Neste trabalho é apresentada a análise de técnicas para a integração de ISFETs (Ion Selective Field Effect Transitors), através do método de montagem por viragem (Flip-chip) usando pasta de solda livre de chumbo e epóxi condutivo de prata, com o objetivo de permitir sua aplicação em Microssistemas de Análise Total (µTAS). Para os testes de integração foram construídas estruturas em dois substratos, o FR-4, pelo método de ligação por fios (wire bonding), e o LTCC, que pode ser aplicado na construção de µTAS. Como os terminais de contato do ISFET tem seu acabamento superficial em alumínio não é possível realizar a montagem por viragem utilizando equipamentos SMT, sendo necessários processos intermediários. Dois processos que permitem o uso de equipamentos SMT foram aplicados: a remetalização, onde camadas de níquel e ouro são depositadas sobre o alumínio do terminal de contato, através do banho químico eletrolítico sem eletrodo (Electroless), e protuberâncias de solda (stud ou ball bumps), que são ligadas ao alumínio do terminal de contato pelo processo conhecido como Stud Ball Bumping (SBB). Na integração do ISFET foi feita a selagem dos terminais de contato e a abertura de uma janela que permite o contato da área ativa (região de porta) do ISFET com as soluções a serem analisadas. A selagem dos terminais de contato foi feita com o fotoresiste SU-8, e a abertura da área ativa foi feita diretamente sobre os substratos de FR-4 e LTCC. Ambos processos apresentaram soldabilidade com a pasta de solda apresentando ponto de refusão em torno de 250°C, indicando que equipamentos SMT podem ser aplicados na montagem por viragem. Verificou-se que o epóxi condutivo de prata foi curado a 100°C por uma hora e também pode ser aplicado na integração do ISFET. Por fim o SU-8 usado na selagem apresentou uma boa adesão aos substratos de FR-4 e LTCC, sendo curado na mesma etapa térmica da pasta de solda e/ou epóxi condutivo de prata ou após estes processos a 150°C por trinta minutos. / In this work is shown the analysis of integration techniques of ISFET (Ion Selective Field Effect Transitor) through the Flip-chip method using lead-free solder paste and silver conductive epoxy, in order to allow its application in Micro Total Analysis System (µTAS). For integration tests two substrates have been made, the FR-4, as already used in the integration of the ISFET, but assembled through wire bonding method, and the LTCC that can be applied in the construction of µTAS. As the ISFET bonding pads has its surface finish in aluminum is not possible assembly through flip-chip method using SMT equipments, requiring intermediate processes. Two process that allow the use of SMT equipment were applied: the remetallization, where nickel and gold layers are deposited on the aluminum bonding pads, through the Electroless chemical baths, and stud or ball bumps, which are connected to bonding pads of aluminum by the process known as Stud Ball Bumping (SBB). In the ISFET integration should be made a seal in the bonding pads and a window that allows the contact of the active area (gate region) of ISFET with the solutions to be analyzed. The sealing of the bonding pads has been made with the photoresist SU-8 and the window of active area were made directly on the FR-4 and LTCC substrates. Both processes presented the solderability with the solder paste reflowed at 250°C, indicating that SMT equipments may be applied to the assembly through flip-chip method, the silver conductive epoxy was cured at 100°C for one hour and can also be applied in ISFET integration. Finally the SU-8 used to sealing have showed a good adherence to the FR-4 and LTCC substrates, being cured in the same thermal step of solder paste and/or silver conductive epoxy or after these processes at 150°C for thirty minutes.

