11 resultados para Three-photon processes
em Helda - Digital Repository of University of Helsinki
Resumo:
There is a need for better understanding of the processes and new ideas to develop traditional pharmaceutical powder manufacturing procedures. Process analytical technology (PAT) has been developed to improve understanding of the processes and establish methods to monitor and control processes. The interest is in maintaining and even improving the whole manufacturing process and the final products at real-time. Process understanding can be a foundation for innovation and continuous improvement in pharmaceutical development and manufacturing. New methods are craved for to increase the quality and safety of the final products faster and more efficiently than ever before. The real-time process monitoring demands tools, which enable fast and noninvasive measurements with sufficient accuracy. Traditional quality control methods have been laborious and time consuming and they are performed off line i.e. the analysis has been removed from process area. Vibrational spectroscopic methods are responding this challenge and their utilisation have increased a lot during the past few years. In addition, other methods such as colour analysis can be utilised in noninvasive real-time process monitoring. In this study three pharmaceutical processes were investigated: drying, mixing and tabletting. In addition tablet properties were evaluated. Real-time monitoring was performed with NIR and Raman spectroscopies, colour analysis, particle size analysis and compression data during tabletting was evaluated using mathematical modelling. These methods were suitable for real-time monitoring of pharmaceutical unit operations and increase the knowledge of the critical parameters in the processes and the phenomena occurring during operations. They can improve our process understanding and therefore, finally, enhance the quality of final products.
Resumo:
The driving force behind this study has been the need to develop and apply methods for investigating the hydrogeochemical processes of significance to water management and artificial groundwater recharge. Isotope partitioning of elements in the course of physicochemical processes produces isotopic variations to their natural reservoirs. Tracer property of the stable isotope abundances of oxygen, hydrogen and carbon has been applied to investigate hydrogeological processes in Finland. The work described here has initiated the use of stable isotope methods to achieve a better understanding of these processes in the shallow glacigenic formations of Finland. In addition, the regional precipitation and groundwater records will supplement the data of global precipitation, but as importantly, provide primary background data for hydrological studies. The isotopic composition of oxygen and hydrogen in Finnish groundwaters and atmospheric precipitation was determined in water samples collected during 1995 2005. Prior to this study, no detailed records existed on the spatial or annual variability of the isotopic composition of precipitation or groundwaters in Finland. Groundwaters and precipitation in Finland display a distinct spatial distribution of the isotopic ratios of oxygen and hydrogen. The depletion of the heavier isotopes as a function of increasing latitude is closely related to the local mean surface temperature. No significant differences were observed between the mean annual isotope ratios of oxygen and hydrogen in precipitation and those in local groundwaters. These results suggest that the link between the spatial variability in the isotopic composition of precipitation and local temperature is preserved in groundwaters. Artificial groundwater recharge to glaciogenic sedimentary formations offers many possibilities to apply the isotopic ratios of oxygen, hydrogen and carbon as natural isotopic tracers. In this study the systematics of dissolved carbon have been investigated in two geochemically different glacigenic groundwater formations: a typical esker aquifer at Tuusula, in southern Finland and a carbonate-bearing aquifer with a complex internal structure at Virttaankangas, in southwest Finland. Reducing the concentration of dissolved organic carbon (DOC) in water is a primary challenge in the process of artificial groundwater recharge. The carbon isotope method was used to as a tool to trace the role of redox processes in the decomposition of DOC. At the Tuusula site, artificial recharge leads to a significant decrease in the organic matter content of the infiltrated water. In total, 81% of the initial DOC present in the infiltrated water was removed in three successive stages of subsurface processes. Three distinct processes in the reduction of the DOC content were traced: The decomposition of dissolved organic carbon in the first stage of subsurface flow appeared to be the most significant part in DOC removal, whereas further decrease in DOC has been attributed to adsorption and finally to dilution with local groundwater. Here, isotope methods were used for the first time to quantify the processes of DOC removal in an artificial groundwater recharge. Groundwaters in the Virttaankangas aquifer are characterized by high pH values exceeding 9, which are exceptional for shallow aquifers on glaciated crystalline bedrock. The Virttaankangas sediments were discovered to contain trace amounts of fine grained, dispersed calcite, which has a high tendency to increase the pH of local groundwaters. Understanding the origin of the unusual geochemistry of the Virttaankangas groundwaters is an important issue for constraining the operation of the future artificial groundwater plant. The isotope ratios of oxygen and carbon in sedimentary carbonate minerals have been successfully applied to constrain the origin of the dispersed calcite in the Virttaankangas sediments. The isotopic and chemical characteristics of the groundwater in the distinct units of aquifer were observed to vary depending on the aquifer mineralogy, groundwater residence time and the openness of the system to soil CO2. The high pH values of > 9 have been related to dissolution of calcite into groundwater under closed or nearly closed system conditions relative to soil CO2, at a low partial pressure of CO2.
