Dissertations / Theses: 'Composition of biomass'

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Rodriguez, Indalesio. "Composition related effects on thermal reactivity of organic feedstocks /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/9895.

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Brereton, Nicholas James Beresford. "SRC willow development, biomass composition and biofuel potential." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/6920.

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The aims of this PhD were to examine nitrogen allocation and partitioning in Short Rotation Coppice (SRC) willow in regard to tree development and to investigate biomass composition and cell wall structure for the purpose of assessing and understanding biofuel potential. To address these topics four major experiments were performed and are presented in the thesis. An investigation of SRC willow development and nitrogen dynamics was conducted as a pot trial comprising 14 different genotypes from a willow mapping population. The genotypes were selected on the extremity and consistency of their field biomass yields. Fertiliser enriched with the stable isotope nitrogen 15 was applied as a means of nitrogen surveillance. One of the findings was that higher biomass yielding varieties of SRC willow had increased nitrogen-use-efficiency yet less (or later) nitrogen remobilisation in the autumn. The recalcitrance of the cell wall to enzymatic saccharification was assessed across 138 field-grown genotypes of the same willow mapping population. The aim was to identify any relationships between glucose yield and several biomass yield traits and to identify any quantitative trait loci (QTL) associated with enzymatic saccharification. Four QTL associated to enzymatic saccharification were identified and no relationship was found between glucose and biomass yield traits. A third experiment aimed to modify cell wall composition and structure of a single cultivar of willow grown in a pot trial. Tension wood, fibre cells containing an extra cell wall layer unique to angiosperms, and cellulose synthesis inhibited phenotypes were both induced. These modifications were accomplished through chemical and environmental treatments during development and their impact on composition and cell wall recalcitrance was assessed. Tension wood formation was found to increase glucose yields. The final main experiment used 35 of the UK’s leading biomass yielding willow varieties, grown in the field, to assess not only the variation in composition and enzymatic saccharification but also to identify any relationships between these two traits and a variety of morphological traits. The final part of the experiment investigated how variation in these traits interacted with dilute acid pretreatment. Surprisingly lignin content did not significantly correlate with cell wall recalcitrance to enzymatic saccharification. Another important finding was that enzymatic saccharification without the pretreatment correlated with enzymatic saccharification after the pretreatment. General introduction and general materials and methods chapters are included. A final summary discussion chapter is also included in order to address the overall impact of these findings on biofuel potential.

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Cromar, Nancy Judith. "Composition of biomass and computer modelling of high rate algal ponds." Thesis, Edinburgh Napier University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394903.

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RABEMANOLONTSOA, HARIFARA F. "QUANTIFICATION OF CHEMICAL COMPOSITION FOR VARIOUS BIOMASS SPECIES AS BIOREFINERY FEEDSTOCKS." Kyoto University, 2012. http://hdl.handle.net/2433/157392.

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Rigdon, Anne R. "Coverage impacts biomass composition, conversion to ethanol yields and microbial communities during storage." Diss., Kansas State University, 2013. http://hdl.handle.net/2097/16541.

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Doctor of Philosophy
Department of Grain Science and Industry
Dirk E. Maier
Increased mandates for the production of transportation fuels from renewable resources have thrust the conversion of lignocellulosic biomass, e.g., energy crops and agricultural residues, to ethanol into commercial production. The conversion of biomass to ethanol has been implemented; transportation and storage logistics are still obstacles to overcome by industry. Limited harvest windows throughout the year necessitate extended periods of biomass storage to maintain a consistent, year-round supply to the biorefinery. Sorghum biomass stored with no coverage (NN), covered with tarp (NT), wrapped in plastic (PN) and covered with a tarp and wrapped in plastic (PT) for six months was analyzed for changes in biomass components—cellulose, hemicellulose and lignin, cellulose and hemicellulose degrading enzymes, and conversion to ethanol yields. Treatment NN had increased enzyme activity, and reduced cellulose content and ethanol yields; while biomass covered maintained enzyme activity, cellulose content and ethanol yields. Sequencing of the Large SubUnit (LSU) region and the internal transcribed spacer (ITS) regions of ribosomal RNA gene gave consistent results of fungal community dynamics in biomass stored as previously described. Fungal community richness and diversity increased, while evenness decreased in uncovered biomass during storage. Covered and uncovered storage treatments and over time were found to exhibit distinctly different fungal communities. In contrast, bacterial communities were found to be unresponsive to storage treatments and durations. Cladosporium, Alternaria and Cryptococcus were found to be the most abundant in the stored biomass. Covering of biomass strongly limits the arrival and establishment of new fungal propagules in stored biomass, reducing biomass degradation by these often pathogenic, saprobic or endophytic communities. Overall, covering of biomass during storage is essential for optimal substrate retention for downstream processing into ethanol. In addition, storage and transportation logistics of three real-world scenarios were evaluated for the conversion of wheat straw, corn stover and sorghum stalks residues to ethanol at a biorefinery located in Southwest Kansas. Economic evaluation revealed that transport and storage of residues at satellite storage facilities was most economical for farmers and would create opportunity for the operation of profitable facilities that would supply the local biorefinery on demand throughout the year.

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Mbambo, Sifiso Walter. "Scales of variability of phytoplankton composition and biomass in Algoa Bay, South Africa." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/9193.

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Includes bibliographical references
This study investigated the variability of environmental drivers of phytoplankton communities and biomass at different time scales in Algoa Bay. This research was motivated by Pacific oyster culturing at an Algoa Bay oyster farm. Time series of winds, sea surface temperatures (SSTs) and fluorescence were presented for the period from September/October 2010 to May/June 2012. The time series showed strong seasonal and interannual variability in the winds and SSTs. SSTs ranged from 12.5–25.5°C with a mean (±S.D.) of 18.4 ± 2.3°C. The dominance of south-easterly and south-westerly winds in summer of 2010/11 resulted in cooler temperatures and higher chlorophyll-a concentrations than were found in 2011/12. The summer of 2011/12 had non-persistent south-westerly winds that lead to warm temperatures and low chlorophyll-a concentrations. Two short field trips in early summer 2011 and early autumn 2012 sampled physical, chemical and biological variables. There was minor variability in the winds during these sampling periods and little spatial variability in SST. However, there were spatial differences in nutrient concentrations and chlorophyll-a distributions. The sampling trip in early summer 2011 found a strong thermocline at a depth of approximately 15 m, and SST ranged between 13.5 and 21°C. In early autumn 2012, deep water mixing was evident when the thermocline dropped to about 30 m, with a range of SSTs from 16.5–21°C. Temperature and nutrient values were significantly correlated (at p < 0.001) for NO3, PO4, and SiO4 in both field trips. Phytoplankton community structure in early summer 2011 showed a 30% level of similarity in grouping of species for stations closest to the shore, which had depleted NO3 concentrations. There was a dominance of dinoflagellates of Gonyaulax polygramma and other species, which are known for creating hypoxic conditions in the water column, leading to shellfish mortalities. In early autumn 2012 there was a strong grouping of samples at a 50% level of similarity alongshore, at stations with high NO3 concentrations. In this period pennate diatoms of Pseudo-nitzschia sp. were abundant; this genus has been reported to produce the neurotoxin, domoic acid. Variable environmental conditions with low chlorophyll-a concentrations at Algoa Bay’s marine culture site indicate unsuitable conditions for Pacific oyster production.

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Kalinauskaitė, Solveiga. "Environmental and energy efficiency evaluation of straw treatment and conversion technology." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20141223_145125-20389.

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Research goal. We seek to validate optimal composition of straw biomass fuel and energy efficiency of straw utilization for energy needs, to assess straw biomass fuel preparation technology in respect to energy efficiency, and to determine emissions that are generated during straw combustion. Research objectives. The following objectives were planned to reach the goal of the research: 1) Process analysis of preparation of biomass fuel (pellets and briquettes) for burning, 2) Validation of mixture of lime additive (CaO) into straw biomass fuel, 3) Property analysis of prepared biomass fuel, 4) Measurement and assessment of emissions generated while burning straw biomass fuel, 5) Assessment of energy consumption by straw pellet production equipment.
Tyrimų tikslas. Pagrįsti šiaudų biokuro optimalios sudėties paruošimo ir panaudojimo energinėms reikmėms efektyvumą, atlikti šiaudų biokuro paruošimo technologijos energinį vertinimą ir nustatyti deginimo metu išskiriamas emisijas. Tyrimų uždaviniai. Tyrimų tikslui pasiekti numatyta: 1) Atlikti šiaudų biokuro (briketų ir granulių) paruošimo deginimui technologinę analizę; 2) Pagristi kalkių priedo (CaO) įmaišymo į šiaudų biokuro sudetį tikslingumą; 3) Ištirti pagaminto šiaudų biokuro savybes; 4) Nustatyti ir įvertinti šiaudų biokuro deginimo metu išskiriamas emisijas; 5) Įvertinti šiaudų granulių gamybos technologinės įrangos energijos sanaudas.

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Saavedra, Rios Carolina del Mar. "Etude des carbones durs issus de la biomasse pour l’application dans les batteries Sodium-ion." Thesis, Université Grenoble Alpes, 2020. https://thares.univ-grenoble-alpes.fr/2020GRALI072.pdf.

