27 resultados para alternative Isoform
Resumo:
Causticizing plant is an important part of kraft pulp mill. It uses green liquor from recovery boiler as a raw material and consumes lime to produce white liquor, which is an important chemical used in pulping. Lime kiln is a part of the causticizing process. It is used to convert lime mud, a by-product obtained from the causticizing back to lime in high temperatures. This conversion requires a lot of energy. The most common fuels used as energy source for lime kiln are heavy fuel oil and natural gas. In a modern pulp mill lime kiln is the only user of significant amount of fossil fuels. Replacing fossil fuels with biofuels can have prominent economical and environmental benefits. Interest in using biofuels as energy source of lime kiln has become a worldwide issue in the recent years. However fuels used for lime kiln have a lot of certain requirements. The purpose of this work is to study the required characteristics from liquid fuels used in pulp mill lime kiln and to map suitable liquid biofuels already available in the markets. Also taxation of liquid biofuels compared to heavy fuel oil in Finland, Sweden and Germany is shortly introduced.
Characterization of Leaf-Type Ferredoxin-NADP+ Oxidoreductase (FNR) Isoforms in Arabidopsis thaliana
Resumo:
Life on earth is based on sunlight, which is captured in chemical form by photosynthetic reactions. In the chloroplasts of plants, light reactions of photosynthesis take place at thylakoid membranes, whereas carbon assimilation reactions occur in the soluble stroma. The products of linear electron transfer (LET), highly-energetic ATP molecules, and reducing power in the form of NADPH molecules, are further used in the fixation of inorganic CO2 molecules into organic sugars. Ferredoxin-NADP+ oxidoreductase (FNR) catalyzes the last of the light reactions by transferring electrons from ferredoxin (FD) to NADP+. In addition to LET, FNR has been suggested to play a role in cyclic electron transfer (CET), which produces ATP without the accumulation of reducing equivalents. CET is proposed to occur via two putative routes, the PGR5- route and the NDH-route. In this thesis, the leaf-type FNR (LFNR) isoforms LFNR1 and LFNR2 of a model organism, Arabidopsis thaliana, were characterized. The physiological roles of LFNRs were investigated using single and double mutant plants. The viability of the single mutants indicates functionality of both isoforms, with neither appearing to play a specific role in CET. The more severe phenotype of low-temperature adapted fnr2 plants compared to both wild-type (WT) and fnr1 plants suggests a specific role for LFNR2 under unfavorable growth conditions. The more severe phenotype of the fnr1 x fnr2 (F1 generation) plants compared to single mutants reflects down-regulated photosynthetic capacity, whereas slightly higher excitation pressure indicates mild over-excitation of electron transfer chain (ETC). However, induction of CET and various photoprotective mechanisms enable adaptation of fnr1 x fnr2 plants to scarcity of LFNR. The fnr1 fnr2 plants (F2 generation), without detectable levels of LFNR, were viable only under heterotrophic conditions. Moreover, drought stress induced acceleration of the rate of P700 + re-reduction in darkness was accompanied by a concomitant up-regulation of the PGR5-route specific components, PGR5 and PGRL1, demonstrating the induction of CET via the PGR5-route. The up-regulation of relative transcriptional expression of the FD1 gene indicates that the FD1 isoform may have a specific function in CET, while no such role could be defined for either of the LFNR isoforms. Both the membrane-bound and soluble LFNR1 and LFNR2 each appear as two distinct spots after 2D-PAGE with different isoelectric points (pIs), indicating the existence of post-translational modifications (PTMs) which do not determine the membrane attachment of LFNR. The possibility of phosphorylation and glycosylation PTMs were excluded, but all four LFNR forms were shown to contain acetylated lysine residues as well as alternative N-termini. N-terminal acetylation was shown to shift the pI of both LFNRs to be more acidic. In addition, all four LFNR forms were demonstrated to interact both with FD1 and FD2 in vitro
Resumo:
Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
Resumo:
The conventional activated sludge processes (CAS) for the treatment of municipal wastewater are going to be outdated gradually due to more stringent environmental protection laws and regulations. The Membrane bioreactors (MBRs) are the most promising modern technology widely accepted in the world of wastewater treatment due to their highly pronounced features such as high quality effluent, less foot print and working under high MLSS concentration. This research project was carried out to investigate the feasibility and effectiveness of MBR technology compare to the CAS process based on the scientific facts and results. The pilot scale MBR pilot plant was run for more than 150 days and the analysis results were evaluated. The prime focus of the project was to evaluate the correlation of permeate flux under different operating MLSS concentrations. The permeate flux was found almost constant regardless of variations in MLSS concentrations. The removal of micropollutant such as heavy metals, PCPPs, PFCs, steroidal hormones was also studied. The micropollutant removal performance of MBR process was found relatively effective than CAS process. Furthermore, the compatibility of submerged membranes within the bioreactor had truly reduced the process footprint.
