Solar energy as the most abundant source of energy is clean, non-pollutant, and completely renewable, which provides energy security, independence, and reliability. Organic-inorganic hybrid perovskite solar cells (PSCs) revolutionized the photovoltaics field not only by showing high efficiency of above 22% in just a few years but also by providing cheap and facile fabrication methods. In this dissertation, fabrication of PSCs in both ambient air conditions and environmentally controlled N2-filled glove-box are studied. Several characterization methods such as SEM, XRD, EDS, Profilometry, four-point probe measurement, EQE, and current-voltage measurements were employed to examine the quality of thin films and the performance of the PSCs. A few issues with the use of equipment for the fabrication of thin films are addressed, and the solutions are provided. It is suggested to fabricate PSCs in ambient air conditions entirely, to reduce the production cost. So, in this part, the preparation of the solutions, the fabrication of thin films, and the storage of materials were performed in ambient air conditions regardless of their humidity sensitivity. Thus, for the first part, the fabrication of PSCs in ambient air conditions with relative humidity above ~36% with and without moisture sensitive material, i.e., Li-TFSI are provided. Perovskite materials including MAPbI3 and mixed cation MAyFA(1-y)PbIxBr(1-x) compositions are investigated. Many solution-process parameters such as the spin-coating speed for deposition of the hole transporting layer (HTL), preparation of the HTL solution, impact of air and light on the HTL conductivity, and the effect of repetitive measurement of PSCs are investigated. The results show that the higher spin speed of PbI2 is critical for high-quality PbI2 film formation. The author also found that exposure of samples to air and light are both crucial for fabrication of solar cells with larger current density and better fill factor. The aging characteristics of the PSCs in air and vacuum environments are also investigated. Each performance parameter of air-stored samples shows a drastic change compared with that of the vacuum-stored samples, and both moisture and oxygen in air are found to influence the PSCs performances. These results are essential towards the fabrication of low-cost, high-efficiency PSCs in ambient air conditions. In the second part, the research is focused on the fabrication of high-efficiency PSCs using the glove-box. Both single-step and two-step spin-coating methods with perovskite precursors such as MAyFA(1-y)PbIxBr(1-x) and Cesium-doped mixed cation perovskite with a final formula of Cs0.07MA0.1581FA0.7719Pb1I2.49Br0.51 were considered. The effect of several materials and process parameters on the performance of PSCs are investigated. A new solution which consists of titanium dioxide (TiO2), hydrochloric acid (HCl), and anhydrous ethanol is introduced and optimized for fabrication of quick, pinhole-free, and efficient hole-blocking layer using the spin-coating method. Highly reproducible PSCs with an average power conversion efficiency (PCE) of 15.4% are fabricated using this solution by spin-coating method compared to the conventional solution utilizing both spin-coating with an average PCE of 10.6% and spray pyrolysis with an average PCE of 13.78%. Moreover, a thin layer of silver is introduced as an interlayer between the HTL and the back contact. Interestingly, it improved the current density and, finally the PCEs of devices by improving the adhesion of the back electrode onto the organic HTL and increasing the light reflection in the PSC. Finally, a highly reproducible fabrication procedure for cesium-doped PSCs using the anti-solvent method with an average PCE of 16.5%, and a maximum PCE of ~17.5% is provided.

Nous avons étudié un procédé de dépôt par décharge à barrière diélectrique à la pression atmosphérique, pour l'obtention de films organosiliciés contenant des fonctions amine. Nous avons étudié l'effet du régime dans lequel opère la décharge sur la production de certaines espèces, telles que CN et CN2. En couplant ces résultats à l'analyse des films réalisés, nous avons pu mettre en évidence le fait que dans un régime filamentaire, le précurseur est fragmenté de manière plus importante. En particulier, les liaisons Si-CH3 sont détruites. Cependant, la quantité d'azote introduite dans le film, qui dépend pour beaucoup de celle de carbone, est plus importante dans le cas d'une décharge de Townsend, et le taux de fonctions amines est plus important. Le taux d'azote dépend également de la nature du substrat. La quantité d'azote introduite dans les films est en effet supérieure dans le cas d'un dépôt sur verre. Aucune explication n'a cependant été apportée à ce phénomène. Des cratères son également apparu dans les films obtenus sur cuivre en régime filamentaire.