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La demande croissante en batteries Lithium-ion a suscité une certaine inquiétude concernant l'approvisionnement en matières premières critiques nécessaires à leur production, en particulier les ressources en Li, Co, Ni et Cu. La technologie Sodium-ion apparait comme une alternative pouvant utiliser des ressources abondantes et uniformément réparties, et qui pourrait réduire le coût des batteries par rapport au Lithium-ion. Toutefois, le débouché commercial des batteries Sodium-ion est encore limité par le développement de matériaux d'électrode négative à haute performance et bas coût. L'option la plus prometteuse est un matériau carboné désordonné appelé carbone dur, obtenu par traitement thermique à haute température de précurseurs organiques. Malgré ses bonnes performances, le carbone dur est toujours plus cher que le graphite utilisé dans les batteries Lithium-ion, étant donné le coût élevé de ses précurseurs synthétiques. La biomasse lignocellulosique a récemment attiré l'attention en tant que précurseur du carbone dur, étant donné sa nature renouvelable, son accessibilité et son faible coût. Cependant, la grande variabilité des matières premières de la biomasse ainsi que le faible rendement de la réaction de pyrolyse, rendent leur application commerciale plutôt difficile. De plus, le rôle de la composition de la biomasse sur les propriétés du carbone dur n’est pas complètement compris. Le travail de recherche présenté ici est une approche interdisciplinaire, visant à élucider l'impact de la composition de la biomasse sur les propriétés physico-chimiques et électrochimiques des carbones durs résultants ainsi que le rendement de leur synthèse. Un ensemble de 25 précurseurs ont été sélectionnés pour cette étude. La composition de chaque précurseur, telles que le contenu organique et inorganique élémentaire, et le contenu macromoléculaire, ont été évaluées. Les carbones durs synthétisés ont été caractérisés par des techniques de XRD, Raman, SEM, TEM, SAXS, XPS et de cyclage galvanostatique. Le contenu et la composition inorganique du précurseur, en particulier la présence de composés de Si, Ca et K, ont semblé jouer un rôle essentiel dans le développement de la structure et de la surface du carbone dur. Par conséquent, ils ont un impact négatif important sur les performances du carbone dur, en produisant des irréversibilités élevées. Compte tenu de leur faible teneur en cendres couplé à leur faible cout et leur faible impact environnemental, les résidus forestiers et certain résidus agricoles, semblent être le meilleur compromis pour l'application du carbone dur
The ever-increasing demand for Lithium-ion batteries has raised some concern regarding the supply of the critical raw materials needed for their production, especially the Li, Co, Ni and Cu resources. The Sodium-ion technology appears to be an alternative which potentially uses abundant, and evenly distributed resources, that is able to reduce the cost of the batteries compared to Lithium-ion. However, the commercial intrusion of Sodium-ion batteries is still limited by the development of low-cost and high-performance negative electrode material. The most promising option is a disordered carbonaceous material called hard carbon obtained from high-temperature thermal treatment of organic precursors. Despite its good performance, hard carbon is still more expensive than the graphite used in Lithium-ion batteries, given the high cost of the synthetic precursors. Lignocellulosic biomass has recently attracted attention as a hard carbon precursor, given its renewable nature, accessibility, and low cost. However, the high variability of biomass feedstock, together with the poor yield of the pyrolysis reaction, make their commercial application rather difficult. Moreover, there is no clear understanding of the biomass composition role on the hard carbon properties. The research work presented here is an interdisciplinary approach, aiming to elucidate the biomass composition's impact on the physicochemical and electrochemical properties of the derived hard carbons as well as their synthesis yield. A set of 25 lignocellulosic biomass precursors have been selected for this study. The composition of each biomass precursor, such as the elemental organic and inorganic content, and the macromolecular contents were evaluated in detail. The synthesised hard carbons were characterised by XRD, Raman, SEM, TEM, SAXS, XPS, and galvanostatic cycling techniques. The inorganic content and composition of the precursor, particularly the presence of Si, Ca, and K compounds, was observed to play a critical role in developing the hard carbon structure and surface. Therefore, they have a strong negative impact on hard carbon performances, producing high irreversibility. Because of their low ash-content, coupled with their low cost and environmental impact, precursors such as forestry residues, and some agricultural residues, appeared to be the best compromise for hard carbon application

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9

Maranan, Melchor C. "Rapid assessment of chemical composition, calorific value and specific gravity of hybrid poplar wood using near infrared spectroscopy." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Summer2006/m%5Fmaranan%5F10704728.pdf.

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10

Stone, Gayle Louise. "Microplankton Biomass and Composition in Relation to the Gulf Stream Front Off Southeast Florida." NSUWorks, 1997. http://nsuworks.nova.edu/occ_stuetd/320.

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The optical front of the Gulf Stream off southeast Florida is an abrupt and distinct visual boundary between green coastal water and deep blue Gulf Stream water. The goal of the research presented in this thesis was to describe phytoplankton biomass and composition in relation to the position and strength of this optical front. Twenty-seven cruises were conducted off the coast of Fort Lauderdale, Florida between July 1990 and March 1992. On each cruise, a transect of vertical CTD casts was conducted across the front to a depth of 100 m. Estimates of vertical frontal strength (buoyancy frequency) and horizontal frontal strength (salinity and density gradients across the front) were calculated from the CTD data. Biological samples were collected at three stations, one at the front and one on each side of the front, for the estimation of chlorophyll concentration by fluorometry and for the microscopic enumeration of the microplankton. Results showed that chlorophyll concentration estimates were not correlated with the estimates of vertical frontal strength, horizontal frontal strength or the distance of the front from shore (via the Spearman rank-order correlation). Chlorophyll concentrations at the Gulf Stream station were significantly lower than those at both the inshore and front stations, but chlorophyll concentrations at the front were not significantly different from those inshore (via the Kruskal-Wallis H test) Chlorophyll concentrations at the front, however, were elevated above average during the late summer/early fall when the mixed layer depth was shallower than average. Total microplankton abundance did not differ significantly between the three stations. However, when the microplankton were divided into major taxonomic categories, significant differences in abundances between the three stations were detected. In general, abundances were highest near shore and declined offshore. Except for a weak correlation between Pyrrhophyta and the salinity gradient across. the front, abundances of microplankton groups did not correlate with the physical variables measured. Scenarios that might explain these results are discussed.

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Pang, Bairen. "Effect of irrigation on grain sorghum ethanol yield and sorghum mutants on biomass composition." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38194.

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Master of Science
Department of Biological & Agricultural Engineering
Donghai Wang
Bioprocessing is widely involved in our daily life and significantly relative to the general public because bio-products are widely used in eating, clothing, and living as well as transportation. Due to the public concern of the environmental deterioration, limited fossil fuel resources, and energy price volatility, biofuel as a clean, safe and sustainable energy needs to be developed in response to this growing concern. Sorghum, an important dryland crop, represents a renewable resource currently grown on 8 million acres throughout the United States. Due to climate variability and the continuous decline of water resources, utilization of dryland to grow sorghum and forage sorghum is critically important in order to ensure available energy resources and sustainable economic development. The objectives of this research were 1) to study the impact of deficit irrigation strategies on sorghum grain attributes and bioethanol production, and 2) to evaluate the potential fermentable sugar yield of pedigreed sorghum mutants. Results showed that average kernel weight and test weight of grain sorghum increased as irrigation capacity increased, whereas kernel hardness index decreased as irrigation capacity increased. Starch content increased as irrigation level increased and protein contents decreased as irrigation level increased. Irrigation also had a significant effect on starch properties and bioethanol yield. Sorghum mutants had a significant effect on chemical composition and physical properties such as glucan content, glucan mass yield, ash content, and high heating value, and also had a significant effect on fermentable sugars yield and enzymatic conversion efficiency.

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Falk, Joel. "Effect of fuel composition and combustion conditions on phosphorus behavior during combustion of biomass." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71240.

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Gustafsson, Eva. "Characterization of particulate matter from atmospheric fluidized bed biomass gasifiers." Doctoral thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-11473.

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Through biomass gasification, biomass can be converted at high temperature to a product gas rich in carbon monoxide, hydrogen, and methane. After cleaning and upgrading, the product gas can be converted to biofuels such as hydrogen; methanol; dimethyl ether; and synthetic diesel, gasoline, and natural gas. Particulate matter (PM) is formed as a contaminant in the gasification process, and the aim of this work was to develop and apply a method for sampling and characterization of PM in the hot product gas. A particle measurement system consisting of a dilution probe combined in series with a bed of granular activated carbon for tar adsorption was developed, with the aim of extracting a sample of the hot product gas without changing the size distribution and composition of the PM. The mass size distribution and concentration, as well as the morphology and elementary composition, of PM in the size range 10 nm to 10 µm in the product gas from a bubbling fluidized bed (BFB) gasifier, a circulating fluidized bed (CFB) gasifier and an indirect BFB gasifier using various types of biomass as fuel were determined. All gasifiers and fuels displayed a bimodal particle mass size distribution with a fine mode in the <0.5 µm size range and a coarse mode in the >0.5 µm size range. Compared with the mass concentration of the coarse mode the mass concentration of the fine mode was low from all gasifiers. The evaluation of the results for the fine-mode PM was complicated by condensing potassium chloride for the CFB gasifier when using miscanthus as fuel and by condensing tars for the indirect BFB gasifier when using wood C as fuel. The mass concentration of the coarse-mode PM was higher from the CFB gasifier than from the two BFB gasifiers. The coarse-mode PM from the BFB gasifier when using wood A as fuel was dominated by char. In the CFB gasifier the coarse-mode PM was mainly ash and bed material when using all fuels. The coarse-mode PM from the indirect BFB gasifier when using wood C as fuel was mainly ash.

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Prieto, Calvo Patricia. "Phenology, biomass and community composition changes in European shrublands submitted to experimental warming and drought." Doctoral thesis, Universitat Autònoma de Barcelona, 2007. http://hdl.handle.net/10803/3691.

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Esta tesis se ha desarrollado como parte del proyecto VULCAN (Vulnerabibilty assessment of shrubland ecosystems under climatic changes), un proyecto de investigación llevado a cabo en seis ecosistemas de matorrales europeos (Gales-Reino Unido, Dinamarca, Holanda, Hungría, Cerdaña-Italia y Catalunya-España), distribuidos en un gradiente de temperatura (8.2 - 15.6 ºC) y precipitación (511 - 1427 mm). En ella se han incluido datos recogidos durante el periodo 1999-2005.
El objetivo global de la investigación fue el de aportar conocimientos y reducir incertidumbres acerca del funcionamiento de los matorrales europeos y del rol que pueden desempeñar éstos como fuente o sumidero de carbono bajo la perspectiva del cambio climático.
En las parcelas de los diferentes países se instalaron novedosas manipulaciones experimentales para aumentar la temperatura y para reducir el agua disponible en campo, simulando los efectos del cambio climático previstos para las décadas futuras.
En este trabajo se han estudiado los efectos de los tratamientos en la diversidad vegetal, en la productividad primaria aérea, así como en la fenología del crecimiento y en la elongación de ramas de las especies vegetales dominantes de los ecosistemas arbustivos europeos. Además en las parcelas experimentales de Garraf se investigó la sensibilidad de los procesos relacionados con la captación de carbono por la vegetación a nivel de hoja (fluorescencia, fotosíntesis, conductancia estomática) y se estudió la respuesta de la floración no primaveral de las dos especies arbustivas dominantes, Erica multiflora y Globularia alypum.
Los efectos del cambio climático a nivel de ecosistema fueron complejos debido a la gran variabilidad de respuestas de las plantas a los tratamientos según las variables medidas, las especies, estaciones u años, sitios y periodos de experimentación.
En Garraf, una zona que sufrió un incendio en 1994, encontramos una clara reducción en el número de especies por transecto en las parcelas de sequía respecto a las control, sin embargo no encontramos efectos similares en el resto de Europa lo que sugiere que la riqueza de especies en comunidades en proceso de recuperación después de una perturbación puede ser especialmente sensible al cambio climático respecto a otras comunidades en estadios más maduros. Concretamente, encontramos que los tratamientos de calentamiento y sequía redujeron la habilidad competitiva de Pinus halepensis (germinador obligado) frente a los arbustos rebrotadores y que la estrategia en el uso del agua pudo ayudar a G. alypum a mantener una posición dominante en las parcelas de sequía de Garraf.
En los países con menor aridez las respuestas de la biomasa anual acumulada al calentamiento fueron más positivas sin embargo, el hecho de que también encontremos especies mediterráneas como E. multiflora que respondieron positivamente al calentamiento, junto con el hecho de que fenómenos extremos como la ola de calor Europea en 2003 redujeran la productividad primaria, matizan la hipótesis de que sea en los ecosistemas más fríos en los que el calentamiento global de lugar a una mayor absorción de carbono. Concretamente, la respuesta a los tratamientos de la biomasa a nivel de cubierta en Garraf pudo anularse debido a respuestas opuestas de las especies dominantes.
En este estudio, el gradiente geográfico que dibuja los matorrales estudiados no determinó la sensibilidad de las especies al calentamiento ni la intensidad de la respuesta en lo que a fenología del crecimiento y elongación de ramas se refiere. La fenología del crecimiento de algunas especies mediterráneas fue tan sensible al calentamiento experimental (se avanzó) como algunas especies de distribución más septentrional.
Aunque nuestro estudió mostró que la floración de E. multiflora y G. alypum, que tiene lugar en otoño-invierno, dependió en gran medida de la lluvia acumulada y su distribución durante el periodo primavera-verano, los tratamientos experimentales no afectaron esta variable. Estos resultados se explican en parte por la mayor variación de humedad que hubo entre años respecto a la diferencia de humedad que hubo entre las parcelas de sequía y controles.
This PhD thesis has been developed as part of the VULCAN project (Vulnerabibilty assessment of shrubland ecosystems during climatic changes), a research project conducted in six European shrublands (Wales, United Kingdom, Denmark, Holland, Hungary, Italy-Cerdagne and Catalonia-Spain), distributed in a gradient of temperature (8.2 - 15.6 ° C) and precipitation (511 - 1427 mm). It includes data collected during the 1999-2005 period.
The overall objective of the research was to provide knowledge and reduce uncertainties about the functioning of the shrublands and the role that they can play as a source or sink of carbon under the prospect of climate change.
At each site, novel experimental manipulations were installed to increase the temperature and to reduce the water available in field, simulating the effects of climate change projected for the future decades.
In this work we have studied the effects of treatments on plant diversity, aboveground primary productivity, as well as on the phenology of growth and on the shoot elongation of dominant species. In addition, in Garraf we investigated other processes at leaf level such fluorescence, photosynthesis, stomatal conductance and other at plant level such the response of the non-spring flowering species, Erica multiflora and Globularia alypum.
The effects of climate change at the ecosystem level were complex because of the great variability of plant responses to treatment according to the variables, species, seasons or years, sites and periods of experimentation.
In Garraf, an area which suffered a fire in 1994, we found a clear reduction in the number of species per transect on drought plots, but no similar effects were found in the rest of Europe, suggesting that communities in process of recovery after disturbance can be particularly sensitive to climate change compared to other communities in more mature stages. Specifically, we found that the experimental treatments reduced the competitive ability of the obligate seeder Pinus halepensis against native resprouter shrubs and that the water spender strategy of G. alypum may allow this species to maintain a dominant position in drought plots in Garraf.
In sites with lower aridity, the responses of the annual accumulated biomass to warming were more positive. However, the fact that we found Mediterranean species such as E. multiflora responding positively to global warming, coupled with the fact that extreme events such as the European heat wave in 2003 reduced primary productivity, challenge the assumption that it is in colder ecosystems where global warming will result in a greater carbon sequestration. Specifically, opposite responses of the dominant species could cancel out a clear response of biomass accumulation at canopy level in Garraf.
In this study, the geographical gradient did not determine the susceptibility of the species or the intensity of the response of the phenology of growth and shoot elongation to the warming treatment. The phenology of growth of some Mediterranean species was very responsive to warming treatment (mainly advances) as some species of northernmost distribution.
The study also shows that although flowering of E. multiflora and G. alypum, which takes place in the autumn-winter, depended largely on the accumulated rainfall and its distribution during the spring-summer period, the experimental treatments did not affect this variable. These results are explained in part by the greater range of soil moisture between years than between drought and controls plots.

