898 resultados para reactive sources


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Nicotine, an oxidizing agent, is certainly one of the most widely used alkaloids in the world. It is, together with its main metabolite, cotinine, responsible for tobacco-dependence. The use of tobacco is closely associated with lung disease, morphological leukocyte modification and generation of oxidant species. The aim of this study was to look for a possible relationship between cotinine, oxidant species generation and oxidative processes. After studying the action of cotinine in some chemical oxidation models and on the enzymatic kinetics of peroxidases (myeloperoxidase and horseradish peroxidase), we concluded that cotinine does not act directly upon H2O2, HOCl, taurine chloramines, horseradish peroxidase or myeloperoxidase.

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In this paper I provide a concise plan about Hegel's Lectures on the Philosophy of Religion critical editions, laying stress on the method followed by editors in order to build a coherent text with the sources at their disposal. The Marheineke's edition (1832) is analysed with special attention since it was the edition that caused the division between a Right and a Left, opening the discussion on speculative theism as a consequence of the difficulty to distinguish the systematic part from the historical one in the reasoning carried out by Hegel.

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Svavel förekommer i kol och olja och oxideras vid förbränning till svaveldioxid (SO2). Årligen utsläpps stora mängder svaveldioxid som åstadkommer sura regn, minskning av stratosfäriskt ozon och sjukdomar. Av dessa orsaker är det nödvändigt att minska utsläppen av svaveldioxid. Den teknologi som rör planering av reaktorer och processer för rökgasavsvavling (FGD) har utvecklats kraftigt och idag använder man olika typer av lösningar. De vanligaste alternativen för FGD är våtskrubber- och semitorra skrubbersystem (Spray Dry Scrubbers, SDS) och injektionsprocesser för absorbenter. SDS-processer har studerats bland annat av Ahlbeck [4] och Klingspor [5] och injektionsprocesser av Alvfors [6]. Kalksten, som i huvusak består av kalciumkarbonat, används i rökgasavsvavling på grund av sin förmåga att binda svavel i form av sulfatsalter. Den vanligaste rökgasavsvavlingsmetoden är våtskrubbning, där det sedimentära stenmaterialets upplösningshastighet är en av de faktorer som påverkar resultatet mest. Utvärdering av kalkstensreaktivitet är därför speciellt viktig vid planering och drift av anläggningar för rökgasavsvavling. Målsättningen med detta arbete var att modellera upplösningen av olika typers kalksten för att få en kvantitativ utvärdering av kvaliteten på de analyserade proverna. Därtill testades även karbonatbiprodukter från stålindustrin för att utvärdera möjligheter att använda andra råmaterial. Det transienta förloppet har analyserats, varvid upplösningshastigheten modellerades bl.a. i avseende på tid och pH. Under arbetets gång har antalet empiriska korrelationer minskats till fördel för fysikaliska modeller av diffusiva och konvektiva masstransportfenomen. En målsättning var att skapa en effektiv och snabb metod för att testa olika absorbenter för rökgasavsvavling under transienta förlopp. I arbetet användes PSD-analys, gjordes pH-mätningar och andra utvärderingar av de fysikaliska parametrar som ingår i beräkningarna. On-line mätningar för de icke-stationära variablerna tid och pH ger möjlighet att eliminera osäkerheter. Vissa modeller kan vara komplicerade. En modell för upplösningshastigheten med mer detaljerad utvärdering av parametrar och färre approximationer är därför nödvändig då man vill utvärdera reaktionshastigheten för fasta partiklar i sur miljö. Arbetet utfördes under fyra år och fem peer review-artiklar ingår i avhandlingen.

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In March 2010, Chinese State Councillor, Dai Bingguo, in a private meeting with US Deputy Secretary of State, James Steinberg, allegedly referred to the South China Sea (SCS) as one of the country’s ‘core interests’, a term normally only used to refer to regions like Taiwan, Tibet and Xinjiang upon whose sovereignty Beijing will make no compromises. This alleged wording by Mr Dai caused a strong global reaction, with many countries around the world expressing a fear that China, on the back of its rise to the status of the world's second largest economic power, was now about to implement a more assertive foreign policy more in keeping with its new status of global superpower. As the use of the term ‘core interest’ took place in a private meeting and appears to have been subsequently leaked, it is impossible to prove what was said or meant, yet in 2011, with China and the US continuing to eye each other with suspicion, the adverse repercussions of people trying to deduce what was meant are undeniable. By analysing the views of experts and the evolution or otherwise of Chinese rhetoric and policy towards the SCS, this thesis will show how the alleged use of a term in a private meeting can have consequences that far exceed what was originally intended. It will also show that it is highly unlikely that China’s maritime policy is becoming more assertive as, at China's present stage of social and economic development, it simply cannot afford the ill will and adverse consequences that would result from an act of international aggression. It will show how easy it seems to be for a country like the US to project a misleading image of another country’s intentions, which can in turn serve partially to mask its own intentions. Finally, it will show that the China’s stance on the SCS is starting to be seen by the world as a litmus test for the assertiveness of overall Chinese foreign policy.

