Trots att det finns många tekniska hjälpmedel ombord, vilka har i uppgift att hjälpa navigatören att framföra fartyget på ett säkert sätt, så fortsätter grundstötningar att inträffa. Denna litteraturstudie sammanställer och granskar grundstötningsolyckor som inträffat på svenska fartyg och på utländska fartyg som befunnit sig på svenskt territorialvatten under åren 2011-2016. Studien behandlar frågeställningar om vilka huvudsakliga faktorer som ligger till grund för att grundstötningar inträffar. Studien omfattar såväl inre som yttre faktorer. De inre faktorerna som behandlas är styrmetod, bryggbemanning och vilken typ av sjökort som använts. Våghöjd, vindstyrka, typ av farvatten, sikt- och ljusförhållande ingår i de yttre faktorerna. Både de inre- och yttre faktorerna sammanställs och presenteras för att kunna ge en bild av vad som kan ha föranlett grundstötningarna. Studiens resultatet visar att passagerar- och bulkfartyg av det mindre tonnaget står för majoriteten av olyckorna. I likhet med tidigare studier är antalet olyckor som beror på den mänskliga faktorn hög. / Even though there are plenty of technological aids onboard modern-day merchant vessels, intended to help the Officer on watch to drive his vessel safely, groundings continue to happen. This literature study summarises and reviews data from several groundings that involved Swedish-registered ships and ships within Swedish territory during the period 2011-2016. This study covers questions about the main factors that have caused the groundings. It covers both internal and external factors. Method of steering, bridge manning and type of chart belong to the internal factors. Factors such as wave height, wind force, type of waters, visibility and light conditons are part of the external factors. This data is then discussed and analysed to give a picture of what may have caused the groundings. The results show that the smaller tonnage passenger and bulk carriers account for the majority of the accidents. Like previous studies the number of accidents due to human factors are high.

Chaque année, le nombre de demandeur d’organe augmente en France comme dans le reste du monde. Pour combattre ce fléau, il existe aujourd’hui des technologies permettant d’imprimer du vivant, telle que la Bioimpression Assistée par Laser (LAB). Robuste et précise, cette méthode s’appuie sur les propriétés d’interaction laser-matière pour éjecter une bio-encre constituée de cellules vivantes. Pour éviter l’utilisation d’une couche absorbante sacrificielle, généralement utilisée, on focalise directement un faisceau laser dans la bioencre afin de générer un plasma puis une bulle de cavitation. La position de cette bulle est essentiellement maitrisée pas la longueur d’onde, et sa taille est gérée par l’énergie et la durée d’impulsion du laser. Ce sont les facteurs clés pour maîtriser l’éjection de matière biologique. Cependant, l’inhomogénéité locale apportée par les cellules perturbe l’impact du laser et donc la reproductibilité des jets, mais une fois imprimées, ces cellules sont viables et permettent de reconstruire des tissus vivants. / Every year, the transplant waiting list gets bigger in France as in all over the world. To fight this curse, Bioprinting makes organ printing possible, especially with Laser Assisted Bioprinting (LAB). Robust and precise, this method use laser-matter interaction to eject a bioink made of living cells. To avoid the use of absorbing sacrificial layer, we directly focalize a laser beam into a living cells bioink, to create a plasma then a cavitation bubble. Its position, which is mainly driven by laser wavelength, and its size, managed by the energy and pulse duration, are the most important keys to control liquid jet ejection. However, the laser energy deposition and jet ejection is disturbed because of cells local concentration disparity, but when cells are printed, they are still viable and able to reconstruct living tissues.

