7 resultados para deconstruction
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Ionic liquids, ILs, have recently been studied with accelerating interest to be used for a deconstruction/fractionation, dissolution or pretreatment processing method of lignocellulosic biomass. ILs are usually utilized combined with heat. Regarding lignocellulosic recalcitrance toward fractionation and IL utilization, most of the studies concern IL utilization in the biomass fermentation process prior to the enzymatic hydrolysis step. It has been demonstrated that IL-pretreatment gives more efficient hydrolysis of the biomass polysaccharides than enzymatic hydrolysis alone. Both cellulose (especially cellulose) and lignin are very resistant towards fractionation and even dissolution methods. As an example, it can be mentioned that softwood, hardwood and grass-type plant species have different types of lignin structures leading to the fact that softwood lignin (guaiacyl lignin dominates) is the most difficult to solubilize or chemically disrupt. In addition to the known conventional biomass processing methods, several ILs have also been found to efficiently dissolve either cellulose and/or wood samples – different ILs are suitable for different purposes. An IL treatment of wood usually results in non-fibrous pulp, where lignin is not efficiently separated and wood components are selectively precipitated, as cellulose is not soluble or degradable in ionic liquids under mild conditions. Nevertheless, new ILs capable of rather good fractionation performance have recently emerged. The capability of the IL to dissolve or deconstruct wood or cellulose depends on several factors, (e.g. sample origin, the particle size of the biomass, mechanical treatments as pulverization, initial biomassto-IL ratio, water content of the biomass, possible impurities of IL, reaction conditions, temperature etc). The aim of this study was to obtain (fermentable) saccharides and other valuable chemicals from wood by a combined heat and IL-treatment. Thermal treatments alone contribute to the degradation of polysaccharides (e.g. 150 °C alone is said to cause the degradation of polysaccharides), thus temperatures below that should be used, if the research interest lies on the IL effectiveness. On the other hand, the efficiency of the IL-treatment can also be enhanced to combine other treatment methods, (e.g. microwave heating). The samples of spruce, pine and birch sawdust were treated with either 1-Ethyl-3-methylimidazolium chloride, Emim Cl, or 1-Ethyl-3-methylimidazolium acetate, Emim Ac, (or with ionized water for comparison) at various temperatures (where focus was between 80 and 120 °C). The samples were withdrawn at fixed time intervals (the main interest treatment time area lied between 0 and 100 hours). Double experiments were executed. The selected mono- and disaccharides, as well as their known degradation products, 5-hydroxymethylfurfural, 5-HMF, and furfural were analyzed with capillary electrophoresis, CE, and high-performance liquid chromatography, HPLC. Initially, even GC and GC-MS were utilized. Galactose, glucose, mannose and xylose were the main monosaccharides that were present in the wood samples exposed to ILs at elevated temperatures; in addition, furfural and 5-HMF were detected; moreover, the quantitative amount of the two latter ones were naturally increasing in line with the heating time or the IL:wood ratio.