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Tillgången på traditionella biobränslen är begränsad och därför behöver man ta fram nya, tidigare outnyttjade biobränslen för att möta de uppställda CO2 emissionsmålen av EU och det ständigt ökande energibehovet. Under de senare åren har intresset riktats mot termisk energiutvinning ur olika restfraktioner och avfall. Vid produktion av fordonsbränsle ur biomassa är den fasta restprodukten ofta den största procesströmmen i produktionsanläggningen. En riktig hantering av restprodukterna skulle göra produktionen mera lönsam och mer ekologiskt hållbar. Ett alternativ är att genom förbränning producera elektricitet och/eller värme eftersom dessa restprodukter anses som CO2-neutrala. Målsättningen med den här avhandlingen var att studera förbränningsegenskaperna hos några fasta restprodukter som uppstår vid framställning av förnybara fordonsbränslen. De fyra undersökta materialen är rapskaka, palmkärnskaka, torkad drank och stabiliserat rötslam. I studien används ett stort urval av undersökningsmetoder, från laboratorieskala till fullskalig förbränning, för att identifiera de huvudsakliga utmaningarna förknippade med förbränning av restprodukterna i pannor med fluidiserad bäddteknik. Med hjälp av detaljerad bränslekarakterisering kunde restprodukterna konstateras vara en värdefull källa för värme- och elproduktion. Den kemiska sammansättningen av restprodukterna varierar stort jämfört med mera traditionellt använda biobränslen. En gemensam faktor för alla de studerade restprodukterna är en hög fosforhalt. På grund av de låga fosforkoncentrationerna i de traditionella biobränslena har grundämnet hittills inte ansetts spela någon större roll i askkemin. Experimenten visade nu att fosfor inte mera kan försummas då man studerar kemin i förbränningsprocesser, då allt flera fosforrika bränslen tränger in på energimarknaden.

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Broiler production is highly dependent on the use of artificial light. The light source may affect the effectiveness of housing conditions due to increasing ambient temperature and concentration of noxious gases. This research aimed to evaluate the effects of different bulb types on the thermal, aerial, and acoustic environment of broiler aviaries. The experiment was carried out at a commercial broiler farm in Dourados, Mato Grosso do Sul State, Brazil. Three aviaries were used, and two flocks of male broilers from Cobb® genetic strain were reared from the first day to slaughter. Each aviary was equipped with a different light source, comprising the adopted treatments (A1 - incandescent light bulb, control; A2 - sodium vapor light bulb; A3 - fluorescent light bulb). The aviaries were divided into nine quadrants, and the environmental data (ambient dry bulb temperature and relative humidity), litter surface temperature, CO2 and NH3 concentrations, and bird sound pressure behavior were recorded in each quadrant. The aviary with incandescent light presented higher air and litter temperatures, and concentration of gases than the other tested alternatives. It also presented higher level of sound pressure in the second week of the growing period; however, from this period up to slaughter, there was no effect of the light source on the results of broiler sound pressure level.

