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Comparison of MP-AES and ICP-MS for thedetermination of potentially toxic elements in (polluted) plant materialBaysal, Ramazan January 2024 (has links)
The purpose of this study was to assess the metal content present in pine needles collected from an old shooting range known for elevated lead levels in the soil by different analytical methods. The focus on conifers originated from their evergreen nature year-round, and their ability to absorb potentially harmful elements. Research on needles as biomonitors for environmental contamination, particularly in areas affected by heavy metal pollution, has gained significant global attention. Four trees, two Norway spruces (Picea abies), and two Scots pines (Pinus sylvestris) were identified within the designated area. Samples of conifer needles were collected in plastic bags. The needles underwent washing, drying, and grinding into powder for subsequent digestion method and quantitative determination of metal content using ICP-MS and MPAES. The study focused on elements commonly found in various types of ammunition, specifically manganese, iron, nickel, copper, zinc, molybdenum, antimony, and lead. Results obtained from both analytical methods, which was only manganese, showed statistically significant differences. During the analysis, only manganese could be quantified using MPAES, as the other analytes were below the detection limit. For ICP-MS, the LOD values were much lower, making this method more suitable, as all analytes were above LOD and could be quantified. The recovery values for the CRM were good for all elements when ICP-MS was utilized. However, the calculated recovery value for manganese decreased based on the results obtained from MPAES compared to the calculated recovery value for manganese based on the results obtained from ICP-MS. Interestingly, the analysis of conifer needles revealed no noticeable contamination from the shooting range. Instead, it highlighted variances among different pine needle species. The metal content in the pine needles remained within acceptable limits according to external literature sources.
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Bifunctionalised pretreatment of lignocellulosic biomass into reducing sugars:use of ionic liquids and acid-catalysed mechanical approachDong, Y. (Yue) 27 October 2017 (has links)
Abstract
Lignocellulosic biomass is the most abundant renewable raw material on the earth and it is so far the most suitable and promising resource for the production of biofuels to replace long-term use of fossil oil. This research aims to convert lignocellulose-based industrial residuals, fibre sludge (FS) from a pulp mill and pine sawdust (PSD) from a sawmill, into platform sugars by two different bifunctionalised pretreatments of lignocellulosic biomass. The bifunctionalised pretreatment combines the ordinary pretreatment (deconstruction) of lignocellulosic biomass with lignocellulosic polysaccharides saccharification. The outcome from both pretreatments can be further transformed into biofuels and chemicals.
PSD and FS were converted into platform sugars by acid-catalysed mechanical depolymerisation in a planetary ball mill in the first part of this research. The efficiency of the conversion was mainly affected by the transferred energy caused by collisions, the total milling time, acid concentration and moisture content in the reaction. Approximately 30 wt% of the sugars was yielded from PSD and FS both in the short milling process with a low acid/substrate (A/S) concentration without any prior treatment.
The second part of this research focuses upon the conversion of FS into platform sugars using hydroxyalkylimidazolium hydrogen sulphate ionic liquids (ILs). Around 29 wt% of the sugars was produced from FS using an IL/water mixture. The added water acted as a co-solvent and played a critical role in the utilisation of these ILs. The blended water reduced the viscosity of the ILs and enhanced the mass transfer between solvent and solute. In addition, the anions of the ILs provided their acidic property in an aqueous solution and offered an acidic environment for hydrolysis simultaneously. / Tiivistelmä
Lignosellulossapohjainen biomassa on runsaimmin saatavilla oleva ja yksi lupaavimmista raaka-aineista biopolttoaineiden valmistukseen korvaamaan fossiilisia polttoaineita. Väitöskirjassa tutkitaan teollisuuden lignoselluloosapohjaisten sivutuotteiden, selluteollisuuden kuitulietteen ja sahateollisuuden sahanpurun (mäntypuru), muuntamista sokereiksi kahdella erilaisella ns. bifunktionaalisella esikäsittelyllä, joissa yhdistyvät lignoselluloosabiomassan perinteinen esikäsittely (hajotus) ja polysakkaridien sokeroituminen. Muodostuneet sokerit voidaan edelleen muuntaa biopolttoaineiksi ja -kemikaaleiksi.
Tutkimuksen ensimmäisessä vaiheessa sahanpuru ja kuituliete muunnettiin sokereiksi happokatalysoidussa mekaanisessa käsittelyssä, joka tehtiin kuulamyllyssä. Reaktiossa katalyyttisen käsittelyn tehokkuuteen vaikuttivat erityisesti jauhatuksen kineettinen energia, jauhatusaika, happokonsentraatio ja reaktioseoksen kosteus. Tulosten perusteella todettiin, että ilman lähtöaineen esikäsittelyä sekä sahanpurun että kuitulietteen sokerisaanto oli noin 30 massa% lyhyen, matalassa happokonsentraatiossa tehdyn jauhatuksen jälkeen.