Resumo:
The purpose of this study is to analyse the development and understanding of the idea of consensus in bilateral dialogues among Anglicans, Lutherans and Roman Catholics. The source material consists of representative dialogue documents from the international, regional and national dialogues from the 1960s until 2006. In general, the dialogue documents argue for agreement/consensus based on commonality or compatibility. Each of the three dialogue processes has specific characteristics and formulates its argument in a unique way. The Lutheran-Roman Catholic dialogue has a particular interest in hermeneutical questions. In the early phases, the documents endeavoured to describe the interpretative principles that would allow the churches to together proclaim the Gospel and to identify the foundation on which the agreement in the church is based. This investigation ended up proposing a notion of basic consensus , which later developed into a form of consensus that seeks to embrace, not to dismiss differences (so-called differentiated consensus ). The Lutheran-Roman Catholic agreement is based on a perspectival understanding of doctrine. The Anglican-Roman Catholic dialogue emphasises the correctness of interpretations. The documents consciously look towards a common future , not the separated past. The dialogue s primary interpretative concept is koinonia. The texts develop a hermeneutics of authoritative teaching that has been described as the rule of communion . The Anglican-Lutheran dialogue is characterised by an instrumental understanding of doctrine. Doctrinal agreement is facilitated by the ideas of coherence, continuity and substantial emphasis in doctrine. The Anglican-Lutheran dialogue proposes a form of sufficient consensus that considers a wide set of doctrinal statements and liturgical practices to determine whether an agreement has been reached to the degree that, although not complete , is sufficient for concrete steps towards unity. Chapter V discusses the current challenges of consensus as an ecumenically viable concept. In this part, I argue that the acceptability of consensus as an ecumenical goal is based not only the understanding of the church but more importantly on the understanding of the nature and function of the doctrine. The understanding of doctrine has undergone significant changes during the time of the ecumenical dialogues. The major shift has been from a modern paradigm towards a postmodern paradigm. I conclude with proposals towards a way to construct a form of consensus that would survive philosophical criticism, would be theologically valid and ecumenically acceptable.
Resumo:
In a search for new phenomena in a signature suppressed in the standard model of elementary particles (SM), we compare the inclusive production of events containing a lepton, a photon, significant transverse momentum imbalance (MET), and a jet identified as containing a b-quark, to SM predictions. The search uses data produced in proton-antiproton collisions at 1.96 TeV corresponding to 1.9 fb-1 of integrated luminosity taken with the CDF detector at the Fermilab Tevatron. We find 28 lepton+photon+MET+b events versus an expectation of 31.0+4.1/-3.5 events. If we further require events to contain at least three jets and large total transverse energy, simulations predict that the largest SM source is top-quark pair production with an additional radiated photon, ttbar+photon. In the data we observe 16 ttbar+photon candidate events versus an expectation from SM sources of 11.2+2.3/-2.1. Assuming the difference between the observed number and the predicted non-top-quark total is due to SM top quark production, we estimate the ttg cross section to be 0.15 +- 0.08 pb.