Neste trabalho foi feita uma ampla pesquisa sobre blocos de RF, VCOs e LNAs, que fazem parte de transceptores. Esses blocos foram projetados utilizando um indutor externo com um alto Q, com o intuito de melhorar as principais características de desempenho de cada um dos blocos. Com a finalidade de ter um ponto de comparação foram projetados os mesmos blocos implementando todos os indutores integrados (internos). Foi proposta a utilização da tecnologia flip chip para interconectar os indutores externos aos dies dos circuitos, devido às vantagens que ela apresenta. Para implementar os indutores externos propôs-se um processo de fabricação completo, incluindo especificação das etapas de processos e dos materiais utilizados para estes indutores. Adicionalmente foi projetado um conjunto de máscaras para fabricar os indutores externos e fazer a montagem e teste dos circuitos que os utilizam. Para validar o processo proposto e caracterizar os indutores externos foram projetadas diferentes estruturas de teste. O Q do indutor externo é da ordem de 6 vezes maior que do indutor integrado, para a tecnologia escolhida. Foram projetados e fabricados dois VCOs LC: FC-VCO (Flip Chip VCO com o indutor externo), OC-VCO (On Chip VCO com o indutor interno), e dois LNAs CMOS de fonte comum cascode com degeneração indutiva: FC-LNA (Flip Chip LNA com o indutor Lg externo) e OC-LNA (On Chip LNA com todos os indutores internos). O objetivo desses quatro circuitos é demonstrar que o desempenho de circuitos RF pode ser melhorado, usando indutores externos com alto Q, conectados através de flip chip. Para implementação desses circuitos utilizou-se a tecnologia de processo AMS 0,35µm CMOS, para aplicações na banda 2,4GHz ISM, considerando o padrão Bluetooth. Foram medidos apenas os blocos com os indutores internos (OC-VCO e OC-LNA). Para os blocos com os indutores externos (FC-VCO e FC-LNA) foram apresentados os resultados de simulação pós-layout. Através da comparação dos resultados de simulação entre os VCOs foi comprovado que o uso de um indutor externo com alto Q conectado via flip chip pode melhorar significativamente o ruído de fase dos VCOs, atingindo -117dBc/Hz a 1MHz de frequência de offset para o FC-VCO, em 2,45GHz, onde a FOM é 8dB maior que o OC-VCO. Outro ganho foi através da área poupada, o FC-VCO tem uma área cerca de 83% menor que a do OC-VCO. Após as medidas elétricas do OC-VCO obteve-se um desempenho do ruído de fase de -110dBc/Hz@1MHz para 2,45GHz, e -112dBc/Hz@1MHz para 2,4GHz, o qual atende as especificações de projeto. O FC-LNA, que foi implementado com o indutor de porta Lg externo ao die, conectado via flip chip, atingiu uma figura de ruído de 2,39dB, 1,1dB menor que o OC-LNA com o mesmo consumo de potência. A área ocupada pelo FC-LNA é aproximadamente 30% menor do que o OC-LNA. Através das medidas elétricas do OC-LNA verificou-se que o circuito apresenta resultados adequados de S11 (perda de retorno da entrada) e S22 (perda de retorno da saída) na banda de frequências de interesse. No entanto, o valor do ganho apresenta uma redução em relação ao esperado. A proposta do trabalho de unir a tecnologia flip chip ao uso de indutores externos, proporciona circuitos mais compactos e consecutivamente mais baratos, pela economia de área de Si. Adicionalmente, após os indutores externos serem caracterizados, os mesmos indutores podem ser reutilizados independente da tecnologia CMOS utilizada facilitando o projeto dos blocos de RF em processos mais avançados. / This work presents a research about RF blocks that are used in Transceivers, VCOs and LNAs. These blocks were designed using a high-Q RF external inductor in order to improve the main performance characteristics. The same blocks were designed implementing all inductors on-chip (internal) in order to have a point of comparison. It was proposed the use of Flip Chip technology to