939 resultados para Gravitational potential energy


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The thesis explores global and national-level issues related to the development of markets for biomass for energy. The thesis consists of five separate papers and provides insights on selected issues. The aim of Paper I was to identify methodological and statistical challenges in assessing international solid and liquid biofuels trade and provide an overview of the Finnish situation with respect to the status of international solid and liquid biofuels trade. We found that, for the Finnish case, it is possible to qualify direct and indirect trade volumes of biofuels. The study showed that indirect trade of biofuels has a highly significant role in Finland and may be a significant sector also in global biofuels trade. The purpose of Paper II was to provide a quantified insight into Finnish prospects for meeting the national 2020 renewable energy targets and concurrently becoming a largescale producer of forest-biomass-based second-generation biofuels for feeding increasing demand in European markets. We found that Finland has good opportunities to realise a scenario to meet 2020 renewable energy targets and for large-scale production of wood-based biofuels. The potential net export of transport biofuels from Finland in 2020 would correspond to 2–3% of European demand. Paper III summarises the global status of international solid and liquid biofuels trade as illuminated by several separate sources. International trade of biofuels was estimated at nearly 1 EJ for 2006. Indirect trade of biofuels through trading of industrial roundwood and material by-products comprises the largest proportion of the trading, with a share of about two thirds. The purpose of Paper IV was to outline a comprehensive picture of the coverage of various certification schemes and sustainability principles relating to the entire value-added chain of biomass and bioenergy. Regardless of the intensive work that has been done in the field of sustainability schemes and principles concerning use of biomass for energy, weaknesses still exist. The objective of Paper V was to clarify the alternative scenarios for the international biomass market until 2020 and identify the underlying steps needed toward a wellfunctioning and sustainable market for biomass for energy purposes. An overall conclusion drawn from this analysis concerns the enormous opportunities related to the utilisation of biomass for energy in the coming decades.

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This study examined solution business models and how they could be applied into energy efficiency business. The target of this study was to find out, what a functional solution business model applied to energy efficiency improvement projects is like. The term “functionality” was used to refer not only to the economic viability but to environmental and legal aspects and also to the implement of Critical Success Factors (CSFs) and the ability to overcome the most important market barriers and risks. This thesis is based on a comprehensive literature study on solution business, business models and energy efficiency business. This literature review was used as a foundation to an energy efficiency solution business model scheme. The created scheme was tested in a case study which studied two different energy efficiency improvement projects, illustrated the functionality of the created business model and evaluated their potential as customer targets. Solution approach was found to be suitable for energy efficiency business. The most important characteristics of a good solution business model were identified to be the relationship between the supplier and customer, a proper network, knowledge on the customer’s process and supreme technological expertise. Thus the energy efficiency solution business was recognized to be particularly suitable for example for energy suppliers or technological equipment suppliers. Because the case study was not executed from a certain company’s point of view, the most important factors such as relationships and the availability of funding could not be evaluated. Although the energy efficiency business is recognized to be economically viable, the most important factors influencing the profitability and the success of energy efficiency solution business model were identified to be the proper risk management, the ability to overcome market barriers and the realization of CSFs.

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The numerous methods for calculating the potential or reference evapotranspiration (ETo or ETP) almost always do for a 24-hour period, including values of climatic parameters throughout the nocturnal period (daily averages). These results have a nil effect on transpiration, constituting the main evaporative demand process in cases of localized irrigation. The aim of the current manuscript was to come up with a model rather simplified for the calculation of diurnal daily ETo. It deals with an alternative approach based on the theoretical background of the Penman method without having to consider values of aerodynamic conductance of latent and sensible heat fluxes, as well as data of wind speed and relative humidity of the air. The comparison between the diurnal values of ETo measured in weighing lysimeters with elevated precision and estimated by either the Penman-Monteith method or the Simplified-Penman approach in study also points out a fairly consistent agreement among the potential demand calculation criteria. The Simplified-Penman approach was a feasible alternative to estimate ETo under the local meteorological conditions of two field trials. With the availability of the input data required, such a method could be employed in other climatic regions for scheduling irrigation.