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Atherosclerotic vascular disease is the leading cause of death in the Western world. Its main three manifestations are coronary heart disease, cerebrovascular disease, and peripheral arterial disease. Asymptomatic peripheral arterial disease is usually diagnosed using the ankle brachial index, and values ≤ 0.90 are used to determine the diagnosis. The classical risk factors of peripheral arterial disease, such as smoking and diabetes, are well known and early interventions are mandatory to improve the prognosis. What is not well known is the role of inflammation as a risk factor. Yet, a novel approach to cardiovascular diseases is the measurement of endothelial function. In this thesis, we studied the ankle-brachial index, C-reactive protein and endothelial function in a cardiovascular risk population. A total of 2856 subjects were invited to the study and 2085 (73%) responded. From these subjects, a cohort of 1756 risk persons was screened. We excluded the subjects with previously known cardiovascular disease or diabetes, because they were already under systematic follow-up. Out of the study subjects, 983 (56%) were women and 773 (44%) men. The ankle brachial index and high-sensitivity C-reactive protein were measured from 1047 subjects. Endothelial function was assessed by measuring reactive hyperemia pulse amplitude tonometry from 66 subjects with borderline peripheral arterial disease. In this study, smoking was a crucial risk factor for peripheral arterial disease. Subclinical peripheral arterial disease seems to be more common in hypertensive patients even without comorbidities. The measurement of the ankle brachial index is an efficient method to identify patients at an increased cardiovascular risk. High-sensitivity C-reactive protein did not correlate with the ankle brachial index or peripheral arterial disease. Instead, it correlated with measures of obesity. In a cardiovascular risk population with borderline peripheral arterial disease, nearly every fourth subject had endothelial dysfunction. This might point out a subgroup of individuals in need of more intensive treatment for their risk factors.

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This dissertation explores the use of internal and external sources of knowledge in modern innovation processes. It builds on a framework that combines theories such as a behavioural theory of the firm, the evolutionary theory of economic change, and modern approaches to strategic management. It follows the recent increase in innovation research focusing on the firm-level examination of innovative activities instead of traditional industry-level determinants. The innovation process is seen as a problem- and slack- driven search process, which can take several directions in terms of organizational boundaries in the pursuit of new knowledge and other resources. It thus draws on recent models of technological change, according to which firms nowadays should build their innovative activities on both internal and external sources of innovation rather than relying solely on internal resources. Four different research questions are addressed, all of which are empirically investigated via a rich dataset covering Finnish innovators collected by Statistics Finland. Firstly, the study examines how the nature of problems shapes the direction of any search for new knowledge. In general it demonstrates that the nature of the problem does affect the direction of the search, although under resource constraints firms tend to use external rather than internal sources of knowledge. At the same time, it shows that those firms that are constrained in terms of finance seem to search both internally and externally. Secondly, the dissertation investigates the relationships between different kinds of internal and external sources of knowledge in an attempt to find out where firms should direct their search in order to exploit the potential of a distributed innovation process. The concept of complementarities is applied in this context. The third research question concerns how the use of external knowledge sources – openness to external knowledge – influences the financial performance of firms. Given the many advantages of openness presented in the current literature, the focus is on how it shapes profitability. The results reveal a curvilinear relationship between profitability and openness (taking an inverted U-shape), the implication being that it pays to be open up to a certain point, but being too open to external sources may be detrimental to financial performance. Finally, the dissertation addresses some challenges in CISbased innovation research that have received relatively little attention in prior studies. The general aim is to underline the fact that comprehensive understanding of the complex process of technological change requires the constant development of methodological approaches (in terms of data and measures, for example). All the empirical analyses included in the dissertation are based on the Finnish CIS (Finnish Innovation Survey 1998-2000).

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In this thesis, the DFMA is presented and used for the purpose of having a design for a vertical transfer line that can be easily manufactured and assembled. The design of the transfer line, the major components and drawings are presented. The ease of assembly, the costs of manufacturing and differences between the use of steel structure and aluminum are compared. The ALARA principle is followed to minimize the risk of radiation exposure by the means of locating the test ion sources outside the radioactive area.

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Whole-mount preparations were prepared and submitted to NADH-diaphorase and NADPH-diaphorase histochemistry techniques. The myenteric plexus arrangement and the number of neurons were comparatively evaluated among the different portions of the cecum. The neurons from the apical and basal regions were distributed in classes at intervals of 100µm², the means of the corresponding intervals being compared. The ganglia, in both techniques, were often connected by fine bundles, which became thicker in the mesenteric region and in the region next to the cecal ampulla. The number of positive NADH-d neurons was higher than that of NADPH-d neurons in all portions, from both regions. The numbers of reactive NADH-d e NADPH-d neurons were significantly different among the different portions of the cecum, except for the antimesenteric basal and intermediate basal regions, considering the NADH-d neurons. The profile area for the reactive NADH-d e NADPH-d neurons was higher in the apical region than in the basal area. Differences in arrangement, distribution and size of positive NADH-d e NADPH-d neurons in the different cecum portions evidenced the importance of the subdivision of the analyzed organ.

