568 research outputs found

    Rolling maneuver load alleviation using active controls

    Get PDF
    Rolling Maneuver Load Alleviation (RMLA) was demonstrated on the Active Flexible Wing (AFW) wind tunnel model in the LaRC Transonic Dynamics Tunnel. The design objective was to develop a systematic approach for developing active control laws to alleviate wing incremental loads during roll maneuvers. Using linear load models for the AFW wind-tunnel model which were based on experimental measurements, two RMLA control laws were developed based on a single-degree-of-freedom roll model. The RMLA control laws utilized actuation of outboard control surface pairs to counteract incremental loads generated during rolling maneuvers and roll performance. To evaluate the RMLA control laws, roll maneuvers were performed in the wind tunnel at dynamic pressures of 150, 200, and 250 psf and Mach numbers of .33, .38, and .44, respectively. Loads obtained during these maneuvers were compared to baseline maneuver loads. For both RMLA controllers, the incremental torsion moments were reduced by up to 60 percent at all dynamic pressures and performance times. Results for bending moment load reductions during roll maneuvers varied. In addition, in a multiple function test, RMLA and flutter suppression system control laws were operated simultaneously during roll maneuvers at dynamic pressures 11 percent above the open-loop flutter dynamic pressure

    Optical properties of metal nanoparticles investigated using polarised light.

    Get PDF
    The number of applications of metal nanoparticles (MNPs) are growing, and one of their most interesting properties is the interactions between MNPs and light. Especially in the visible regime, MNPs are very good at absorbing light at specific wavelengths, which opens interesting opportunities for use in many technological branches ranging from quantum dot displays to solar energy conversion. The principle behind the light absorption is the localised surface plasmon (LSPR) effect, in which the oscillating electric field of the light wave excites the electrons of the particle. The resonance of these oscillations is dependent on the size, shape, metal type and surrounding medium of the particle, and as such these parameters can be tailored depending on the application. Because of the surrounding mediums effect on the resonance wavelength, nanoparticles can be used in sensors to detect changes in refractive index. The goal of this thesis work is to investigate the viability of nanoparticle arrays as sensor devices, and more specifically explore a phenomenon in which the LSPR is selectively supressed to decrease the width of the plasmon peak, enhancing the sensitivity of potential sensor applications. Large arrays (1 x 1 mm) of gold nanoparticles with varying interparticle distances were fabricated using electron beam lithography (EBL), and the fabrication process was iteratively improved due to an initial lack of particle adhesion to the substrate surface, resulting in samples with a quality high enough to perform optical measurements. The particles were analysed by means of transmission spectroscopy, employing both polarised and unpolarised light, the former using a novel spectrometer. The measurements presented here are the first measurements carried out with polarised light at the UiB nanostructures laboratory. The results demonstrate the suppression of the LSPR, and the spectral positions of these suppression dips, as well as the relationship between the optical response of the particles when subjected to polarised light as compared to unpolarised light. This lays the foundation for further investigation into a refractive index sensor based on nanoparticles.Masteroppgave i nanovitenskapMAMN-NANONANO39

    A family with atypical CADASIL

    Get PDF

    Dialogical practices : diving into the poetic movement exploring ‘supervision’ and ‘therapy’

    Get PDF
    A thesis submitted for the degree of Doctorate in Systemic Practice of the University of BedfordshireThis thesis explores a dialogical approach – in relation to supervision, therapy and research. I have as supervisor inquired into my relationship with groups of supervisees who were training to become family therapists or systemic practitioners. Through my doctoral portfolio, I speak from within my practice and I show in some detail the micro processes in relational encounters which help dialogue to evolve. I also address grand narratives about what it means to be a human being, and show how perceiving a human being as dialogical has extensive and governing consequences for how we think about a person’s movements in the world, how we think about them as person, in relation to other people, and how we understand problems, and approach problem solving. My research has been a doing, an experiencing and a creation of knowing in a reflexive flow. My research philosophy, mode of approaching my practice as therapist and supervisor (and as a person in the world) has reflexively been created through my being in practice. I show how an embodied belief in fluidity and complexity, enables me as supervisor to contribute to a space in the context of supervision which welcomes the freedom of a kind of orientation which is open towards situated, emerging, novel and provisional understanding. By attending to here-and-now interactions, becoming answerable in the moment and by embracing intuition, ambiguity and relational compassion, we have been able to welcome risk-taking and improvisation. This mode of dialogical supervision demonstrates a willingness to spontaneously dive into the uniqueness of every new encounter and every new movement. I see this as the poetics of the dialogical meeting. I have experienced how this space has opened up quite unexpected aspects of the supervisees’ experiences and has served as an incitement for them to question different aspects of their relationship to life. This has reflexively created a certain spirit and atmosphere that has invited us all to be bolder in our sharing and exploration of our lives, practice and our ideas. This thesis makes a contribution concerning: how we can be with people in ways that opens up more understanding and creates a sense of belonging and liberation; challenging and transgressively exploring discursive boundaries which attempt to define and fix what research is, what therapy is, what supervision is, and welcomes the infinity of opportunities and possibilities life may offer us. Thus I suggest that it may become significant for the profession to review the usefulness and legitimacy of distinct categorization between therapy and supervision. Through my choice of genre I offer the reader a possibility to respond emotionally as well as intellectually to my writing. I believe the way I have chosen to re-present my research through a mix of genre and evocative texts not ‘frozen’ findings, permits and anticipates novel ways of going on in relation to research in a manner that I don’t believe have been described in this way before within the community of family therapy and systemic practice