interconnect the external inductors to the dies of the circuits due to the advantages that this technology offers. A full manufacturing process was proposed to implement the external inductors, including the specification of process steps and materials used for these inductors. Additionally, a set of masks was designed to fabricate the external inductors, to mount and test the circuits that used these inductors. Different test structures were designed to validate the proposed process and to characterize the external inductors. Q factor of the external inductor is around 6 times larger than the inductor integrated into the chosen IC technology. Two LC VCOs and two common-source cascode CMOS LNAs with inductive degeneration were designed and fabricated: FC-VCO (Flip Chip VCO using external inductor), OC-VCO (On Chip VCO using on-chip inductor), FCLNA (Flip Chip LNA using an external Lg inductor) and OC-LNA (On Chip LNA with all inductors implemented on-chip). The purpose of these four circuits is to demonstrate that the performance of RF circuits can be improved by using high-Q external inductors, connected by flip chip. The 0.35µm CMOS AMS technology was used to implement these circuits intended for applications in the 2.4 GHz ISM band, considering the Bluetooth standard. Were measured only the blocks with internal inductors (OC-VCO and OC-LNA). For the blocks with external inductors (FCVCO and FC-LNA) were presented the results of post-layout simulation. The comparison between the VCOs simulations results demonstrates that using an external high-Q inductor connected by flip chip can significantly improve the phase noise of VCOs. FC-VCO reached a phase noise of -117dBc/Hz at 1MHz offset frequency and a FOM 8dB greater than the OC-VCO. Another important improvement was the saved area, the FC-VCO has an area approximately 83% lower than that of OC-VCO. After electrical characterizations of the OC-VCO, phase noise performances of -110dBc/Hz@1MHz for 2.45GHz and -112dBc/Hz@1MHz for 2.4GHz were obtained, that accomplish the design specifications. FC-LNA reached a noise figure of 2.39dB, 1.1dB lower than that of OC-LNA with the same power comsumption. The total area occupied by FC-LNA is around 30% lower than that OC-LNA. Measurement results of the OC-LNA showed that the circuit presents suitable S11 (input return loss) and S22 (output return loss) values in the desired frequency band. However, the gain value presents a reduction compared with the expected values. The proposal to use the flip chip technology together with external inductors, allows more compact and cheap circuits, because Silicon area can be saved. Moreover, after the external inductors being characterized, the same inductors can be reused regardless of the CMOS technology facilitating the design of RF blocks in more advanced processes.

We explore the problem of transforming plane triangulations using simultaneous diagonal flips. Wagner showed that any n-vertex plane triangulation can be transformed to any other plane triangulation on equal number of vertices using a finite sequence of diagonal flips. Later on it has been established that O(n) individual flips suffice to complete this transformation. Bose et al. showed that the transformation can also be done in 4 × ( 2 / log 54/53 + 2 / log 6/5 ) logn + 2 ≈ 327.1 log n simultaneous flips. This bound is asymptotically tight. We present two algorithms to improve the leading coefficient of this bound for transforming any plane triangulation into any other. The first of the two algorithms lowers this bound down to 4 × ( 2 / log 12/11 + 2 / log 9/7 ) logn + 2 ≈ 85.8 log n. By processing and preprocessing the interior and exterior of the triangulation’s Hamiltonian cycle parallelly in an interlaced fashion, we make further improvement of the algorithm from ≈ 327.1 log n down to 12 / log 6/5 logn + 2 ≈ 45.6 log n.