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Kotsedi, Daisy. "The response of microalgal biomass and community composition to environmental factors in the Sundays Estuary." Thesis, Nelson Mandela Metropolitan University, 2011. http://hdl.handle.net/10948/1434.

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The Sundays Estuary is permanently open to the sea and has been described as channel-like along its entire length with a narrow intertidal area (mostly less than 5 - 6 m in width). The estuary experiences regular freshwater inflow with large supplies of nutrients, derived from the Orange River transfer scheme and agricultural return flow. In particular, nitrate concentrations are high as a result of fertilisers used in the Sundays River catchment area. The objectives of this study were to measure microalgal biomass and community composition and relate to flow, water quality and other environmental variables. Surveys in August 2006, March 2007, February, June and August 2008 showed that salinity less than 10 percent mostly occurred from 12.5 km from the mouth and this was also where the highest water column chlorophyll a (>20 μg l-1) was found. Different groups of microalgae formed phytoplankton blooms for the different sampling sessions, which were correlated with high chlorophyll a. These included blooms of green algae (August 2006), flagellates (March 2007), dinoflagellates (June 2008) and diatom species (February and August 2008). The dominant diatom (Cyclotella atomus) indicated nutrient-rich conditions. Green algae and diatoms were associated with low salinity water in the upper reaches of the estuary. Flagellates were dominant throughout the estuary particularly when nutrients were low, whereas the dinoflagellate bloom in June 2008 was correlated with high ammonium and pH. Maximum benthic chlorophyll a was found at 12.5 km from the mouth in February, June and August 2008 and was correlated with high sediment organic and moisture content. Benthic diatoms were associated with high temperature whereas some species in June 2008 were associated with high ammonium concentrations. The middle reaches of the estuary characterise a zone of deposition rather than suspension which would favour benthic diatom colonization. Phytoplankton cells settling out on the sediments may account for the high benthic chlorophyll a because maximum water column chlorophyll a was also found in the REI zone (where salinity is less than 10 percent and where high biological activity occurs) in the Sundays Estuary. The estuary was sampled over five consecutive weeks from March to April 2009 to identify environmental factors that support different microalgal bloom species. Phytoplankton blooms, defined as chlorophyll a greater than 20 μg l-1, were found during Weeks 1, 4 and 5 from the middle to the upper reaches of the estuary. Diatom species (Cylindrotheca closterium, Cyclotella atomus and Cyclostephanus dubius) occurred in bloom concentrations during these weeks. These diatom species are cosmopolitan and indicate brackish nutrient-rich water. Flagellates were the dominant group in Weeks 2 to 4, but positive correlations with chlorophyll a were found during Weeks 1 and 2. During the first week of this study the conditions were warm and calm (measured as temperature and wind speed) and there was a well developed bloom (38 μg l-1). There was a strong cold front from 17 to 19 March, which mixed the water column resulting in the decrease of the chlorophyll a levels (<20 μg l-1) and the bloom collapsed during Weeks 2 and 3. However, in Weeks 4 and 5 conditions were again calm and warmer, which appeared to stimulate the phytoplankton bloom. Nanoplankton (2.7 - 20 μm) was dominant during each week sampled and contributed a considerable amount (55 - 79 percent) to the phytoplankton biomass. Once again subtidal benthic chlorophyll a and water column chlorophyll a were highest 12.5 km from the mouth. Deposition of phytoplankton cells from the water column was evident in the benthic samples. The study showed that the Sundays Estuary is eutrophic and characterised by microalgal blooms consisting of different phytoplankton groups.

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GonÃalves, Josemir de Souza. "Chemical composition and carbohydrate fractionation of Panicum maximum cv. TanzÃnia biomass under three rest periods." Universidade Federal do CearÃ, 2006. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1409.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
O experimento foi conduzido no campo avanÃado do NÃcleo de Pesquisa em Forragicultura - NPF (www.npf.ufc.br) localizado na Fazenda Experimental do Vale do Curu â FEVC, pertencente Ã Universidade Federal do CearÃ â UFC. Objetivou-se avaliar a composiÃÃo quÃmica e o fracionamento dos carboidratos da biomassa de Panicum maximum cv. TanzÃnia sob trÃs perÃodos de descanso (PDs) baseados no nÃmero de novas folhas expandidas por perfilho (1,5; 2,5 e 3,5F). Utilizou-se o delineamento inteiramente casualizado em arranjo fatorial 3x3 (3 fraÃÃes e 3 PDs). A colheita das amostras foi feita antes da entrada e apÃs a saÃda dos animais dos piquetes. Posteriormente, as amostras foram separadas nas fraÃÃes folha, colmo e material morto. No LaboratÃrio de NutriÃÃo Animal do Departamento de Zootecnia da UFC (LNA/DZ/UFC), foram determinados os teores de Fibra em Detergente Neutro (FDN), Fibra em Detergente Ãcido (FDA), Hemicelulose (HEM), Celulose (CEL), Lignina (LIG), Extrato EtÃreo (EE), ProteÃna Bruta (PB), NitrogÃnio InsolÃvel em Detergente Neutro (NIDN), NitrogÃnio InsolÃvel em Detergente Ãcido (NIDA), Carboidratos Totais (CT), Carboidratos NÃo Fibrosos (CNF), e das fraÃÃes que compÃem os CT: A+B1, B2 e C. Os teores de FDN e de FDA foram elevados (P<0,05) com o avanÃo dos PDs. A planta inteira (PI) do pasto sob maior PD (3,5F), no prÃ-pastejo, apresentou teores, respectivamente, de 74,0 e 46,3% sendo estes elevados para 77,3 e 50,9% no pÃs pastejo. Os teores de LIG da fraÃÃo folha do pasto sob PD 3,5F (4,2%) sofreram elevaÃÃes (P<0,05) no prÃ-pastejo. Os teores de LIG na PI foram superiores (P<0,05) naquelas submetidas ao PD 3,5F em comparaÃÃo Ãs PIs do PD 1,5F tanto no prÃ-pastejo (4,7 e 5,3%) quanto no pÃs-pastejo (4,7 e 5,3%). Os maiores teores de PB da fraÃÃo folha foram encontrados nos pastos sob PD 1,5F (10,9 e 8,6%), no prÃ e pÃs-pastejo. Os teores de PB na planta inteira variaram de 8,8 a 6,4% (P<0,05) e 6,2 e 4,4% (P<0,05) entre os PDs 1,5 e 3,5F, respectivamente no prÃ e pÃs-pastejo. Os teores de NIDA, tambÃm foram elevados (P<0,05) na PI do PD 3,5F (20,3 e 28,5%), respectivamente no prÃ e pÃs-pastejo. Os teores de CT da fraÃÃo folha e da PI apresentaram teores mÃdios (P>0,05) de 75,4 e 77,4% no prÃ-pastejo e 79,2 e 89,2% no pÃs pastejo. A fraÃÃo C dos carboidratos apresentou variaÃÃo mÃdia de 11,4 a 11,9%, na fraÃÃo folha, enquanto que na PI do pasto sob PD 3,5 F, foram observados os maiores teores (P<0,05) desta fraÃÃo (14,4 e 15,7%), em ambos os casos quando observados no prÃ e pÃs-pastejo. O pasto de capim TanzÃnia manejado sob PD 1,5F apresentou a melhor composiÃÃo quÃmica dos que foram avaliados. Contudo Ã necessÃrio que informaÃÃes sobre a composiÃÃo quÃmica dos pastos sejam levadas em consideraÃÃo em conjunto com as mudanÃas ocorridas na estrutura do pasto para que se possa ter uma maior exatidÃo na avaliaÃÃo da qualidade dos pastos.
The experiment was carried out in the advanced field of the Forage Research Sector - NPF (www.npf.ufc.br) located in the Experimental Farm of the Vale do Curu - FEVC, belonging to Federal University of CearÃ - UFC. The objective was evaluate the chemical composition and the carbohydrate fractionation of Panicum maximum cv. TanzÃnia biomass under three rest periods (RPs) based in the new leaf (L) number expanded for tiller (1.5; 2.5 and 3.5L). Was used the completely randomized design in a factorial arrangement 3x3 (3 fractions and 3 RPs). The harvest of the samples was made before the entrance and after the exit the animals the poles. Later, the samples had been separate in the fractions leaf, culm and death material, being droughts in greenhouse of forced ventilation 65Â C for 72 hours, and processed. In the Laboratory of Animal Nutrition of the Animal Science Department of UFC (LNA/DZ/UFC), were determined the levels of Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Hemi-cellulose (HC), Cellulose (CEL), Lignin (LIG), Etereal Extract (EE), Crude Protein (PB), Insoluble Nitrogen in Neutral Detergent (INND), Insoluble Nitrogen in Acid Detergent (INAD), Total Total Carbohydrates (TC), Non Fiber Carbohydrates (NFC), and of the fractions that compose the TC: A+B1, B2 and C. The levels of NDF and ADF had been raised (P<0.05) with the advance of the RPs. The entire plant (EP) of the grass under bigger RP (3.5L), in the before grazing, presented levels, respectively, of 74.0 and 46.3% being these raising for 77,3 and 50,9% after grazing. The levels of LIG of leaf fraction of the grass under RP 3.5L (4.2%) had suffered rises (P<0.05) after grazing. The LIG levels in the RP were higher (P<0.05) in those submitted to 3.5L RP in comparison to the EPs of the 1.5L RP in such a way in before grazing (4.7 and 5.3%) how much after grazing (4.7 and 5.3%). The biggest levels of PB of the leaf fraction had been found in the grass under 1.5L RP (10,86 and 8.59%), before grazing and after grazing. The levels of CP in the entire plant had varied of 8.8 6.4% (P<0.05) and 6.16 and 4.4% (P<0.05) between 3.5 and 1.5L RPs, respectively before and after grazing. The INAD levels, had been also raised (P<0.05) in the EP of 3.5L RP (20.3 and 28.5%), respectively before and after grazing. The levels of TC of the leaf fraction and the EP had presented average levels (P>0.05) of 75.4 and 77.4% before grazing and 79.2 and 89.2% after grazing. The C carbohydrates fraction presented average between 11.4 11.9%, in the leaf fraction, whereas in the EP of the grass under 3.5L RP, had been observed biggest levels (P<0.05) of this fraction (14.3 and 15.7), in both cases when observed before grazing and pos-grazing. The TanzÃnia grass under 1.5L RP presented the best chemical composition of that they had been evaluated. However, it is necessary that information on the chemical composition of the grass are taken in consideration in set with the occured changes in the structure of the grass so that if can have a bigger exactness in the evaluation of the quality of the grass.

