Response function analysis of excited-state kinetic energy functional constructed by splitting k-space

Over the past decade, fundamentals of time independent density functional theory for excited state have been established. However, construction of the corresponding energy functionals for excited states remains a challenging problem. We have developed a method for constructing functionals for excited states by splitting k-space according to the occupation of orbitals. In this paper we first show the accuracy of kinetic energy functional thus obtained. We then perform a response function analysis of the kinetic energy functional proposed by us and show why method of splitting the k-space could be the method of choice for construction of energy functionals for excited states.Comment: 11 page

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Sin resume

Estudo do acoplamento magnetoelétrico em BaTiO3 contendo Fe

Mestrado em Engenharia FísicaEsta dissertação destina-se a tentar compreender a natureza de comportamentos magnéticos anómalos do BaTiO3 que se demonstrou que possuía 113 ppm de Fe na sua composição, provenientes dos reagentes utilizados na produção deste material. Prepararam-se dois conjuntos de amostras para tentar compreender se e como o Fe é responsável pelos comportamentos anómalos que se podem observar no terceiro capítulo desta dissertação. Um dos conjuntos consistiu na preparação de 5 pastilhas de Titanato de Bário (com as 113 ppm de Fe) com diferentes tratamentos térmicos. O segundo conjunto consistiu em utilizar 5 monocristais de BaTiO3 adquiridos comercialmente nos quais foi feita uma dopagem de iões Fe com diferentes concentrações. Fez-se a caracterização estrutural destas amostras utilizando Difração de raios-X, espectroscopia de Raman, SEM e EDS. Por fim fez-se caracterização magnética medindo-se curvas M-H e M-T utilizando um VSM e/ou SQUID. Concluiu-se que o efeito Magnetolétrico presente nas amostras de BTO estudadas nesta dissertação deve ocorrer através de efeitos nas fronteiras de grão onde clusters de óxido de ferro se acumulam resultando num efeito de interfaces. Podemos dizer que este BaTiO3: Fe é um Multiferróico não convencional, uma vez que através do efeito Magnetolétrico, o Fe pode ser utilizado como uma sonda Multiferróica utilizável no estudo magnético de transições de fase elétricas do BaTiO3! Como trabalho futuro irão fazer-se estudos usando a espetroscopia de Mössbauer e PAC para determinar a natureza magnética local do composto magnético envolvido no acoplamento ME.This work aims to understand the nature of the anomalous magnetic behaviors of BaTiO3 which has 113 ppm of Fe in Its composition from the reactants used to synthesize this material. Two sets of samples were prepared to try to understand whether the Fe influences the anomalous behavior observed in the third chapter of this work. One set of samples involved the preparation of 5 pellets barium titanate (with 113 ppm of Fe) with different thermal treatments. The second group consisted of 5 BaTiO3 single crystals commercially obtained, in which ion doping was made using different Fe concentrations. Structural characterization of these samples was made using X-ray diffraction, Raman spectroscopy, SEM and EDS. Finally we made the magnetic characterization by measuring M-T and M-H curves using a VSM and/or a SQUID. We concluded that the Magnetoelectric effect present in the BTO samples should occur because the iron oxide clusters which accumulate at the grain boundaries result in interface effects. We can say that this BaTiO3: Fe is an unconventional Multiferroic were the Fe can be used as a Magnetoelectric probe that can be used in the magnetic study of electric phase transitions of BaTiO3! Future work will be made using Mössbauer spectroscopy and PAC to determine the local magnetic nature of the magnetic compound involved in Magnetoelectric effect