Made available in DSpace on 2017-07-21T20:43:48Z (GMT). No. of bitstreams: 1 Charles Betuel Mansende Mvumbi.pdf: 3357827 bytes, checksum: 822a91a949448c4769ce680ef684f74d (MD5) Previous issue date: 2016-01-29 / The ceramic porcelains are produced from natural raw materials (silica, feldspar and kaolin). In some applications other materials are added to increase the mechanical and dielectric strength. They are used in the manufacture of several products. Therefore, they are very studied and have been developed for long time. In this work, porcelains with different compositions were characterized and submitted to fragmentation by mechanical disruption in a ballistic impact testing. Generally the mechanical disruption in the materials produces a power dissipation forming cracks and fracture surfaces having an irregular geometry. The main objective of this work was to characterize the microstructure and the fractal fracture surface in porcelains. For comparison, the impact tests were also performed on commercial glass and acrylic. The evaluation of the fracture surface and the fractal dimension of rupture was performed by analyzing the fraction of the fragments as a function of the probability of fracture. The samples were prepared in the form of cylindrical disks with a thickness and fixed diameters. Mechanical impact test was made on the center of the disks for different materials, maintaining the same test conditions. The results of the size and mass of the fragments were obtained as a function of the impact energy, thickness, diameter and kind of material. Thus, it was possible to obtain a correlation between the test conditions and the composition of the material with the fractal pattern breakage. It has been found that the compositions used in porcelain, has a fracture toughness which is between the glass and acrylic. A correlation between strength properties to the patterns of formed crack was made. It was noticed that the number, the shape of cracks and the branches form a pattern that is associated with the impact energy and material type. / As porcelanas são cerâmicas produzidas a partir de matérias primas naturais (sílica, feldspato e caulim). Em algumas aplicações são adicionadas outras matérias primas para o aumento da resistência mecânica e dielétrica. Elas são usadas na fabricação de variados produtos. Portanto, elas são muito estudadas e vêm sendo desenvolvidas há muito tempo. Neste trabalho, porcelanas com diferentes composições foram caracterizadas e submetidas à fragmentação por ruptura mecânica em um ensaio de impacto balístico. A ruptura mecânica nos materiais em geral produz uma dissipação de energia formando trincas e superfícies de fratura que tem uma geometria irregular. O principal objetivo deste trabalho foi a caracterização da microestrutura e a caracterização fractal da superfície de fratura de porcelanas. Para comparação, os ensaios de impacto também foram feitos em vidro e acrílico comercial. A avaliação da superfície de fratura e da dimensão fractal de ruptura foi feita pela análise da fração de fragmentos em função da probabilidade de fratura. Os corpos de prova foram preparados na forma de discos cilíndricos, com espessura e diâmetros fixos. O ensaio de impacto mecânico foi feito sobre o centro dos discos, para os diferentes materiais, mantendo-se as mesmas condições de ensaios. Os resultados, do tamanho e massa dos fragmentos, foram obtidos em função da energia, espessura, diâmetro e do tipo de material. Desta forma, foi possível obter uma correlação entre as condições de ensaio e a composição do material com o padrão de ruptura fractal. Verificou-se que a porcelana nas composições usadas possui uma tenacidade à fratura que se situa entre a do vidro a do acrílico. Finalmente foi feita uma correlação entre as propriedades de resistência mecânica com os padrões de trinca formado. Percebeu-se que o número, a forma das trincas e as ramificações formam um padrão que está relacionado com a energia de impacto e o tipo de material.