Magnetic Resonance Imaging (MRI) is a non-ionizing form of medical imaging which has practical uses in diagnosing, characterizing, and studying diseases in vivo. Current clinical practice utilizes a highly trained radiologist to view MR images and qualitatively diagnose, characterize, or study a disease. There is no easy way to compare qualitative data. That is why developing quantitative measures in MRI show promise. Quantitative measures of disease can be compared across a population, MRI sites, and over time. Osteoarthritis is one disease where those who have it may benefit from the development of quantitative MRI measures. Those benefits may include earlier diagnosis and treatment of the disease or treatment which may halt or even reverse the damage from the disease.The work presented in this dissertation focuses on analyzing and developing new methods of radiofrequency (B1) field mapping to improve quantitative MRI measures. The dissertation opens with an introduction and a brief primer on MRI physics, followed by an introduction to B1 and flip-angle mapping in MRI (Chapters 1-3). Chapter 4 presents a careful statistical analysis of a recent and popular B1 mapping method, the Bloch-Siegert shift (BSS) method, along with a comparison of the technique to other common B1 mapping methods. The statistical models developed in chapter 4 are verified using both Monte Carlo simulation and actual MRI experiments in phantoms. Chapter 5 analyzes and details the potential errors introduced in B1 mapping when a 3D slab-selective excitation is employed. A method for correcting errors introduced by 3D slab-selective B1 mapping is then introduced in chapter 6, along with metrics to quantify the error involved. The thesis closes with a summary of other scientific contributions made by the author in chapter 7. The chapters comprising the bulk of the presented research (4-7) are briefly summarized below. Chapter 4, the statistical analysis of B1 mapping methods, demonstrates the effectiveness of deriving the B1 estimate from the phase of the MR image. These techniques are shown to perform particularly well in low signal-to-noise ratio (SNR) applications. However, there are benefits and drawbacks of each B1 mapping technique. The BSS method deposits a significant amount of radiofrequency (RF) power into the patient, causing a concern that tissue heating may occur. The Phase-Sensitive (PS) method of B1 mapping outperforms the other techniques in many situations, but suffers from significant sensitivity to off-resonance. The Dual-Angle (DA) method is very simple to implement and the analysis is straightforward, but it can introduce significant mean bias in the estimate. No B1 mapping technique performs well for all situations. Therefore, the best B1 mapping method needs to be determined for each situation. The work in chapter 4 provides guidance for that choice. Many B1 mapping techniques rely on a linear relationship between flip angle and transmit voltage. That assumption breaks down when a 3D slab-selective excitation is used. 3D slab-selective excitation is a common technique used to reduce the field-of-view (FOV) in MRI, which can directly reduce scan time. The problem with slab-selective excitation in conjunction with B1 mapping has been documented, but the potential errors in B1 estimation have never been properly analyzed across different techniques. The analysis in chapter 5 demonstrates that the errors introduced in B1 mapping using a slab-selective excitation in conjunction with the ubiquitous DA B1 mapping method can be significant. It is then shown that another B1 mapping technique, the Actual Flip Angle Imaging (AFI) method, doesn't suffer from the same limitation. The analysis presented in Chapter 6 demonstrates that some errors introduced by 3D slab-selective B1 mapping may be modeled and corrected allowing the use of 3D slab-selective excitation to reduce field-of-view, and potentially reduce scan time. The errors are modeled and corrected with a general numerical method using Bloch simulations. The general method is applied to the DA method as an example, but is general and could easily be extended to other methods as well. Finally, a set of metrics are proposed and briefly explored that can be used to better understand the topology and severity of errors introduced into B1 mapping methods. With a better understanding of the errors introduced, the need for correction can be determined. Chapter 7 details other significant ancillary contributions made by the author including: (1) presentation of a new B1 mapping method, the decoupled RF-pulse phase-sensitive B1 mapping method, which has potential for parallel transmit MRI; (2) demonstration of an ultra-short TE method which has potential for imaging Alzheimers brain lesions in vivo; (3) introduction of a new steady-state diffusion tensor imaging technique; (4) phase-sensitive B1 mapping in sodium is demonstrated, a feat not previously demonstrated; (5) a comparison between a dual-tuned and single-tuned sodium coil; (6) introduction of a water- and fat-separation technique using multiple acquisition SSFP; (7) an inter-site and inter-vendor quantitative MRI study is introduced; (8) a relaxation and contrast optimization for laryngeal imaging at 3T is introduced; and (9) diffusion imaging with insert gradients is introduced.

