in Si and Mg than the matrix grains, whereas the leucosome clinopyroxene is richer in Al. Micro-exsolutions in clinopyroxene in the leucosome also hampers the comparison of its \"real\" composition with the grains of the rock matrix. Thermobarometric calculations were done on samples from the structural top and bottom of amphibolite, using the garnet-clinopyroxene thermometer and garnetclinopyroxene- plagioclase-quartz barometer, besides the THERMOCALC. The conventional thermobarometry provides lower P-T values for temperature and similar pressure to those calculated with the THERMOCALC, and results are not very different from those that have been previously calculated. Results for the top are 870 ºC and 10.9 kbar and for the basis 881 ºC and 9.8 kbar. If quartz is not used in the P-T calculations, raise of 2 to 3 kbar occurs in the results. The calculated P-T data are compatible or something lower than the results of experiments for melting of hornblende-bearing mafic rocks with production tonalitic liquid and clinopyroxene and garnet residue. The hornblende-bearing leucosome of the top of the unit may be associated with influx of H2O in the system during melting, unlike what occurs at the base of the body. It is also possible that the liquid formed in basal portion oozes toward the upper portions of amphibolite, rehydrating it to form the hornblende porphyroblasts within the leucosome. An important conclusion drawn here is that the protolith of amphibolite Cafelândia can be bottom amphibolite of the Juscelândia sequence, which overly the Cafelândia amphibolite, and that the banding was generated by metamorphism, melting and segregation / loss of melt and not by metamorphism of layered gabbro.

Selective electron beam melting (SEBM) is a promising powder bed Additive Manufacturing technique for near-net-shape manufacture of high-value titanium components. An extensive research program has been carried out to characterise in 3D the size, volume fraction, and spatial distribution of the pores in model samples, using X-ray computed tomography (XCT), and correlate them to the SEBM process variables. The average volume fraction of the pores (97.5 %) where fatigue cracks would initiate based on the relative stress intensity factor of all the pores. In contrast, crack growth was found to be insensitive to porosity, which was attributed to the much higher stress concentration generated by the crack in comparison to the pores. Some crack diversion was associated with the local microstructure, with prior β grain boundaries often coincident with crack diversion.

>Magister Scientiae - MSc / The objective of this study is to deduce paternal ancestry using ancestry informative single nucleotide polymorphisms (SNPs) by means of High Resolution Melting (HRM). This was completed by producing a multiplex system that was designed in a hierarchical manner according to the YSNP tree. This project mainly focused on African ancestry and was used to infer paternal ancestral lineages on the Johannesburg Coloured population. South Africa has a diverse population that has ancestral history from across the globe. The South African Coloured population is the most admixed population as it is derived from at least five different population groups: these being Khoisan, Bantu, Europeans, Indians and Southeast Asians. There have been studies done on the Western Cape/ Cape Town Coloured populations before but this study focused on the Johannesburg Coloured population.

Magister Scientiae - MSc (Biotechnology) / The objective of this study is to deduce paternal ancestry using ancestry informative single nucleotide polymorphisms (SNPs) by means of High Resolution Melting (HRM). This was completed by producing a multiplex system that was designed in a hierarchical manner according to the YSNP tree. This project mainly focused on African ancestry and was used to infer paternal ancestral lineages on the Johannesburg Coloured population. South Africa has a diverse population that has ancestral history from across the globe. The South African Coloured population is the most admixed population as it is derived from at least five different population groups: these being Khoisan, Bantu, Europeans, Indians and Southeast Asians. There have been studies done on the Western Cape/ Cape Town Coloured populations before but this study focused on the Johannesburg Coloured population. The first step was to design the multiplex system. This was done by using inhouse SNPs. A total of seven multiplexes were designed and optimised, each consisting of two, three or four different SNPs respectively. A total of 143 saliva and buccal samples were collected from male Johannesburg Coloureds. DNA was extracted from the saliva samples using an optimised organic method. DNA was extracted from the buccal samples using an optimised salting out method. DNA was successfully extracted from 77 of the male samples. A total of 69 samples were screened using Multiplex 1; of the 69 samples 56 samples were successfully screened to infer the paternal lineage of the samples. The results show that the most frequent haplogroup of the Johannesburg male samples was haplogroup CF (39%). The second most frequent haplogroup was haplogroup DE (38%). Under further analysis of haplogroup DE it was seen that 37% of those samples were derived for the haplogroup E1b1b.