Resumo:
Kirjallisuusarvostelu
Resumo:
Kirjallisuusarvostelu
Resumo:
Väitöskirjani tarjoaa laajasti tietoa sotamuistomerkeistä koko Suomen alueelta. Työ purkaa suomalaisten sotamuistomerkkien ilmaisutapoja ja modaalisia keinoja, joilla taideteokset sovittelevat voitetun tai hävityn sodan tarinaa ja kokemuksellisia jännitteitä toisiinsa. Suurin osa analyysin kohteena olevista taideteoksista on pystytetty Suomen itsenäisyyden ajalla vapaudenpatsaiksi tai sankarihautojen, taisteluiden ja vakaumuksensa puolesta kuolleiden muistomerkeiksi. Tutkimus painottuu voiton ideologian vaikutukseen sotakuvaston muotoutumisessa. Avainkysymyksiä ovat, miten sotamuistomerkki viestittää poliittis-ideologisia tavoitteita tai miten muistomerkkien figuurien asennot, eleet ja attribuutit välittävät sotatarinan yhteisöllisiä sisältöjä. Tutkimus tarkentuu teosten modaalisiin piirteisiin ja merkityksenmuodostuksen vuorovaikutteisuuteen. Erikoishuomion kohteena ovat aiheiden sisällölliset ristiriidat ja ilmaisun murtumakohdat. Suurten teosmäärien ja aihetyyppien jaottelussa ja analysoimisessa on hyödynnetty ikonografian, kuvaretoriikan ja eleiden tutkimusta. Suomalaisen aineiston vertailukohtina ovat antiikin sotilasaiheinen taide, keskiaikainen Kristuksen kärsimyskuvasto sekä sotamuistomerkkiperinne Saksassa, Ranskassa, Yhdistyneessä kuningaskunnassa ja Amerikan yhdysvalloissa. Sotien muistokultin merkitysten avaamisessa käytetään diskurssianalyysin välineitä. Tutkimus osoittaa, että sotamuistomerkit rakentavat yhteisön turvallisuudentunnetta ja muokkaavat sotilasimagoa maskuliinisten ideaalien ja implisiittisen vihollis- tai vastakuvan varassa. Kansallisen paatoksen ohessa sotamuistomerkit vahvistavat sotilaiden aseveliaatetta ja luovat kuvaa rikkumattomasta yhteishengestä sekä kotirintamasta. Teokset tulkitsevat valmistumisaikansa usein ristiriitaista tunneilmapiiriä ja tulevaisuuden odotuksia sekä neuvottelevat paikallisesta erityisyydestä ja valtakysymyksistä. Veistosten modaaliset keinot suhteessa toimijarooleihin, kuten autonomisuuden korostus, tunteenomainen toiseen tukeutuminen tai sodan velvoitteisiin suuntautuminen perustuvat yleensä figuurien asentoihin. Sen sijaan figuurien eleet ja attribuutit, tärkeimpinä kypärä, ase, univormu ja lumipuku, tarkentavat suuntautumisen tavoitetta ja ideologista sanomaa. Koska sodassa on kyse vaikeasti käsiteltävistä väkivaltakulttuurin ilmiöistä, muistomerkeillä on hämärretty ja muokattu kuvaa historian tapahtumista. Siten teosten välittämät ideat uhrivalmiudesta ja tunteiden hillinnän velvoitteesta auttavat sotatraumojen ja surun kanavoimisessa sekä purkavat tapahtumiin liittyvää häpeää.
Resumo:
In this master’s thesis, I examine the development of writer-characters and metafiction from John Irving’s The World According to Garp to Last Night in Twisted River and how this development relates to the development of late twentieth century postmodern literary theory to twenty-first century post-postmodern literary theory. The purpose of my study is to determine how the prominently postmodern feature metafiction, created through the writer-character’s stories-within-stories, has changed in form and function in the two novels published thirty years apart from one another, and what possible features this indicates for future post-postmodern theory. I establish my theoretical framework on the development of metafiction largely on late twentieth-century models of author and authorship as discussed by Roland Barthes, Wayne Booth and Michel Foucault. I base my close analysis of metafiction mostly on Linda Hutcheon’s model of overt and covert metafiction. At the end of my study, I examine Irving’s later novel through Suzanne Rohr’s models of reality constitution and fictional reality. The analysis of the two novels focuses on excerpts that feature the writer-characters, their stories-within-stories and the novels’ other characters and the narrators’ evaluations of these two. I draw examples from both novels, but I illustrate my choice of focus on the novels at the beginning of each section. Through this, I establish a method of analysis that best illustrates the development as a continuum from pre-existing postmodern models and theories to the formation of new post-postmodern theory. Based on my findings, the thesis argues that twenty-first century literary theory has moved away from postmodern overt deconstruction of the narrative and its meaning. New post-postmodern literary theory reacquires the previously deconstructed boundaries that define reality and truth and re-establishes them as having intrinsic value that cannot be disputed. In establishing fictional reality as self-governing and non-intrudable, post-postmodern theory takes a stance against postmodern nihilism, which indicates the re-founded, non-questionable value of the text’s reality. To continue mapping other possible features of future post-postmodern theory, I recommend further analysis solely on John Irving’s novels’ published in the twenty-first century.