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17

Pisani, Olivia. "Local Biomass Control on the Composition and Reactivity of Particulate Organic Matter in Aquatic Environments." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/446.

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Freshwater ecosystems have been recognized as important components of the global carbon cycle, and the flux of organic matter (OM) from freshwater to marine environments can significantly affect estuarine and coastal productivity. The focus of this study was the assessment of carbon dynamics in two aquatic environments, namely the Florida Everglades and small prairie streams in Kansas, with the aim of characterizing the biogeochemistry of OM. In the Everglades, particulate OM (POM) is mostly found as a layer of flocculent material (“floc”). While floc is believed to be the main energy source driving trophic dynamics in this oligotrophic wetland, not much is known about its biogeochemistry. The objective of this study was to determine the origin/sources of OM in floc using biomarkers and pigment-based chemotaxonomy to assess specific biomass contributions to this material, on a spatial (freshwater marshes vs. mangrove fringe) and seasonal (wet vs. dry) scales. It was found that floc OM is derived from the local vegetation (mainly algal components and macrophyte litter) and its composition is controlled by seasonal drivers of hydrology and local biomass productivity. Photo-reactivity experiments showed that light exposure on floc resulted in photo-dissolution of POC with the generation of significant amounts of both dissolved OM (DOM) and nutrients (N & P), potentially influencing nutrient dynamics in this ecosystem. The bio-reactivity experiments determined as the amount and rate of CO2 evolution during incubation were found to vary on seasonal and spatial scales and were highly influenced by phosphorus limitation. Not much is known on OM dynamics in small headwater streams. The objective of this study was to determine carbon dynamics in sediments from intermittent prairie streams, characterized by different vegetation cover for their watershed (C4 grasses) vs. riparian zone (C3 plants). In this study sedimentary OM was characterized using a biomarker and compound specific carbon stable isotope approach. It was found that the biomarker composition of these sediments is dominated by higher plant inputs from the riparian zone, although inputs from adjacent prairie grasses were also apparent. Conflicting to some extent with the River Continuum Concept, sediments of the upper reaches contained more degraded OM, while the lower reaches were enriched in fresh material deriving from higher plants and plankton sources as a result of hydrological regimes and particle sorting.

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Brown, Carol A. "Biomass production, composition, and ethanol potential of switchgrass grown on reclaimed surface mines in West Virginia." Thesis, West Virginia University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1573301.

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Growing crops for biofuel production on agricultural land has caused a debate between whether we should grow corn grain on productive, agricultural lands to feed a growing human population or to fuel our vehicles. This has increased interest in growing cellulosic biofuel feedstocks on marginal lands. Switchgrass (Panicum virgatum L.), a warm-season perennial grass, has been shown to be a viable bioenergy crop because it produces high yields on marginal lands under low water and nutrient conditions. West Virginia contains immense acreages of reclaimed surface mine lands and could offer enough area for the production of switchgrass as a feedstock for a biofuel industry.

The first study was established in 2008 to determine switchgrass yields of three different cultivars on two mine sites in West Virginia. The first site, which was reclaimed in the early 1990s using top soil and treated municipal sludge, consistently had the highest yield of the two sites with a sixth-year yield of 8.4 Mg Dry Matter (DM) ha^-1 averaged across varieties. Cave-in-Rock variety produced 13.0 Mg ha^-1 of biomass which was more than the other two varieties. The other site, Hobet, was prepared using crushed, unweathered sandstone in 2008 and average yields were 1.0 Mg ha^-1 for the sixth year of production.

The second study was conducted on two sites which were reclaimed with a layer of topsoil over gray overburden and seeded with Cave-in-Rock 2011. Fertilizer was applied at rates of 0, 33.6, and 67 kg N ha^-1. No fertilizer treatment yielded 0.32 Mg ha^-1 while the fertilizer treatments produced significantly higher yields.

The objective of the third study was to determine if cultivars and samples from fertilizer treatments differed in composition and theoretical ethanol yield. Compositional analysis was done using near infrared reflectance spectroscopy. It was determined that cultivars did not differ in theoretical ethanol yield with averages ranging from 364 to 438 L Mg^-1. Theoretical ethanol production from Cave-in-Rock was significantly higher ranging from 6,092 to 7,348 L ha^-1 due to its high biomass production. Fertilizer treatments did not greatly effect composition of switchgrass, but since it did improve yield this was reflected in greater ethanol production for fertilized treatments. Based on the information presented here, high biomass should be the goal for switchgrass grown for biofuel production. With proper soil substrate and fertilizer regime, switchgrass grown on reclaimed surface mines may have high enough yield and quality to support ethanol production in the future.

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Takeda, Yuri. "Generation of transgenic rice with altered lignin composition and comparative characterization of their biomass utilization properties." Kyoto University, 2019. http://hdl.handle.net/2433/242693.

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Kyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第21816号
農博第2329号
新制||農||1066(附属図書館)
学位論文||H31||N5188(農学部図書室)
京都大学大学院農学研究科応用生命科学専攻
(主査)教授梅澤俊明, 教授矢﨑一史, 教授植田充美
学位規則第4条第1項該当

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Shih, Chien-Ju. "Determination of saccharides and ethanol from biomass conversion using Raman spectroscopy effects of pretreatment and enzyme composition /." [Ames, Iowa : Iowa State University], 2010. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3403834.

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Richardson, Jennifer Lynn. "An investigation of large-scale tropical biomass burning and the impact of its emissions on atmospheric composition." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25768.

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Romero, Millán Lina. "Steam gasification of tropical lignocellulosic agrowaste : impact of biomass characteristics on the gaseous and solid by-products." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2018. http://www.theses.fr/2018EMAC0011.

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Dans le contexte économique de la plupart des pays en voie de développement, la gazéification sous vapeur d’eau de résidus agricoles lignocellulosiques pourrait être un procédé intéressant, à la fois pour la génération d’énergie dans des régions isolées et pour la production des produits à valeur ajoutée. Étant donné que la disponibilité des résidus agricoles est souvent saisonnière, différents types de biomasse doivent être utilisés pour assurer le fonctionnement des installations de gazéification. A cet égard, ce travail est axé sur la compréhension de l'impact des caractéristiques de la biomasse sur le procédé de gazéification et les propriétés des sous-produits gazeux et solides. Trois biomasses lignocellulosiques à composition macromoléculaire et inorganique différentes ont été sélectionnées pour cette étude : coques de noix de coco (CS), bambou guadua (BG) et coques de palmier à huile (OPS). La cinétique de décomposition thermique des biomasses a été étudiée sur une échelle thermogravimétrique sous atmosphère inerte et sous vapeur d’eau. Malgré les différences dans la structure macromoléculaire des échantillons, la composition inorganique s’est avérée être le paramètre le plus important influençant la réactivité et la cinétique de gazéification. L'impact bénéfique des métaux alcalins et alcalino-terreux a été confirmé, ainsi que l'effet inhibiteur du Si et du P. Plus précisément, le ratio K/(Si+P) est considéré approprié pour décrire et comparer le comportement des biomasses pendant la gazéification sous vapeur d’eau. En conséquence, une nouvelle approche pour la modélisation de la cinétique de gazéification à partir de la composition inorganique de l’échantillon a été proposée. La validité du ratio K/(Si+P) pour classifier et prédire le comportement des biomasses a également été confirmée par des expériences dans un réacteur à lit fluidisé à l’échelle laboratoire. Les échantillons avec un ratio K/(Si+P) au-dessus de 1 ont montré des réactivités de gazéification supérieures à celles des échantillons dont le ratio était inférieur à 1, et donc, une production de gaz et un rendement énergétique plus élevés. De plus, la composition inorganique a non seulement impacté le taux de gazéification des échantillons, mais également les propriétés du sous-produit solide. En particulier, une réactivité de gazéification plus élevée est liée à des chars avec une surface spécifique et un nombre de groupes fonctionnels plus importants. Une température de 850°C et une fraction de vapeur de 30% dans l’agent de réaction ont été identifiées comme les conditions les plus adaptées à la production simultanée de gaz combustible et de char pouvant être valorisé dans des applications agricoles. Le modèle de gazéification sous vapeur d'eau et les résultats expérimentaux présentés dans ce travail peuvent être une référence pour des applications réelles de gazéification travaillant avec différents types de résidus. Par ailleurs, dans le contexte présenté, la gazéification sous vapeur d’eau de déchets lignocellulosiques peut améliorer l’accès à l’énergie des zones rurales isolées, en promouvant simultanément le développement de projets productifs susceptibles de générer de nouveaux revenus pour les communautés locales
In the context of most developing countries, steam gasification could be a very interesting process for both energy generation in isolated areas and the production of value-added products from lignocellulosic agrowaste. Considering that the availability of agricultural residues is often seasonal, gasification facilities should operate with different feedstocks. In consequence, this work is focused on the understanding of the impact of biomass characteristics on the gasification process and the properties of the gaseous and solid by-products. Three lignocellulosic agrowastes with different macromolecular structure and inorganic composition were selected for this study: Coconut shells (CS), bamboo guadua (BG) and oil palm shells (OPS). The thermal decomposition kinetics of the selected feedstocks was analyzed in a thermogravimetric scale under inert and steam atmosphere. Despite the differences in their macromolecular composition, inorganics showed to be the most important parameter influencing the steam gasification reactivity and kinetics of the samples. The beneficial impact of AAEM was confirmed, as well as the inhibitory effect of Si and P. More specifically, the ratio K/(Si+P) proved to be suitable to describe and compare the steam gasification behavior of lignocellulosic agrowastes. In accordance, a new kinetic modeling approach was proposed to predict the gasification behavior of samples, from the knowledge of their inorganic composition. The validity of the ratio K/(Si+P) to classify and predict the biomass steam gasification behavior was also confirmed from experiments in a lab-scale fluidized bed gasifier. Samples with K/(Si+P) above 1 exhibited higher gasification reactivities compared to samples with ratios below 1, resulting in greater gas yields and higher gas efficiencies. Moreover, inorganics impacted not only the gasification rate of the samples, but also the properties of the gasification solid by-products. In particular, higher gasification reactivities were related to greater char surface areas and contents of oxygenated surface functional groups. A temperature of 850°C and a steam fraction of 30% in the reacting atmosphere proved to be the most suitable gasification conditions for the simultaneous production of fuel gases for energy applications, and a valuable char that could be valorized in soil amendment applications. The gasification model and experimental results presented in this work might be an important reference for real gasification applications working with different kind of residues, when both the gaseous and solid by-products valorization is intended. Moreover, in the presented context, steam gasification of lignocellulosic agrowaste may improve the energy access in rural isolated areas, and simultaneously promote the development of productive projects that could generate new incomes for local communities