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Kuumahiertoprosessi on erittäin energiaintensiivinen prosessi, jonka energianominaiskulutus (EOK) on yleisesti 2–3.5 MWh/bdt. Noin 93 % energiasta kuluu jauhatuksessa jakautuen niin, että kaksi kolmasosaa kuluu päälinjan ja yksi kolmasosa rejektijauhatuksessa. Siksi myös tämän työn tavoite asetettiin vähentämään energian kulutusta juuri pää- ja rejektijauhatuksessa. Päälinjan jauhatuksessa tutkimuskohteiksi valittiin terityksen, tehojaon ja tuotantotason vaikutus EOK:een. Rejektijauhatuksen tehostamiseen pyrittiin yrittämällä vähentää rejektivirtaamaa painelajittelun keinoin. Koska TMP3 laitoksen jauhatuskapasiteettia on nostettu 25 %, tavoite oli nostaa päälinjan lajittelun kapasiteettia saman verran. Toisena tavoitteena oli pienentää rejektisuhdetta pää- ja rejektilajittelussa ja siten vähentää energiankulutusta rejektijauhatuksessa. Näitä tavoitteita lähestyttiin vaihtamalla päälinjan lajittimiin TamScreen-roottorit ja rejektilajittimiin Metso ProFoil-roottorit ja optimoimalla kuitufraktiot sihtirumpu- ja prosessiparametrimuutoksin. Syöttävällä terätyypillä pystyttiin vähentämään EOK:ta 100 kWh/bdt, mutta korkeampi jauhatusintensiteetti johti myös alempiin lujuusominaisuuksiin, korkeampaan ilmanläpäisyyn ja korkeampaan opasiteettiin. Myös tehojaolla voitiin vaikuttaa EOK:een. Kun ensimmäisen vaiheen jauhinta kuormitettiin enemmän, saavutettiin korkeimmillaan 70 kWh/bdt EOK-vähennys. Tuotantotason mittaamisongelmat heikensivät tuotantotasokoeajojen tuloksia siinä määrin, että näiden tulosten perusteella ei voida päätellä, onko EOK tuotantotasoriippuvainen vai ei. Päälinjan lajittelun kapasiteettia pystyttiin nostamaan TS-roottorilla vain 18 % jääden hieman tavoitetasosta. Rejektilajittelussa pystyttiin vähentämään rejektimäärää huomattavasti Metso ProFoil-roottorilla sekä sihtirumpu- ja prosessiparametrimuutoksin. Lajittamokehityksellä saavutettu EOK-vähennys arvioitiin massarejektisuhteen pienentymisen ja rejektijauhatuksessa käytetyn EOK:n avulla olevan noin 130 kWh/bdt. Yhteenvetona voidaan todeta, että tavoite 300 kWh/bdt EOK-vähennyksestä voidaan saavuttaa työssä käytetyillä tavoilla, mikäli niiden täysi potentiaali hyödynnetään tuotannossa.

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Cyanobacteria are a diverse group of oxygenic photosynthetic bacteria that inhabit in a wide range of environments. They are versatile and multifaceted organisms with great possibilities for different biotechnological applications. For example, cyanobacteria produce molecular hydrogen (H2), which is one of the most important alternatives for clean and sustainable energy. Apart from being beneficial, cyanobacteria also possess harmful characteristics and may become a source of threat to human health and other living organisms, as they are able to form surface blooms that are producing a variety of toxic or bioactive compounds. The University of Helsinki Culture Collection (UHCC) maintains around 1,000 cyanobacterial strains representing a large number of genera and species isolated from the Baltic Sea and Finnish lakes. The culture collection covers different life forms such as unicellular and filamentous, N2-fixing and non-N2-fixing strains, and planktonic and benthic cyanobacteria. In this thesis, the UHCC has been screened to identify potential strains for sustainable biohydrogen production and also for strains that produce compounds modifying the bioenergetic pathways of other cyanobacteria or terrestrial plants. Among the 400 cyanobacterial strains screened so far, ten were identified as high H2-producing strains. The enzyme systems involved in H2 metabolism of cyanobacteria were analyzed using the Southern hybridization approach. This revealed the presence of the enzyme nitrogenase in all strains tested, while none of them are likely to have contained alternative nitrogenases. All the strains tested, except for two Calothrix strains, XSPORK 36C and XSPORK 11A, were suggested to contain both uptake and bidirectional hydrogenases. Moreover, 55 methanol extracts of various cyanobacterial strains were screened to identify potent bioactive compounds affecting the photosynthetic apparatus of the model cyanobacterium, Synechocystis PCC 6803. The extract from Nostoc XPORK 14A was the only one that modified the photosynthetic machinery and dark respiration. The compound responsible for this effect was identified, purified, and named M22. M22 demonstrated a dual-action mechanism: production of reactive oxygen species (ROS) under illumination and an unknown mechanism that also prevailed in the dark. During summer, the Baltic Sea is occupied by toxic blooms of Nodularia spumigena (hereafter referred to as N. spumigena), which produces a hepatotoxin called nodularin. Long-term exposure of the terrestrial plant spinach to nodularin was studied. Such treatment resulted in inhibition of growth and chlorosis of the leaves. Moreover, the activity and amount of mitochondrial electron transfer complexes increased in the leaves exposed to nodularin-containing extract, indicating upregulation of respiratory reactions, whereas no marked changes were detected in the structure or function of the photosynthetic machinery. Nodularin-exposed plants suffered from oxidative stress, evidenced by oxidative modifications of various proteins. Plants initiated strategies to combat the stress by increasing the levels of alpha-tocopherol, mitochondrial alternative oxidase (AOX), and mitochondrial ascorbate peroxidase (mAPX).