Resumo:
The aim of the study was to analyze and facilitate collaborative design in a virtual learning environment (VLE). Discussions of virtual design in design education have typically focused on technological or communication issues, not on pedagogical issues. Yet in order to facilitate collaborative design, it is also necessary to address the pedagogical issues related to the virtual design process. In this study, the progressive inquiry model of collaborative designing was used to give a structural level of facilitation to students working in the VLE. According to this model, all aspects of inquiry, such as creating the design context, constructing a design idea, evaluating the idea, and searching for new information, can be shared in a design community. The study consists of three design projects: 1) designing clothes for premature babies, 2) designing conference bags for an international conference, and 3) designing tactile books for visually impaired children. These design projects constituted a continuum of design experiments, each of which highlighted certain perspectives on collaborative designing. The design experiments were organized so that the participants worked in design teams, both face-to-face and virtually. The first design experiment focused on peer collaboration among textile teacher students in the VLE. The second design experiment took into consideration end-users needs by using a participatory design approach. The third design experiment intensified computer-supported collaboration between students and domain experts. The virtual learning environments, in these design experiments, were designed to support knowledge-building pedagogy and progressive inquiry learning. These environments enabled a detailed recording of all computer-mediated interactions and data related to virtual designing. The data analysis was based on qualitative content analysis of design statements in the VLE. This study indicated four crucial issues concerning collaborative design in the VLE in craft and design education. Firstly, using the collaborative design process in craft and design education gives rise to special challenges of building learning communities, creating appropriate design tasks for them, and providing tools for collaborative activities. Secondly, the progressive inquiry model of collaborative designing can be used as a scaffold support for design thinking and for reflection on the design process. Thirdly, participation and distributed expertise can be facilitated by considering the key stakeholders who are related to the design task or design context, and getting them to participate in virtual designing. Fourthly, in the collaborative design process, it is important that team members create and improve visual and technical ideas together, not just agree or disagree about proposed ideas. Therefore, viewing the VLE as a medium for collaborative construction of the design objects appears crucial in order to understand and facilitate the complex processes in collaborative designing.
Resumo:
The aim of this study was to explore soil microbial activities related to C and N cycling and the occurrence and concentrations of two important groups of plant secondary compounds, terpenes and phenolic compounds, under silver birch (Betula pendula Roth), Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.) as well as to study the effects of volatile monoterpenes and tannins on soil microbial activities. The study site, located in Kivalo, northern Finland, included ca. 70-year-old adjacent stands dominated by silver birch, Norway spruce and Scots pine. Originally the soil was very probably similar in all three stands. All forest floor layers (litter (L), fermentation layer (F) and humified layer (H)) under birch and spruce showed higher rates of CO2 production, greater net mineralisation of nitrogen and higher amounts of carbon and nitrogen in microbial biomass than did the forest floor layers under pine. Concentrations of mono-, sesqui-, di- and triterpenes were higher under both conifers than under birch, while the concentration of total water-soluble phenolic compounds as well as the concentration of condensed tannins tended to be higher or at least as high under spruce as under birch or pine. In general, differences between tree species in soil microbial activities and in concentrations of secondary compounds were smaller in the H layer than in the upper layers. The rate of CO2 production and the amount of carbon in the microbial biomass correlated highly positively with the concentration of total water-soluble phenolic compounds and positively with the concentration of condensed tannins. Exposure of soil to volatile monoterpenes and tannins extracted and fractionated from spruce and pine needles affected carbon and nitrogen transformations in soil, but the effects were dependent on the compound and its molecular structure. Monoterpenes decreased net mineralisation of nitrogen and probably had a toxic effect on part of the microbial population in soil, while another part of the microbes seemed to be able to use monoterpenes as a carbon source. With tannins, low-molecular-weight compounds (also compounds other than tannins) increased soil CO2 production and nitrogen immobilisation by soil microbes while the higher-molecular-weight condensed tannins had inhibitory effects. In conclusion, plant secondary compounds may have a great potential in regulation of C and N transformations in forest soils, but the real magnitude of their significance in soil processes is impossible to estimate.