    Economic Effects of Workfare Reforms for Single Mothers: Benefit Substitution and Labour Supply Responses

    Get PDF
    Under embargo until: 2021-03-14We analyse the economic effects of nationwide Norwegian reforms on the state benefit programme targeting single mothers. Our results show that for each reduction of 100 Norwegian kroner (NOK) in benefit payments from the programme, single mothers replaced 65 NOK through benefit substitution. Their labour supply and disposable income also increased in the short term. However, the reforms doubled the poverty rate among single mothers in the long term. The reforms led to a total net gain to public expenditure of 3.6 billion NOK (449 million euros) during the 1998–2008 period, corresponding to a 14 percent decrease in total benefit payments to single mothers.acceptedVersio

    The effect of negative income shocks on pensioners

    Get PDF
    This paper provides the first evidence on the labor supply response to negative income shocks among full-time retirees, exploiting an institutional feature that caused differential and unexpected income losses among otherwise identical individuals in a sharp regression discontinuity design. We conclude that full-time retirees do not return to work despite losing a meaningful share of their annual income. Specifically, we can rule out response elasticities larger than 0.051. This precisely estimated null effect also extends to retirees who have limited savings, who face little demand-side obstacles to reentering the labor force, and to younger individuals who just recently entered retirement. The paper further shows that the negative income shock had no impact on the health of pensioners as measured by their utilization of the health care system. The lack of an employment and health care utilization response suggests that a reduction in benefit levels may have little impact on individuals in our context. At the height of an ongoing global crisis in which public pension funds are rapidly losing value, these results are particularly important.acceptedVersio

    DAC-3 Pointing Stability Analysis Results for SAGE 3 and Other Users of the International Space Station (ISS) Payload Attachment Sites (PAS)

    Get PDF
    The purpose of this paper is to provide final results of a pointing stability analysis for external payload attachment sites (PAS) on the International Space Station (ISS). As a specific example, the pointing stability requirement of the SAGE III atmospheric science instrument was examined in this paper. The instrument requires 10 arcsec stability over 2 second periods. SAGE 3 will be mounted on the ISS starboard side at the lower, outboard FIAS. In this engineering analysis, an open-loop DAC-3 finite element model of ISS was used by the Microgravity Group at Johnson Space Flight Center to generate transient responses at PAS to a limited number of disturbances. The model included dynamics up to 50 Hz. Disturbance models considered included operation of the solar array rotary joints, thermal radiator rotary joints, and control moment gyros. Responses were filtered to model the anticipated vibration attenuation effects of active control systems on the solar and thermal radiator rotary joints. A pointing stability analysis was conducted by double integrating acceleration transient over a 2 second period. Results of the analysis are tabulated for ISS X, Y, and Z Axis rotations. These results indicate that the largest excursions in rotation during pointing occurred due to rapid slewing of the thermal radiator. Even without attenuation at the rotary joints, the resulting pointing error was limited to less than 1.6 arcsec. With vibration control at the joints, to a maximum 0.5 arcsec over a 2 second period. Based on this current level of model definition, it was concluded that between 0 - 50 Hz, the pointing stability requirement for SAGE 3 will not be exceeded by the disturbances evaluated in this study

    Samarbeidende autonomistÞtte. Skole-hjem-samarbeid som pedagogisk fenomen i videregÄende skole