Tutkimuksen toisessa vaiheessa kuituliete muutettiin sokereiksi käyttämällä ionista liuotinta (IL), hydroksialkyyli-imidatsoliumvetysulfaattia. Sokerisaanto kuitulietteestä oli noin 29 massa% IL-vesiseoksessa. Vesi toimi reaktiossa apuliuottimena ja sen rooli on keskeinen ionisten liuottimien käytössä. Sekoittunut vesi laski ionisen liuottimen viskositeettia sekä edisti aineensiirtoa liuottimen ja liukenevan aineen välillä. IL:n anionit lisäsivät happamuutta vesiliuoksessa ja mahdollistivat happamat olosuhteet samanaikaiselle hydrolyysille. / Abstract
Biomasse aus Lignocellulose ist der am häufigsten vorkommende nachwachsende Rohstoff der Erde und wird aktuell als eine der besten Alternativen für die Produktion von Biokraftstoffen gesehen. Diese sollen langfristig die fossilen Öl-basierten Produkte ersetzen. Diese Forschungsarbeit untersucht die Herstellung von Zucker aus Lignocellulose basierten Abfällen. Faserschlamm aus der Zellstoffindustrie und Kiefern-Sägemehl aus der Holzverarbeitung wurden durch zwei unterschiedliche Bifunktionelle Vorbehandlungen aufgespalten. Diese Bifunktionelle Vorbehandlung kombiniert zwei Schritte in einem Prozess; die gewöhnliche Dekonstruktion der Biomasse und die Verzuckerung von Polysacchariden aus der Lignocellulose. Das so erzeugte Produkt dient als Ausgangsstoff für die weitere Herstellung von Biokraftstoffen und Chemikalien.
Im ersten Teil dieser Forschungsarbeit wurden Kiefern-Sägemehl und Faserschlamm in einer Planeten-Kugelmühle zermahlen und gleichzeitig durch eine Säure depolymerisiert. Der Wirkungsgrad dieser säurekatalysierten mechanischen Depolymerisation wurde hauptsächlich durch die Übertragung der Reibungsenergie, der Mahldauer der Zerkleinerung, der Konzentration der Säure und der Feuchtegehalt der Proben beeinflusst. Etwa 30 wt% Zucker wurde so durch den kurzen Zermahlungsprozess aus Kiefern-Sägemehl und Faserschlamm gewonnen. Dabei wurden die Proben nicht vorbehandelt und enthielten eine geringe Säure/Probe Konzentration.
Der zweite Teil der Forschungsarbeit untersucht die Umwandlung von Faserschlamm in Zucker mittels der Ionischen Flüssigkeit (ILs) Hydroxyalkyl Imidazolium Hydrogensulfat. Aus den Faserschlamm Proben konnte 29 wt% Zucker durch eine Mischung von ILs und Wasser gewonnen werden. Das zugesetzte Wasser spielte als Co-Lösemittel eine wichtige Rolle in der Nutzung der Ionischen Flüssigkeit, dessen Viskosität so reduziert wurde. Dies führte zu einem erhöhten Stoffübergang zwischen dem Lösemittel und dem Solvat. Zusätzlich sorgten die Anionen der Ionischen Flüssigkeit für ein saures Milieu in der wässrigen Lösung und ermöglichten so eine gleichzeitige Hydrolyse.