Resumo:
This thesis focuses on how elevated CO2 and/or O3 affect the below-ground processes in semi-natural vegetation, with an emphasis on greenhouse gases, N cycling and microbial communities. Meadow mesocosms mimicking lowland hay meadows in Jokioinen, SW Finland, were enclosed in open-top chambers and exposed to ambient and elevated levels of O3 (40-50 ppb) and/or CO2 (+100 ppm) for three consecutive growing season, while chamberless plots were used as chamber controls. Chemical and microbiological analyses as well as laboratory incubations of the mesocosm soils under different treatments were used to study the effects of O3 and/or CO2. Artificially constructed mesocosms were also compared with natural meadows with regards to GHG fluxes and soil characteristics. In addition to research conducted at the ecosystem level (i.e. the mesocosm study), soil microbial communities were also examined in a pot experiment with monocultures of individual species. By comparing mesocosms with similar natural plant assemblage, it was possible to demonstrate that artificial mesocosms simulated natural habitats, even though some differences were found in the CH4 oxidation rate, soil mineral N, and total C and N concentrations in the soil. After three growing seasons of fumigations, the fluxes of N2O, CH4, and CO2 were decreased in the NF+O3 treatment, and the soil NH4+-N and mineral N concentrations were lower in the NF+O3 treatment than in the NF control treatment. The mesocosm soil microbial communities were affected negatively by the NF+O3 treatment, as the total, bacterial, actinobacterial, and fungal PLFA biomasses as well as the fungal:bacterial biomass ratio decreased under elevated O3. In the pot survey, O3 decreased the total, bacterial, actinobacterial, and mycorrhizal PLFA biomasses in the bulk soil and affected the microbial community structure in the rhizosphere of L. pratensis, whereas the bulk soil and rhizosphere of the other monoculture, A. capillaris, remained unaffected by O3. Elevated CO2 caused only minor and insignificant changes in the GHG fluxes, N cycling, and the microbial community structure. In the present study, the below-ground processes were modified after three years of moderate O3 enhancement. A tentative conclusion is that a decrease in N availability may have feedback effects on plant growth and competition and affect the N cycling of the whole meadow ecosystem. Ecosystem level changes occur slowly, and multiplication of the responses might be expected in the long run.
Resumo:
Genetic studies on phylogeography and adaptive divergence in Northern Hemisphere fish species such as three-spined stickleback (Gasterosteus aculeatus) provide an excellent opportunity to investigate genetic mechanisms underlying population differentiation. According to the theory, the process of population differentiation results from a complex interplay between random and deterministic processes as well historical factors. The main scope in this thesis was to study how historical factors like the Pleistocene ice ages have shaped the patterns molecular diversity in three-spined stickleback populations in Europe and how this information could be utilized in the conservation genetic context. Furthermore, identifying footprints of natural selection at the DNA level might be used in identifying genes involved in evolutionary change. Overall, the results from phylogeographic studies indicate that the three-spined stickleback has colonized the Atlantic basin relatively recently but constitutes three major evolutionary lineages in Europe. In addition, the colonization of freshwater appears to result from multiple and independent invasions by the marine conspecifics. Molecular data together with morphology suggest that the most divergent freshwater populations are located in the Balkan Peninsula and these populations deserve a special conservation genetic status without warranting further taxonomical classification. In order to investigate the adaptive divergence in Fennoscandian three-spined stickleback populations several approaches were used. First, sequence variability in the Eda-gene, coding for the number of lateral plates, was concordant with the previously observed global pattern. Full plated allele is in high frequencies among marine populations whereas low plated allele dominates in the freshwater populations. Second, a microsatellite based genome scan identified both indications of balancing and directional selection in the three-spined stickleback genome, i.e. loci with unusually similar or unusually different allele frequencies over populations. The directionally selected loci were mainly associated with the adaptation to freshwater. A follow up study conducting a more detailed analysis in a chromosome region containing a putatively selected gene locus identified a fairly large genomic region affected by natural selection. However, this region contained several gene predictions, all of which might be the actual target of natural selection. All in all, the phylogeographic and adaptive divergence studies indicate that most of the genetic divergence has occurred in the freshwater populations whereas the marine populations have remained relatively uniform.
Resumo:
Recent evidence from adult pronoun comprehension suggests that semantic factors such as verb transitivity affect referent salience and thereby anap- hora resolution. We tested whether the same semantic factors influence pronoun comprehension in young children. In a visual world study, 3-year- olds heard stories that began with a sentence containing either a high or a low transitivity verb. Looking behaviour to pictures depicting the subject and object of this sentence was recorded as children listened to a subsequent sentence containing a pronoun. Children showed a stronger preference to look to the subject as opposed to the object antecedent in the low transitivity condition. In addition there were general preferences (1) to look to the subject in both conditions and (2) to look more at both potential antecedents in the high transitivity condition. This suggests that children, like adults, are affected by semantic factors, specifically semantic prominence, when interpreting anaphoric pronouns.
