937 resultados para Salovaara, Hannu


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Kirjallisuusarvostelu

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Kirjallisuusarvostelu

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Kirjallisuusarvostelu

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Sellaiset ilmaisut kuin ”sosiaalinen romaani” ja ”yhteiskunnallinen romaani” toistuvat nykykirjallisuutta koskevissa luonnehdinnoissa. Luonnehdintoja ei tavallisesti perustella lajiteorioiden avulla, eikä niissä ole tapana viitata sosiaalisen romaanin ja yhteiskuntaromaanin lajihistorioihin. Artikkeli tarkastelee sosiaalisen romaanin ja yhteiskuntaromaanin lajikategorioiden yleistymistä ja niiden myöhempää kehitystä eu-rooppalaisessa ja suomalaisessa kirjallisuudessa 1800-luvulla ja 1900-luvulla. Lisäksi se analysoi lajien nykyisten suomalaisten edustajien – Kari Hotakaisen, Tommi Melenderin, Hannu Raittilan, Arto Salmi-sen ja Juha Seppälän – tuotantoa.

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The steel industry produces, besides steel, also solid mineral by-products or slags, while it emits large quantities of carbon dioxide (CO2). Slags consist of various silicates and oxides which are formed in chemical reactions between the iron ore and the fluxing agents during the high temperature processing at the steel plant. Currently, these materials are recycled in the ironmaking processes, used as aggregates in construction, or landfilled as waste. The utilization rate of the steel slags can be increased by selectively extracting components from the mineral matrix. As an example, aqueous solutions of ammonium salts such as ammonium acetate, chloride and nitrate extract calcium quite selectively already at ambient temperature and pressure conditions. After the residual solids have been separated from the solution, calcium carbonate can be precipitated by feeding a CO2 flow through the solution. Precipitated calcium carbonate (PCC) is used in different applications as a filler material. Its largest consumer is the papermaking industry, which utilizes PCC because it enhances the optical properties of paper at a relatively low cost. Traditionally, PCC is manufactured from limestone, which is first calcined to calcium oxide, then slaked with water to calcium hydroxide and finally carbonated to PCC. This process emits large amounts of CO2, mainly because of the energy-intensive calcination step. This thesis presents research work on the scale-up of the above-mentioned ammonium salt based calcium extraction and carbonation method, named Slag2PCC. Extending the scope of the earlier studies, it is now shown that the parameters which mainly affect the calcium utilization efficiency are the solid-to-liquid ratio of steel slag and the ammonium salt solvent solution during extraction, the mean diameter of the slag particles, and the slag composition, especially the fractions of total calcium, silicon, vanadium and iron as well as the fraction of free calcium oxide. Regarding extraction kinetics, slag particle size, solid-to-liquid ratio and molar concentration of the solvent solution have the largest effect on the reaction rate. Solvent solution concentrations above 1 mol/L NH4Cl cause leaching of other elements besides calcium. Some of these such as iron and manganese result in solution coloring, which can be disadvantageous for the quality of the PCC product. Based on chemical composition analysis of the produced PCC samples, however, the product quality is mainly similar as in commercial products. Increasing the novelty of the work, other important parameters related to assessment of the PCC quality, such as particle size distribution and crystal morphology are studied as well. As in traditional PCC precipitation process, the ratio of calcium and carbonate ions controls the particle shape; a higher value for [Ca2+]/[CO32-] prefers precipitation of calcite polymorph, while vaterite forms when carbon species are present in excess. The third main polymorph, aragonite, is only formed at elevated temperatures, above 40-50 °C. In general, longer precipitation times cause transformation of vaterite to calcite or aragonite, but also result in particle agglomeration. The chemical equilibrium of ammonium and calcium ions and dissolved ammonia controlling the solution pH affects the particle sizes, too. Initial pH of 12-13 during the carbonation favors nonagglomerated particles with a diameter of 1 μm and smaller, while pH values of 9-10 generate more agglomerates of 10-20 μm. As a part of the research work, these findings are implemented in demonstrationscale experimental process setups. For the first time, the Slag2PCC technology is tested in scale of ~70 liters instead of laboratory scale only. Additionally, design of a setup of several hundreds of liters is discussed. For these purposes various process units such as inclined settlers and filters for solids separation, pumps and stirrers for material transfer and mixing as well as gas feeding equipment are dimensioned and developed. Overall emissions reduction of the current industrial processes and good product quality as the main targets, based on the performed partial life cycle assessment (LCA), it is most beneficial to utilize low concentration ammonium salt solutions for the Slag2PCC process. In this manner the post-treatment of the products does not require extensive use of washing and drying equipment, otherwise increasing the CO2 emissions of the process. The low solvent concentration Slag2PCC process causes negative CO2 emissions; thus, it can be seen as a carbon capture and utilization (CCU) method, which actually reduces the anthropogenic CO2 emissions compared to the alternative of not using the technology. Even if the amount of steel slag is too small for any substantial mitigation of global warming, the process can have both financial and environmental significance for individual steel manufacturers as a means to reduce the amounts of emitted CO2 and landfilled steel slag. Alternatively, it is possible to introduce the carbon dioxide directly into the mixture of steel slag and ammonium salt solution. The process would generate a 60-75% pure calcium carbonate mixture, the remaining 25-40% consisting of the residual steel slag. This calcium-rich material could be re-used in ironmaking as a fluxing agent instead of natural limestone. Even though this process option would require less process equipment compared to the Slag2PCC process, it still needs further studies regarding the practical usefulness of the products. Nevertheless, compared to several other CO2 emission reduction methods studied around the world, the within this thesis developed and studied processes have the advantage of existing markets for the produced materials, thus giving also a financial incentive for applying the technology in practice.