Resumo:
There are many opportunities to utilise coconut in Nzema to support farmers. Coconut oil that is mainly used for food preparation in Nzema can be utilized as fuel to support overcoming of the energy crisis in the Ghana. Coconut oil in Nzema is not used in both transportation and electricity generation. A few of the waste husk and shell are mainly used as fuel in homes for heating but greater amount is left to rot or burn the coconut plantation. In addition, some portion of the granulated coconut kernel is sometime used as feed for piggery feed and the rest of the granulated kernel are left as waste on the oil processing site. In this thesis, the author identified alternative utilization of cocoanut, for instance the use of coconut husk and shell for charcoal production, and the use of coconut trunks as construction materials. It is envisaged that exploring these alternatives will not only reduce carbon emission in the country but will also contribute significantly to the sustainability of the local agro-industry.
Resumo:
SUMMARY Organizational creativity – hegemonic and alternative discourses Over the course of recent developments in the societal and business environment, the concept of creativity has been brought into new arenas. The rise of ‘creative industries’ and the idea of creativity as a form of capital have attracted the interests of business and management professionals – as well as academics. As the notion of creativity has been adopted in the organization studies literature, the concept of organizational creativity has been introduced to refer to creativity that takes place in an organizational context. This doctoral thesis focuses on organizational creativity, and its purpose is to explore and problematize the hegemonic organizational creativity discourse and to provide alternative viewpoints for theorizing about creativity in organizations. Taking a discourse theory approach, this thesis, first, provides an outline of the currently predominant, i.e. hegemonic, discourse on organizational creativity, which is explored regarding themes, perspectives, methods and paradigms. Second, this thesis consists of five studies that act as illustrations of certain alternative viewpoints. Through these exemplary studies, this thesis sheds light on the limitations and taken-for-granted aspects of the hegemonic discourse and discusses what these alternative viewpoints could offer for the understanding of and theorizing for organizational creativity. This study leans on an assumption that the development of organizational creativity knowledge and the related discourse is not inevitable or progressive but rather contingent. The organizational creativity discourse has developed in a certain direction, meaning that some themes, perspectives, and methods, as well as assumptions, values, and objectives, have gained a hegemonic position over others, and are therefore often taken for granted and considered valid and relevant. The hegemonization of certain aspects, however, contributes to the marginalization of others. The thesis concludes that the hegemonic discourse on organizational creativity is based on an extensive coverage of certain themes and perspectives, such as those focusing on individual cognitive processes, motivation, or organizational climate and their relation to creativity, to name a few. The limited focus on some themes and the confinement to certain prevalent perspectives, however, results in the marginalization of other themes and perspectives. The negative, often unintended, consequences, implications, and side effects of creativity, the factors that might hinder or prevent creativity, and a deeper inquiry into the ontology and epistemology of creativity have attracted relatively marginal interest. The material embeddedness of organizational creativity, in other words, the physical organizational environment as well as the human body and its non-cognitive resources, has largely been overlooked in the hegemonic discourse, although thereare studies in this area that give reason to believe that they might prove relevant for the understanding of creativity. The hegemonic discourse is based on an individual-centered understanding of creativity which overattributes creativity to an individual and his/her cognitive capabilities, while simultaneously neglecting how, for instance, the physical environment, artifacts, social dynamics and interactions condition organizational creativity. Due to historical reasons, quantitative as well as qualitative yet functionally- oriented studies have predominated the organizational creativity discourse, although studies falling into the interpretationist paradigm have gradually become more popular. The two radical paradigms, as well as methodological and analytical approaches typical of radical research, can be considered to hold a marginal position in the field of organizational creativity. The hegemonic organizational creativity discourse has provided extensive findings related to many aspects of organizational creativity, although the con- ceptualizations and understandings of organizational creativity in the hegemonic discourse are also in many respects limited and one-sided. The hegemonic discourse is based on an assumption that creativity is desirable, good, necessary, or even obligatory, and should be encouraged and nourished. The conceptualiza- tions of creativity favor the kind of creativity which is useful, valuable and can be harnessed for productivity. The current conceptualization is limited to the type of creativity that is acceptable and fits the managerial ideology, and washes out any risky, seemingly useless, or negative aspects of creativity. It also limits the possible meanings and representations that ‘creativity’ has in the respective discourse, excluding many meanings of creativity encountered in other discourses. The excessive focus on creativity that is good, positive, productive and fits the managerial agenda while ignoring other forms and aspects of creativity, however, contributes to the dilution of the notion. Practices aimed at encouraging the kind of creativity may actually entail a risk of fostering moderate alterations rather than more radical novelty, as well as management and organizational practices which limit creative endeavors, rather than increase their likelihood. The thesis concludes that although not often given the space and attention they deserve, there are alternative conceptualizations and understandings of organizational creativity which embrace a broader notion of creativity. The inability to accommodate the ‘other’ understandings and viewpoints within the organizational creativity discourse runs a risk of misrepresenting the complex and many-sided phenomenon of creativity in organizational context. Keywords: Organizational creativity, creativity, organization studies, discourse theory, hegemony