Resumo:
Background: The onset of many chronic diseases such as type 2 diabetes can be delayed or prevented by changes in diet, physical activity and obesity. Known predictors of successful behaviour change include psychosocial factors such as selfefficacy, action and coping planning, and social support. However, gender and socioeconomic differences in these psychosocial mechanisms underlying health behaviour change have not been examined, despite well-documented sociodemographic differences in lifestyle-related mortality and morbidity. Additionally, although stable personality traits (such as dispositional optimism or pessimism and gender-role orientation: agency and communion) are related to health and health behaviour, to date they have rarely been studied in the context of health behaviour interventions. These personality traits might contribute to health behaviour change independently of the more modifiable domain-specific psychosocial factors, or indirectly through them, or moderated by them. The aims were to examine in an intervention setting: (1) whether changes (during the three-month intervention) in psychological determinants (self-efficacy beliefs, action planning and coping planning) predict changes in exercise and diet behaviours over three months and 12 months, (2) the universality assumption of behaviour change theories, i.e. whether preintervention levels and changes in psychosocial determinants are similar among genders and socioeconomic groups, and whether they predict changes in behaviour in a similar way in these groups, (3) whether the personality traits optimism, pessimism, agency and communion predict changes in abdominal obesity, and the nature of their interplay with modifiable and domain-specific psychosocial factors (self-efficacy and social support). Methods: Finnish men and women (N = 385) aged 50 65 years who were at an increased risk for type 2 diabetes were recruited from health care centres to participate in the GOod Ageing in Lahti Region (GOAL) Lifestyle Implementation Trial. The programme aimed to improve participants lifestyle (physical activity, eating) and decrease their overweight. The measurements of self-efficacy, planning, social support and dispositional optimism/pessimism were conducted pre-intervention at baseline (T1) and after the intensive phase of the intervention at three months (T2), and the measurements of exercise at T1, T2 and 12 months (T3) and healthy eating at T1 and T3. Waist circumference, an indicator of abdominal obesity, was measured at T1 and at oneyear (T3) and three-year (T4) follow-ups. Agency and communion were measured at T4 with the Personal Attributes Questionnaire (PAQ). Results: (1) Increases in self-efficacy and planning were associated with three-month increases in exercise (Study I). Moreover, both the post-intervention level and three-month increases (during the intervention) in self-efficacy in dealing with barriers predicted the 12-month increase in exercise, and a high postintervention level of coping plans predicted the 12-month decrease in dietary fat (Study II). One- and three-year waist circumference reductions were predicted by the initial three-month increase in self-efficacy (Studies III, IV). (2) Post-intervention at three months, women had formed more action plans for changing their exercise routines and received less social support for behaviour change than men had. The effects of adoption self-efficacy were similar but change in planning played a less significant role among men (Study I). Examining the effects of socioeconomic status (SES), psychosocial determinants at baseline and their changes during the intervention yielded largely similar results. Exercise barriers self-efficacy was enhanced slightly less among those with low SES. Psychosocial determinants predicted behaviour similarly across all SES groups (Study II). (3) Dispositional optimism and pessimism were unrelated to waist circumference change, directly or indirectly, and they did not influence changes in self-efficacy (Study III). Agency predicted 12-month waist circumference reduction among women. High communion coupled with high social support was associated with waist circumference reduction. However, the only significant predictor of three-year waist circumference reduction was an increase in health-related self-efficacy during the intervention (Study IV). Conclusions: Interventions should focus on improving participants self-efficacy early on in the intervention as well as prompting action and coping planning for health behaviour change. Such changes are likely to be similarly effective among intervention participants regardless of gender and educational level. Agentic orientation may operate via helping women to be less affected by the demands of the self-sacrificing female role and enabling them to assertively focus on their own goals. The earlier mixed results regarding the role of social support in behaviour change may be in part explained by personality traits such as communion.
Resumo:
This paper summarizes literature explaining workplace bullying and focuses on organisational antecedents of bullying. In order to better understand the logic behind bullying, a model discussing different types of explanations is put forward. Thus, explanations for and factors associated with bullying are classified into three groups, i.e. enabling structures or necessary antecedents (e.g. perceived power imbalances, low perceived costs, and dissatisfaction and frustration), motivating structures or incentives (e.g. internal competition, reward systems, and expected benefits), and precipitating processes or triggering circumstances (e.g. downsizing and restructuring, organisational changes, changes in the composition of the workgroup). The paper concludes that bullying is often an interaction between structures and processes from all three groupings.