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Assessment of carbon sequestration and timber production of Scots pine across Scotland using the process-based model 3-PGNXenakis, Georgios January 2007 (has links)
Forests are a valuable resource for humans providing a range of products and services such as construction timber, paper and fuel wood, recreation, as well as living quarters for indigenous populations and habitats for many animal and bird species. Most recent international political agreements such as the Kyoto Protocol emphasise the role of forests as a major sink for atmospheric carbon dioxide mitigation. However, forest areas are rapidly decreasing world wide. Thus, it is vital that efficient strategies and tools are developed to encourage sustainable ecosystem management. These tools must be based on known ecological principles (such as tree physiological and soil nutrient cycle processes), capable of supplying fast and accurate temporal and spatial predictions of the effects of management on both timber production and carbon sequestration. This thesis had two main objectives. The first was to investigate the environmental factors affecting growth and carbon sequestration of Scots pine (Pinus sylvestris L.) across Scotland, by developing a knowledge base through a statistical analysis of old and novel field datasets. Furthermore, the process-based ecosystem model 3-PGN was developed, by coupling the existing models 3-PG and ICBM. 3-PGN calibrated using a Bayesian approach based on Monte Carlo Markov Chain simulations and it was validated for plantation stands. Sensitivity and uncertainty analyses provided an understanding of the internal feedbacks of the model. Further simulations gave a detailed eco-physiological interpretation of the environmental factors affecting Scots pine growth and it provided an assessment of carbon sequestration under the scenario of sustainable, normal production and its effects from the environment. Finally, the study investigated the spatial and temporal patterns of timber production and carbon sequestration by using the spatial version of the model and applying advanced spatial analyses techniques. The second objective was to help close the gap between environmental research and forest management, by setting a strategic framework for a process-based tool for sustainable ecosystem management. The thesis demonstrated the procedures for a site classification scheme based on modelling results and a yield table validation procedure, which can provide a way forward in supporting policies for forest management and ensuring their continued existence in the face of the present and future challenges.
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Above Ground Durability of Swedish SoftwoodBlom, Åsa, Bergström, Mikael January 2005 (has links)
This thesis describes aspects of durability of Swedish softwood in above ground applications. The thesis consists of a summary of nine papers, which all aim to explain the existing variation in above ground microbial durability and moisture sensitivity of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris). The methods used were two field tests, one accelerated durability test, and three water permeability tests. The main conclusions made in the study were that Norway spruce sapwood is more susceptible to discolouring fungi than heartwood. With respect to Scots pine, the only important factor for its natural durability above ground was whether the samples consisted of heartwood or of sapwood. There was also no systematic variation between pine heartwood from different stand origins in above ground conditions. Origin had no influence on durability in practice for neither spruce nor pine. Furthermore, in contradiction with traditional thinking, annual ring width and density had no influence on durability in any of the tests. The material came from two different samplings. The ‘old’ material was sampled in the beginning of the 1980s and consisted of Scots pine and Norway spruce from three different origins: the north, the central area, and the south of Sweden. The material was subjected to different handling conditions and surface and end-grain treatments. The ‘old’ material was used in a large above ground field test, carried out between 1985 and 1994. Unfortunately, the spruce sapwood and heartwood was not separated in this field test. In the field trial with the ‘old’ material, the most important factor for the durability of Norway spruce was the samples’ surface- and end-grain treatment. It was also observed that untreated spruce showed better durability than samples that were painted but without proper end-grain treatment. Samples originating from one of the stands were more sensitive towards air-drying than samples from the other two, which was reflected in a higher average moisture content and mass loss for the untreated samples. With respect to Scots pine, the most important factor was whether the sample consisted of heartwood or of sapwood. The heartwood samples were durable irrespective of their previous treatment. The Scots pine sapwood samples, on the other hand, had a very fluctuating moisture content if they were not surface- and end-painted. This was also reflected in higher mass losses in these samples. Even when properly surface- and end grain treated, the sapwood samples did not perform as well as the heartwood samples. The ‘new’ material consisted of Scots pine taken from six different stands, and Norway spruce from five different stands, all from areas in southern Sweden. The sampling was performed in order to achieve a large variation in wood properties. Thus, logs from areas with different climate and growth conditions were collected. This material was used for laboratory tests, and also for the second field test, which was evaluated after a test period of two years. In the second field test untreated Scots pine and Norway spruce samples from the ‘new’ material were investigated. Effects of origin and different tree diameters were examined. Furthermore, Scots pine was separated to heartwood and sapwood, and Norway spruce to mature and juvenile wood. The Norway spruce samples were sawn with vertical or horizontal annual rings. For the Norway spruce in the second field test, vertical annual rings were shown to be very beneficial for avoiding crack formation, while samples with horizontal annual rings displayed a large number of cracks. Despite this, the larger number of cracks did not result in a higher moisture content or more fungal discoloration. Juvenile wood had a slightly higher average discolouring fungal growth grading than the other spruce samples. For Scots pine, the only factor of importance was whether the samples consisted of heartwood or of sapwood. Annual ring width, density and origin had no significant effect on either fungal growth or moisture uptake. This observation held for both Norway spruce samples and Scots pine samples. An accelerated test was run in order to investigate Norway spruce sapwood and heartwood with respect to their differences in durability towards discolouring fungi and moisture uptake. The Mycologg method was used to accelerate fungal growth during a number of forced moisture cycles. The results showed that sapwood was much more sensitive to discolouring fungi than heartwood. Sapwood also recorded a higher average moisture content than heartwood. The differences that were observed between the types of samples were not due to annual ring width, density or origin. It was observed that Norway spruce sapwood samples and heartwood samples showed differences in liquid water permeability. This observation was made especially evident in a droplet absorption test. Water droplets were absorbed much faster on the sapwood samples in comparison with the heartwood samples. This higher affinity to water suggested that a sapwood surface would reach a higher moisture content than a heartwood surface. This observation provides a major explanation of why the sapwood samples showed poorer durability towards discolouring fungi in the Mycologg trials.
