3 resultados para Four-level alkaline earth atomic systems
em Helda - Digital Repository of University of Helsinki
Resumo:
This work studied the creative process of musicians. The subject was chosen partly due to the attention given to creativity in social discussion. The approach was material-based, because during the work it became clear that the theoretical models describing the creative process in general did not provide adequate tools for the examination of musical creation. In this study, the creative process was defined as a process, which generated a work found by the musician novel to him or her. There were two principal research questions: 1) How does the creative process of musicians progress? 2) What makes a process creative? The main emphasis was on the first question, because the study aimed at modeling the creative process of musicians. The material for this study was collected by interviewing five professional musicians, each qualified by an expert of music to be creative. The interviews were thematically linked with each musician’s recently implemented creative process. The work generated in the process was used as a stimulant in the interview. The main themes of the interview dealt with the musician’s concrete action, cognitive functioning and affective experience during the process. Secondary themes included his or her goals as well as the factors that enhanced or inhibited the process. A material-based analysis was made of the interviews. The conceptualization and modelling of the creative process was founded on a phenomenological-hermeneutic interpretation. In addition to the primary interviews, also supplementary interviews were made in order to ensure that the description of the musician was understood correctly. Further supplementary interviews were made when the material was analyzed and results were deduced. This aimed at increasing the reliability of interpretations and conclusions. The study resulted in a four-level model representing the progress of a creative process. The levels were defined by means of the conception of state. The levels used in defining the process were 1) the state determining the potential of the process, 2) the state delimiting the process, 3) the state orienting the process, and 4) the state determined by the process. The progress of the process was described as changes taking place in the state. It was discovered that the factors having an effect on the creativity of the process were the dynamism of the process, the musician’s work in relation to his or her inner standard and the impulses that caused variation in the musician’s thinking. The interview method used in this study proved to be a very suitable tool in an examination of a creative process. Thus it may well be applicable in other research contexts associated with creative processes. The outcome of this study, the model of the progress of a creative process, should also provide a feasible basis for the examination of different kinds of creative processes. It enables a comprehensive examination of a creative process, simultaneously justifying the dynamic nature of the process.
Resumo:
The chemical and physical properties of bimetallic clusters have attracted considerable attention due to the potential technological applications of mixed-metal systems. It is of fundamental interests to study clusters because they are the link between atomic surface and bulk properties. More information of metal-metal bond in small clusters can be hence released. The studies in my thesis mainly focus on the two different kinds of bimetallic clusters: the clusters consisting of extraordinary shaped all metal four-membered rings and a series of sodium auride clusters. As described in most general organic chemistry books nowadays, a group of compounds are classified as aromatic compounds because of their remarkable stabilities, particular geometrical and energetic properties and so on. The notation of aromaticity is essentially qualitative. More recently, the connection has been made between aromaticity and energetic and magnetic properties. Also, the discussions of the aromatic nature of molecular rings are no longer limited to organic compounds obeying the Hückel’s rule. In our research, we mainly applied the GIMIC method to several bimetallic clusters at the CCSD level, and compared the results with those obtained by using chemical shift based methods. The magnetically induced ring currents can be generated easily by employing GIMIC method, and the nature of aromaticity for each system can be therefore clarified. We performed intensive quantum chemical calculations to explore the characters of the anionic sodium auride clusters and the corresponding neutral clusters since it has been fascinating in investigating molecules with gold atom involved due to its distinctive physical and chemical properties. As small gold clusters, the sodium auride clusters seem to form planar structures. With the addition of a negative charge, the gold atom in anionic clusters prefers to carry the charge and orients itself away from other gold atoms. As a result, the energetically lowest isomer for an anionic cluster is distinguished from the one for the corresponding neutral cluster. Mostly importantly, we presented a comprehensive strategy of ab initio applications to computationally implement the experimental photoelectron spectra.
Resumo:
Human activities extract and displace different substances and materials from the earth s crust, thus causing various environmental problems, such as climate change, acidification and eutrophication. As problems have become more complicated, more holistic measures that consider the origins and sources of pollutants have been called for. Industrial ecology is a field of science that forms a comprehensive framework for studying the interactions between the modern technological society and the environment. Industrial ecology considers humans and their technologies to be part of the natural environment, not separate from it. Industrial operations form natural systems that must also function as such within the constraints set by the biosphere. Industrial symbiosis (IS) is a central concept of industrial ecology. Industrial symbiosis studies look at the physical flows of materials and energy in local industrial systems. In an ideal IS, waste material and energy are exchanged by the actors of the system, thereby reducing the consumption of virgin material and energy inputs and the generation of waste and emissions. Companies are seen as part of the chains of suppliers and consumers that resemble those of natural ecosystems. The aim of this study was to analyse the environmental performance of an industrial symbiosis based on pulp and paper production, taking into account life cycle impacts as well. Life Cycle Assessment (LCA) is a tool for quantitatively and systematically evaluating the environmental aspects of a product, technology or service throughout its whole life cycle. Moreover, the Natural Step Sustainability Principles formed a conceptual framework for assessing the environmental performance of the case study symbiosis (Paper I). The environmental performance of the case study symbiosis was compared to four counterfactual reference scenarios in which the actors of the symbiosis operated on their own. The research methods used were process-based life cycle assessment (LCA) (Papers II and III) and hybrid LCA, which combines both process and input-output LCA (Paper IV). The results showed that the environmental impacts caused by the extraction and processing of the materials and the energy used by the symbiosis were considerable. If only the direct emissions and resource use of the symbiosis had been considered, less than half of the total environmental impacts of the system would have been taken into account. When the results were compared with the counterfactual reference scenarios, the net environmental impacts of the symbiosis were smaller than those of the reference scenarios. The reduction in environmental impacts was mainly due to changes in the way energy was produced. However, the results are sensitive to the way the reference scenarios are defined. LCA is a useful tool for assessing the overall environmental performance of industrial symbioses. It is recommended that in addition to the direct effects, the upstream impacts should be taken into account as well when assessing the environmental performance of industrial symbioses. Industrial symbiosis should be seen as part of the process of improving the environmental performance of a system. In some cases, it may be more efficient, from an environmental point of view, to focus on supply chain management instead.