No description available.

Obwohl Böden des Kronendachs (canopy soils) deutlich zur oberiridischen labilen Biomasse beitragen können, werden sie oft in Studien über Nährstoffkreisläufe übersehen. In Wäldern mit einem großen Vorkommen an Böden im Kronendach, wie beispielsweise jene in tropischen Bergregionen, könnte dies zu einem unvollständigen Verständnis der Gesamt-Nährstoffprozesse des Waldes beitragen. Böden im Kronendach sind Ansammlungen organischen Materials, welche gewöhnlich auf Zweigen von Bäumen tropischer Wälder zu finden sind. Sie bestehen in erster Linie aus zersetztem epiphytischen Material aber umfassen auch herunterfallendes Laub, Staub, wirbellose Tiere, Pilze und Mikroorganismen. Es gibt nur eine Handvoll Studien, die Stickstoff (N) Kreisläufe und/oder Treibhausgas (THG) Flüsse in Böden des Kronendachs untersucht haben und keine hat versucht die tatsächlichen Feldraten zu bestimmen oder herauszufinden, wie sich diese Böden – welche besonders sensibel gegenüber atmosphärischen Prozessen sind – mit Nährstoffdeposition ändern könnten. Diese Dissertation stellt die Ergebnisse einer Forschungsstudie dar, welche N-Umsatzraten und THG Flüsse von Böden des Kronendachs quantifiziert und untersucht, wie diese Raten durch zunehmende Mengen an N und Phosphor (P) im Boden verändert werden. In Gebieten mit atmosphärischer N- und P-Deposition, erhalten Böden des Kronendaches sowohl direkte als auch indirekte Nährstoffeinträge auf Grund von angereichertem Bestandsniederschlag und Pflanzenstreu. Es wurden folgende Umsatzraten in Böden des Kronendachs tropische Bergwälder entlang eines Höhengradienten (1000 m , 2000 m , 3000 m) gemessen: (1) asymbiotische biologische N2-Fixierung, (2) Netto- und Brutto-N-Transformation, und (3) Kohlendioxid (CO2), Methan (CH4) und Lachgas (N2O) Flüsse. Zudem wurden indirekte Auswirkungen von N-und P-Gaben, die auf dem Waldboden ausgebracht wurden, untersucht. Umsatzraten der N2-Fixierung, des N Kreislaufes und von THG Flüssen, welche in Böden des Kronendachs gemessen wurden, wurden mit denen vom Waldboden verglichen (entweder als Teil dieser Arbeit oder in parallelen Studien von zwei anderen Mitgliedern unserer Arbeitsgruppe), um die Aktivität von Böden des Kronendachs in den Kontext des gesamten Waldes zu stellen. N2-Fixierung wurde mit der Acetylenreduktionsmethode, Netto-N-Umsatzraten wurden mittels in situ Inkubationen (buried bag method) und Brutto-N-Umsatzraten wurden mit der 15N-Verdünnungsmethode (15N pool dilution technique) bestimmt. Gasflüsse wurden sowohl unter Verwendung statischer Kammern gemessen, deren Sockel permanent im Boden angebracht waren, als auch unter Verwendung regelmäßig entfernter intakter Bodenproben, die zur Gasmessung in luftdichten Einweckgläsern inkubiert wurden. Messungen der N2-Fixierung und des N Kreislaufes erfolgten während der Regen- und Trockenzeit im Feld unter Verwendung intakter Bodenproben. THG Messungen wurden fünf Mal während des Zeitraumes von einem Jahr durchgeführt. Der Waldboden unserer Standorte war 4 Jahre lang zweimal im Jahr mit moderaten Mengen an N ( 50 kg N ha-1 Jahr-1) und P (10 kg P ha-1 Jahr-1) gedüngt worden und umfasste folgende Behandlungen: Kontrolle, N-, P- und N+P-Zugaben. Das Kronendach trug 7-13 % zur gesamten Boden N2-Fixierung (Kronendach + Waldboden) bei, welche zwischen 0,8 und 1,5 kg N ha-1 Jahr-1 lag. N2-Fixierungsraten