Resumo:
In oxygenic photosynthesis, the highly oxidizing reactions of water splitting produce reactive oxygen species (ROS) and other radicals that could damage the photosynthetic apparatus and affect cell viability. Under particular environmental conditions, more electrons are produced in water oxidation than can be harmlessly used by photochemical processes for the reduction of metabolic electron sinks. In these circumstances, the excess of electrons can be delivered, for instance, to O2, resulting in the production of ROS. To prevent detrimental reactions, a diversified assortment of photoprotection mechanisms has evolved in oxygenic photosynthetic organisms. In this thesis, I focus on the role of alternative electron transfer routes in photoprotection of the cyanobacterium Synechocystis sp. PCC 6803. Firstly, I discovered a novel subunit of the NDH-1 complex, NdhS, which is necessary for cyclic electron transfer around Photosystem I, and provides tolerance to high light intensities. Cyclic electron transfer is important in modulating the ATP/NADPH ratio under stressful environmental conditions. The NdhS subunit is conserved in many oxygenic phototrophs, such as cyanobacteria and higher plants. NdhS has been shown to link linear electron transfer to cyclic electron transfer by forming a bridge for electrons accumulating in the Ferredoxin pool to reach the NDH-1 complexes. Secondly, I thoroughly investigated the role of the entire flv4-2 operon in the photoprotection of Photosystem II under air level CO2 conditions and varying light intensities. The operon encodes three proteins: two flavodiiron proteins Flv2 and Flv4 and a small Sll0218 protein. Flv2 and Flv4 are involved in a novel electron transport pathway diverting electrons from the QB pocket of Photosystem II to electron acceptors, which still remain unknown. In my work, it is shown that the flv4-2 operon-encoded proteins safeguard Photosystem II activity by sequestering electrons and maintaining the oxidized state of the PQ pool. Further, Flv2/Flv4 was shown to boost Photosystem II activity by accelerating forward electron flow, triggered by an increased redox potential of QB. The Sll0218 protein was shown to be differentially regulated as compared to Flv2 and Flv4. Sll0218 appeared to be essential for Photosystem II accumulation and was assigned a stabilizing role for Photosystem II assembly/repair. It was also shown to be responsible for optimized light-harvesting. Thus, Sll0218 and Flv2/Flv4 cooperate to protect and enhance Photosystem II activity. Sll0218 ensures an increased number of active Photosystem II centers that efficiently capture light energy from antennae, whilst the Flv2/Flv4 heterodimer provides a higher electron sink availability, in turn, promoting a safer and enhanced activity of Photosystem II. This intertwined function was shown to result in lowered singlet oxygen production. The flv4-2 operon-encoded photoprotective mechanism disperses excess excitation pressure in a complimentary manner with the Orange Carotenoid Protein-mediated non-photochemical quenching. Bioinformatics analyses provided evidence for the loss of the flv4-2 operon in the genomes of cyanobacteria that have developed a stress inducible D1 form. However, the occurrence of various mechanisms, which dissipate excitation pressure at the acceptor side of Photosystem II was revealed in evolutionarily distant clades of organisms, i.e. cyanobacteria, algae and plants.
Resumo:
Attracting outside capital is a common problem for start-up companies. Capital markets define the funding options for companies and firms which suffer the most from these capital market imperfections are small start-up companies. Therefore it is important to study any new funding model which can offer a new solution to this inefficiency of capital markets. This study explains the traditional funding models for start-ups such as founders, friends & family, banks, business angels and venture capitalist. After giving background to traditional start-up funding this study delves into crowfunding (CF) and introduces it as a new funding method. The objective of the thesis is to answer one broad research question: Why and how should start-up companies use CF as an alternative funding method? To properly delve into this, this question has the following sub-questions: What kind of funding alternatives do start-up companies have? What are the pros and cons of CF compared to other funding options? How can start-ups benefit from CF? This study gives background on the rise of CF and the reasons why this new model is needed. Author will explain the different components of CF such as platforms, crowdfunders and projects. Also benefits and challenges of the crowdfunding model are investigated. As a new funding model CF has had to clear out many obstacles from its way. These are, for example, legal and regulatory issues as well education of crowd investors to understand this new investment option. . Start-up entrepreneurs can gain valuable insight from this study. The author has attempted to form best practices and guidelines of how to operate in the CF environment. This study was conducted by performing expert interviews, collecting data from previous studies and performing a content analysis of successful crowdfunding cases. Main findings from the study were that CF has huge potential in funding entrepreneurial projects. It is still a niche way for funding but growing rapidly. CF is earning its place among traditional funding options and has potential to fund projects which otherwise would struggle to find funding. With CF entrepreneur can tap into geographically diverse audience. It is a powerful validation tool for products and ideas and has the power to bring democratic elements to entrepreneurial funding.