Kutane T-Zell-Lymphome (CTCL) stellen eine heterogene Gruppe von non-Hodgkin-Lymphomen dar. Die häufigsten Entitäten sind die Mycosis fungoides, das Sézary-Syndrom sowie CD30+ lymphoproliferativen Erkrankungen (cALCL). Todesliganden-vermittelte Apoptose ist auch für die Lymphozyten-Homöostase von essentieller Bedeutung. Zunächst wurden die CTCL-Zelllinien mit systemischen T-Zell-Lymphomzellen hinsichtlich ihrer Apoptosesensitivität verglichen. Hierbei zeigte sich eine ausgesprochene Resistenz aller kutanen Zelllinien gegenüber TRAIL- und TNF-α-induzierter Apoptose. Anhand der Aktivierung der Caspasensignalkaskade war eine frühe Blockierung der Apoptose nachweisbar. Überdies konnte der Verlust von CD95, TNF-R1, Caspase-10 sowie von Bid in verschiedenen CTCL-Zelllinien nachgewiesen werden. Die Apoptoseresistenz konnte hingegen mit einer generellen und starken Expression des anti-apoptotischen Proteins c-FLIP korreliert werden. Des Weiteren wurde der Einfluss von CD30-Stimulation auf die durch CD95-induzierte Apoptose in CD30+-Zelllinien untersucht. Hierbei zeigte sich, dass CD30 Stimulation zur Aktivierung von NF-kB und zu erhöhter c-FLIP Expression führt, was mit Apoptoseresistenz korrelierte. Die Bedeutung der in vitro-Ergebnisse zeigte sich auch durch eine weitgehende Parallelität dieser zu untersuchten Biopsieproben von CTCL-Patienten. Schließlich wurden verschiedene NSAIDs auf ihre Fähigkeit hin untersucht, die Expression von c-FLIP zu vermindern und Apoptose zu induzieren. Dies wurde sowohl in CTCL-Zelllinien als auch in Tumor-T-Zellen von CTCL-Patienten untersucht. NSAIDs aktivierten beide Apoptosesignalwege und Diclofenac sensitiviert überdies für TRAIL-vermittelte Apoptose. In Ihrer Gesamtheit vermittelt die vorliegende Arbeit einen Einblick in die komplexen Apoptoseregulationsmechanismen in kutanen T-Zell-Lymphomen und identifiziert c-FLIP als einen zentralen Resistenzfaktor sowie NSAIDs als mögliche CTCL-Therapieoption. / Cutaneous T cell lymphomas (CTCL) form a heterogeneous group of non-Hodgkin lymphomas. Its most frequent forms are Mycosis fungoides, Sézary syndrome and CD30-positive cutaneous anaplastic large-cell lymphoma. Death ligands critically contribute to lymphocyte homeostasis by induction of apoptosis and may further represent safeguard mechanisms to prevent lymphoma development and tumor growth. First, we analyzed induction of apoptosis by death ligands in CTCL cell lines and compared it to that in systemic T-cell lymphoma cells. This revealed for CTCL cells a pronounced resistance to death ligands. In particular, there was no caspase activation in non-responsive CTCL cells, indicating an early blockade of the apoptosis signal. Furthermore a loss of CD95, TNF-R1, caspase-10, as well as of Bid was found in several cell lines. Changes at the receptor expression level were largely ruled out, whereas, consistent and strong expression of c-FLIP was correlated with resistance. In addition, we investigated the CD30/CD95 crosstalk in CD95-sensitive cALCL cell lines. Experiments showed that CD30 ligation leads to NF-κB-mediated c-FLIP upregulation in cALCL cells, which in turn conferred resistance to CD95-induced apoptosis. Parallels with regard to expression of apoptosis regulators were seen in peripheral blood mononuclear cells and biopsies of CTCL patients. Finally, we evaluated non-steroidal anti-inflammatory drugs (NSAIDs) for their capacity to downregulate c-FLIP expression and apoptosis induction in CTCL cells as well as in tumor T cells from CTCL patients. NSAID treatment resulted in an activation of both apoptosis signaling pathways and, furthermore, Diclofenac pre-treatment sensitized for TRAIL-induced apoptosis. In conclusion, this study elucidates defects in apoptosis regulation, proved the significance of c-FLIP for the survival of CTCL cells and provides a rationale for the use of NSAIDs as a potentially new therapeutic option for CTCL patients.

