As we emerge into an age of hyperconnectivity, technology becomes increasingly pervasive in our daily lives. And with this change, our behavior and values progressively shift towards instant access, constant availability and multi-tasking. Recent research studies in cognitive psychology have indicated a change in the wiring of our brain due to these behavior shifts.  In this thesis project, technology’s role in our lives was explored, particularly within the context of home, a traditionally restorative environment.  By identifying key problem areas from user research and drawing inspirations from slow technology and other relevant fields of expertise, key concepts were conceptualized. The result is a collection of computer-mediated objects designed to support downtime and reflective behavior, as well as, integrate into our everyday living.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Zugl.: Veränd. Diss.

Thesis (doctoral)--Universität Göttingen, 2001. / Includes bibliographical references (p. 285-294).

Baigiamajame magistro darbe pirmame skyriuje nagrinėjama precizinių mechatroninių sistemų veikimo principai, medžiagų savybės, aliekama konstrukcijų analizė, tyrimų analizė. Antrame skyriuje apžvelgtas precizinių mechatroninių sistemų modeliavimas, pateikti skaitiniai modeliai, ištirta precizinių mechatroninių sistemų geometrinių parametrų įtaka, pateikta dominavimo koeficientų nauda. Trečiame skyriuje pateikti praktinio tyrimo rezultatai. Atlikus teorinės medžiagos ir praktines užduoties analizę, pateikiamos baigiamojo darbo išvados. Darbą sudaro 6 dalys: įvadas, precizinių mechatroninių sistemų veikimo principai, precizinių mechatroninių sistemų modeliavimas, precizinių mechatroninių sistemų tyrimas, išvados, literatūros sąrašas. Darbo apimtis – 54 p. teksto be priedų, 19 iliustr., 8 lent. Atskirai pridedami darbo priedai. / In the first section of the final master thesis precision mechatronic system‘s operating principles, characteristics of materials are analyzed, analysis of constructions and research are accomplished. In the second section precision mechatronic system‘s simulation is reviewed, numerical models are given, precision mechatronic system‘s influence of geometrical parameters is studied, advantage of the dominance coefficients is represented. In the third section practical results are presented. After the theoretical material and practical task analysis accomplishment, the conclusions of final thesis are presented. The work contains 6 sections: introduction, precision mechatronic system‘s operating principles, precision mechatronic system‘s simulation, precision mechatronic system‘s research, conclusions, references. The volume of the thesis – 54 p. of text without supplements, 19 ill., 8 tab. Separately are attached thesis supplements.