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Tässä diplomityössä on tutkittu mediatalon hiilijalanjäljen pienentämismahdollisuuksia yhteistyössä Otava-konsernin kanssa. Työ on siis osa Otava-konsernin yritysvastuun kehittämistä. Yritysvastuuseen ja sen raportointiin on perehdytty myös yleisesti mediasektorin tasolla. Työssä perehdytään myös hiilijalanjäljen laskentaohjeisiin sekä lasketaan Otavakonsernin hiilijalanjälki tietyin rajauksin. Yrityksen hiilijalanjäljen laskentaa voidaan toteuttaa esimerkiksi Greenhouse Gas Protokollan laskentaohjeiden mukaisesti. Yleisiä ohjeita kasvihuonekaasuinventaarin laskentaan antaa ISO 14064-1 standardi. Otava-konsernin laskenta on toteutettu ClimateCalc-laskuria soveltuvilta osin hyväksikäyttäen. Laskennan tulokset on esitetty konsernin yhtiöittäin vuoden 2013 tietojen pohjalta. Valittu laskuri toimi parhaiten kirjapainon käytössä. Muiden konsernin yhtiöiden osalta laskuria on jouduttu soveltamaan. Konsernin päästöistä myös merkittävä osa syntyi kirjapainossa, mikä osaltaan johtuu muita yhtiöitä laajemmasta laskennasta. Tulevaisuudessa laskentaa on hyvä laajentaa myös muiden yhtiöiden osalta, jolloin laskurin ominaisuuksia pystytään käyttämään laajemmin hyväksi.

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Collective Action in Commons: Its Diverse Ends and Consequences explores new ways in which collective action theories can contribute to our understanding of natural resource management, especially the management of common-pools. Combining classical collective action theories and lessons from earlier empirical works, the study shows that cooperation among resource users is not only a possible solution to “the tragedy of the commons”, but it can be a part of the problem as well. That is, successful cooperation may increase the likelihood of resource depletion, for example, through more effective resource utilization or collusion against sanctioning and monitoring systems. The study also explores how analytic narratives can be used to tell the story behind problems of resource use and their solutions, including the diverse roles of cooperation.

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Älytelevisiomarkkinat ovat nykyisellään pirstaloituneet eri valmistajien kehittäessä omia älytelevisioalustoitaan, mikä tekee sovelluskehittämisestä erittäin työlästä, kun kehitystyö pitää tehdä jokaiselle alustalle erikseen. LG:n ja Philipsin perustama Smart TV Alliance pyrkii yksinkertaistamaan sovelluskehittäjien työtä, samalla houkutellen lisää kehittäjiä alalle. Työssä tutustutaan tuotealustoihin, avoimeen ja suljettuun innovaatioon, sekä alliansseihin. Lisäksi perehdytään älytelevisioihin sekä tietenkin itse Smart TV Allianceen. Lisäksi tarkastellaan nykyistä markkina-asetelmaa ja arvioidaan yksittäisten toimijoiden tilannetta ja mahdollisia toimenpiteitä. Työn painopiste on fyysisen laitevalmistajan ja käyttöjärjestelmän kehittäjän/ylläpitäjän näkökulmasta. Työn kannalta tärkeässä roolissa ovat ohjelmistopohjaiset tuotealustat. Eritoten työssä käsitellään älytelevisioiden ohjelmistoa tuotealustana, mutta hyvä vaihtoehtoinen ja eritoten monille käytännönläheisempi esimerkki on tietokoneen käyttöjärjestelmä, kuten Microsoft Windows tai useat Linux-pohjaiset käyttöjärjestelmät. Keskeisenä ominaisuutena näissä kaikissa on, että itse käyttöjärjestelmä toimii yhteisenä pohjana, jonka päälle voidaan rakentaa muuta toiminnallisuutta, kuten pelejä ja toimistosovelluksia.