A demanda por energia fotovoltaica vem aumentando a razão de mais de 20% ao ano no mercado internacional nos últimos dez anos. O silício com pureza entre 99,999% e 99,99999% é utilizado na fabricação de células fotovoltaicas. O silício metalúrgico tem pureza entre 98,5% e 99%. Este estudo visa investigar o refino a vácuo como um processo alternativo de menor custo para se obter o silício para células fotovoltaicas. Este processo pode remover o fósforo do silício, que é um dos elementos prejudiciais à célula fotovoltaica. Isso permitiria agregar valor à produção brasileira de silício metalúrgico, que alcança um preço de aproximadamente US$2,5 por quilo, enquanto o silício para células fotovoltaicas varia entre US$20 e 60 por quilo. Foram realizados experimentos de fusão em forno de indução a vácuo, variando parâmetros como temperatura, tempo e pressão. O teor de fósforo caiu de 33 ppm para cerca de 0,1 ppm e os resultados foram comparados com um modelo matemático da literatura. Conclui-se que o refino por este processo é tecnicamente viável. / The demand for photovoltaics is increasing at a ratio over 20 % per year in the international market in the last ten years. Silicon with purity of 99.999 % and 99.99999 % is used in the manufacture of photovoltaic cells. The purity of metallurgical silicon is between 98.5% and 99%. This study aims to investigate the vacuum refining process as a lower cost alternative to obtain silicon for photovoltaic cells. This process can remove phosphorus from silicon, which is a harmful element to the photovoltaic cell. This would add value to Brazilian production of metallurgical silicon, that reaches a price of approximately U.S.$ 2.5 per kilogram, while the silicon for photovoltaic cells varies between U.S.$ 20 and 60 per kilo . Melting experiments were performed in a vacuum induction furnace by varying such parameters as temperature, time and pressure. The phosphorus content dropped from 33 ppm to about 0.1 ppm and the results were compared with a mathematical model from literature. It is concluded that refining of this process is technically feasible.

Exhumation of high-pressure and ultrahigh-pressure eclogites in large orogens and associated petrological change during the process remain enigmatic problems. This dissertation examines eclogites from high-pressure (HP) and ultrahigh-pressure (UHP) terranes in the North-East Greenland Eclogite Province, aiming to decipher their metamorphic pressure-temperature (P-T) paths, evaluate spatial variation of P-T paths, and understand petrological changes during the exhumation. Kyanite-bearing UHP eclogites from North-East Greenland contain a peak mineral assemblage of phengite, garnet, omphacite, kyanite, coesite, rutile and probably epidote-group minerals. Thermodynamic modeling with an XRF-derived bulk composition yielded a peak P-T condition of 3.4 GPa and 920 °C. Petrographic textures, such as graphic intergrowth of amphibole and plagioclase, cusps of plagioclase into garnet and quartz, and neoblasts of garnet indicate that the eclogites were partially melted through dehydration melting of phengite and epidote-group minerals. Since thermodynamic modeling could not yield a satisfactory solidus curve, experimental phase relations were considered in interpreting the melting process, and show a near isothermal decompression path across the epidote mineral melting curve. Additional thermodynamic modeling of a symplectite after omphacite, consisting of amphibole, plagioclase and clinopyroxene, yields a P-T condition of ~ 1.2 GPa and 800 °C. Thermodynamic modeling of a melt pocket yields a further P-T constraint of 1.4 GPa and 740 °C. The HP zoisite eclogites from the Storstrømmen shear zone in the Sanddal area preserve partial melting textures both in garnet and in the matrix. The textures include multiphase solid inclusions of albite and K-feldspar in garnet, graphic intergrowth of amphibole and plagioclase, cuspate textures, and leucosome. Thermodynamic modeling combined with mineral composition and modes yielded an exhumation P-T path from subsolidus conditions at ~1.95 GPa and ~670 °C, to ~1.85 GPa and 715 °C at suprasolidus, to ~1.45 GPa and 640 °C. Paragonite, phengite, and amphibole were the major dehydration melted phases along the exhumation path. The HP kyanite eclogite from the Danmarkshavn area contains disequilibrium textures developed during retrograde stages. Petrographic observation documents two groups of textures: a strongly zoned plagioclase (anorthite to andesine) enclosing a poorly developed symplectite of sapphirine + spinel + plagioclase after kyanite, and a less zoned plagioclase (labradorite to andesine) enclosing a fully developed symplectite after kyanite. Thermodynamic modeling of the bulk rock returns a peak P-T condition of 1.9 GPa and 840 °C. Thermodynamic modeling of a symplectite domain yields poor P-T constraints of 0.8 – 1.3 GPa and 700 – 900 °C. Modeling also indicates the plagioclase development would be richer in Ca during decompression while progressive replacement of kyanite induced the plagioclase rim to be less Ca-rich. This study reveals that HP and UHP eclogites may experience partial melting on their exhumation path. Dehydration melting of hydrous minerals (e.g. phengite and zoisite) is the most plausible way in partially melt the eclogites, because of limited amounts of free fluid. The partial melting does not trigger exhumation of the eclogites, but may facilitate the exhumation process. The near-isothermal exhumation path for the UHP terranes suggests that it was initially exhumed through vertical extrusion. Lateral extrusion by the Storstrømmen and Germania Land shear zones is suggested to have further exhumed the HP and UHP rocks, which is analogous to the lateral escape tectonics in the Tibetan Plateau