[pt] Consideramos o problema de contar e classificar coberturas por dominós de toros quadriculados. O problema de contagem para retângulos foi estudado por Kasteleyn e usamos muitas de suas ideias. Coberturas por dominós de regiões planares podem ser representadas por funções altura; para um toro dado por um reticulado L, estas funções exibem L-quasiperiodicidade aritmética. As constantes aditivas determinam o fluxo da cobertura, que pode ser interpretado como um vetor no reticulado dual (2L) asterisco. Damos uma caracterização dos valores de fluxo efetivamente realizados e de como coberturas correspondentes se comportam. Também consideramos coberturas por dominós do reticulado quadrado infinito; coberturas de toros podem ser vistas como um caso particular destas. Descrevemos a construção e uso de matrizes de Kasteleyn no problema de contagem, e como elas podem ser aplicadas para contar coberturas com valores de fluxo prescritos. Finalmente, estudamos a distribuição limite do número de coberturas com um dado valor de fluxo quando o reticulado L sofre uma dilatação uniforme. / [en] We consider the problem of counting and classifying domino tilings of a quadriculated torus. The counting problem for rectangles was studied by Kasteleyn and we use many of his ideas. Domino tilings of planar regions can be represented by height functions; for a torus given by a lattice L, these functions exhibit arithmetic L-quasiperiodicity. The additive constants determine the flux of the tiling, which can be interpreted as a vector in the dual lattice (2L) asterisk. We give a characterization of the actual flux values, and of how corresponding tilings behave. We also consider domino tilings of the infinite square lattice; tilings of tori can be seen as a particular case of those. We describe the construction and usage of Kasteleyn matrices in the counting problem, and how they can be applied to count tilings with prescribed flux values. Finally, we study the limit distribution of the number of tilings with a given flux value as a uniform scaling dilates the lattice L.

Cette thèse fait partie des efforts de recherche pour étudier l’intégration hétérogène sur le substrat souple des nœuds de communicants pour les réseaux de capteurs sans fil dans la bande à 60GHz. Le System in Package (SiP) devrait avoir une consommation d'énergie très faible et être faible coût pour répondre aux exigences des applications telles que la Surveillance de Santé de Structure (Structure Health Monitoring - SHM en anglais) dans le domaine aéronautique par exemple. Chaque nœud est composé des nano-capteurs, des transceivers et des antennes d’émission et de réception. Les nanotechnologies ont permis le développement de nano-capteurs ultra-sensibles à base de nanoparticules. Les transceivers deviennent de plus en plus miniaturisés et donc permettre la possibilité de les reporter sur le substrat flexible. Les antennes peuvent être intégrés sur le substrat flexible avec les nano-capteurs développés et émetteurs miniaturisés, ce qui est l'approche très innovante. Dans cette thèse, nous présenterons les procédés technologiques adaptés pour réaliser les différents circuits passifs (résonateurs, antennes, rectennas, etc…) sur le substrat souple en utilisant la photolithographie conventionnelle. La technique de la puce retournée a été choisie pour l’intégration des transceivers à 60 GHz, la formation des bosses d’interconnexion en or directement sur le substrat souple par les dépôts électrolytiques est présentée ici pour la première fois. La concordance entre les mesures expérimentales et les simulations numériques démontre la fiabilité et la reproductibilité des procédés choisis. De plus, pour une application à volume élevé comme les réseaux de capteurs sans fil, le coût de fabrication par nœud peut être considérablement réduit, et devient comparable avec l’impression jet d'encre qui est un procédé à faible coût. / This thesis is part of research effort to develop a 3D heterogeneous integration of wireless sensor node on flexible substrate for the unlicensed 60GHz band. The System in Package (SiP) should have a very low power consumption and very low cost to meet the requirements of applications like Wireless Sensor Networks (WSNs) for Structure Health Monitoring (SHM). Using a flexible substrate for wireless sensor node integration can offer the advantage of being localized in areas with access difficulty especially in non-planar area. Each node is composed of nano-sensors, transceivers and TX/RX antenna. Nanotechnologies made it possible the development of ultra-sensitive nano-sensors based on nanoparticles deposition. Transceivers become more and more miniaturized and hence enable the possibility of postpone them onto flexible substrate. The antennas can be integrated on the flexible substrate along with the developed nano-sensors and miniaturized transceivers, which is the very innovative approach. In this work, we propose customized photolithography processes to manufacture the passive element circuits (resonators, antennas, rectennas, etc…) on flexible substrate. The technique of flip-chip was used for the integration of 60 GHz transceivers, a novel technique to form Au interconnection bump directly onto the flexible substrate by using electrodeposition process is also presented here for the first time. The concordance between the simulations and the measurements is observed, which proves the reliability and reproducibility of such process technique. Furthermore, for a high-volume application like the node deployment of WSNs, wafer cost reductions can significantly lower the total cost per node and became comparable to a low-cost inkjet printing process.