Baseada na abordagem da cognição enativa (VARELA, F.,1990), a temática principal deste estudo tem como objetivo abordar o acesso e exploração dos conhecimentos pré-refletidos numa experiência vivida em primeira pessoa. Para tanto, primordialmente, utiliza-se como eixo teórico, o desenvolvimento husserliano (1913/2006) sobre a redução fenomenológica-èpoché. Por sua vez, o fio condutor do desenvolvimento da práxis da pesquisa, orienta-se pelos estudos dos pesquisadores Depraz, Varela e Vermersch (2003) que a partir da releitura da obra de Husserl, propõem uma abordagem pragmática da experiência de como podemos nos tornar cientes da nossa própria consciência em ação, denominada de devir-consciente. Esta modalidade de atenção é acessada em primeira pessoa e para ser alcançada necessita ser cultivada. Na pesquisa que realizamos, os eventos em primeira pessoa aconteceram a partir de experiências de aprendizagem da matemática vivenciadas por dois alunos que apresentaram dificuldades de aprendizagem nesta área do conhecimento: ambos alunos frequentavam o Laboratório de Aprendizagem (LA) da Rede Municipal de Ensino de Porto Alegre. Utilizou-se a técnica da Entrevista de Explicitação (VERMERSCH, P.,2003) com os alunos durante as sessões de aula do LA, como instrumento de acesso aos conhecimentos pré-refletidos e como ferramenta de intervenção pedagógica para o acolhimento de breakdowns e cultivo do processo de devirconsciente. Esta técnica foi criada por Vermersch (2003), sendo embasada nos pressupostos da fenomenologia husserliana e na teoria de Piaget (1973,1977) sobre a tomada de consciência. O estudo sugeriu que é possível desenvolver nos alunos o cultivo da habilidade de torná-los cientes do seu fluxo cognitivo. Esta possibilidade foi alcançada a partir de um trabalho prático e disciplinado de atenção e acesso às experiências singulares de aprendizagem e conhecimentos ainda pré-egóicos e portanto, pré-refletidos nos alunos. Igualmente, o emergir dos momentos de breakdowns demonstraram ser sinalizadores importantes (DE-NARDIN, SORDI, 2007) e que, quando acolhidos pelo aluno e professor, podem servir como disparadores do processo de devir-consciente. Do ponto de vista da cognição, o desenvolvimento desta modalidade atencional que resgata os conhecimentos pré-refletidos do aluno, pode trazer a tona um manancial de conhecimentos e saberes teoricamente acessíveis, porém usualmente pouco explorados em situações de ensino-aprendizagem. / Based on the enactive cognitive approach (VARELA, F.,1990) , the main theme of this study is concerned to the access of one’s pre-reflected knowledge in a vivid experience in first person. The main theoretical ground comes from Husserl´s phenomenological development of èpoché (1913/2006). In turn, the main stream of the research praxis is guided by studies performed by researchers such as Depraz, Verela and Vermersch (2003), who reread Husserl’s work and proposed a pragmatic approach of the experience of becoming-aware of one’s own awareness in action. This modality of attention can be accessed in first person and, to be achieved, it needs to be cultivated. In this research, the first person events were developed in math learning experiences lived by two students who showed learning disabilities in that field. Both students attended the Learning Laboratory (LL) in a municipal public school of Porto Alegre. The Explicitation Interview Method (VERMERSCH, P.; 2003) was used with the students during the LL class sessions as a tool to access pre-reflected knowledge as well as a tool for pedagogical intervention during breakdowns and becoming-aware process of development. This method was based on Husserl’s phenomenology and on Piaget’s assumptions about the grasp of consciousness (1973,1977). The study suggested that it is possible to develop the student’s ability of becoming aware of her/his own cognitive flow. This possibility was achieved from a practical and disciplined work of attention in order to access to the particular experiences of learning which were still pre-reflexive and pre-egoic. Likewise, the emergence of breakdown moments showed to be an important sign (DENARDIN, M.H. & SORDI, R. 2007) which, once accepted by student and teacher, served as a trigger the becoming-aware process. From the point of view of cognition, the development of this modality of attention that recovers the student’s pre-reflected knowledge, can bring to surface a great variety of theoretical known devices although usually less explored in teaching-learning situations.

Neste trabalho estudamos o processo de deposição do filme de silício policristalino dopado com oxigênio (SIPOS) depositado por LPCVD, a partir da mistura entre a silana (SiH4) e o óxido nitroso (N2O); para a sua aplicação como camada de passivação superficial em dispositivos de potência. As características físicas e elétricas do filme SIPOS foram analisadas em função dos seguintes parâmetros de deposição: pressão, razão gasosa entre (N2O/SiH4), espaçamento entre as lâminas de processo, tempo para a formação de uma camada de pré-oxidação entre SIPOS-Si e tempo de processo. Observamos que o espaçamento entre as lâminas de processo é um importante parâmetro de processo, pois este influi diretamente na uniformidade em espessura e na concentração de oxigênio presente nos filmes depositados. A caracterização elétrica dos filmes SIPOS foi realizada através de capacitores MSS. Verificamos a validade do modelo sobre o comportamento da condutividade elétrica em função da proporção gasosa (N2O/SiH4) proposto por Ni e Arnold. Uma vez determinado as melhores condições de processo, os filmes SIPOS foram depositados sobre diodos de potência pré processados fornecidos pela AEGIS Semicondutores Ltda. Estes diodos foram então caracterizados quanto a sua tensão de ruptura reversa e a sua corrente de fuga reversa. Os histogramas dos dados experimentais mostraram que diminuindo-se o tempo para a formação de uma camada de pré-oxidação entre a interface SIPOS-Si, temos uma diminuição da corrente reversa que flui pelo filme SIPOS. Os diodos de potência fornecidos pela Aegis Semicondutores Ltda foram projetados para suportarem uma tensão de ruptura reversa de 650 V. Os diodos passivados com SIPOS suportaram tensões de ruptura de até 1.200 V. / In this work, the SIPOS (Semi-Insulating Polycrystalline Silicon) LPCVD deposition process was studied to be applied as passivation layer in power devices. It was used a mixture of silane and nitrous oxide to promote the deposition process. The physical and electrical characteristics were analyzed in function of the follow process parameters: total pressure, gas ratio (N2O/SiH4), distance between samples in the LPCVD wafer holder; pre oxidation time and total process time. It was observed that the distance between samples in the LPCVD wafer holder is direct related to the thickness uniformity and in the oxygen concentration present in the SIPOS thin films. MSS capacitors were fabricated to perform the electrical characterization of the deposited SIPOS films. The validity of the model proposed by Ni and Arnold, to the behavior of the electrical conductivity in function of gas ratio (N2O/SiH4), was confirmed. The SIPOS thin film was deposited over pre processed diodes samples, supplied by AEGIS Semicondutores Ltda, in the best process conditions obtained in the previous experiments. The behavior of the leakage current and the breakdown voltage were analyzed. The histograms of the breakdown voltage data showed that decreasing the pre oxidation time of the SIPOS-Si interface, the leakage current through the SIPOS films decreases. The power diodes supplied by Aegis Semicondutores Ltda was designed to support a breakdown voltage of 650 V. The power diodes passivated with SIPOS films supported a breakdown voltage up to 1200 V.