veränderten sich nur geringfüging mit der Höhenstufe, waren aber in der Trockenzeit deutlich höher als in der Regenzeit. N2-Fixierung im Waldboden wurde in N-Parzellen im Vergleich zu Kontroll- und P-Parzellen gehemmt, währen sie in Böden des Kronendachs in P-Parzellen im Vergleich zu Kontrollparzellen stimuliert wurde. Böden des Kronendachs trugen bis zu 23% zur gesamten mineralischen N-Produktion (Kronendach + Waldboden) bei; Brutto-N-Mineralisierung in Böden des Kronendachs lag zwischen 1,2 und 2,0 mg N kg-1 d-1. In Kontrollparzellen nahmen Brutto-Umsatzraten von Ammonium (NH4+) mit zunehmender Höhe ab, wohingegen Brutto-Umsatzraten von Nitrat (NO3-) keinen klaren Trend mit der Höhenstufe aufwiesen, aber signifikant durch die Saison beeinflusst wurden. Effekte durch Nährstoff-Zugabe unterschieden sich je nach Höhenstufe, aber kombinierte N+P-Zugabe erhöhte in der Regel auf allen Höhenstufen die N-Umsatzraten. CO2 Emissionsraten von Böden des Kronendachs berechnet auf der Basis der Fläche von Gaskammern (10,5 bis 109,5 mg CO2-C m-2 h-1) waren ähnlich denen vom Waldboden ähnlich und nahmen mit zunehmender Höhenstufe ab. Emissionen vom Kronendach, berechnet auf der Basis der Waldfläche (0,15 bis 0,51 Mg CO2-C m-2 h-1), machten jedoch nur 5-11% der gesamten Boden-CO2 Emissionen (Kronendach + Waldboden) aus. CH4 Flüsse (-0,07 bis 0,02 kg CH4-C ha-1 Jahr-1) und N2O Flüsse (0,00 bis 0,01 kg N2O-N ha-1 Jahr-1) von Böden des Kronendachs machten weniger als 5% der Gesamtflüsse von Böden aus. P-Zugabe reduzierte CH4 Emissionen in allen Höhenstufen, so dass Böden des Kronendachs als leichte CH4 Senken agierten (-10,8 bis -2,94 μg CH4-C m-2 h-1). Nur in 2000 m wurden Böden des Kronendachs unter N Zugabe zu leichten N2O Quellen (2,43 ± 3,72 μg N2O-N m-2 h-1), wohingegen P Zugabe die CO2 emissionen um ungefähr 50% reduzierte. Die Ergebnisse zeigen, dass Böden des Kronendachs eine aktive Mikrobengemeinschaft besitzen, welche wertvolle Dienstleistungen hinsichtlich von Nährstoffkreisläufen für das Ökosystem des Kronendachs erbringt. Zusätzlich, war der Nährstoffkreislauf der Böden des Kronendachs in unseren Wäldern eindeutig an die Nährstoffverfügbarkeit des Waldbodens gekoppelt, was im Gegensatz zu Theorien steht, die besagen dass Böden des Kronendachs vom Nährstoffkreislauf der Waldböden entkoppelt seien. Wir haben festgestellt, dass Böden des Kronendachs in höheren Lagen eher einen wesentlichen Anteil des gesamten Wald-Nährstoffkreislaufes ausmachen; dies sollte in Studien berücksichtigt werden, die sich mit Nährstoffkreisläufen solcher Gegenden beschäftigen. Langfristige atmosphärische N- und P-Deposition verfügt über das Potenzial, die Dynamik von Nährstoffflüssen im Kronendach erheblich zu verändern. N-Deposition könnte die N2-Fixierung hemmen, wobei “hotspots“ weiterhin in Bereichen mit großen Mengen an P vorkommen. Interne N-Kreisläufe in Böden des Kronendachs werden wahrscheinlich durch N -und P-Deposition stimuliert werden, aber chronischen Nährstoffzugabe könnte auch zu erhöhten mineralischen N-Verlusten aus dem Bodensystem des Kronendachs führen. THG-relevante Prozesse in Böden des Kronendachs werden wahrscheinlich auch auf N- und P-Deposition reagieren, aber mit Ausnahme von CO2-Emissionen ist es unwahrscheinlich, dass Gasflüsse von Böden des Kronendachs wesentlich zum gesamten THG-Budget des Waldes beitragen.

