937 resultados para share of no par value
Resumo:
The conversion of glycerol in supercritical water (SCW) was studied at 510-550 °C and a pressure of 350 bars using both a bed of inert and non-porous ZrO2 particles (hydrothermal experiments), and a bed of a 1% Ru/ZrO2 catalyst. Experiments were conducted with a glycerol concentration of 5 wt% in a continuous isothermal fixed-bed reactor at a residence time between 2 and 10 s. Hydrothermolysis of glycerol formed water-soluble products such as acetaldehyde, acetic acid, hydroxyacetone and acrolein, and gases like H2, CO and CO2. The catalyst enhanced the formation of acetic acid, inhibited the formation of acrolein, and promoted gasification of the glycerol decomposition products. Hydrogen and carbon oxides were the main gases produced in the catalytic experiments, with minor amounts of methane and ethylene. Complete glycerol conversion was achieved at a residence time of 8.5 s at 510 °C, and at around 5 s at 550 °C with the 1 wt% Ru/ZrO2 catalyst. The catalyst was not active enough to achieve complete gasification since high yields of primary products like acetic acid and acetaldehyde were still present. Carbon balances were between 80 and 60% in the catalytic experiments, decreasing continuously as the residence time was increased. This was attributed partially to the formation of methanol and acetaldehyde, which were not recovered and analyzed efficiently in our set-up, but also to the formation of carbon deposits. Carbon deposition was not observed on the catalyst particles but on the surface of the inert zirconia particles, especially at high residence time. This was related to the higher concentration of acetic acid and other acidic species in the catalytic experiments, which may polymerize to form tar-like carbon precursors. Because of carbon deposition, hydrogen yields were significantly lower than expected; for instance at 550 °C the hydrogen yield potential was only 50% of the stoichiometric value.
Resumo:
The main purposes of this study are analyzing of forest sector of North-West and research of potentials of wood fuel market in this region. Research is focused on definition of the most perspective areas for export of wood fuel: logging residues, industrial wood processing residues, pellets and briquettes. Russian wood energy industry is very young in comparison with European countries. Nowadays there are no support and serious attention from the government to this sector. Hence almost all wood fuel market is oriented to the Western Europe. Export of wood fuel is dominated over the internal consumption. Pellet production in North –West is rapidly growing. Despite internal market has been developed the lion's share of pellets goes to export. Part of industrial wood processing residues is used by producers for their own goals, part goes to the export and rest of them is not used at all. Logging residues as raw materials for fuel have great potentials; most of them are left in a forest. Special techniques for their processing are too expensive for Russian entrepreneur. Some parts of North –West, which are situated close to the border with European countries, are potential for export. Political, economical and logistical challenges are complicated facilities for foreign customer to purchase wood fuel in remote parts of North-West. However some decisions for solving this problem exist and Russian manufactures are still interested in export of their products.
Resumo:
The role of transport in the economy is twofold. As a sector of economic activity it contributes to a share of national income. On the other hand, improvements in transport infrastructure create room for accelerated economic growth. As a means to support railways as a safe and environmentally friendly transportation mode, the EU legislation has required the opening of domestic railway freight for competition from beginning of year 2007. The importance of railways as a mode of transport has been great in Finland, as a larger share of freight has been carried on rails than in Europe on average. In this thesis it is claimed that the efficiency of goods transport can be enhanced by service specific investments. Furthermore, it is stressed that simulation can and should be used to evaluate the cost-efficiency of transport systems on operational level, as well as to assess transportation infrastructure investments. In all the studied cases notable efficiency improvements were found. For example in distribution, home delivery of groceries can be almost twice as cost efficient as the current practice of visiting the store. The majority of the cases concentrated on railway freight. In timber transportation, the item with the largest annual transport volume in domestic railway freight in Finland, the transportation cost could be reduced most substantially. Also in international timber procurement, the utilization of railway wagons could be improved by combining complementary flows. The efficiency improvements also have positive environmental effects; a large part of road transit could be moved to rails annually. If impacts of freight transport are included in cost-benefit analysis of railway investments, up to 50 % increase in the net benefits of the evaluated alternatives can be experienced, avoiding a possible inbuilt bias in the assessment framework, and thus increasing the efficiency of national investments in transportation infrastructure. Transportation systems are a typical example of complex real world systems that cannot be analysed realistically by analytical methods, whereas simulation allows inclusion of dynamics and the level of detail required. Regarding simulation as a viable tool for assessing the efficiency of transportation systems finds support also in the international survey conducted for railway freight operators; operators use operations research methods widely for planning purposes, while simulation is applied only by the larger operators.