This research presents a novel microfabrication approach and testing methodology for cylindrical ion trap (CIT) microarray tunable for mass- spectrometers. The growing interest in cylindrical ion trap (CIT) mass-spectrometers is primarily due to ease with which cylindrical geometry can be realized as compared to hyperbolic surfaces found in conventional quadrupole ion traps. Also due to the fact that the potential at the center of hyperbolic electrode in quadrupole ion trap and cylindrical electrode in cylindrical ion trap (CIT) does not differ significantly[2]. Since the RF voltage required to eject a given mass-to-charge ion scales as the square of the ion trap radius, a decrease in ion trap dimensions provides a significant reduction in electronics requirements, thereby providing a pathway for overall system miniaturization. The reduction in sensitivity due to reduced ion storage capacity as a result of miniaturization can be improved by employing an array of identically sized ion traps. Microfabrication approach promises excellent uniformity in the fabrication of identically sized holes which in turn leads to low-cost high performance CIT microarray for mass spectrometers[1,2]. The criterion used for the determination of trap diameter was to ensure that the hole to be 1.09 times the wafer thickness to provide optimal potential to trap ions[1]. The end- plates were designed to optimize the electron and ion transmission into and out of the ion trap and provide a high quality electric field definition within each cylindrical ion trap (CIT)[3]. Two different approaches, namely deep reactive ion etching (DRIE) and mechanical drilling using ultrasonic disc cutter were proposed and used for the fabrication of ring-electrode which forms the main body of the ion trap. Excellent uniformity in hole diameter was observed in both the approaches. The end-plates were fabricated using deep reactive ion etching (DRIE) which provided high transmission rigid grid structure for ions and electrons. Standard Bosch process was used for deep reactive ion etching (DRIE). The two electrodes were metallized using electroless plating which provides excellent uniformity of coating even on end-plate structures with 5micro m through holes. CYTOP[trademark], a cyclized perfluoro polymer, was used as an insulation layer and intermediate bonding layer between the ring electrode and end-plates. The breakdown voltage for a released 16 micro m thick CYTOP[trademark] layer was found to be 1.47KV. An assembly for testing miniature cylindrical ion trap (CIT) was designed and built. An electron impact ionization source was used for generation of ions. Mass selective instability scan was used to selectively eject ions with different mass-to-charge ratio. A cylindrical ion trap (CIT) with 4mm diameter was fabricated and tested for analyte gases such as krypton and xenon.

The superior characteristics of silicon carbide, compared with silicon, have suggested considering this material for the next generation of power semiconductor devices. Among the different power switches, the bipolar junction transistor (BJT) can provide a very low forward voltage drop, a high current capability and a fast switching speed. However, in order to compete on the market, it is crucial to a have high current gain and a breakdown voltage close to ideal. Moreover, the absence of conductivity modulation and long-term stability has to be solved. In this thesis, these topics are investigated comparing simulations and measurements. Initially, an efficient etched JTE has been simulated and fabricated. In agreement with the simulations, the fabricated diodes exhibit the highest BV of around 4.3 kV when a two-zone JTE is implemented. Furthermore, the simulations and measurements demonstrate a good agreement between the electric field distribution inside the device and the optical luminescence measured at breakdown. Additionally, an accurate model to simulate the forward characteristics of 4H-SiC BJTs is presented. In order to validate the model, the simulated current gains are compared with measurements at different temperatures and different base-emitter geometries. Moreover, the simulations and measurements of the on-resistance are compared at different base currents and different temperatures. This comparison, coupled with a detailed analysis of the carrier concentration inside the BJT, indicates that internal forward biasing of the base-collector junction limits the BJT to operate at high current density and low forward voltage drop simultaneously. In agreement with the measurements, a design with a highly-doped extrinsic base is proposed to alleviate this problem. In addition to the static characteristics, the comparison of measured and simulated switching waveforms demonstrates that the SiC BJT can provide fast switching speed when it acts as a unipolar device. This is crucial to have low power losses during transient. Finally, the long-term stability is investigated. It is observed that the electrical stress of the base-emitter diode produces current gain degradation; however, the degradation mechanisms are still unclear. In fact, the analysis of the measured Gummel plot suggests that the reduction of the carrier lifetime in the base-emitter region might be only one of the causes of this degradation. In addition, the current gain degradation due to ionizing radiation is investigated comparing the simulations and measurements. The simulations suggest that the creation of positive charge in the passivation layer can increase the base current; this increase is also observed in the electrical measurements. / QC 20120522