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23

An, Le Van. "Sweet potato leaves for growing pigs : biomass yield, digestion and nutritive value /." Uppsala : Dept. of Animal Nutrition and Management, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a470.pdf.

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Mallet, Marc D. "Water uptake and composition of natural Australian cloud condensation nuclei." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/104437/1/Marc_Mallet_Thesis.pdf.

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This project was an investigation of atmospheric aerosols emitted from the Great Barrier Reef and north Australian fires. The chemical and physical properties of these aerosols were examined to determine their role in cloud formation. Interactions between aerosols and clouds are associated with the largest uncertainty in global climate models. The work of this thesis will contribute towards reducing this uncertainty by providing data for these poorly characterised regions in Australia.

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Kifle, Demeke. "Seasonal and spatial variations in species composition, abundance, biomass and primary production of phytoplankton in Southampton Water, U.K." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334609.

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Burghart, Scott E. "Micronektonic community composition and trophic structure within the bathypelagic zone in the eastern Gulf of Mexico." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001746.

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Bartsch, Annette. "Die Eisalgenflora des Weddelmeeres (Antarktis): Artenzusammensetzung und Biomasse sowie Ökophysiologie ausgewählter Arten = Sea ice algae of the Wedddell Sea (Antarctica): species composition, biomass, and ecophysiology of selected species /." Bremerhaven : Alfred-Wegener-Inst. für Polar- und Meeresforschung, 1989. http://www.gbv.de/dms/bs/toc/016186044.pdf.

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Keane, Michael Gerard. "Aspects of needle morphology, biomass allocation and foliar nutrient composition in a young fertilized stand of repressed lodgepole pine." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25811.

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The dramatic decline in stand productivity associated with very high stand densities in naturally regenerated post-fire interior lodgepole pine (Pinus contorta var. latifolia) stands is called "repression". The reasons for it are unknown. Biomass allocation, needle morphology and foliar nutrition associated with repression were studied in a 20-year-old stand on plots at five densities ranging from 3,500 to 109,000 sph and fertilized at 0, 100 and 200 kg N ha⁻¹ with ammonium nitrate. At higher stand densities, specific leaf area increased while leaf area index declined and light intensities increased below the canopy. As stand density increased from 5000 sph to 90,000 sph, the above-ground biomass decreased from 61 t ha⁻¹ to 16 t ha⁻¹, the proportion allocated to the stem increased from 58% to 78% and the leaf area/sapwood area decreased from 0.3 to 0.13 m² cm⁻². Mean earlywood percentage decreased from 62% to 8% in codominants at 6,500 and 109,000 sph respectively. Although nitrogen deficiency was evident in all stand densities, there were no significant differences between vigorous and repressed stands for the various macro- (N, P, K, S) or micro-nutrients (Cu, Fe, 'active' Fe) examined. It is hypothesized that the decreased proportion of earlywood in repressed trees causes a reduction in stem conductivity leading to the reported drop in the leaf area/sapwood area ratio. The resulting decrease in the photosynthetic/respiratory surface area ratio in repressed stands may lead to their reduced productivity.
Forestry, Faculty of
Graduate

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29

James, Aryanna Lee. "Quantifying changes in macroinvertebrate community composition, biomass, and emergence in response to mining-induced salinization in central Appalachian streams." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103598.

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Many ecosystems are losing biodiversity, raising concern for the services they provide. However, the extent of loss is uncertain, especially for insects that use freshwater during their life. Further study is needed to assess freshwater insect abundances and diversity. In Central Appalachian streams, macroinvertebrate diversity declines in response to mining-induced salinization and resulting changes to ecosystem processes remain largely unknown, such as how the availability and movement of macroinvertebrate biomass is altered in stream food webs. However, taxa observed are dependent upon sampling effort that could bias diversity-process interpretation. Taxon sampling curves can be used to estimate sampling effort that maximizes the probability of complete community characterization. We sampled six streams in the Central Appalachian region for benthic macroinvertebrates and explored the number of samples needed to capture taxonomic richness in salinized streams. Sampling effort did not differ between reference and salinized streams, though more uneven distributions of macroinvertebrates in salinized streams seemed to necessitate greater sampling effort relative to reference streams. We also used taxon and trait-based sampling curves to expand our understanding of biodiversity and functional responses to environmental change. Because macroinvertebrate biomass and emergence can assess the movement and changes in organic material and energy in response to a salinization gradient, we added them as additional metrics. Macroinvertebrates may have varied responses to a stressor dependent upon life stage, suggesting that assessments relying only on immatures may not fully characterize the effects of salinization. We sampled benthic macroinvertebrate biomass and emergent insect biomass from six streams in the Central Appalachian region to be representative of a salinization gradient. We predicted benthic biomass would either decrease, be maintained by greater density and biomass of salt-tolerant taxa, or increase from a salt subsidy effect, while emergent biomass would decrease disproportionately relative to benthic biomass due to late instar and pupae succumbing to stress. Our results suggest that total benthic macroinvertebrate biomass is maintained along a salinization gradient despite the loss of salt-sensitive mayflies due to compensation by salt-tolerant taxa that experience a subsidizing effect. Emergent biomass was variable among streams with peak emergence occurring in spring, with no apparent negative response to increasing conductivity. The present study can help to further develop metrics of stream ecosystem processes in response to a disturbance gradient.
Master of Science in Life Sciences
Freshwater salinization is a growing, global concern. Pollution and accelerated weathering of rock, caused by human activities, introduce salts to streams and other freshwaters. Surface coal mining is a common land use in the Central Appalachian region and increases leaching of sulfate and other major ions that increase stream salinity, leading to losses of aquatic insect species. Aquatic insects are important to stream processes, such as providing food to other animals, and they can serve as the bioassessments when impacts are suspected. For example, the impacts of salinization on streams are not fully understood despite bioassessments. We sampled aquatic insects from six Appalachian streams with varying levels of salinity. We estimated the sampling effort needed to characterize aquatic larval insect communities in streams with low salinity compared to streams with high salinity. We found that about six samples captured 80 percent of estimated total taxa and that insect communities with greater unevenness required more sampling effort. Such comparisons will allow us to make more informed decisions when sampling aquatic insects and assessing the effects of salts on streams. We also estimated insect biomass in streams using two life stages, larvae and adults, to determine if these life stages would respond differently to salinization. As we expected, total larval biomass slightly increased as the concentration of salt increased, but mayfly biomass decreased. Mayflies are an important and diverse group of insects in Appalachian streams and decreases in their biomass can have consequences for insect communities and stream food webs. Even though emergent insect biomass was found to represent only a small proportion of the larval biomass observed in streams, they represent critical food for terrestrial animals. Estimates of benthic and emergent biomass could be considered to refine bioassessments that support future management and policy regarding surface mining and the rising issue of freshwater salinization.

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Cotiyane, Phumlile L. "The response of microalgal biomass and community composition to the chemical and physical dynamics of two Eastern Cape estuaries." Thesis, Rhodes University, 2017. http://hdl.handle.net/10962/4999.

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Water quality characteristics of estuaries are influenced by both natural and anthropogenic activities. Estuaries situated in coastal urban areas are exposed to more perturbations than those in rural settings. This study determined the drivers of phytoplankton biomass and community composition in two Eastern Cape estuaries and evaluated the anthropogenic activities that influence the overall health of each estuary. The estuaries were sampled in summer and winter (2014, 2015). The water quality of the estuaries was determined by measuring the variability in physico-chemical parameters (salinity, temperature, dissolved oxygen and pH), nutrients, phytoplankton biomass and composition and faecal bacteria. Results show that both Mngazana and Nahoon are well oxygenated (~ 6.0 mg l-¹) and are saline systems (~ 35 ppt) due to low freshwater inputs into both estuaries. Mngazana Estuary exhibited low nutrient inputs along the length of the estuary including Creeks 1 and 2 with low chlorophyll a (4.0 ± 0.2 µg Chl-a r¹) being recorded during this study while Nahoon Estuary had an overall chlorophyll a of 3.5 ± 0.3 µg Chl-a r¹. The two estuaries were dominated by flagellates with phytoplankton blooms recorded seasonally. Possible eutrophic conditions were evident along the upper reaches of Nahoon indicated by nutrient accumulation and by the presence of cyanobacteria. This also this reflected the possible anthropogenic nutrient inputs originating from the Nahoon catchment despite the low freshwater inflow. The presence of faecal bacteria counts along both estuaries indicates the need for further investigation into the source of faecal contamination. The use of nutrient analyses and phytoplankton composition during this study enabled a clear description of the water characteristics of the investigated estuaries. Furthermore, the need for the adherence to freshwater flow requirements of estuaries to limit the dominance of marine waters was clearly illustrated. Urban runoff due to impervious surfaces increases nutrient inputs into estuaries while rural use of estuarine waters introduces contaminants into the system; coupled with low freshwater inputs and eutrophic conditions, the deterioration of estuarine water quality over time demonstrates the need for effective monitoring of these systems.

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Wagner, Heiko, Anne Jungandreas, and Christian Wilhelm. "Surveillance of c-allocation in microalgal cells." Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-147318.