As estrelas Be compreendem uma grande faixa de massas e temperaturas. Por definição, são objetos de tipo B com classe de luminosidade entre V e III que apresentam, ou apresentaram alguma vez, linhas de Balmer em emissão (eventualmente metais uma vez ionizados) e/ou linhas com padrões de absorção shell, possivelmente formadas em um envelope circunstelar. Embora se saiba há muito tempo que esses objetos são rodadores rápidos e que giram pelo menos 1,5 a 2 vezes mais rápido do que as estrelas B normais, ainda é incerto se esses objetos são ou não em média rodadores crticos, não obstante as recentes observações interferométricas de HD 10144 (Achernar) (uma estrela Be tpica) indicarem se tratar de um rodador crtico. Devido às suas altas taxas de rotação, as quais originam distorções geométricas e distribuições não uniformes de temperatura dependentes da latitude estelar, os valores de velocidade de rotação derivados por métodos clássicos são sistematicamente subestimados. Além disso, os efeitos da rotação, aliados à presença do envelope circunstelar, mascaram as condições fsicas desses objetos, resultando em diferenças significativas em seus estágios evolutivos na seqüência principal. Neste trabalho apresentamos os resultados do estudo espectroscópico de estrelas Be em duas vertentes. Na primeira tratamos o tema da formação e estrutura do envelope circunstelar de estrelas Be, através das análises de duas estrelas, HD 127972 ( Cen) e HD 10144 (Achernar). Nesse estudo identificamos e caracterizamos seus modos de pulsação, os quais se constituem em um possvel mecanismo de perda de massa e formação do envelope. Além disso, estudamos a estrutura de seus envelopes circunstelares através da modelagem de perfis de Balmer em emissão. Na segunda vertente quantificamos as condições fsicas de 141 estrelas de campo, onde 114 são de tipo Be e 27 estrelas são B normais. Nesse estudo, comparamos os estágios evolutivos desses objetos obtidos através de métodos clássicos com os estágios evolutivos corrigidos dos efeitos da rotação elevada. Concluimos que o \"fenômeno Be\" pode ocorrer em todas as fases da evolução estelar na seqüência principal. / Be stars encompass a large mass and temperature range. By definition, they are B-type objects with luminosity classes V to III that have, or have shown at least once, Balmer lines in emission (eventually single-ionized metals) and/or lines with shell absorption patterns possibly formed in a circumstellar envelope. Though it has long been known that these objects are fast rotators and that they rotate at least 1.5 to 2 times faster than normal B stars, it is still uncertain whether or not these objects are in average critical rotators, although recent interferometric observations on Achernar (a typical Be star) pointed it out to be a critical rotator. Due to their high rotation rates which originate geometrical distortions and non-uniform temperature distributions dependent on the stellar latitude, the rotation velocity values derived from classical methods are systematically underestimated. Moreover, the rotation effects allied to the continuum emission due to the presence of a circumstellar envelope disguise the physical conditions of these objects, resulting in significative differences of their main-sequence evolutionary stages. In this work we present the results of the spectroscopic study of Be stars in two approaches. In the first one we treat the subject of formation and structure of the circumstellar envelope of Be stars through the analyses of two stars, HD 127972 ( Cen) and HD 10144 (Achernar). In this study we identify and characterize their pulsation modes, which constitute in a possible mechanism of mass loss and envelope formation. Moreover we study the structure of their circumstellar envelopes through the modeling of Balmer profiles in emission. In the second approach we quantify the physical conditions of 141 field stars, where 114 are Be-type stars and 27 stars are normal B stars. In this study, we compared the evolutionary stages of these objects obtained through classical methods with evolutionary stages corrected for high rotation effects. We conclude that the \"Be phenomenon\" can occur at whatever stage of the stellar evolution on the main sequence.

Estrelas Be são reconhecidas pela sua rápida rotação e pulsação não radial. São as únicas estrelas da Sequência Principal que apresentam discos circunstelares, os quais são formados por meio de processos ainda não completamente compreendidos. A modelagem das forças que atuam neste sistema conduz a previsões teóricas sobre a estrutura do disco que podem ser comparadas com dados observacionais. Podemos estudar as propriedades físicas dos discos de estrelas Be pelo efeito que a luz estelar sofre ao passar por eles, por exemplo, modelando a transferência radiativa. Neste ponto, a polarização surge como uma ferramenta muito útil para a investigação destes discos, permitindo a determinação de quantidades físicas importantes do sistema, como a densidade numérica de partículas e o ângulo de inclinação. Uma variabilidade intrigante observada em estrelas Be é a transição aperiódica entre uma fase B normal (sem disco) e uma fase Be (com disco). Estudos de monitoramento recentes encontraram, a partir da análise da polarização intrínseca decorrente da transição entre estas fases, uma relação significante entre a mudança da polarização através do salto de Balmer versus a polarização na banda V, fazendo surgir uma estrutura em loop como função do tempo, no assim denominado Diagrama Cor-Polarização. Neste trabalho, apresentamos uma análise do Diagrama Cor-Polarização por meio de modelos diversos. Fazemos uso do Disco de Decréscimo Viscoso que é o paradigma atual para explicar a formação e evolução dos discos de estrelas Be. Com isso, visamos determinar como a polarimetria pode contribuir para a compreensão dos mecanismos fundamentais envolvidos no processo de formação e dissipação do disco. / Be stars are recognized by their rapid rotation and non-radial pulsation. They are the only stars in the Main Sequence that have circumstellar disks that are formed by processes not yet fully understood. The modeling of the forces acting on this system leads to theoretical predictions about the structure of the disk that can be compared to observational data. We can study physical the properties of Be disks by modeling how stellar light is reprocessed by them. This requires solving the detailed radiative transfer problem involved. In this point, the study of polarization arise as a useful tool to investigate these disks, allowing for the determination of important physical quantities of the system, such as the particle number density and inclination angle. An intriguing variability observed in Be stars is the aperiodic transition between a B normal phase (without disk) to a Be phase (with disk). Recent monitoring studies found, from the analysis of the intrinsic polarization arising of the transition between these phases, a significant relation between the polarization change through the Balmer jump versus the V-Band polarization, giving rise to a loop structure as a function of time, in the so-called Color-Polarization Diagram. This work presents an analysis of the Color-Polarization Diagram by several models. We make use of the Viscous Decretion Disk Model, which assumes the existence of some injection mechanism of material at keplerian velocities in the disk base, where the turbulent viscosity acts carrying angular momentum from de inner parts to the outer regions. With this, we aimed to extend our knowledge about the fundamental mechanisms involved in the formation and dissipation processes of the disk.