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In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

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ABSTRACT The present study aims to present the main concepts of the sugarcane straw to energy planning. Throughout the study, the subject is contextualized highlighting broader aspects of sustainability, which is considered the main driver towards agro-energy modernization. Concerning sugarcane straw, we first evaluated its availability regarding technical and economic aspects, and then it summarized the straw production chain for energy supply purposes. As a proposal to support agro-energy planning, it is presented some spatial tools that have been barely used in the Brazilian energy planning context so far. Therefore, working on straw to electricity associated with supply chain basis, we developed a conceptual model to spatially assess this bioenergy system. Using the model proposed, it is described the whole supply chain at state level, which accounted the potential of a single mill to explore straw, as well as main costs associated with straw acquisition, investments on the straw recovery routes and electricity transmission. Bearing these concepts in mind, it is fully believed that spatial analysis can bring important information for agro-energy action plans.

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The melanocortin peptides, including melanocyte-stimulating hormones, α-, β- and γ-MSH, are derived from the precursor peptide proopiomelanocortin and mediate their biological actions via five different melanocortin receptors, named from MC1 to MC5. Melanocortins have been implicated in the central regulation of energy balance and cardiovascular functions, but their local effects, via yet unidentified sites of action, in the vasculature, and their therapeutic potential in major vascular pathologies remain unclear. Therefore, the main aim of this thesis was to characterise the role of melanocortins in circulatory regulation, and to investigate whether targeting of the melanocortin system by pharmacological means could translate into therapeutic benefits in the treatment of cardiovascular diseases such as hypertension. In experiments designed to elucidate the local effects of α-MSH on vascular tone, it was found that α-MSH improved blood vessel relaxation via a nitric oxide (NO)-dependent mechanism without directly contracting or relaxing blood vessels. Furthermore, α-MSH was shown to regulate the expression and function of endothelial NO synthase in cultured human endothelial cells via melanocortin 1 receptors. In keeping with the vascular protective role, pharmacological treatment of mice with α-MSH analogues displayed therapeutic efficacy in conditions associated with vascular dysfunction such as obesity. Furthermore, α-MSH analogues elicited marked diuretic and natriuretic responses, which together with their vascular effects, seemed to provide protection against sodium retention and blood pressure elevation in experimental models of hypertension. In conclusion, the present results identify novel effects for melanocortins in the local control of vascular function, pointing to the potential future use of melanocortin analogues in the treatment of cardiovascular pathologies.

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The aim of this report is to describe the current status of the waste-to-energy chain in the province of Northern Savonia in Finland. This work is part of the Baltic Sea Region Programme project Remowe-Regional Mobilizing of Sustainable Waste-to-Energy Production (2009-2012). Partnering regions across Baltic Sea countries have parallelly investigated the current status, bottle-necks and needs for development in their regions. Information about the current status is crucial for the further work within the Remowe project, e.g. in investigating the possible future status in target regions. Ultimate result from the Northern Savonia point of view will be a regional model which utilizes all available information and facilitates decision-making concerning energy utilization of waste. The report contains information on among others: - waste management system (sources, amounts, infrastructure) - energy system (use, supply, infrastructure) - administrative structure and legislation - actors and stakeholders in the waste-to-energy field, including interest and development ideas The current status of the regions will be compared in a separate Remowe report, with the focus on finding best practices that could be transferred among the regions. In this report, the current status has been defined as 2006-2009. In 2009, the municipal waste amount per capita was 479 kg/inhabitant in Finland. Industrial waste amounted 3550 kg/inhabitant, respectively. The potential bioenergy from biodegradable waste amounts 1 MWh/inhabitant in Northern Savonia. This figure includes animal manure, crops that would be suitable for energy use, sludge from municipal sewage treatment plants and separately collected biowaste. A key strategy influencing also to Remowe work is the waste plan for Eastern Finland. Currently there operate two digestion plants in Northern Savonia: Lehtoniemi municipal sewage treatment sludge digestion plant of Kuopion Vesi and the farm-scale research biogas plant of Agrifood Research Finland in Maaninka. Moreover, landfill gas is collected to energy use from Heinälamminrinne waste management centre and Silmäsuo closed landfill site, both belonging to Jätekukko Oy. Currently there is no thermal utilization of waste in Northern Savonia region. However, Jätekukko Oy is pretreating mixed waste and delivering refuse derived fuel (RDF) to Southern Finland to combustion. There is a strong willingness among seven regional waste management companies in Eastern Finland to build a waste incineration plant to Riikinneva waste management centre near city of Varkaus. The plant would use circulating fluidized bed (CFB) boiler. This would been a clear boost in waste-to-energy utilization in Northern Savonia and in many surrounding regions.