Resumo:
This study considered the current situation of solid and liquid biomass fuels in Finland. The fact that industry consumes more than half of the total primary energy, widely applied combined heat and power production and a high share of solid biomass fuels in the total energy consumption are specific to the Finnish energy system. Wood is the most important source of bioenergy in Finland, representing 20% of the total energy consumption in 2007. Almost 80% of the woodbased energy is recovered from industrial by-products and residues. As a member of the European Union, Finland has committed itself to the Union’s climate and energy targets, such as reducing its overall emissions of green house gases to at least 20% below 1990 levels by 2020, and increasing the share of renewable energy in the gross final consumption. The renewable energy target approved for Finland is 38%. The present National Climate and Energy Strategy was introduced in November 2008. The strategy covers climate and energy policy measures up to 2020, and in brief thereafter, up to 2050. In recent years, the actual emissions have exceeded the Kyoto commitment and the trend of emissions is on the increase. In 2007, the share of renewable energy in the gross final energy consumption was approximately 25% (360 PJ). Without new energy policy measures, the final consumption of renewable energy would increase to 380 PJ, which would be approximately only 31% of the final energy consumption. In addition, green house gas emissions would exceed the 1990 levels by 20%. Meeting the targets will need the adoption of more active energy policy measures in coming years. The international trade of biomass fuels has a substantial importance for the utilisation of bioenergy in Finland. In 2007, the total international trading of solid and liquid biomass fuels was approximately 77 PJ, of which import was 62 PJ. Most of the import is indirect and takes place within the forest industry’s raw wood imports. In 2007, as much as 21% of wood energy was based on foreign-origin wood. Wood pellets and tall oil form the majority of export streams of biomass fuels. The indirect import of wood fuels peaked in 2006 to 61 PJ. The foreseeable decline in raw wood import to Finland will decrease the indirect import of wood fuels. In 2004– 2007, the direct trade of solid and liquid biomass fuels has been on a moderate growth path. In 2007, the import of palm oil and export of bio-diesel emerged, as a large, 170 000 t/yr biodiesel plant came into operation in Porvoo.
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This paper uses the possibilities provided by the regression-based inequality decomposition (Fields, 2003) to explore the contribution of different explanatory factors to international inequality in CO2 emissions per capita. In contrast to previous emissions inequality decompositions, which were based on identity relationships (Duro and Padilla, 2006), this methodology does not impose any a priori specific relationship. Thus, it allows an assessment of the contribution to inequality of different relevant variables. In short, the paper appraises the relative contributions of affluence, sectoral composition, demographic factors and climate. The analysis is applied to selected years of the period 1993–2007. The results show the important (though decreasing) share of the contribution of demographic factors, as well as a significant contribution of affluence and sectoral composition.
Resumo:
In the Russian Wholesale Market, electricity and capacity are traded separately. Capacity is a special good, the sale of which obliges suppliers to keep their generating equipment ready to produce the quantity of electricity indicated by the System Operator. The purpose of the formation of capacity trading was the maintenance of reliable and uninterrupted delivery of electricity in the wholesale market. The price of capacity reflects constant investments in construction, modernization and maintenance of power plants. So, the capacity sale creates favorable conditions to attract investments in the energy sector because it guarantees the investor that his investments will be returned.