La fusion laser sélective d’un lit de poudres (Selective Laser Melting – SLM) connait un véritable essor depuis quelques années,notamment en ce qui concerne la production de pièces métalliques. La faible densité des alliages d’aluminium, conjuguée à l’optimisation de conception rendue possible grâce aux procédés de fabrication additive, assure un gain de masse des structures conséquent, ce qui intéresse fortement les industriels des domaines automobile et aéronautique. Cependant, les propriétés finales des pièces aluminium fabriquées par SLM dépendent des nombreux défauts sont générés lors de la fabrication (porosités, fissuration à chaud, état de surface, …). Cette thèse s’intéresse aux moyens de mieux maîtriser ces problèmes en explorant trois axes : Une identification et sélection des méthodes de caractérisations adaptées aux spécificités des matériaux métalliques élaborés par les procédés de fabrication additive « lit de poudre » a été mise en place. Par exemple, la comparaison de différentes méthodes de détermination de la densité relative de pièces nous a permis de montrer les avantages et inconvénients de chacune des techniques employées ; Une étude du moyen de fabrication SLM a mis en évidence l’influence de différents facteurs (flux de gaz, position des éprouvettes sur le plateau de construction, méthodes de dépôt de la poudre) sur les propriétés finales des pièces produites.Ces éléments ont un impact sur la densité des pièces, leurs propriétés de surface et leurs propriétés mécaniques. Nous avons ainsi constaté que la façon de positionner une pièce sur le plateau est une étape de la préparation d’une fabrication à ne pas négliger ; Les études paramétriques menées sur deux types d’alliages d’aluminium, AlSi7Mg0,6 et AM205, ont montré que la composition chimique de l’alliage d’aluminium employé influence de façon non négligeable le jeu de paramètres opératoires à appliquer pour fabriquer une pièce de manière optimale. La densité d’énergie volumique ψ, rapport de la puissance laser avec le produit de la vitesse de lasage, de la distance inter-cordons et de l’épaisseur de couche, est utilisée de façon classique pour l’optimisation des conditions opératoires en SLM. Nos études expérimentales à différentes échelles (1D et3D) ont permis de mettre en évidence les limites de ce critère. La combinaison de ces résultats à la simulation numérique du lasage d’un cordon de poudre a servi de base à la définition d’un premier modèle dont l’objectif sera à terme d’optimiser le choix des paramètres de fabrication. / Interest in selective laser melting (SLM) has been growing in recent years, particularly with regard to the production of metal parts.The low density of aluminum alloys, combined with the possible design optimization enabled by additive manufacturing processes,ensures a significant decrease in the mass of structures which is very interesting for manufacturers in the automotive and aerospaceindustries. However, it is difficult to control the final properties of aluminum parts manufactured by SLM because many defects, suchas porosity, hot cracking, and surface roughness, are generated during the process. To better understand how to optimize theperformance of SLM aluminium parts, several studies were conducted during this work: An identification and selection of characterization methods well-adapted to the specificities of metallic materials developedby powder bed additive manufacturing processes was established. For instance, the comparison of different methods ofdetermining the relative density of parts showed the advantages and disadvantages of each of the techniques; A study of the SLM machine highlighted the influence of various factors (gas flow, positions of specimens on the constructionplate, or methods of depositing the powder) on the final properties of the produced parts. These elements have an impacton the density of the parts, their surface properties, and their mechanical properties. We found that the positioning of a pieceon the tray is a critical step in the preparation of a build that is not to be neglected; Parametric studies carried out on two types of aluminum alloys—AlSi7Mg0,6 and AM205—have shown that the chemicalcomposition of the aluminum alloy used has a significant influence on the set of operating parameters required tomanufacture an acceptable aluminum alloy part. The energy density, ψ, which is the ratio of the laser power to the productof the lasing speed, the hatching distance, and the layer thickness, is conventionally used for the optimization of the operatingconditions in SLM. Our experimental studies performed at different scales (1D and 3D) have shown the limits of this criterion.The combination of these results with the numerical simulation of the lasing of a single powder bead served as a basis forthe definition of an initial model, the final objective of which will be to optimize the choice of manufacturing parameters.