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Chronic inflammation is the underlying cause of many common disabling conditions such as rheumatoid arthritis (RA), multiple sclerosis, coeliac disease, type I diabetes and coronary artery disease. NOX2 complex derived reactive oxygen species (ROS) are known to regulate joint inflammation in rats and mice, and additionally recent genetic evidence associates phagocyte ROS and the development RA in humans. Ncf1mutated mice have lost the functionality of their NOX2 complex and thus have no phagocyte ROS production. These mice suffer from exacerbated arthritis. The immune suppressive effect of the NOX2 complex derived ROS is mediated by monocytes/macrophages that downregulate the activation of autoreactive T cells. The aim of this thesis was to study how ROS modulate immune responses in different arthritis models and in tumor development. Additionally, genome wide gene expression profiling was carried out to assess the global effects of NOX2 complex derived ROS. Firstly, these results confirmed the potent anti-inflammatory nature of phagocyte ROS in arthritis models that were driven by the adaptive immune system. Secondly, arthritis models with predominantly innate immunity induced pathophysiology were moderately enhanced by phagocyte, more specifically, neutrophil derived ROS. Thirdly, the ROS induced immune suppression mediated by the adaptive immune system allowed development of bigger implanted tumors, while phagocyte ROS production did not affect the development of spontaneously growing tumors. Lastly, genome wide gene expression analysis revealed that both humans and mice with abrogated phagocyte NOX2 complex ROS production had an enhanced type I interferon signature in blood, reflecting their hyperinflammatory immune status.

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Mobile technology has been employed in banking for already two decades. However, its significance this far has been modest. It is expected that the industry will change a lot in the future. Elements of this change include tightening of competition, considering customer’s individual and changing needs, becoming involved in customer’s life and being where customers are. The goal of this study is to explore these fields with regard to Finnish banking as well as investigate selected consumers’ views towards this kind of new service approach. It can be divided into three questions: • What kinds of mobile services does the Finnish banking industry currently offer for consumers and what expectations do experts and consumers have towards them? o What is consumers’ attitude towards a context-aware service approach in the banking industry and what are the suggested tools for it? o What factors define clients’ adoption intentions towards the new context-aware service approach? Which factors do they consider most important? In order to create the framework for the study, both Finnish and foreign scientific and professional literature considering evolution of the industry and innovation adoption has been used. The empirical part of the study consists of 11 interviews, including 6 expert interviews and 5 consumer interviews. The results show that the selected consumers reacted very positively to the suggested new service approach that considers them as a person and aims at simplifying their banking. The consumers appreciated especially solutions that simplified their everyday banking. Also proactive actions from a bank was considered important especially in everyday banking, as long as the customer was able to define the amount and way of contacts he received. According to the findings banks should aim at supporting their customers more than they do now. However, they also need to pay attention to not irritate their customers by excessive contacts. Banks should also open-mindedly introduce new technologies to their customers. Key words

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Being a top of high technology industries, the aerospace represents one of the most complex fields of study. While the competitiveness of aircraft systems’ manufacturers attracts a significant number of researchers, some of the issues remain to be a blank spot. One of those is the after-sale modernization. The master thesis investigates how this concept is related to the theory of competitive advantages. Finding the routes in the framework of complex technological systems’ lifecycle, the key drivers of the aircraft modernization market are revealed. The competitive positioning of players is defined through multiple case studies in a form of several in-depth interviews. The key result of the research is the conclusion that modernization should be considered as an inherent component of strategy of any aircraft systems’ manufacturer, while the master thesis aims to support managerial decision making.

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Blood-derived products are commonly administered to horses and humans to treat many musculoskeletal diseases, due to their potential antioxidant and anti-inflammatory effects. Nevertheless, antioxidant effects have never been shown upon horse synovial fluid cells in vitro. If proved, this could give a new perspective to justify the clinical application of blood-derived products. The aim of the present study was to investigate the antioxidant effects of two blood-derived products - plasma (unconditioned blood product - UBP) and a commercial blood preparation (conditioned blood product - CBP)¹ - upon stimulated equine synovial fluid cells. Healthy tarsocrural joints (60) were tapped to obtain synovial fluid cells; these cells were pooled, processed, stimulated with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA), and evaluated by flow cytometry for the production of reactive oxygen species (ROS). Upon addition of any blood-derived product here used - UBP and CBP - there was a significant decrease in the oxidative burst of synovial fluid cells (P<0.05). There was no difference between UBP and CBP effects. In conclusion, treatment of stimulated equine synovial cells with either UBP or CBP efficiently restored their redox equilibrium.