Resumo:
Previous studies have demonstrated that volatile organic compounds (VOCs), produced by the yeast Saccharomyces cerevisiae, were able to inhibit the development of phytopathogenic fungi. In this context, the nematicidal potential of the synthetic mixture of VOCs, constituted of alcohols and esters, was evaluated for the control of the root-knot nematode Meloidogyne javanica, which causes losses to crops of high economic value. The fumigation of substrate containing second-stage juveniles with VOCs exhibited nematicidal effect higher than 30% for the lowest concentration tested (33.3 µL g-1 substrate), whereas at 66.6 and 133.3 µL g-1 substrate, the nematode mortality was 100%. The present results stimulate other studies on VOCs for nematode management.
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The objective of the dissertation is to examine organizational responses of public actors to customer requirements which drive the transformation of value networks and promote public-private partnership in the electricity distribution industry and elderly care sectors. The research bridges the concept of offering to value networks where capabilities can be acquired for novel product concepts. The research contributes to recent literature, re-examining theories on interactions of customer requirements and supply management. A critical realist case study approach is applied to this abductive the research which directs to describe causalities in the analyzed phenomena. The presented evidence is based on three sources, which are in-depth interviews, archival analysis and the Delphi method. Service provision requires awareness on technology and functionalities of offering. Moreover, service provision includes interactions of multiple partners, which suggests the importance of the co-operative orientation of actors. According to the findings,portfolio management has a key role when intelligent solutions are implemented in public service provision because its concepts involve a variety of resources from multiple suppliers. However, emergent networks are not functional if they lack leaders who have access to the customer interface, have power to steer networks and a capability to build offerings. Public procurement policies were recognized to focus on a narrow scope in which price is a key factor in decisions. In the future, the public sector has to implement technology strategies and portfolio management, which mean longterm platform development and commitment to partnerships. On the other hand, the service providers should also be more aware of offerings into which their products will be integrated in the future. This requires making the customer’s voice in product development and co-operation in order to increase the interconnectivity of products.
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Eucalyptus plantations represent a short term and cost efficient alternative for sequestrating carbon dioxide from the atmosphere. Despite the known potential of forest plantations of fast growing species to store carbon in the biomass, there are relatively few studies including precise estimates of the amount of carbon in these plantations. In this study it was determined the carbon content in the stems, branches, leaves and roots of a clonal Eucalyptus grandis plantation in the Southeast of Brazil. We developed allometric equations to estimate the total amount of carbon and total biomass, and produced an estimate of the carbon stock in the stand level. Altogether, 23 sample trees were selected for aboveground biomass assessment. The roots of 9 of the 23 sampled trees were partially excavated to assess the belowground biomass at a singletree level. Two models with DBH, H and DBH2H were tested. The average relative share of carbon content in the stem, branch, leaf and root compartments was 44.6%, 43.0%, 46.1% and 37.8%, respectively, which is smaller than the generic value commonly used (50%). The best-fit allometric equations to estimate the total amount of carbon and total biomass had DBH2H as independent variable. The root-to-shoot ratio was relatively stable (C.V. = 27.5%) probably because the sub-sample was composed of clones. Total stand carbon stock in the Eucalyptus plantation was estimated to be 73.38 MgC ha-1, which is within the carbon stock range for Eucalyptus plantations.