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Chemodiversity and Functions of Monoterpene Hydrocarbons in ConifersPersson, Monika January 2003 (has links)
No description available.
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Treeline dynamics in short and long term perspectives : observational and historical evidence from the southern Swedish ScandesÖberg, Lisa January 2010 (has links)
Against the background of past, recent and future climate change, the present thesis addresses elevational shifts of alpine treelines in the Swedish Scandes. By definition, treeline refers to the elevation (m a.s.l.) at a specific site of the upper trees of a specific tree species, at least 2 m tall. Based on historical records, the first part of the thesis reports and analyzes the magnitude of treeline displacements for the main trees species (Betula pubescens ssp. czerepanovii, Picea abies and Pinus sylvestris) since the early 20th century. The study covered a large and heterogeneous region and more than 100 sites. Concurrent with temperature rise by c. 1.4 °C over the past century, maximum treeline advances of all species amount to about 200 m. That is virtually what should be predicted from the recorded temperature change over the same period of time. Thus, it appears that under ideal conditions, treelines respond in close equilibrium with air temperature evolution. However, over most parts of the landscape, conditions are not that ideal and treeline upshifts have therefore been much smaller. The main reason for that discrepancy was found to be topoclimatic constraints, i.e. the combined action of geomorphology, wind, snow distribution, soil depth, etc., which over large parts of the alpine landscape preclude treelines to reach their potential thermal limit. Recorded treeline advance by maximum 200 m or so over the past century emerges as a truly anomalous event in late Holocene vegetation history. The second part of the thesis is focused more on long-term changes of treelines and one specific and prevalent mechanism of treeline change. The first part of the thesis revealed that for Picea and Betula, treeline shift was accomplished largely by phenotypic transformation of old-established stunted and prostrate individuals (krummholz) growing high above the treeline. In obvious response to climate warming over the past century, such individuals have transformed into erect tree form, whereby the treeline (as defined here) has risen. As a means for deeper understanding of this mode of positional treeline change, extant clonal spruces, growing around the treeline, were radiocarbon dated from megafossil remains preserved in the soil underneath their canopies. It turned out that Picea abies in particular may attain almost eternal life due to its capability for vegetative reproduction and phenotypic plasticity. Some living clones were in fact inferred to have existed already 9500 years ago, and have thus persisted at the same spot throughout almost the entire Holocene. This contrasts with other tree species, which have left no living relicts from the early Holocene, when they actually grew equally high as the spruce. Thereafter they retracted by more than 300 m in elevation supporting that also on that temporal scale, treelines are highly responsive to climate change. The early appearance of Picea in the Scandes, suggests that Picea “hibernated” the last glacial phase much closer to Scandinavia than earlier thought. It has also immigrated to northern Sweden much earlier than the old-established wisdom. The experiences gained in this thesis should constitute essential components of any model striving to the project landscape ecological consequences of possible future climate shifts.
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Waldmonitoring unter besonderer Berücksichtigung der aus Stereoluftbildern abgeleiteten 3. DimensionSysavath, Vithoone 13 July 2009 (has links) (PDF)
Results of the investigation has been presented to derive digital elevation models of forest areas for the determination of the parallax measuring accuracy from AATE (Adaptive Automatic Terrian Extraction) with the PCI software Geomatica. It has been used the informations from the threefold overlaps of aerial stereoscopic pairs. The parallax measuring errors on forest areas are three times larger than on the arable and pasturelands. It has been shown that the third dimension can be used for the derivative of crown of tree profiles and their roughness and the rates of timber growth can be derived with sufficiently high accuracy from the repeatability flying.