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When microalgae are exposed to changing environmental conditions, e.g., light-dark cycles or oscillations in nutrient availability (CO2, nitrogen, phosphate or silicate) they respond with metabolic changes in the carbon allocation pattern. Short time regulations in the time range of few seconds to minutes can be mirrored best by mass spectroscopy based metabolomics. However, these snap shots do not reflect the alterations in the carbon flow to the cellular macromolecules like protein, carbohydrate or lipid. In this review it is shown how the combination of FTIR spectroscopy and Chla-in-vivo-fluorescence based electron transport rates can reveal changes in the metabolic flux rates of carbon during a shift of the environmental conditions. The review will demonstrate in which time range FTIR spectroscopy can deliver significant information and how FTIR spectroscopy data can synergistically support metabolome analysis by mass-spectroscopy.

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Milic, Andelija. "Chemical characterization and aging of ambient aerosols in Australian urban and remote areas with a focus on biomass burning organic aerosols." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/102843/1/Andelija_Milic_Thesis.pdf.

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This thesis presents a study of chemical composition of rural and urban ambient aerosols in Australia. Aerosol mass spectrometry and new statistical analytical packages were applied to determine the sources of observed aerosols, as well as to determine atmospheric aging that occurred in the measured air masses. The focus of the study was on examination of the aerosols generated from prescribed and wild biomass burnings. The main aim of this research is to provide insight into the characterization and aging of organic biomass burning-related aerosols in Australian urban and remote areas.

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Keys, Matthew. "Effect of future CO2 and temperature regimes on phytoplankton community composition, biomass and photosynthetic rates in the western English Channel." Thesis, University of Essex, 2018. http://repository.essex.ac.uk/23601/.

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CO2 storage in the oceans is strongly affected by biological processes. Production of organic matter through phytoplankton photosynthesis drives CO2 sequestration, which feeds back to atmospheric CO2 and global climate. The ongoing increase in atmospheric CO2 and temperature is strongly associated with changes in ocean chemistry and increasing seawater temperatures. To investigate these impacts on coastal phytoplankton under conditions predicted for the year 2100 (pCO2 elevated to 800 μatm and +4 °C temperature), three factorial experiments were conducted with natural communities sampled from the western English Channel (WEC). Elevated pCO2 increased phytoplankton biomass by up to 20-fold while elevated temperature resulted in an increase of up to 14-fold. Light-saturated photosynthetic carbon fixation rates increased > 6-fold under elevated pCO2 while an increase of up to 3-fold resulted from elevated temperature. The combined effects of elevated pCO2 and temperature reduced biomass in late summer and had no effects on biomass in the autumn with no significant effects on photosynthetic carbon fixation rates in either season. Individual treatments of elevated pCO2 and temperature resulted in near mono-specific communities: diatoms in late summer and nanophytoplankton in autumn. Combined effects of both factors resulted in the most diverse phytoplankton communities and promoted increased dinoflagellate and Synechococcus biomass at the expense of diatoms and nanophytoplankton. Elevated pCO2 alone promoted dominance of the harmful algal bloom (HAB) species, Phaeocystis in spring and autumn, while the combination of elevated pCO2 and temperature promoted biomass of the HAB species, Prorocentrum minimum in autumn. The results indicate that experimental simulations of year 2100 pCO2 and temperature may significantly modify phytoplankton community structure with a positive feedback on atmospheric CO2 in late summer and no change on feedback in autumn. In either scenario, no increase in phytoplankton productivity during a period of changes in bulk carbonate chemistry resulting from ongoing anthropogenic carbon uptake, may be expected to negatively influence carbon biogeochemistry in the WEC.

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Infantes-López, Alba [Verfasser], and C. [Akademischer Betreuer] Syldatk. "Advancing towards biomass-derived syngas fermentation - Evaluation of process parameters and gas composition effects / Alba Infantes-López ; Betreuer: C. Syldatk." Karlsruhe : KIT-Bibliothek, 2020. http://d-nb.info/1220359084/34.

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Silva, Caroline Aparecida da. "Caracterização da fração orgânica dos resíduos sólidos urbanos do Aterro municipal de Santo André visando seu aproveitamento energético via biodigestão anaeróbia." reponame:Repositório Institucional da UFABC, 2016.

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Orientadora: Prof. Dra. Juliana Tófano de Campos Leite Toneli
Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2016.
A geração de resíduos sólidos é um problema que vem se agravando com o passar dos anos. A proteção ao ambiente, o combate à poluição e a oferta de saneamento básico são direitos do cidadão, segundo a Constituição Federal, portanto, o governo deve se responsabilizar pelas práticas de controle ambiental. O Plano Nacional de Resíduos Sólidos é um documento elaborado a partir da Política Nacional de Resíduos Sólidos que fortalece os princípios da gestão integrada e sustentável de resíduos, propõe medidas de incentivo nos sistemas de coleta, tratamento e destinação de resíduos sólidos. Esse trabalho apresenta um panorama geral dos Resíduos Sólidos Urbanos do município de Santo André, com o objetivo de caracterizar a fração orgânica para avaliar a possibilidade de tratamento com aproveitamento energético via processo bioquímico de biodigestão anaeróbia. Para tal, foram determinadas as características químicas da fração orgânica dos RSU dispostos no Aterro Municipal de Santo André, tais como teor de umidade, sólidos fixos e voláteis, relação carbono/nitrogênio (C/N) e composição centesimal. Foram estudados resíduos de origens domiciliar e comercial, da CRAISA (Companhia Regional de Abastecimento Integrado de Santo André) e de feiras livres. Os resultados obtidos foram comparados e relacionados. Os valores médios obtidos foram: Sólidos totais de (65,75 ± 8,9)% para as rotas dos resíduos úmidos, (81,61 ± 2,18)% para a CRAISA e (71,8% ± 14,7)% para as feiras livres; Sólidos Voláteis de (72,23% ± 12,28)% para as rotas dos resíduos úmidos, (85,35% ± 1,21)% para a CRAISA e (84,33% ± 9,36)% para as feiras livres; o teor de lipídios foi de (5,43% ± 0,51)% para as rotas dos resíduos úmidos, (2,31% ± 0,44)% para a CRAISA e (3,24% ± 0,23)% para as feiras livres; o teor de proteína foi de (12,23% ± 2,10)% para as rotas dos resíduos úmidos, (8,75% ± 0,44)% para a CRAISA e (9,69% ± 1,17)% para as feiras livres; a razão C/N de 21,63 para as rotas dos resíduos úmidos, 27,97 para a CRAISA e 28,59 para as feiras livres, situando-se, portanto, dentro dos resultados ótimos para que o processo de biodigestão anaeróbia ocorra.
Solid Waste production is a problem it has intensified over the years. The environment protection, that pollution and sanitation availablity is a civil right, according to Federal Constitution, so the government must be responsable for environmetal control practices. The Solid Waste National Plan is a document drawn up from the Solid Waste National Policy that strengthens the principles of integrated and sustainable waste management, it proposes measures to promote the collection, treatment and disposal of solid waste. This study presents an overview of Municipal Solid Waste of Santo André in Brazil, in order to characterize the organic fraction to evaluate the possibility of energy recovery treatment by biochemical process of anaerobic digestion. To this end, it was determined the chemical characteristics of the organic fraction of MSW disposed in the Municipal Landfill of Santo André, such as moisture content, fixed and volatile solids, carbon / nitrogen ratio (C/N) and chemical composition. It were studied the household and commercial waste sources, the CRAISA (Regional Integrated Supply Company of St. Andrew) and fairs. Some results were compared and interrelated. Average values form: Total Solids 65.75 ± 8.9% for the routes of solid waste, 81.61 ± 2.18% for CRAISA and 71.8% ± 14.7% for open-market; Volatile Solids of 72.23% ± 12.28% for the routes of wet waste, 85.35% ± 1.21% for CRAISA and 84.33% ± 9.36% for for open-market; the 5.43% lipid content ± 0.51% for the routes of wet waste, 2.31% ± 0.44% for CRAISA and 3.24% ± 0.23% for for open-market; the protein content was 12.23% ± 2.10% for the routes of wet waste, 8.75% ± 0.44% for CRAISA and 9.69% ± 1.17% for for open-market; the C / N ratio of 21.63 for the routes of wet waste, 27.97 to 28.59 and CRAISA for for open-market, standing therefore in the excellent results for the process of anaerobic digestion occurs.

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Gao, Xiu. "Long-term and seasonal response of rotifer biomass and phenology to environmental variability in a eutrophic reservoir." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1622278284537733.

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Costa, da Cruz Ana Rita. "Compositional and kinetic modeling of bio-oil from fast pyrolysis from lignocellulosic biomass." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1006/document.

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La pyrolyse rapide est une des voies de conversion thermochimique qui permet la transformation de biomasse lignocellulosique en bio-huiles. Ces bio-huiles, différentes des coupes lourdes du pétrole ne peuvent pas être directement mélangés dans les procédés de valorisation. En effet, en raison de leur forte teneur en oxygène, les bio-huiles nécessitent une étape de pré-raffinage, telle que l’hydrotraitement, pour éliminer ces composants.L’objectif de ce travail est de comprendre la structure, la composition et la réactivité de la bio-huile grâce à la modélisation de données expérimentales. Pour comprendre leur structure et leur composition, des techniques de reconstruction moléculaire basées sur des données analytiques, ont été appliquées, générant un mélange synthétique, dont les propriétés correspondent à celles du mélange. Pour comprendre leur réactivité, l'hydrotraitement de molécules modèles a été étudié: gaïacol et furfural. Pour cela, un modèle déterministe et stochastique a été créé pour chacun d’eux. L’approche déterministe visait à récupérer une gamme de paramètres cinétiques, qui ont ensuite été affinés par l’approche stochastique créant un nouveau modèle. Cette approche a permis de générer un réseau de réactions en définissant et en utilisant un nombre limité de familles et règles des réactions. Finalement, le mélange synthétique a été utilisé dans la simulation stochastique de l’hydrotraitement de la bio-huile, étayée par la cinétique des molécules modèles.En conclusion, ce travail a permis de recréer la fraction légère de la bio-huile et de simuler leur l'hydrotraitement, via les paramètres cinétiques des composés modèles, qui prédisent de manière raisonnable les effluents de l'hydrotraitement de celles-ci, mais sont inadéquat pour le bio-huile
Fast pyrolysis is one of the thermochemical conversion routes that enable the transformation of solid lignocellulosic biomass into liquid bio-oils. These complex mixtures are different from oil fractions and cannot be directly integrated into existing petroleum upgrading facilities. Indeed, because of their high levels of oxygen compounds, bio-oils require a dedicated pre-refining step, such as hydrotreating, to remove these components.The aim of the present work is to understand the structure, composition and reactivity of bio-oil compounds through modeling of experimental data. To understand the structure and composition, molecular reconstruction techniques, based on analytical data, were applied generating a synthetic mixture, whose properties are consistent with the mixture properties. To understand the reactivity, the hydrotreating of two model molecules was studied: Guaiacol and Furfural. A deterministic and stochastic model were created for each compounds. The deterministic approach intended to retrieve a range of kinetic parameters, later on refined by the stochastic simulation approach into a new model. This approach generates an reaction network by defining and using a limited number of reaction classes and reaction rules. To consolidate the work, the synthetic mixture was used in the stochastic simulation of the hydrotreating of bio-oils, supported by the kinetics of the model compounds.In sum, the present work was able to recreate the light fraction of bio-oil and simulate the hydrotreating of bio-oils, via the kinetic parameters of model compounds, which can reasonably predict the effluents of the hydrotreating of these, but are unsuitable for bio-oil.Fast pyrolysis is one of the thermochemical conversion routes that enable the transformation of solid lignocellulosic biomass into liquid bio-oils. These complex mixtures are different from oil fractions and cannot be directly integrated into existing petroleum upgrading facilities. Indeed, because of their high levels of oxygen compounds, bio-oils require a dedicated pre-refining step, such as hydrotreating, to remove these components.The aim of the present work is to understand the structure, composition and reactivity of bio-oil compounds through modeling of experimental data. To understand the structure and composition, molecular reconstruction techniques, based on analytical data, were applied generating a synthetic mixture, whose properties are consistent with the mixture properties. To understand the reactivity, the hydrotreating of two model molecules was studied: Guaiacol and Furfural. A deterministic and stochastic model were created for each compounds. The deterministic approach intended to retrieve a range of kinetic parameters, later on refined by the stochastic simulation approach into a new model. This approach generates an reaction network by defining and using a limited number of reaction classes and reaction rules. To consolidate the work, the synthetic mixture was used in the stochastic simulation of the hydrotreating of bio-oils, supported by the kinetics of the model compounds.In sum, the present work was able to recreate the light fraction of bio-oil and simulate the hydrotreating of bio-oils, via the kinetic parameters of model compounds, which can reasonably predict the effluents of the hydrotreating of these, but are unsuitable for bio-oil