    Get PDF
    Avhandlinga utforsker og teoretiserer skole-hjem-samarbeid som pedagogisk fenomen i videregÄende skole. Forskningsdesignet er kvalitativt og dialogkafé anvendes som metode for Ä utforske praksiserfaringer og skape dialoger. I tillegg inngÄr en analyse av juridiske dokumenter. Praksisteori anvendes for Ä redegjÞre for og analysere samarbeidet som pedagogisk praksis. Teori om danning og autonomistÞtte anvendes for Ä analysere elevenes behov og posisjon i samarbeidet. Den fÞrste artikkelen utforsket hvordan skole-hjem-samarbeid praktiseres i videregÄende skole. Analysene avdekket tre forhold av betydning for videreutvikling av skole-hjem-samarbeid: a) klargjÞre lÊrerprofesjonens juridiske forpliktelser, b) engasjere og myndiggjÞre elevenes aktÞrskap og c) unngÄ ei problemorientert tilnÊrming som driver i skolenes tilnÊrming til foreldre. Den andre artikkelen utforsket hvordan lovgivningen pÄvirker skole-hjem-samarbeid. Analysene avdekket tre spenninger i gjeldende lovgivning: elevenes selvbestemmelse versus foreldrenes forpliktelser, foreldregruppas manglende representasjon i videregÄende skole og til dels motstridende sprÄklig omtale av foreldre pÄ tvers av juridiske dokumenter. Den tredje artikkelen utforsket elevenes erfaringer og behov, nÄr det gjelder stÞtte og posisjon i dette samarbeidet. Resultatene viste at skole-hjem-samarbeid er en fÞlelsesladet praksis for elevene. Positive erfaringer forsterket elevenes motivasjon, stimulerte skolearbeidet og bidro til hÄndtering av ulike utfordringer. Det var likevel de negative erfaringene som dominerte. Resultatene viste en ambivalens der elevene bÄde hadde et Þnske om Ä vÊre selvstendige, men samtidig hadde behov for foreldrestÞtte. Studien viste videre at elevene trer frem i posisjon som bÄde subjekt og objekt i samarbeidet. For Ä drÞfte resultatene pedagogisk-filosofisk teori anvendt om elevenes danningsprosess og pedagogisk-psykologisk teori om elevenes behov for autonomistÞtte. PÄ den mÄten utdypes skole-hjem-samarbeid i videregÄende skole som samarbeidende autonomistÞtte i elevenes danningsprosess og argumenterer for Ä styrke elevenes subjektposisjon i dette samarbeidet.The dissertation explores and theorizes school-home collaboration as a pedagogical phenomenon in upper secondary school. The research design is qualitative and dialogue café is used as a method for exploring experiences and creating dialogues. In addition, an analysis of legal documents has been carried out. Practice theory is used to account for and analyse collaboration as a pedagogical practice. Theory of bildung and autonomy support is used to analyse students' needs and position in the collaboration. The first article explored how school-home collaboration is practiced in upper secondary school. The analyses revealed three factors of importance, for further development of school-home collaboration: a) clarify the teaching profession's legal obligations, b) engage and empower students' participation, and c) avoid a fire-fighting approach as the schools' main approach to parents. The second article explored how the legislation affects school-home collaboration. The analyses revealed three tensions in current legislation: students' self-determination versus parents' obligations, the parent group's lack of representation in upper secondary school, and partly contradictory linguistic mention of parents across legal documents. The third article explored students' needs, in terms of support and position in this collaboration. The results showed that school-home collaboration is an emotional practice for students. Positive experiences strengthened the students' motivation, stimulated schoolwork, and contributed to dealing with various challenges. Nevertheless, it was the negative experiences that dominated. The results showed an ambivalence where the students both had a desire to be independent, but at the same time needed parental support. The study further showed that the students emerge in a position as both subject and object in the collaboration. To discuss the results, I have applied pedagogical-philosophical theory about the students' bildung process and pedagogical-psychological theory about the students' need for autonomy support. In this way, I elaborate school-home collaboration in upper secondary school as collaborative autonomy support in the students' bildung process and argue for strengthening the students' subject position in this collaboration

    Margareta Nockert og Göran Possnert 2002. Att datera textilier

    Get PDF
    Att datera textilier er en bok om hvilke muligheter som finnes til Ä datere historiske og arkeologiske tekstiler. Boken har et sterkt fokus pÄ radiologisk datering, og da spesielt gjennom tandemakseleratorsystemet. En stor del av boken presenterer nye og til dels oppsiktsvekkende dateringer av velkjent materialtilfang fra Norden, fortrinnsvis fra Sverige og Norge. Her fÄr vi resultater av akseleratoranalyser utfÞrt over en rekke Är pÄ 1990-tallet, i en periode hvor det foregikk en suksessiv utvikling og forbedring av denne metoden. Forfatterne henvender seg i fÞrste rekke til museumssektoren og til humanister innenfor tekstil og draktvitenskap
    • 

    corecore