Submitted by Izabel Franco (izabel-franco@ufscar.br) on 2016-09-19T19:41:33Z No. of bitstreams: 1 DissBGS.pdf: 2899470 bytes, checksum: a3a468cd5c6b79bbc4f8adf4720788bd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-20T14:03:37Z (GMT) No. of bitstreams: 1 DissBGS.pdf: 2899470 bytes, checksum: a3a468cd5c6b79bbc4f8adf4720788bd (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-20T14:03:44Z (GMT) No. of bitstreams: 1 DissBGS.pdf: 2899470 bytes, checksum: a3a468cd5c6b79bbc4f8adf4720788bd (MD5) / Made available in DSpace on 2016-09-20T14:03:52Z (GMT). No. of bitstreams: 1 DissBGS.pdf: 2899470 bytes, checksum: a3a468cd5c6b79bbc4f8adf4720788bd (MD5) Previous issue date: 2014-03-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The increasing use of fossil fuels in combustion enginees and power generation plants has caused a large increase in the emission of sulfur oxides, nitrogen oxides (NOx) and carbon monoxide into the atmosphere which creates serious environmental problems. Catalytic processes are used in the abatement of NOx and a promising alternative is the reduction of NOx using CO as reducing agent on catalysts containing supported transition metal oxides. Taking this into account, the aim of this study was to prepare catalysts based on Fe2O3, NiO or Fe2O3-NiO supported on ceria-zirconia (molar ratios Ce:Zr equal to 1:1 and 1:4), incorporating the metal precursor salt in the sun of the support (in situ addition). The results of XRD data, Rietveld refinement and TEM indicated the formation of a solid solution CeO2-ZrO2 with cubic structure fluorite type; furthermore, it was not observed diffraction peaks of intense X-ray of Fe or Ni oxide as a consequence of a proper distribution of these oxides in the supports. The addition of Fe2O3 and/or NiO led to a decrease of the average crystallite size, causing an increase in SBET of the catalysts compared to the pure support. N2 physisorption measurements showed that the catalysts showed significant mesoporosity, which was attributed to the addition of Tween 80 during the sol-gel preparation, moreover, RTPH2 results confirm that the Fe2O3 reduction occurs at lower temperatures in the presence NiO. In addition, the catalysts showed satisfactory performance in the reduction of NO to N2 with CO, suggesting that the sol-gel method is adequate in their preparation. Furthermore, the catalyst 0,90Fe - 1Ce:1Zr reached the highest values of CO conversion to CO2 and NO to N2 at lower temperatures. The Fe2O3 catalysts were more selective to N2 formation compared to those containing NiO. In conclusion, the conversion NO to N2 was significantly affected when in contact with O2 and H2O interferences; however, this conversion did not change significantly in the presence of SO2. The catalysts showed a more significant reduction in conversion of NO to N2 when evaluated in the simultaneous presence of O2, SO2 and H2O. / O crescente uso de combustíveis fósseis em motores de combustão e usinas de geração de energia vem causando um grande aumento na emissão de óxidos de enxofre, óxidos de nitrogênio (NOx) e monóxido de carbono na atmosfera, o que gera sérios problemas ambientais. No abatimento de NOx, em particular, utiliza-se processos catalíticos e uma alternativa promissora é a redução dos NOx utilizando CO como agente redutor sobre catalisadores à base de óxidos de metais de transição suportados. Nessa direção, a pesquisa teve por objetivo preparar catalisadores à base de Fe2O3, NiO ou Fe2O3-NiO suportados em céria-zircônia (proporções molares entre Ce e Zr iguais a 1:1 e 1:4), incorporando o sal precursor do metal no sol do suporte (adição in situ). Dados de DRX e MET indicaram a formação de uma solução sólida CeO2-ZrO2 com estrutura cúbica tipo fluorita, não se observando picos de difração de raios X intensos dos óxidos de Fe ou Ni, o que foi interpretado como uma consequência de uma adequada distribuição desses óxidos nos suportes. Os resultados do refinamento de Rietveld confirmaram os dados de DRX, indicando uma composição mássica baixa para os óxidos de Fe e/ou Ni. A adição de Fe2O3 e/ou NiO levou à uma diminuição do tamanho médio de cristalitos, causando um aumento na SBET dos catalisadores em relação ao suporte puro. Medidas de fisissorção de N2 mostraram que os catalisadores apresentaram mesoporosidade considerável, que foi atribuída à adição de Tween 80 durante a preparação sol-gel, além do mais, resultados de RTP-H2 