As estrelas Be compreendem uma grande faixa de massas e temperaturas. Por definição, são objetos de tipo B com classe de luminosidade entre V e III que apresentam, ou apresentaram alguma vez, linhas de Balmer em emissão (eventualmente metais uma vez ionizados) e/ou linhas com padrões de absorção shell, possivelmente formadas em um envelope circunstelar. Embora se saiba há muito tempo que esses objetos são rodadores rápidos e que giram pelo menos 1,5 a 2 vezes mais rápido do que as estrelas B normais, ainda é incerto se esses objetos são ou não em média rodadores crticos, não obstante as recentes observações interferométricas de HD 10144 (Achernar) (uma estrela Be tpica) indicarem se tratar de um rodador crtico. Devido às suas altas taxas de rotação, as quais originam distorções geométricas e distribuições não uniformes de temperatura dependentes da latitude estelar, os valores de velocidade de rotação derivados por métodos clássicos são sistematicamente subestimados. Além disso, os efeitos da rotação, aliados à presença do envelope circunstelar, mascaram as condições fsicas desses objetos, resultando em diferenças significativas em seus estágios evolutivos na seqüência principal. Neste trabalho apresentamos os resultados do estudo espectroscópico de estrelas Be em duas vertentes. Na primeira tratamos o tema da formação e estrutura do envelope circunstelar de estrelas Be, através das análises de duas estrelas, HD 127972 ( Cen) e HD 10144 (Achernar). Nesse estudo identificamos e caracterizamos seus modos de pulsação, os quais se constituem em um possvel mecanismo de perda de massa e formação do envelope. Além disso, estudamos a estrutura de seus envelopes circunstelares através da modelagem de perfis de Balmer em emissão. Na segunda vertente quantificamos as condições fsicas de 141 estrelas de campo, onde 114 são de tipo Be e 27 estrelas são B normais. Nesse estudo, comparamos os estágios evolutivos desses objetos obtidos através de métodos clássicos com os estágios evolutivos corrigidos dos efeitos da rotação elevada. Concluimos que o \"fenômeno Be\" pode ocorrer em todas as fases da evolução estelar na seqüência principal. / Be stars encompass a large mass and temperature range. By definition, they are B-type objects with luminosity classes V to III that have, or have shown at least once, Balmer lines in emission (eventually single-ionized metals) and/or lines with shell absorption patterns possibly formed in a circumstellar envelope. Though it has long been known that these objects are fast rotators and that they rotate at least 1.5 to 2 times faster than normal B stars, it is still uncertain whether or not these objects are in average critical rotators, although recent interferometric observations on Achernar (a typical Be star) pointed it out to be a critical rotator. Due to their high rotation rates which originate geometrical distortions and non-uniform temperature distributions dependent on the stellar latitude, the rotation velocity values derived from classical methods are systematically underestimated. Moreover, the rotation effects allied to the continuum emission due to the presence of a circumstellar envelope disguise the physical conditions of these objects, resulting in significative differences of their main-sequence evolutionary stages. In this work we present the results of the spectroscopic study of Be stars in two approaches. In the first one we treat the subject of formation and structure of the circumstellar envelope of Be stars through the analyses of two stars, HD 127972 ( Cen) and HD 10144 (Achernar). In this study we identify and characterize their pulsation modes, which constitute in a possible mechanism of mass loss and envelope formation. Moreover we study the structure of their circumstellar envelopes through the modeling of Balmer profiles in emission. In the second approach we quantify the physical conditions of 141 field stars, where 114 are Be-type stars and 27 stars are normal B stars. In this study, we compared the evolutionary stages of these objects obtained through classical methods with evolutionary stages corrected for high rotation effects. We conclude that the \"Be phenomenon\" can occur at whatever stage of the stellar evolution on the main sequence.