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Untersuchung des Wuchsverhaltens von Kiefern (Pinus sylvestris L.) auf Extremstandorten im Nationalpark "Sächsische Schweiz" / Analysis of Growth of Scots Pine (Pinus sylvestris L.) on Extreme Sites in the Saxon Switzerland National ParkSchildbach, Marek 26 May 2010 (has links) (PDF)
Die exponierten Sandstein-Felsriffe im Nationalpark Sächsische Schweiz stellen einen Waldgrenzstandort dar. Erkenntnisse über das Baumwachstum unter diesen nährstoffarmen und trockenen Bedingungen können dazu beitragen, die Reaktionen normaler Bestände auf mögliche Klimaveränderungen besser vorherzusagen. Für die vorliegende Arbeit erfolgte die Anlage von insgesamt zwölf Versuchsflächen in den zwei Teilgebieten des Nationalparks Sächsische Schweiz, auf denen das Wachstum der Kiefern und die zuwachsbeeinflussenden Faktoren untersucht wurden. Die Auswertung der entnommenen Bohrspäne zeigt, dass Kiefern auch bei äußerst geringen Zuwachsraten jahrelang überleben können. Es wurden vielfach schmale Jahrringe aus lediglich zwei bis drei Zellreihen sowie Einzelbäume mit bis zu 29 vollständig ausgefallenen Jahrringen gefunden. Die Analyse der Zusammenhänge von Radialzuwachs, Höhenzuwachs, Bestandesdaten, Konkurrenzindizes, Standort- und Witterungsparametern nimmt einen großen Teil der Arbeit ein und mündet in der Darstellung entsprechender Wuchsmodelle.
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Chemodiversity and Functions of Monoterpene Hydrocarbons in ConifersPersson, Monika January 2003 (has links)
No description available.
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Croissance et δ13C des cernes de trois essences forestières tempérées (Fagus sylvatica, Quercus petraea et Pinus sylvestris) face aux variations climatiques à l'échelle interannuelle et saisonnièreMichelot, Alice 01 July 2011 (has links) (PDF)
Il est probable que les changements climatiques futurs diminuent la croissance forestière en région tempérée. Cette vulnérabilité des espèces face aux contraintes du climat peut être étudiée via les cernes des arbres. Ces derniers sont en effet des archives du carbone utilisé par les arbres pour leur croissance, en lien avec les caractéristiques spécifiques de gestion du carbone et de réponse au climat. L'objectif principal de cette thèse est de déterminer, à partir des cernes, les réponses fonctionnelles de trois essences forestières tempérées (Fagus sylvatica, Quercus petraea et Pinus sylvestris) aux variations climatiques. Pour cela, nous avons réalisé une approche expérimentale en étudiant deux proxys (ou indices climatiques) : la croissance et la composition isotopique en 13C (δ13C) des cernes, à deux échelles temporelles : interannuelle et saisonnière. A l'échelle interannuelle, sur la période 1960-2007, une étude dendrochronologique a été réalisée sur les trois essences et a été complétée par l'analyse du δ13C des cernes (en relation avec le climat). A l'échelle saisonnière, nous avons déterminé précisément, sur une année (2009), les dynamiques de croissance du cerne et les variations de δ13C intra-cerne. Nos résultats mettent en évidence une sensibilité de la croissance et du δ13C des cernes des trois essences aux sécheresses estivales. Grâce à la complémentarité des proxys et des échelles temporelles, nous avons également trouvé des réponses climatiques contrastées entre espèces. La croissance du Hêtre est la plus réactive au climat d'une année à l'autre. Cette croissance ainsi que le δ13C des cernes sont fortement sensibles aux températures de juillet, en plus des précipitations printanières et estivales. Cette réponse immédiate au climat peut être expliquée par une forte dépendance de la croissance au fonctionnement foliaire et une faible utilisation des réserves carbonées pour assurer le début de la croissance. Le Chêne présente lui des arrières-effets climatiques sur sa croissance, via une forte sensibilité aux sécheresses de l'automne précédent, contrairement aux deux autres espèces. Ce résultat est à mettre en relation avec l'utilisation importante de réserves carbonées par rapport aux assimilats pour la croissance du bois initial, cette dernière étant très rapide, comme nous l'avons observé grâce à l'analyse saisonnière de la croissance. Concernant le Pin, la croissance, parce qu'elle dure plus longtemps que celle des décidues, est influencée par les températures et les précipitations de juin jusqu'à août. Le δ13C des cernes de pins est celui qui enregistre le plus la réponse au VPD, aussi bien à l'échelle saisonnière qu'interannuelle, probablement du fait d'une forte sensibilité de la conductance stomatique à ce paramètre. Les informations fournies par les cernes permettent d'appréhender la survie des espèces face aux changements climatiques futurs et peuvent être utilisées pour comprendre le dépérissement lié à ces changements.
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