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Cyanobacteria are the only prokaryotic organisms performing oxygenic photosynthesis. They comprise a diverse and versatile group of organisms in aquatic and terrestrial environments. Increasing genomic and proteomic data launches wide possibilities for their employment in various biotechnical applications. For example, cyanobacteria can use solar energy to produce H2. There are three different enzymes that are directly involved in cyanobacterial H2 metabolism: nitrogenase (nif) which produces hydrogen as a byproduct in nitrogen fixation; bidirectional hydrogenase (hox) which functions both in uptake and in production of H2; and uptake hydrogenase (hup) which recycles the H2 produced by nitrogenase back for the utilization of the cell. Cyanobacterial strains from University of Helsinki Cyanobacteria Collection (UHCC), isolated from the Baltic Sea and Finnish lakes were screened for efficient H2 producers. Screening about 400 strains revealed several promising candidates producing similar amounts of H2 (during light) as the ΔhupL mutant of Anabaena PCC 7120, which is specifically engineered to produce higher amounts of H2 by the interruption of uptake hydrogenase. The optimal environmental conditions for H2 photoproduction were significantly different between various cyanobacterial strains. All suitable strains revealed during screening were N2-fixing, filamentous and heterocystous. The top ten H2 producers were characterized for the presence and activity of the enzymes involved in H2 metabolism. They all possess the genes encoding the conventional nitrogenase (nifHDK1). However, the high H2 photoproduction rates of these strains were shown not to be directly associated with the maximum capacities of highly active nitrogenase or bidirectional hydrogenase. Most of the good producers possessed a highly active uptake hydrogenase, which has been considered as an obstacle for efficient H2 production. Among the newly revealed best H2 producing strains, Calothrix 336/3 was chosen for further, detailed characterization. Comparative analysis of the structure of the nif and hup operons encoding the nitrogenase and uptake hydrogenase enzymes respectively showed minor differences between Calothrix 336/3 and other N2-fixing model cyanobacteria. Calothrix 336/3 is a filamentous, N2-fixing cyanobacterium with ellipsoidal, terminal heterocysts. A common feature of Calothrix 336/3 is that the cells readily adhere to substrates. To make use of this feature, and to additionally improve H2 photoproduction capacity of the Calothrix 336/3 strain, an immobilization technique was applied. The effects of immobilization within thin alginate films were evaluated by examining the photoproduction of H2 of immobilized Calothrix 336/3 in comparison to model strains, the Anabaena PCC 7120 and its ΔhupL mutant. In order to achieve optimal H2 photoproduction, cells were kept under nitrogen starved conditions (Ar atmosphere) to ensure the selective function of nitrogenase in reducing protons to H2. For extended H2 photoproduction, cells require CO2 for maintenance of photosynthetic activity and recovery cycles to fix N2. Application of regular H2 production and recovery cycles, Ar or air atmospheres respectively, resulted in prolongation of H2 photoproduction in both Calothrix 336/3 and the ΔhupL mutant of Anabaena PCC 7120. However, recovery cycles, consisting of air supplemented with CO2, induced a strong C/N unbalance in the ΔhupL mutant leading to a decrease in photosynthetic activity, although total H2 yield was still higher compared to the wild-type strain. My findings provide information about the diversity of cyanobacterial H2 capacities and mechanisms and provide knowledge of the possibilities of further enhancing cyanobacterial H2 production.

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Tässä julkaisussa käsitellään kerääjäkasvien toimivuutta typen huuhtoutumisen vähentäjänä ja soveltuvuutta käytännön viljelyyn. Ensimmäisessä osassa käsitellään kerääjäkasvien mahdollisuuksia vähentää typen huuhtoutumista tieteelliseltä tutkimuspohjalta ja toisessa osassa paneudutaan viljelijöiden tilakohtaisiin kerääjäkasvikokemuksiin. Tutkimusten ja tilakohtaisten kokeilujen pohjalta kerääjäkasvit estävät typen huuhtoutumista. Kerääjäkasveilla on myös suotuisa vaikutus maan rakenteeseen ja se vähentää eroosiota ja rikkakasvien määrää kasvustoissa. Julkaisu on suunniteltu auttamaan viljelijöitä, jotka harkitsevat aloittavansa kerääjäkasvien viljelyä. Tämä opas on osa TEHO Plus -hankkeen tuottamaa materiaalia viljelijöiden ja neuvojien käyttöön, mikä täydentää hankkeen laatimaa Maatilan ympäristökäsikirjaa.

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Den här publikationen går in på hur fånggrödorna minskar kväveurlakningen och hur de lämpar sig för odling i praktiken. I första delen behandlar vi fånggrödornas möjligheter att minska urlakningen av kväve på en vetenskaplig forskningsgrund och i andra delen går vi in på jordbrukarnas erfarenheter av fånggrödor gårdsvis. Forskningen och de gårdsvisa försöken visar att fånggrödorna hindrar kväveurlakningen. Fånggrödorna har också en gynnsam verkan på markstrukturen och den minskar erosionen och mängden ogräs i växtligheten. Publikationen är avsedd att vara till hjälp för de jordbrukare som planerar att börja odla fånggrödor. Denna guide ingår i det material som producerats inom TEHO Plus-projektet för jordbrukare och rådgivare. Den kompletterar Gårdens miljöhandbok, som också sammanställts inom projektet.