Resumo:
The Andean area of South America is a very important center for the domestication of food crops. This area is the botanical origin of potato, peanut and tomato. Less well- known crops, such as quinoa (Chenopodium quinoa), kañiwa (Chenopodium pallidicaule) and kiwicha (Amaranthus caudatus), were also domesticated by ancient Andean farmers. These crops have a long history of safe use with the local populations and they have contributed to the nutrition and wellbeing of the people for centuries. Several studies have reported the nutritional value of Andean grains. They contain proteins with a balanced essential amino acid composition that are of high biological value, good quality oil and essential minerals, for example iron, calcium and zinc. They are potential sources of bioactive compounds such as polyphenols and dietary fiber. The main objective of the practical work was to assess the nutritional value of Andean native grains with a special emphasis on the bioactive components and the impact of processing. The compounds studied were phenolic acids, flavonoids, betalains and dietary fiber. The radical scavenging activity was measured as well. Iron, calcium and zinc content and their bioavailability were analyzed as well. The grains were processed by extrusion with the aim to study the effect of processing on the chemical composition. Quinoa, kañiwa and kiwicha are very good sources of dietary fiber, especially of insoluble dietary fiber. The phenolic acid content in Andean crops was low compared with common cereals like wheat and rye, but was similar to levels found in oat, barley, corn and rice. The flavonoid content of quinoa and kañiwa was exceptionally high. Kiwicha did not contain quantifiable amounts of these compounds. Only one variety of kiwicha contained low amounts of betalains. These compounds were not detected in kañiwa or quinoa. Quinoa, kañiwa and kiwicha are good sources of minerals. Their calcium, zinc and iron content are higher than the content of these minerals in common cereals. In general, roasting did not affect significantly mineral bioavailability. On the contrary, in cooked grains, there was an increase in bioavailability of zinc and, in the case of kañiwa, also in iron and calcium bioavailability. In all cases, the contents of total and insoluble dietary fiber decreased during the extrusion process. At the same time, the content of soluble dietary fiber increased. The content of total phenolics, phytic acid and the antioxidant activity decreased in kiwicha varieties during the extrusion process. In the case of quinoa, the content of total phenolic compounds and the radical scavenging activity increased during the extrusion process in all varieties. Taken together, the studies presented here demonstrate that the Andean indigenous crops have excellent potential as sources of minerals, flavonoids and dietary fiber. Further studies should be conducted to characterize the phenolic compound and antioxidant composition in processed grains and end products. Quinoa, kañiwa and kiwicha grains are consumed widely in Andean countries but they also have a significant, worldwide potential as a new cultivated crop species and as an imported commodity from South America. Their inclusion in the diet has the potential to improve the intake of minerals and health-promoting bioactive compounds. They may also be interesting raw materials for special dietary foods and functional foods offering natural sources of specific health-promoting components.
Resumo:
Studies on the effects of temperature and time of incubation of wastewater samples for the estimation of biodegradable organic matter through the biochemical oxygen demand (BOD), that nowadays are rare, considering that the results of the classic study of STREETER & PHELPS(1925) have been accepted as standard. However, there are still questions how could be possible to reduce the incubation time; whether the coefficient of temperature (θ) varies with the temperature and with the type of wastewater and if it approaches 1.047. Aiming the elucidation of these questions, wastewater samples of dairy, swine and sewage treated in septic tanks were incubated at temperatures of 20, 30 and 35 °C, respectively for 5, 3.16 and 2.5 days. From the parameter of deoxygenation coefficient at 20 °C (k20), θ30 and θ35 were calculated. The results indicated that θ values changes with the type of wastewater, however does not vary in the temperature range between 30 and 35 °C, and that the use of 1.047 value did not implied significant differences in obtaining k in a determined T temperature. Thus, it is observed that the value of θ can be used to estimate the required incubation time of the samples at different temperatures.
Resumo:
ABSTRACT Knowledge of natural water availability, which is characterized by low flows, is essential for planning and management of water resources. One of the most widely used hydrological techniques to determine streamflow is regionalization, but the extrapolation of regionalization equations beyond the limits of sample data is not recommended. This paper proposes a new method for reducing overestimation errors associated with the extrapolation of regionalization equations for low flows. The method is based on the use of a threshold value for the maximum specific low flow discharge estimated at the gauging sites that are used in the regionalization. When a specific low flow, which has been estimated using the regionalization equation, exceeds the threshold value, the low flow can be obtained by multiplying the drainage area by the threshold value. This restriction imposes a physical limit to the low flow, which reduces the error of overestimating flows in regions of extrapolation. A case study was done in the Urucuia river basin, in Brazil, and the results showed the regionalization equation to perform positively in reducing the risk of extrapolation.