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Information gained from the human genome project and improvements in compound synthesizing have increased the number of both therapeutic targets and potential lead compounds. This has evolved a need for better screening techniques to have a capacity to screen number of compound libraries against increasing amount of targets. Radioactivity based assays have been traditionally used in drug screening but the fluorescence based assays have become more popular in high throughput screening (HTS) as they avoid safety and waste problems confronted with radioactivity. In comparison to conventional fluorescence more sensitive detection is obtained with time-resolved luminescence which has increased the popularity of time-resolved fluorescence resonance energy transfer (TR-FRET) based assays. To simplify the current TR-FRET based assay concept the luminometric homogeneous single-label utilizing assay technique, Quenching Resonance Energy Transfer (QRET), was developed. The technique utilizes soluble quencher to quench non-specifically the signal of unbound fraction of lanthanide labeled ligand. One labeling procedure and fewer manipulation steps in the assay concept are saving resources. The QRET technique is suitable for both biochemical and cell-based assays as indicated in four studies:1) ligand screening study of β2 -adrenergic receptor (cell-based), 2) activation study of Gs-/Gi-protein coupled receptors by measuring intracellular concentration of cyclic adenosine monophosphate (cell-based), 3) activation study of G-protein coupled receptors by observing the binding of guanosine-5’-triphosphate (cell membranes), and 4) activation study of small GTP binding protein Ras (biochemical). Signal-to-background ratios were between 2.4 to 10 and coefficient of variation varied from 0.5 to 17% indicating their suitability to HTS use.

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Operation of pulp and paper mills generates waste including wastewater treatment sludge and deinking sludge. Both sludge types are generated in large amounts and are mainly disposed of in landfills in the Leningrad Region resulting in environmental degradation. The thesis was aimed at seeking new sustainable ways of sludge utilization. Two paper mills operating in the Leningrad Region and landfilling their sludge were identified: “SCA Hygiene Products Russia” and “Knauf”. The former generates 150 t/day of deinking sludge, the latter – 145 t/day of secondary sludge. Chemical analyses of deinking sludge were performed to assess applicability of sludge in construction materials production processes. Higher heating value on dry basis of both sludge types was determined to evaluate energy potential of sludge generated in the Leningrad Region. Total energy output from sludge incineration was calculated. Deinking sludge could be utilized in the production process of “LSR-Cement” or “Slantsy Cement Plant Cesla” factories, and “Pobeda” and “Nikolsky” brick mills without exceeding current sludge management costs.

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As the rapid development of the society as well as the lifestyle, the generation of commercial waste is getting more complicated to control. The situation of packaging waste and food waste – the main fractions of commercial waste in different countries in Europe and Asia is analyzed in order to evaluate and suggest necessary improvements for the existing waste management system in the city of Hanoi, Vietnam. From all waste generation sources of the city, a total amount of approximately 4000 tons of mixed waste is transported to the composting facility and the disposal site, which emits a huge amount of 1,6Mt of GHG emission to the environment. Recycling activity is taking place spontaneously by the informal pickers, leads to the difficulty in managing the whole system and uncertainty of the overall data. With a relative calculation, resulting in only approximately 0,17Mt CO2 equivalent emission, incinerator is suggested to be the solution of the problem with overloaded landfill and raising energy demand within the inhabitants.