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Goring, Simon J., David J. Mladenoff, Charles V. Cogbill, Sydne Record, Christopher J. Paciorek, Stephen T. Jackson, Michael C. Dietze, et al. "Novel and Lost Forests in the Upper Midwestern United States, from New Estimates of Settlement-Era Composition, Stem Density, and Biomass." PUBLIC LIBRARY SCIENCE, 2016. http://hdl.handle.net/10150/622487.

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Background EuroAmerican land-use and its legacies have transformed forest structure and composition across the United States (US). More accurate reconstructions of historical states are critical to understanding the processes governing past, current, and future forest dynamics. Here we present new gridded (8x8km) reconstructions of pre-settlement (1800s) forest composition and structure from the upper Midwestern US (Minnesota, Wisconsin, and most of Michigan), using 19th Century Public Land Survey System (PLSS), with estimates of relative composition, above-ground biomass, stem density, and basal area for 28 tree types. This mapping is more robust than past efforts, using spatially varying correction factors to accommodate sampling design, azimuthal censoring, and biases in tree selection. Changes in Forest Structure We compare pre-settlement to modern forests using US Forest Service Forest Inventory and Analysis (FIA) data to show the prevalence of lost forests (pre-settlement forests with no current analog), and novel forests (modern forests with no past analogs). Differences between pre-settlement and modern forests are spatially structured owing to differences in land-use impacts and accompanying ecological responses. Modern forests are more homogeneous, and ecotonal gradients are more diffuse today than in the past. Novel forest assemblages represent 28% of all FIA cells, and 28% of pre-settlement forests no longer exist in a modern context. Lost forests include tamarack forests in northeastern Minnesota, hemlock and cedar dominated forests in north-central Wisconsin and along the Upper Peninsula of Michigan, and elm, oak, basswood and ironwood forests along the forest-prairie boundary in south central Minnesota and eastern Wisconsin. Novel FIA forest assemblages are distributed evenly across the region, but novelty shows a strong relationship to spatial distance from remnant forests in the upper Midwest, with novelty predicted at between 20 to 60km from remnants, depending on historical forest type. The spatial relationships between remnant and novel forests, shifts in ecotone structure and the loss of historic forest types point to significant challenges for land managers if landscape restoration is a priority. The spatial signals of novelty and ecological change also point to potential challenges in using modern spatial distributions of species and communities and their relationship to underlying geophysical and climatic attributes in understanding potential responses to changing climate. The signal of human settlement on modern forests is broad, spatially varying and acts to homogenize modern forests relative to their historic counterparts, with significant implications for future management.

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de, Abreu Thomaka Carlos Fellipe. "Recycling of the water-phase from hydrothermal conversion of biomass : Comparative study of water composition using lignin and microalgae as feedstocks." Thesis, Umeå universitet, Kemiska institutionen, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-184232.

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Dyck, Barbara S. "The species composition, aboveground biomass and carbon content of vegetation in two basin bogs in the Experimental Lakes area, north-western Ontario." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ32097.pdf.

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Mukengele, Michael Mutombo Verfasser], and Thomas [Akademischer Betreuer] [Jungbluth. "Biochemical composition of biomass and its impact on the prediction of the specific methane yield potential / Michael Mutombo Mukengele ; Betreuer: Thomas Jungbluth." Hohenheim : Kommunikations-, Informations- und Medienzentrum der Universität Hohenheim, 2017. http://d-nb.info/1135259828/34.

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Rodriguez, Correa Catalina [Verfasser]. "Understanding the Effects of Biomass Composition and Carbonization Process on the Textural Properties and Adsorption Capacity of Activated Carbon / Catalina Rodríguez Correa." Aachen : Shaker, 2018. http://d-nb.info/1162794143/34.

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Snover, Amy Katherine. "The stable hydrogen isotopic composition of methane emitted from biomass burning and removed by oxic soils : application to the atmospheric methane budget /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/11570.

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Pereira, Juliano Bicalho. "Composição, distribuição, biomassa e produção secundária do zooplâncton do Sistema estuarino de Santos, São Paulo, Brasil." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/21/21131/tde-09082011-135919/.

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A composição, distribuição, abundância, biomassa e produção secundária do zooplâncton do Sistema estuarino de Santos foram estudadas na baía de Santos (4 estações), canal de Santos (3 estações) e canal da Bertioga (4 estações), entre novembro de 2004 e outubro de 2005, em relação à temperatura, salinidade, material em suspensão, nutrientes dissolvidos e clorofila-a. Nas 114 amostras analisadas, o zooplâncton foi constituído de 101 táxons distribuídos em 10 filos: Arthropoda (subfilo Crustacea), Annelida (classe Polychaeta), Bryozoa, Chaetognatha, Chordata (subfilo Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca e Phoronida, sendo o primeiro dominante. Os copépodes constituíram, em média, 85,5% do zooplâncton total. A comunidade zooplanctônica das três áreas incluiu táxons estuarinos, costeiros e oceânicos, sendo dominantes Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (náuplios), Paracalanus quasimodo, Paracalanus spp. (copepoditos), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica e as larvas de Polydora spp., Aonides spp., Spionidae e Bivalvia. A abundância, biomassa e a produção secundária zooplanctônica foram maiores no canal da Bertioga, enquanto a produtividade foi maior na baía de Santos. Esses fatores estiveram associados, principalmente, à salinidade, temperatura da água e material em suspensão total.
The zooplankton´s composition, distribution, abundance, biomass and secondary production of Santos estuarine system were studied on Santos bay (4 stations), Santos channel (3 stations) and Bertioga channel (4 stations) between November 2004 and October 2005 in relation to temperature, salinity, suspended matter, dissolved nutrients and chlorophyll-a. On the 114 analyzed samples, zooplankton was constituted of 101 taxa distributed among 10 phyla: Arthropoda (subphylum Crustacea), Annelida (class Polychaeta), Bryozoa, Chaetognatha, Chordata (subphylum Tunicata), Cnidaria, Ctenophora, Echinodermata, Mollusca and Phoronida, being Arthropoda the dominant phylum. Copepoda (subphylum Crustacea) constituted on average 85,5% of total zooplankton. The zooplankton community among the three areas included estuarine, coastal and oceanic taxa, being Oithona hebes, Oithona oswaldocruzi, Acartia lilljeborgi, Acartia tonsa, Bestiolina similis, Balanus spp. (naupli), Paracalanus quasimodo, Paracalanus spp. (copepodite), Parvocalanus scotti, Euterpina acutifrons, Pseudodiaptomus acutus, Oikopleura dioica and the larvae of Polydora spp., Aonides spp., Spionidae and Bivalvia dominant. The abundance, biomass and zooplanktonic secondary production were higher on Bertioga channel, whereas the productivity was higher on Santos bay. These factors were associated mainly to salinity, water temperature and total suspended matter.

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Tigma, Mohammed. "Effects of Chiselling and Sulfur Fertilization on Infiltration, Soil Water Content, Peak Season Biomass Production, and Botanical Composition in the Ait Rbaa Perimeter." DigitalCommons@USU, 1990. https://digitalcommons.usu.edu/etd/6466.

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This study evaluated the effectiveness of chiselling and elemental sulfur fertilization in improving an upland and a swale range site with fine loamy, carbonatic, typic calcixeroll soils in the Ait Rbaa Perimeter of central Morocco. Ponding infiltration, soil water content on a mass basis of the 0- to 10-cm and 10- to 20-cm soil layers, peak season biomass production, and botanical composition were monitored during the two growing seasons following the treatments (1984/85 and 1985/86). Chiselling significantly improved infiltration on both sites, although the improvement was greater on the finer and less stony swale site, where chiselling resulted in more stable ridges. The land treatment also increased the average water content by weight of the 0- to 20-cm soil layer. The increase was more frequent on the upland site and most pronounced on its o- to 10-cm surface soil layer. In the chiselled treatments, average soil water content decreased with soil depth on the upland site while it increased on the swale site because of differential furrow stability and soil texture. Both the average infiltration rates of 5 cm of water and the average water content varied with sampling time, although generally in opposite directions. The application of elemental sulfur at the rates of 0, 30, and 60 kg ha-1 did not significantly affect any of the measured variables. Average peak season biomass production was 11% greater with chiselling. Chiselling also positively affected botanical composition on the upland site by depressing average forb proportion and increasing legume ratio in the first growing season. The gain in biomass does not seem to be high enough to strongly recommend chiselling in the Ait Rbaa Perimeter before performing an economic analysis of the operation.

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Pierre, Floran. "Traitement thermique du bois en vue de sa valorisation énergétique : effet de l'intensité de traitement sur la composition chimique, les propriétés énergétiques et la résilience mécanique." Phd thesis, AgroParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-01066141.