Resumo:
Social media is a rather new phenomenon which has revolutionised the world of online communication. However, academic research on how companies can benefit from social media is lacking. The research objective of this thesis was to examine the use of social media in international brand communication of small Finnish design-intensive companies. Therefore, this research contributes also to the research gap in SME branding. The focus was on communication targeted at consumers. The research was carried out as a mixed methods research employing the questionnaire and multiple case study methods. The questionnaire was used to gather preliminary information on Finnish design-intensive companies and to provide an eligible list of companies for deeper examination. Then, four case companies were studied in more depth. The empirical evidence of the case companies was mainly gathered through theme interviews. The results of the questionnaire shed light on the internationalisation of small Finnish designintensive companies. On average, the companies had internationalised rather quickly after they had been founded. However, the share of exports was rather low in most of the companies. The results revealed also that social media was already used widely in the exporting companies and the use can be expected to grow in future. The findings of the multiple case study suggest that branding activities in small Finnish designintensive companies are constrained by limited resources and skills. In addition, the branding activities are strongly guided by the vision and values of the entrepreneur(s) rather than extensive marketing research. The brand structure was simple in all case companies and they aimed at having a standardised brand image across markets. However, all case companies had faced a need for some adaptation of their international brand communication. Internationally important brand communication channels were international fairs, the internet, word-of-mouth and social media. Social media offered a cost-effective brand communication channel for the case companies. It was used for various purposes, such as creating brand awareness and affecting how the brand is perceived. The entrepreneurs found the use of social media to be rather easy and the case companies had not faced any major challenges. However, the companies had recognised that communication in social media requires consistency and planning. The planning was rather informal and stayed on a general level. Overall, the utilisation of social media in the case companies was limited by a lack of resources. It seemed to affect especially the follow-up of brand communication in social media which stayed rather superficial.
Resumo:
Tutkimus tehtiin STX Finlandin Turun telakalle osana suurempaa kehitysohjelmaa, joka tähtää läpimenoaikojen lyhentämiseen ja kilpailukyvyn paranemiseen. Työntutkimuksesta saatujen tietojen avulla toimintaa pyritään kehittämään tuottavammaksi ja läpimenoaikaa lyhyemmäksi. Työssä pyrittiin löytämään valmistusteknillisiä keinoja läpimenoajan lyhentämiseksi käyttäen hyväksi Lean-ajattelutapaa. Mittaustuloksista voidaan nähdä, miten aika jakaantuu lohkonkoonnissa ja mihin aikaa hukataan. Tuloksista huomataan, että lisäarvoa tuottavan työn osuutta työajasta voidaan lisätä. Kasvattamalla jalostavan työn osuutta voidaan tuotannosta tehdä tehokkaampaa ja läpimenoaikaa lyhentää. Tuloksista selviää, minkälaisia Lean-ajattelutavan hukkia työvaiheet sisältävät ja kuinka paljon aikaa niihin kuluu. Tutkimus tehtiin tunnettuja työntutkimuksen keinoja hyväksikäyttäen. Käytössä oli havainnointitutkimus sekä ajankäyttötutkimus. Havainnointitutkimuksen avulla saatiin selville tuotannon epäkohtia. Työntutkimuksen avulla selvisi myös, ettei mekanisointien käyttö hitsauksessa ole riittävällä tasolla. Suuri osa hitsauksesta tehdään manuaalisesti ilman kuljettimia, jolloin paloaikasuhde pysyy matalana. Tuotannossa esiintyvät virheet jäävät liian usein raportoimatta. Tutkimuksessa on esitetty toimintamalli tuotannon epäkohtien raportoinnin toteutukselle. Johtopäätöksinä syntyi kehitysideoita lohkovalmistuksen tehostamiseksi. Tutkimuksen avulla luotiin pohja työntutkimuksen uudelleenkäynnistämiselle. Luotuja työntutkimuskaavioita voidaan käyttää tulevissa työntutkimuksissa. Johtopäätöksinä syntyi kehitysideoita lohkovalmistuksen tehostamiseksi. Menetelmien avulla lohkovalmistuksen läpimenoaikaa saadaan tehostettua.