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Distillation is a unit operation of process industry, which is used to separate a liquid mixture into two or more products and to concentrate liquid mixtures. A drawback of the distillation is its high energy consumption. An increase in energy and raw material prices has led to seeking ways to improve the energy efficiency of distillation. In this Master's Thesis, these ways are studied in connection with the concentration of hydrogen peroxide at the Solvay Voikkaa Plant. The aim of this thesis is to improve the energy efficiency of the concentration of the Voikkaa Plant. The work includes a review of hydrogen peroxide and its manufacturing. In addition, the fundamentals of distillation and its energy efficiency are reviewed. An energy analysis of the concentration unit of Solvay Voikkaa Plant is presented in the process development study part. It consists of the current and past information of energy and utility consumptions, balances, and costs. After that, the potential ways to improve the energy efficiency of the distillation unit at the factory are considered and their feasibility is evaluated technically and economically. Finally, proposals to improve the energy efficiency are suggested. Advanced process control, heat integration and energy efficient equipment are the most potential ways to carry out the energy efficient improvements of the concentration at the Solvay Voikkaa factory. Optimization of the reflux flow and the temperatures of the overhead condensers can offer immediate savings in the energy and utility costs without investments. Replacing the steam ejector system with a vacuum pump would result in savings of tens of thousands of euros per year. The heat pump solutions, such as utilizing a mechanical vapor recompression or thermal vapor recompression, are not feasible due to the high investment costs and long pay back times.

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The aim of this thesis is to study whether the use of biomethane as a transportation fuel is reasonable from climate change perspective. In order to identify potentials and challenges for the reduction of greenhouse gas (GHG) emissions, this dissertation focuses on GHG emission comparisons, on feasibility studies and on the effects of various calculation methodologies. The GHG emissions calculations are carried out by using life cycle assessment (LCA) methodologies. The aim of these LCA studies is to figure out the key parameters affecting the GHG emission saving potential of biomethane production and use and to give recommendations related to methodological choices. The feasibility studies are also carried out from the life cycle perspective by dividing the biomethane production chain for various operators along the life cycle of biomethane in order to recognize economic bottlenecks. Biomethane use in the transportation sector leads to GHG emission reductions compared to fossil transportation fuels in most cases. In addition, electricity and heat production from landfill gas, biogas or biomethane leads to GHG reductions as well. Electricity production for electric vehicles is also a potential route to direct biogas or biomethane energy to transportation sector. However, various factors along the life cycle of biomethane affect the GHG reduction potentials. Furthermore, the methodological selections have significant effects on the results. From economic perspective, there are factors related to different operators along the life cycle of biomethane, which are not encouraging biomethane use in the transportation sector. To minimize the greenhouse gas emissions from the life cycle of biomethane, waste feedstock should be preferred. In addition, energy consumption, methane leakages, digestate utilization and the current use of feedstock or biogas are also key factors. To increase the use of biomethane in the transportation sector, political steering is needed to improve the feasibility for the operators. From methodological perspective, it is important to recognize the aim of the life cycle assessment study. The life cycle assessment studies can be divided into two categories: 1.) To produce average GHG information of biomethane to evaluate the acceptability of biomethane use compared to fossil transportation fuels. 2.) To produce GHG information of biomethane related to actual decision-making situations. This helps to figure out the actual GHG emission changes in cases when feedstock, biogas or biomethane are already in other use. For example directing biogas from electricity production to transportation use does not necessarily lead to additional GHG emission reductions. The use of biomethane seems to have a lot of potential for the reduction of greenhouse gas emissions as a transportation fuel. However, there are various aspects related to production processes, to the current use of feedstock or biogas and to the feasibility that have to be taken into account.

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The renewable energy industry in Zambia is poised for growth and offers many possibilities for Finnish firms willing to enter the market. The Zambian government’s deliberate policy measures aim at attracting foreign direct investment (FDI) into this sector. This study rationalises that this could be the pull factor for Finnish firms. The thesis gives an overview of the industry and investigates an appropriate mode of entry, basing its arguments on the comparison analysis of the two economies with the use of the world forum’s stages of economic development as a framework. The theoretical part of the study examines internationalisation theories, entry mode choice and factors influencing the choice. The multiple case study approach is implored, analysing four case companies from Finland with the use of extant literature on internationalisation relevant to the study. The research design involves the use of documentation, secondary data, interviews and observation. The results of the case analyses show that the Finnish firm’s most preferred entry mode initially is exporting because it is considered to be less risky. Additionally, the findings also reveal that the selection of a suitable mode of entry is dependent on the firms’ size, orientation and international experience and could therefore be considered to be subjective. Paramount is the act of gaining market knowledge. The study shows that only hydro-electrical, solar energies and biomass are by far the most used and known forms of renewable energy in Zambia, while other alternative sources still remain un-exploited thus highlighting a growth potential. However, policy formulation and the regulatory framework in the renewable energy sector were found to be wanting.