corroboraram que a redução de Fe2O3 ocorre em temperaturas menores quando na presença de NiO. Os catalisadores apresentaram comportamento satisfatório na redução de NO a N2 com CO, indicando que o método sol-gel se mostrou adequado na sua preparação, sendo o sólido 0,90Fe - 1Ce:1Zr o que atingiu maiores valores de conversão de CO a CO2 e de NO a N2 em menores temperaturas. Em comparação aos catalisadores de NiO, os de Fe2O3 foram mais seletivos à formação de N2. Quando em contato com os interferentes O2 e H2O, a conversão NO a N2 foi consideravelmente afetada e na presença de SO2, essa conversão não se alterou significativamente. Quando avaliados na presença simultânea de O2, SO2 e H2O, os catalisadores apresentaram quedas de conversão de NO a N2 mais consideráveis.

Alder (Alnus glutinosa L. Gaertn.) is a species of a pioneer plant usually colonizing sites in the early stage of ecological succession, such as spoil heaps after open-cast brown coal mining in the Sokolov mining district in north western Bohemia, Czech Republic. These spoil heaps are very poor in nutrients available for plants, yet alders grow in a mutualistic relationship with actinomycetes Frankia, which live in root nodules of the alder plants. Frankia are able of fixing atmospheric nitrogen (N2) to ammonia (NH3) molecules, which can be then assimilate by alders, via enzyme nitrogenase. Thus, in the early stages of succession, alders have a competitive advantage to other non- fixing plant species living only on nitrates (NO3 - ) and ammonia ions (NH4 + ) present in soils. The aim of this study was to conduct and assess two greenhouse experiments. The first experiment studied the response of alder growth to presence of Frankia and arbuscular mycorrhizal fungi of order Glomerales. The performance of alder growth was significantly higher when alders were inoculated with both Frankia and mycorrhizal fungi in comparison to when alders have grown on their own or only with a mycorrhizal symbiont - both on 14 and 60 years old soils from Sokolov mines. In the second experiment, soil pH and iron (Fe) and...

La déficience des sols en éléments minéraux, particulièrement le phosphore (P) est une limitation majeure pour la croissance et le développement des légumineuses fixatrices d’azote. L’application des fertilisants phosphatés est une pratique traditionnelles pour satisfaire les besoins des plantes en P. Ainsi, pour tester l’efficacité d'utilisation du P pour la fixation symbiotique de l’azote (FSN) sous déficience en P, plusieurs lignées recombinantes (RILs) de haricot contrastantes dans leurs tolérance au déficit en P ont été utilisées. L’objectif principal de cette étude est d’évaluer l’aptitude de ces RILs pour l’amélioration de la fertilité phosphatée des sols déficients en P et sa relation avec la croissance et la nodulation de la légumineuse. Pour atteindre ces objectifs, des expériences ont été réalisées sous serre et en champs d'agriculteurs. Sous conditions contrôlées (serre) et non contrôlées (champs), les résultats ont montré une diminution du pH des sols associée à une augmentation du P assimilable. Une telle augmentation de la disponibilité du P a eu un effet positif sur la nodulation et la croissance de certaines des RILs testées. Aussi, l’amélioration de l’aptitude de ces RILs à fixer l’azote atmosphérique et l’élévation de la libération des protons H+ par les racines nodulées ont été quantifiés en milieu contrôlé. Ainsi la diminution du pH du sol a permis de réduire l’indisponibilité du P dans la solution du sol en le transformant en une forme directement biodisponible pour ces plantes. En outre, les résultats ont montré des différences significatives entre les différentes RILs en termes de la biomasse aérienne et nodulaire selon les sites d'observation. Nous concluons que, outre leur aptitude de fixation d’azote, l’utilisation efficace du phosphore pour sauver des engrais minéraux et de réduire les risques de pollution et pourrait améliorer la disponibilité des sols P. / The deficiency of soil minerals, particularly phosphorus (P) is a major limitation for growth and development of nitrogen-fixing by legumes. The application of phosphate fertilizers is a traditional practice to meet the needs of plant P. Thus, to test the effectiveness of use of P for symbiotic nitrogen fixation (NSF) under P deficiency, several recombinant inbred lines (RILs) of beans in their contrasting tolerance to P deficiency