I ett projektarbete i en ingenjörsutbildning används olika metoder och verktyg, för att planera och strukturera arbetet. En möjlighet är att använda fysiska projekttavlor. Det finns även interaktiva smartskärmar med uppkoppling till internet, som möjliggör arbete på distans. Detta arbete fokuserar på smartskärmen Samsung Flip 2, och undersöker om det går att använda den för projektarbeten i ingenjörsutbildningar. Projektet inleds med en förstudie, vars fokus är på whiteboardtavlor, planeringstavlor och interaktiva skärmar. Vidare utförs opinionsundersökningar med två olika studentgrupper. Med hjälp av de svar som erhållits, identifieras de funktioner som anses viktiga när projekttavlor används i utbildningen. Dessutom för- och nackdelar vägs för olika typer projekttavlor. En önskebild av en projekttavla, som är en samling av önskade egenskaper, tas fram baserad på förstudien och opinionsundersökningarna. Sedan testas mjukvaruverktygen Lucidchart, Notion, Trello och Jira i samband med smartskärmen Samsung Flip 2, för att se om det går att uppnå önskebilden. Resultaten av testningen används sedan för att utvärdera Samsung Flip 2. Det visar sig att den inte är en lämplig ersättning för en fysisk whiteboardtavla i projektarbeten. Utvärdering av andra smarskärmar och andra mjukvaruverktyg kan ge andra resultat. / In a project in an engineering education, different methods and tools are used, to plan and structure the work. One possibility is to use physical project boards. Another alternative is using an interactive smart-screen with access to the internet, which gives the opportunity to work remotely. This work focuses on the smart-screen Samsung Flip 2, and examines if it is possible to use it for projects in an engineering education. The project is initiated with a pre-study, where the focus is on whiteboards, project boards and interactive screens. Further on opinion polls are executed with two different student-groups. The answers help identify which functions that are important when project boards are used within the education, as well as pros and cons for different types of project boards. An ideal-picture of a project board, which is a collection of desired functionalities, is made based on the pre-study and opinion polls. After that the softwares Lucidchart, Notion, Trello and Jira are tested in combination with the smart-screen Samsung Flip 2, to see if it can fulfil the ideal-picture. The result from the tests is used to evaluate Samsung Flip 2. The evaluation shows that Samsung Flip 2 is not a suitable replacement for a physical whiteboard. Evaluations on other smart-boards and other softwares may yield a different result.