Engagement in cultural activity and public health: The HUNT Study, Norway

Cultural life and engagement in cultural activity have been part of human daily life throughout the ages. In recent years, interest has increased in the public health significance of engagement in cultural activity and more than 3000 studies have identified possible impacts of participation in culture and arts. However, despite growing public awareness, there is limited evidence of whether such engagement affects public health because most research into factors affecting engagement has focused on individual-level characteristics. 'Passive' and 'active' engagement modes, attending as an observer or audience (receptive) vs active participation (creative) may have different health effects. Earlier research is characterized by diverging approaches and often lacks consideration of a broad spectrum of activities, broad age groups, and gender differences. Some studies suggest that engagement in cultural activity enhances longevity and may protect against cause-specific mortality, although knowledge about this is limited and insufficient. It has been suggested that high consumers of health services are often low consumers of cultural engagement. However, this association appears to be undocumented. The overall objective of this thesis was to study receptive and creative engagement with cultural activity and its relationship with all-cause and cause-specific mortality and with general practitioner consultations. Further, the aim was to explore possible gender differences in both receptive and creative engagement. Data were obtained from the Trnndelag Health Study (The HUNT Study) in Norway. All citizens aged 20 years and older were invited, and participation was voluntary. Data from the HUNT3 survey (2006-08) were extracted, which contained self­ reported information on engagement with a variety of receptive and creative activities, and relevant covariates. These data were linked to the Cause of Death registry (Paper I and II), and to an administrative register using activity data from all general practitioners' (GP) offices nationwide (Paper lll) and up to the end of 2015. The first aim was to examine the activities, number of different activities (variety) and the frequency of engagement in cultural activity that protected against all-cause mortality (Paper I). A total of I 905 participants died during the mean 8.15-year follow-up. The variety of activities seems to enhance longevity cumulatively with an increasing number of different activities, to a greater extent than weekly frequency. When the number of receptive activities was associated with all-cause mortality, reduced mortality risk occurred. Gender-specific analyses suggest the association was attributable to men. Gender-specific analyses showed a clear gradient of the protective effect of participation in creative activity both in terms of variety and frequency, for both women and men. The second aim was to explore the association between activities, variety, and frequency of engagement in cultural activity and cardiovascular disease (CVD) and cancer-related mortality (Paper 11). During an average of 8.15 years of follow-up, there were 563 cardiovascular-disease and 752 cancer-related deaths in the sample. Cultural engagement in creative activities less than once a week, and less than twice per week was associated with a reduced risk of CVD mortality. However, gender-specific findings show that men had a risk reduction when participating less than once a week For the overall sample, participating between two to nine times per week in combined receptive and creative activities may reduce cancer-related mortality. Participation in creative activity from once up to less than twice per week, may lower the risk of cancer­ related mortality. The total variety of activities lowers the CVD and cancer-related mortality risk for all participants, whereas reduction in cancer-related mortality was evident in men. The final aim was to investigate the associations between activities, variety and the frequency of cultural activity engagement and the number of GP consultations an individual had (Paper lll). In total 31 847 participants, aged 30-79, were included in a seven-year follow-up with a mean of 3.57 GP consultations. Findings revealed that participating in creative activities and a combination of receptive and creative activities was associated with lower demand for GP consultation among men who participated, compared to non-engaged men. However, no such findings were found among the engaged women. The variety of activities seem to lower GP consultations to a greater extent than weekly frequency, and the total variety (combined receptive and creative activities) may lower the likelihood of GP consultations among the engaged men. In conclusion, the findings indicate that people who are engaged in cultural activities have lower mortality overall, and lower mortality from cardiovascular disease and cancer-related diseases specifically. Men who are engaged in cultural activities also have fewer GP consultations. However, given the limitations of the studies, there is no evidence to claim that there is a causal relationship between any of these associations. Based on these findings, future public health policy and initiatives that facilitate citizens' participation may be health promoting. But it is important to note that our studies are observational and not intervention studies. The results do not say anything for certain about what effects measures to increase culteral participatation in society will have on health. It is also imporatnt that there is a real opportunity for the entire population to become involved in cultural activities, regardless fo socioeconomic living conditions

Zero-field ODMR and relaxation of Si-vacancy centers in 6H-SiC

Silicon vacancies in silicon carbide (SiC) have been proposed as interesting candidates for quantum technology applications such as quantum sensing and quantum repeaters. SiC exists in many polytypes with different plane stacking sequences, and in each polytype, the vacancies can occupy a variety of different lattice sites. In this work, we focus on the three important charged silicon vacancies in the 6H-SiC polytype. We record the photoluminescence and continuous-wave optically detected magnetic resonance (ODMR) spectra at different radio-frequency power levels and different temperatures. We individually select the zero-phonon lines of the different silicon vacancies at low temperatures and record the corresponding ODMR spectra. ODMR allows us to correlate optical and magnetic resonance spectra and thereby separate signals from V1 and V3. The results also explain the observed sign change of the ODMR signal as a function of temperature