have been used. The main objective of this study is to assess the ability of these RILs to improve the fertility of soils deficient in phosphorus (P) and its relationship with growth and nodulation of the legume. To achieve these objectives, some experiments were conducted in greenhouses and fields. Under controlled conditions (greenhouse) and uncontrolled conditions (field), the results showed decreasing in soil pH associated with Proton release H+ and P acquisition. The increasing in available P had a positive effect on nodulation and growth of some RILs tested. Also, improving the ability of these RILs to fix atmospheric nitrogen and release H+ by nodulated roots were quantified in a controlled environment. Thus the decreasing in soil pH has reduced the un-availability of P in soil solution by transforming it into a bio-available form to the plants. In addition, the results showed significant differences between RILs in biomass and nodulation as observation in sites. We conclude that, in addition to their ability to fix nitrogen, effective use of phosphorus to save mineral fertilizer and reduce the pollution risks and could improve the availability of soil P.

As same as other countries in the world, China is also facing the problem of a severe shortage of energy. Specifically, the demand for natural gas is rising explosively after the energy consumption structure has changed from oil to gas. Due to various reasons and motivations, shale has been considered having great reserves and believed in alleviating the energy crisis. Nevertheless, the massive investment in developing shale has a disappointing interest with low-yielding production. Scholars have done many researches and experiments for investigating the causes and increasing the productivity of shale formation, in field and in laboratory respectively. Based on the statistics, more details, and further discussion, in this dissertation a probable method for more effectively producing was demonstrated. Although the hydro-fracturing technology has been conducted in field frequently, sometimes the decrease of permeability has been observed after the treatment. To figure out this phenomenon, the investigation started from the basic characterization of matrix. Believed in the most component in shale, quartz consisted of silica which could dissolve in fluid. Been assigned as variables, temperature, pH, and salinity have been implemented for explanation of dissolution. Temperature played a great role in the process. Combined with confining pressure, the reconsolidation happened inside samples. Through more experiments the mechanism of reconsolidation has been discovered that both confining pressure and temperature are necessary for gelling in fracture. Perspective on the whole formation, well logs were a super supplement to laboratory experiments. It serviced not only a further confirmation, but also pointed out the relationship between desorption capacity and different components. Samples from upper and lower formations have been used for going further. The exchange which exists between N2 and CH4 could be a great idea to exploit gas from reservoir. Feldspar supported space for adsorbed gas, and it was also easy to release. In contrast, the organic matter in which a network of pores developed has ability to trap the gas deeply because of the specific surface area. Quartz had positive effect on production because of containing the organic matter, while the influence of clay minerals on adsorption and desorption could be neglected. Based on the analysis of reconsolidation and desorption, an idea has been conceived using foam as fracturing fluid for increasing gas production. Compared to the pure fluid, foam has less water, which could prevent the reconsolidation. Nitrogen could be the gas to foam. The exchange between N2 and CH4 will increase the production of gas. In order to serve the condition that increases the time of exchange and makes negative effect on reconsolidation simultaneously, the foaming test with ABS and K12 has been evaluated first. For better stability of foam more experiment have been done. Three formulas were recommended which could keep the balance between the increasing viscosity and decreasing volume. The work interpreted in this thesis has enhanced our understanding of microscopic properties of shale and was expected to make contribution to further research of fracturing and production design.