Victory Garden, Stuart Moulthrop’s 1991 classic hyperfiction, presents a nonlinear story of U. S. home front involvement in the First Gulf War in a way that facilitates confusion and mimics a "fog of war" sort of (un)awareness. Using Storyspace to build his complex narrative, Moulthrop incorporates poetry, fiction, historical references, and low-tech graphic novel type elements. Among the graphic components are all-black and all-white screens that function as variables. Overtly, these screens speak of closure and signify unconsciousness; however, their nonverbal role may also be linked to the ineffability trope as used by Dante Alighieri and re-interpreted by contemporary linguist Ruiging Liang. To date, critics and meta-readers have incorrectly assumed that the protagonist, Emily Runbird, becomes a fatality. By failing to read her life or death as undecidable, we deny the fiction its full power as a postmodern interpretive dilemma. This assumption plays into what might be posited as Moulthrop’s real thesis: syllogism in a corrupted (war time) information system is potentially tragic. A summary of theories and critical approaches relevant to the blank screen’s use as interstice together with sample engagements with relevant texts—reading Victory Garden, as per Wolfgang Iser’s phenomenological approach, Stanley Fish’s reader response theory, and Jacques Derrida’s deconstruction—prove Victory Garden, to be a challenging but consistent literary breakdown (staged malfunction of reading habits). Ultimately, ineffability is shown to be a reading strategy and the action Aristotle characterizes as key to the definition of tragedy is seen as performed by the reader. Moulthrop dangles the question about Emily’s demise as a critical reading moment prone to corruption. The classical anagnorisis is not Emily’s; the revelation Moulthrop intends is reserved for the reader and is precipitated by the need to resolve aporia.

The fully quantum mechanical 'direct-potential-fit' (DPF) method has become increasingly widely used in the reduction of diatomic spectra. The central problem of this method is the representation of the potential energy and Born-Oppenheimer breakdown (BOB) correction functions. There are a number of problems associated with the existing method and potential forms. This thesis delineates these problems and finds solutions to some of them. In particular, it is shown that use of a different expansion variable and a new treatment of some of the expansions resolves most of the problems. These techniques have been successfully tested on the ground electronic states of the coinage metal hydrides and the Rb2 molecule. To address the problem of representing 'barrier' potential curves, a flexible new functional form, the 'double-exponential long-range' (DELR) potential function, is introduced and applied to the B barrier state of Li2. In addition, the Lambda-doubling level splitting which occurs for singlet Pi electronic states has been taken into account by extending the effective Schrodinger equation. The computer program DSPotFit developed in our laboratory for performing DPF analyses has been extended to incorporate the ability to fit the analytical potential energy functions to tunneling predissociation line widths for quasibound levels. Finally, an attempt is made to investigate whether there exists a hump in the ground state rotationless potential curve of beryllium hydride.

The fully quantum mechanical 'direct-potential-fit' (DPF) method has become increasingly widely used in the reduction of diatomic spectra. The central problem of this method is the representation of the potential energy and Born-Oppenheimer breakdown (BOB) correction functions. There are a number of problems associated with the existing method and potential forms. This thesis delineates these problems and finds solutions to some of them. In particular, it is shown that use of a different expansion variable and a new treatment of some of the expansions resolves most of the problems. These techniques have been successfully tested on the ground electronic states of the coinage metal hydrides and the Rb2 molecule. To address the problem of representing 'barrier' potential curves, a flexible new functional form, the 'double-exponential long-range' (DELR) potential function, is introduced and applied to the B barrier state of Li2. In addition, the Lambda-doubling level splitting which occurs for singlet Pi electronic states has been taken into account by extending the effective Schrodinger equation. The computer program DSPotFit developed in our laboratory for performing DPF analyses has been extended to incorporate the ability to fit the analytical potential energy functions to tunneling predissociation line widths for quasibound levels. Finally, an attempt is made to investigate whether there exists a hump in the ground state rotationless potential curve of beryllium hydride.