The primary objective of this work is to propose a state-of-the-art physics based multiscale modeling framework for simulating material phase change problems. Both ice melting and copper crystallization problems are selected to demonstrate this multiscale modeling and simulation. The computational methods employed in this thesis include: classical molecular dynamics, finite element method, phase-field method, and multiscale (nano/micro coupling) methods. Classical molecular dynamics (MD) is a well-known method to study material behaviors at atomic level. Due to the limit of MD, it is not realistic to provide a complete molecular model for simulations at large length and time scales. Continuum methods, including finite element methods, should be employed in this case. In this thesis, MD is employed to study phase change problems at the nanoscale. In order to study material phase change problems at the microscale, a thermal wave method one-way coupling with the MD and a phase-field method one-way coupling with MD are proposed. The thermal wave method is more accurate than classical thermal diffusion for the study of heat transfer problems especially in crystal based structures. The second model is based on the well-known phase-field method. It is modified to respond to the thermal propagation in the crystal matrix by the thermal wave method, as well as modified to respond to temperature gradients and heat fluxes by employing the Dual-Phase-Lag method. Both methods are coupled with MD to obtain realistic results. It should be noted that MD simulations can be conducted to obtain material/thermal properties for microscopic and/or macroscopic simulations for the purpose of hierarchical/sequential multiscale modeling. These material parameters include thermal conductivity, specific heat, latent heat, and relaxation time. Other type of interfacial parameters that occur during the phase change process, such as nucleus shape, interfacial energy, interfacial thickness, etc., are also obtained by MD simulation since these have so far been too difficult to measure experimentally. I consider two common phase change phenomena, ice melting and copper crystallization, in this thesis. For the case of ice melting, MD is first employed to study its phase change process and obtain thermal properties of ice and water. Several potential models are used. I conduct simulations of both bulk ice and ice/water contacting cases. It is found that various potential models result in similar melting phenomena, especially melting speed. Size effects are also studied and it is found that the melting time is longer for larger bulk ice segments but that the average melting speed is size dependent. There is no size effect for the melting speed at ice/water interface at the nanoscale if the same temperature gradient is applied. The melting speed of ice should depend on the temperature gradient. To study ice melting at the microscale, the thermal wave model is employed with parameters obtained from MD simulations. It is found that ice melting speed is scale, for both length scale and time scale, dependent. For the case of copper crystallization, an EAM potential is first employed to conduct MD simulations for studying the copper crystallization process at the nanoscale. I obtain thermal properties and interfacial parameters, including thermal diffusion coefficient, latent heat, relaxation time, interfacial thickness, interfacial energy and the anisotropy coefficients, and nucleus shape etc. A central symmetry parameter is used to identify an atom in solid state or liquid state. And then an initial nucleus shape is obtained and used as the input for microscale simulation, in which the phase-field method is used to study copper crystallization at the microscale.