<p>This thesis deals with the atmospheric distribution of the cosmogenic isotopes ⁷Be (half-life 53 days) and ¹⁰Be (half-life 1.51 million years) as well as the anthropogenic isotope ¹³⁷Cs (half-life 30 years) in aerosols and precipitation. Samples covering continuous or selected parts of the period 1972-2005 in Sweden and Europe are evaluated with respect to production, air mass transport and fallout processes. Such information is valuable in assessing the potential of these isotopes as indicators of air mass mixing and solar modulation factors that affect climate change. The results of ⁷Be and ¹⁰Be show seasonal variability and an 11-year cyclic pattern which is anti-correlated with the solar activity. Variations in seasonal trends of ⁷Be and ¹³⁷Cs in aerosols during the post- and pre-Chernobyl period reflect tropospheric influence from ¹³⁷Cs-heavily contaminated regions. A clear latitude dependence is observed in our beryllium isotope data where highest fallout is found in mid-latitudes compared to high and low latitude regions in the Northern hemisphere. This pattern reflects the general air mass circulation in the troposphere. However, stratospheric air mass influence was also identified in mainly single events and through tropopause folding during spring-summer seasons. The ratio of ¹⁰Be/⁷Be is used to estimate effects of air mass transport on production signal. The results show ratios between 1 and 3, much higher than the theoretically predicted value (0.6) in the atmosphere, which suggests contribution from ⁷Be-depleted (old) air masses. The relationship between monthly ⁷Be atmospheric activity and Total Fractional Cloud Cover (TFCC), collected from satellite imagery, over Sweden for the years (1991-2000) indicates a negative seasonal correlation. This observation can be related to depletion of aerosol from the atmosphere due to trapping in clouds. </p>

This thesis deals with the atmospheric distribution of the cosmogenic isotopes 7Be (half-life 53 days) and 10Be (half-life 1.51 million years) as well as the anthropogenic isotope 137Cs (half-life 30 years) in aerosols and precipitation. Samples covering continuous or selected parts of the period 1972-2005 in Sweden and Europe are evaluated with respect to production, air mass transport and fallout processes. Such information is valuable in assessing the potential of these isotopes as indicators of air mass mixing and solar modulation factors that affect climate change. The results of 7Be and 10Be show seasonal variability and an 11-year cyclic pattern which is anti-correlated with the solar activity. Variations in seasonal trends of 7Be and 137Cs in aerosols during the post- and pre-Chernobyl period reflect tropospheric influence from 137Cs-heavily contaminated regions. A clear latitude dependence is observed in our beryllium isotope data where highest fallout is found in mid-latitudes compared to high and low latitude regions in the Northern hemisphere. This pattern reflects the general air mass circulation in the troposphere. However, stratospheric air mass influence was also identified in mainly single events and through tropopause folding during spring-summer seasons. The ratio of 10Be/7Be is used to estimate effects of air mass transport on production signal. The results show ratios between 1 and 3, much higher than the theoretically predicted value (0.6) in the atmosphere, which suggests contribution from 7Be-depleted (old) air masses. The relationship between monthly 7Be atmospheric activity and Total Fractional Cloud Cover (TFCC), collected from satellite imagery, over Sweden for the years (1991-2000) indicates a negative seasonal correlation. This observation can be related to depletion of aerosol from the atmosphere due to trapping in clouds.