No description available.

A large amount of low-rise unreinforced masonry structures (URM) can be foundin Groningen, the Netherlands. More and more induced earthquakes with shortduration have been detected in this region due to gas exploitation. Local unreinforcedmasonry (URM) buildings were initially not designed for withstanding seismicactions, so that unexpected damage may occur due to their vulnerability, raising insecurityamong residents. Existing low-rise masonry buildings in Groningen can bedivided into different categories based on their characteristics. Two types of residentialmasonry buildings that fulfil the prerequisites for performing non-linear seismicassessment are chosen to be studied in this thesis project, including the terracedhouse and the detached house.The seismic assessment of structures requires the use of both a discretization methodand a seismic assessment method. The discretization method is used to translate themechanical model into a finite element model used for the numerical analysis. Severalmethods have previously shown to be applicable for seismic assessment, but thiswork investigates the implications of using a continuum model (CM) and an equivalentframe model (EFM) approach to discretization in the general-purpose finiteelement package described in DIANA-FEA-BV (2017). The continuum model approachadopted was in a previous work by Schreppers et al. (2017) validated againstexperimental results and is as such deemed representative of the physical behaviourof the mechanical models investigated. An equivalent frame model approach to beused with DIANA is proposed in the work by Nobel (2017). The continuum modelapproach uses continuum elements with a constitutive model developed for the seismicassessment of masonry structures. This constitutive model captures both shearand flexural failure mechanisms. The equivalent frame model approach uses a combinationof numerically integrated beam elements and nodal interfaces, each witha distinct constitutive model, thus decoupling the description of the flexural andshear behaviour. This approach aims to capture the macro-behaviour at the structurallevel. The applicability of the proposed equivalent frame model approach isevaluated by how well it replicates the validated continuum model approach results.The two discretization methods described are evaluated using two types of seismicassessment methods. The first seismic assessment method used consists of first performinga quasi-static non-linear pushover analysis (NLPO) on the model. Thisresults in the pushover curve, which describes the global behaviour of the modelunder an equivalent lateral load based on the fundamental mode shape of the structure.The pushover curve is then used with the N2-method described in EN1998-1iii(2004) to assess at which peak ground acceleration (PGA) that the model reachesthe near-collapse (NC) limit state. The second seismic assessment method consistsof performing dynamic non-linear time-history analyses (NLTH). This method usesrecorded accelerograms to impose the inertial forces. The PGA for the accelerogramwhere the near-collapse limit state is reached is compared to the PGA fromthe use of the N2-method. The applicability of the pushover analysis in conjunctionwith the N2-method is evaluated by how well it replicates the PGA found from thetime-history analyses and by how well it replicates local failure mechanisms.Therefore, the main objectives of this project can be described by the following twoquestions:i. To what extent can the equivalent frame method be applicable as a properdiscretization method for pushover analyses and time-history analyses oflow-rise unreinforced masonry residential buildings in the Groningen region?ii. To what extent can the non-linear pushover method be adopted toassess the seismic behaviour of low-rise unreinforced masonry residentialbuildings in the Groningen region?The applicability of the equivalent frame model showed to vary. For describing localfailure mechanisms its applicability is poor. Further work on connecting the edgepiers to transverse walls is needed. For seismic assessment using the N2-method theapplicability of the equivalent frame model approach is sensible. The conservativedisplacement capacity counteracts the fact that it is worse at describing local unloading,which produced a larger initial equivalent stiffness of the bi-linear curvesin comparison to the continuum model. For seismic assessment using the timehistorysignals, its applicability is possible. While it could show different behaviourin terms of displacement and damping forces, it still showed a similar PGA at thenear-collapse limit state for the cases at hand.The seismic assessment of the terraced and detached houses by the N2-method issimilar to the seismic prediction by applying time-history analyses. However, thereare still some variations in the initial stiffness, force capacity and displacement capacitybetween these two assessment methods due to the assumptions and limitationsin this study. Overall, considering the pros and cons of the quasi-static pushovermethod, it is deemed applicable during the seismic assessment of the unreinforcedmasonry structures in the Groningen area.