[pt] Nessa dissertação estudamos coberturas por dominós de regiões tridimensionais. Em particular, consideramos o problema de conectividade por flips de cilindros, ou seja, regiões da forma D ×[0,N]. Um flip é um movimento local: dois dominós adjacentes são removidos e recolocados em outra posição. Em duas dimensões, duas coberturas de uma mesma região contrátil podem ser conectadas por flips. Em dimensão 3, o problema é mais sutil. Apresentamos o twist, um invariante por flips que associa uma cobertura a um número inteiro. Para muitas regiões 3D, existem exemplos de coberturas com o mesmo twist que não podem ser ligadas por uma sequência de flips. Artigos recentes mostram que para muitos discos D, chamados regulares, duas coberturas do cilindro D × [0,N] com o mesmo twist podem ser ligadas por flips uma vez que adicionamos espaço vertical ao cilindro. Esses resultados são apresentados e discutidos. Nós então demonstramos a regularidade ou irregularidade de vários discos. Verificamos que um gargalo muitas vezes implica na irregularidade. / [en] In this dissertation we study domino tilings of three-dimensional regions. In particular, we consider the flip connectivity problem for cylinders, i.e, regions of the form D×[0,N]. A flip is a local move: two adjacent dominoes are removed and placed back in a different position. In two dimensions, two domino tilings of the same contractible region are connected by flips. In dimension 3, the problem is subtler. We present the twist, a flip invariant that associatean integer number with a tiling. For many 3D regions, there exist examples of tilings with the same twist which can not be joined by a sequence of flips. Recent papers prove that for certain disks D, called regular, two tilings of the cylinder D × [0,N] with the same twist can be joined by a sequence of flips once we add vertical space to the cylinder. These results are presented and discussed. We then prove regularity or irregularity for new families of quadriculated disks. It turns out that a bottleneck often implies irregularity.

A common method of cancer treatment is radiation therapy. In radiation therapy, a treatment planning system is made to specify the dose of X-rays needed to eradicate the tumor. To assure the right amount of X-ray dosage a quality assurance is using a phantom containing radiation sensors. The sensors are made of semiconductor materials with heavy metal-based contacts. Irradiating heavy elements with a high-intensity beam such as Xrays causes secondary scattering of electrons, resulting in an additional photocurrent which may distort the signal used in the quality analysis. By exchanging the heavy-metal contact material to a lighter version such as a carbon-based material, preventing secondary scattering, the error obtained from the quality analysis can be minimized.In this thesis, characterization of contacts between radiation diodes and a copper substrate by flip-chip bonding with reduced graphene oxide-based anisotropic conducting adhesive is made. The parameters of the connections are characterized with respect to electrical, thermal and mechanical properties.Analysis of the novel contact material is done by comparing different types of graphene-based anisotropic fillers with a commercial metal-based filler. Results obtained indicate that it is possible to exchange the metal-based fillers in an anisotropic conducting adhesive with reduced graphene oxide coated polymer spheres as a contacting material for radiation sensing technology. / En vanlig metod som används för att behandla cancer är strålningsterapi. I strålningsterapi görs ett behandlingsplaneringssystem för att specificera en exakt dos av röntgenstrålning som krävs för att slå ut en tumör. För att säkerställa att man ger rätt dos av röntgenstrålning utförs en kvalitetssäkring genom att använda en fantom innehållande strålningssensorer. Sensorerna är gjorda av halvledarmaterial men har oftast anslutningar gjorda av tunga metalliska material. När man bestrålar metaller med hög intensitet, exempelvis röntgenstrålning, emitteras en sekundär spridning av elektroner i form av en fotoström som kan störa signalen i kvalitetsäkrningen. Genom att byta ut metallen som används i anslutningarna till ett kontaktmaterial med lägre atomnummer som exempelvis kolbaserade material, förhindras den sekundära spridningen av elektroner, som troligtvis minskar felet som uppstår vid kvalitetssäkringen.I detta arbete har en kartläggning av kontakter mellan stålningsdioder och ett kopparsubstrat, genom en flip-chip-bindning process med ett ledande adhesiv baserat på reducerad grafenoxid gjorts. Kontaktparametrarna som kartlagts är baserade på termiska, elektriska och mekaniska egenskaper.Kartläggningen av kontakterna har i mestadels gjort genom att jämföra olika typer av grafen baserade partiklar ett kommersiellt metalbaserat material gjort för flip-chipbindning. Resultaten från arbetet indikerar att det är möjligt att byta ut det metallbaserade partiklarna i ett anisotropt ledande adhesiv med reducerade grafenoxid-belagda polymersfärer som ett ledande material för strålningsapplikationer.