Ionic liquid forming compounds often display low melting points (a lack of crystallisation at ambient temperature and pressure) due to decreased lattice energies in the crystalline state. The degree of anion-cation contact with respect to the type, strength and number of interactions is a major factor determining the lattice energies, melting point and general behaviour of ionic liquid forming salts. Intermolecular interactions between the anion and cation and the conformational states of each component of the salt are of interest since distinctive properties ascribed to ionic liquids are determined to a significant extent by these interactions. The direct insight into the spatial relationship between cation and anion provided by the analysis of crystal structures provides a basis from which features of the ionic liquid can be generally understood, since the short range order and interactions of related, non-crystalline compounds may be similar to those of the crystalline form. However, it is difficult to predict whether a particular ionic pair will produce a liquid at room temperature, due to numerous possible combinations of cations and anions and the subtleties of their interactions. Crystal engineering is the ability to assemble molecular or ionic components into the desired crystalline architecture by engineering a target network of supramolecular interactions known as synthons. In this investigation the problem of ionic liquid design is addressed using the concepts of crystal engineering in an inverse sense, the so-called anti crystal-engineering approach. A topical area in which the anti crystal-engineering concept may be of some value is that of Ionic Liquid Phases of Pharmaceutically Active Ions (Active Ionic Liquids). Thus, by using the knowledge gained of the intermolecular interactions, packing and ionic conformation which occur within ‘traditional’ ionic liquids, combined with the knowledge of which functional group combinations yield supramolecular synthons resulting in crystalline subjects, and the subsequent prevention thereof (anti crystal-engineering), appropriate ions shall be selected which may result in ionic liquid formation. The intermolecular interactions of a series of: • crystallised bis(trifluoromethanesulfonyl)amide (NTf2) and bis(methanesulfonyl)amide (NMes2) ionic liquids, • low melting N-alkyl-2-methyl-3-benzylimidazolium iodide salts with a range of alkyl chain lengths, from n=1 to 6 and including both n-butyl and s-butyl chains, • 1-methyl-1-propylpyrrolidinium chloride and, • a number of low melting salts containing trihalide and monohalide ions, in combination with typical IL organic cations namely, 1-ethyl-3-methylimidazolium, 1-ethyl-1-methylpyrrolidinium and 1-propyl-1-methylpyrrolidinium, were qualitatively investigated and/or compared using a combination of crystallographic, Hirshfeld surface and thermal analysis techniques. The NMes2 salts are known to exhibit higher glass transitions and higher viscosities than those of the NTf2 salts. The origins of these differences were analysed in terms of the importance of factors such as the C-H•••O hydrogen bond, fluorination, presence of an aromatic moiety and length of alkyl chain, using the Hirshfeld surfaces and their associated fingerprint plots. Additionally, the existence of C-F•••π and C-H•••π interactions were elucidated and the significance of anion-anion interactions was recognised. Thermal analysis of the N-alkyl-2-methyl-3-benzylimidazolium iodide salts revealed that the methyl- and (s-)butyl substituted salts have a significantly higher melting point than the rest of the series. Analysis of these crystal structures allowed examination of the influence of the substitutions on the different cation-anion and cation-cation interactions and thus the physical properties of the salts. Thermal analysis of the monohalide and trihalide salts revealed that the tribromide salts are lower melting than their monohalide analogues. Analysis of these crystal structures revealed the influence of the anions and the crystal packing on the physical properties of the salts. A series of crystalline and liquid salts were prepared from cations and anions drawn from Active Pharmaceutical Ingredients (APIs) and Generally Recognized As Safe (GRAS) materials. The solid-state structures of the crystalline salts were used as a basis for the anti-crystal engineering approach in the preparation of several “Active Ionic Liquids” (AILs). However, a side product also resulted during the synthetic route namely, methyl 9H-xanthene-9-carboxylate, a side product resulting from the API, propantheline. The results and methodology of the anti-crystal engineering procedure and the subsequent successful preparation and characterization of pharmaceutical ionic compounds are reported herein.

<p>This master thesis deals with problems in the arc length control in Pulsed MIG/MAG Welding. The main problem is that it is not possible to measure the arc length. In the present solution the voltage over both the electrode and the arc represents the arc length. </p><p>To improve the arc length control a model of the electrode melting has been built. One output from the model is the voltage over the electrode and with this voltage together with the measured voltage it is possible to calculate the voltage over just the arc. Then, having the arc voltage as a value of arc length the arc length control can be improved, which is showed in the end by simulations. Simulations with the present control system are compared with the new one, when the controller is able to control the arc voltage instead of the sum of both the electrode voltage and the arc voltage.</p>