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Le contexte global de réchauffement climatique et de fin programmée des carburants d'origine fossile a conduit depuis quelques décennies au développement des biocarburants. Les nombreux inconvénients liés à la première génération de biocarburants ont peu à peu donné naissance aux biocarburants de seconde génération dont l'avantage notable est d'utiliser la partie ligno-cellulosique des plantes. La principale voie de conversion envisagée consiste en une gazeification suivie d'une synthèse Fisher-Tropsch. Mais la dispersion énergétique et géographique de la biomasse ainsi que les nombreuses contraintes liées au processus de fabrication nécessitent la mise au point d'un préconditionnement adéquat. Le matériau utilisé devra en effet être homogène, concentré énergétiquement, stockable et facilement transportable. Il devra aussi être facilement broyable en vue de son injection sous pression dans les gazéifieurs. Une voie de prétraitement possible consiste à torréfier la biomasse. Le présent travail s'inscrit dans cette thématique puisqu'il a permis une caractérisation chimique, énergétique et mécanique du bois (Pinus pinaster et Quercus robur) traité thermiquement (T°C<300°C). Dans une première partie du travail, des analyses chimiques et énergétiques de bois traités thermiquement à différentes intensités ont été réalisées. Les résultats ont permis de quantifier la dégradation chimique et la densification énergétique lorsque l'intensité du traitement augmente. Il s'avère que la perte de masse est un excellent indicateur de ces modifications : des relations de prédiction de l'évolution de ces propriétés ont été établies. Un dispositif d'impact original a été développé dans la seconde partie du travail. Les résultats obtenus montrent une augmentation de la broyabilité du bois lorsque l'intensité de son traitement thermique augmente. Avec l'intensité du traitement, le bois perd d'abord sa résilience, puis son comportement fibreux.Cela permet la formation de fines particules particulièrement adaptées aux processus de fabrication des biocarburants de seconde génération.

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Seese, Megan Rebecca. "Effects of Laurencia and Palisada Spp. on Epifaunal Composition Within Thalassia Testudinum Beds on Abaco, the Bahamas." NSUWorks, 2009. http://nsuworks.nova.edu/occ_stuetd/226.

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We examined effects of the macroalgae Laurencia and Palisada spp. on epifauna within seagrass beds of Thalassia testudinum. First we conducted a field survey of Thalassia testudinum beds with varying densities of Laurencia and Palisada spp. Second, we conducted a field experiment, manipulating natural and simulated Laurencia and Palisada spp. In the field survey, we found that total faunal biomass (g m-2) increased significantly with Laurencia and Palisada spp. cover. In the experiment, natural Laurencia and Palisada spp. supported an increased density (No. m-2) of fauna, however, faunal values were highest in the simulated algae treatment. This suggests that the mechanism of increased density/biomass due to Laurencia and Palisada spp. is structural complexity. Since habitat quality in Thalassia testudinum beds may be mediated by associated macroalgae, these small-scale habitat factors need to be incorporated in habitat and ecosystem conservation plans.

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Amde, Yosef Amha [Verfasser]. "Microbial activity and biomass of peats in relation to the intrinsic organic matter composition, pH, moisture, and C and N inputs / Yosef Amha Amde." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2011. http://d-nb.info/101336614X/34.

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49

Bopape-Mabapa, Moshidi Paulina. "Yield characteristics, carbon capture and chemical composition of moringa oleifera under diverse planting population and agro-ecological conditions of the Limpopo Province." Thesis, University of Limpopo, 2019. http://hdl.handle.net/10386/2860.

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Thesis (Ph. D. Agric. (Plant Production)) --University of Limpopo, 2019
Moringa oleifera is a multipurpose fast growing tree which is widely cultivated in tropical and subtropical regions of the world due to its numerous benefits. The benefits include medicinal use, industrial use, soil fertility, water purification, climate change mitigation as well as of nutritional value for humans and livestock. Recently, many areas globally have been rendered vulnerable to climate change as well as food insecurity. Climate change increases irregularities of rainfall and temperature patterns in semi-arid conditions. One practical way to address this challenge in the agricultural sector is to introduce more trees crop species which are found to be more tolerant than annual crops under harsh growing conditions. Moringa is one species that could be considered under variable climatic conditions for positive outcomes through climate change adaptation and mitigation as well as life sustenance against food insecurity threats. Production of moringa in South Africa is exclusively for leaf processing and consumption. To date, there is no documented information available about seed and oil yield production of moringa mainly in the Limpopo Province of South Africa. The aim of the study was to generate knowledge on moringa growth, nutritional composition, seed and oil yield production as well as its response to drought through gaseous exchange parameters, as influenced by plant density under diverse agro-ecological locations in Limpopo Province. The study was conducted in the Limpopo Province, South Africa, from November 2013 to January 2016. The study area falls within the semi-region which is characterized by low and erratic rainfall which predominately falls in summer as well as extremely low or high temperatures. A survey was conducted from November 2013 to September 2014 in five districts of the Limpopo Province. Focus group discussion, questionnaires and field observations were used for data collection. A total of 150 moringa growers formed part of the focus group and a questionnaire was administered to only thirty-one farmers, who constitute the population of farmers producing moringa within an area of 0.25 ha or more. A second study was conducted at two experimental sites in the Limpopo Province of northern part of South Africa to evaluate for the first time, the effect of plant density and cutting interval on biomass production and chemical composition of moringa grown under two diverse climatic conditions. Four different planting densities (435 000, 300 000, 200 000 and 100 000 plants/ha) were arranged in a randomized complete block design and experimental samples were replicated four times. A third study was conducted over two years to achieve additional objectives which included evaluation of gaseous exchange, biomass, seed, and oil yield. Untreated seeds of Moringa oleifera were used for establishing the trial at densities of 5 000, 2 500, 1 667 and 1 250 plants ha-1, with eight replicates. The same study was used to achieve the objective on gaseous exchange in comparison with other two naturally growing tree species of mopane (Colophospermum mopane) and marula (Sclerocarya birrea) trees growing within the moringa trial vicinity. The study was further used to evaluate the effect of planting density on biomass, grain, oil yield production and nutritional composition of Moringa oleifera trees. The last part of the study was carried out in the five districts of the Limpopo Province to determine the influence of soil physical and chemical properties on the nutritional composition of moringa leaves. The farms that were identified during the survey were also used to achieve other objectives of the study. In order to determine soil and leaf nutritional composition, soil samples were collected and analyzed for physical and chemical properties. The harvested leaves were dried at room temperature and their nutritional compositions were determined using standard methods. Findings from the studies revealed the following: The survey indicated that there are potential moringa farmers in all the districts of the province, with the intention to commercialize the tree. Majority of farmers grow moringa on 0.251.0 ha and have been producing the crop for the past 2 years. The study on planting density and cutting frequency revealed satisfactory nutritional composition in the leaves across the cutting frequencies and that, an increase in the plant density led to enhanced biomass production. The study on the monthly and seasonal gaseous exchange revealed significant differences in net photosynthetic rate, transpiration, sub-stomatal CO2 and stomatal conductance. However, planting densities of Moringa oleifera had no significant effect on all the gaseous exchange parameters measured. In a comparison of moringa with other tree species growing in the vicinity of moringa, the results differed significantly in gaseous exchange. The highest activity in photosynthetic rate (A), stomatal conductance (gs), transpiration rate (E) and sub-stomatal CO2 (Ci), as well as higher stomatal density, was found in moringa. The findings from the biomass, seed yield and oil yield study showed that the increase in measured biomass, seed and oil yield increased with increasing planting density. However, seed oil concentration was non-significant. Findings from the ecology study revealed that moringa improved soil nutritional composition; mainly in areas where the trees were more than three years old as compared to control soils where moringa had not been planted. The soil nutritional composition differed with soil textural classes with the clay soils recording higher nutrient ion values. The study revealed that moringa can be produced in many locations of the Limpopo Province without negatively affecting leaf nutritional composition. Moringa leaves contain high level of nutrients even under marginal production areas irrespective of the planting density. A population of 5000 plants ha-1 can be used for seed and oil yield production where temperatures are favourable for improved farmers’ livelihoods. The results strongly showed with no doubt, the superiority of moringa in capturing more carbon among the three species. Moringa maintained good leaf yield even under drought condition, which is an indication of its potential to act as a good sink for carbon dioxide absorption. It can, therefore, be recommended for many parts of Limpopo Province for climate change mitigation and adaptation strategies and food security. KEY CONCEPTS: agro-ecology, biomass, climate change, commercialization, drought, food security, gas exchange, leaf chemical composition, location, Moringa oleifera, oil, seed, soil textural class, survey, trees, weather, yield

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Karlson, Martin. "Remote Sensing of Woodland Structure and Composition in the Sudano-Sahelian zone : Application of WorldView-2 and Landsat 8." Doctoral thesis, Linköpings universitet, Tema Miljöförändring, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121536.

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Woodlands constitute the subsistence base of the majority of people in the Sudano-Sahelian zone (SSZ), but low availability of in situ data on vegetation structure and composition hampers research and monitoring. This thesis explores the utility of remote sensing for mapping and analysing vegetation, primarily trees, in the SSZ. A comprehensive literature review was first conducted to describe how the application of remote sensing has developed in the SSZ between 1975 and 2014, and to identify important research gaps. Based on the gaps identified in the literature review, the capabilities of two new satellite systems (WorldView-2 and Landsat 8) for mapping woodland structure and composition were tested in an area in central Burkina Faso. The results shows that WorldView-2 represents a useful data source for mapping individual trees: 85.4% of the reference trees were detected in the WorldView-2 data and tree crown area was estimate with an average error of 45.6%. In addition, WorldView-2 data produced high classification accuracies for five locally important tree species. The highest overall classification accuracy (82.4%) was produced using multi-temporal WorldView-2 data. Landsat 8 data proved more suitable for mapping tree canopy cover as compared to aboveground biomass in the woodland landscape. Tree canopy cover and aboveground biomass was predicted with 41% and 66% root mean square error, respectively, at pixel level. This thesis demonstrates the potential of easily accessible data from two satellite systems for mapping important tree attributes in woodland areas, and discusses how the usefulness of remote sensing for analyzing vegetation can be further enhanced in the SSZ.
Merparten av befolkningen i Sudano-Sahel zonen (SSZ) är beroende av naturresurser och ekosystemtjänster från woodlands (öppen torrskog) för att säkra sin försörjning. Tillgången av fältmätningar av vegetationens struktur och sammansättning är mycket låg i detta område, vilket utgör ett problem för forskning och miljöövervakning. Denna avhandling undersöker nyttan av fjärranalys för att kartlägga och analysera vegetation, främst träd, i SSZ. En omfattande litteraturöversikt genomfördes först för att undersöka hur tillämpningen av fjärranalys har utvecklats i SSZ mellan 1975 och 2014, samt att identifiera viktiga forskningsluckor. Några av de luckor som konstaterades i litteraturgenomgången låg till grund för de följande studierna där två nya satellitsystem (Worldview-2 och Landsat 8) utvärderades för deras användbarhet att kartlägga trädtäckets struktur och artsammansättning i ett woodland-område i centrala Burkina Faso. Resultaten visar att Worldview-2 är en värdefull datakälla för kartering av enskilda träd: 85.4% av referensträden detekterades och trädkronornas storlek uppskattades med ett medelfel av 45.6%. Worldview-2-data producerade även hög klassificeringsnoggrannhet för de fem lokalt viktigaste trädslagen. Den högsta noggrannheten (82.4%) uppnåddes med multi-temporal Worldview-2-data. Landsat 8 data visade sig mer lämpade för kartering av krontäcke, jämfört med biomassa. Medelfelet för karteringen var 41% för krontäcke och 66% för biomassa, på pixelnivå. Avhandlingen visar att lättillgängliga data från två satellitsystem är användbara för kartläggning av viktiga trädattribut i woodlands, samt diskuterar hur nyttan av fjärranalys för vegetationsanalys kan ökas ytterligare i SSZ.

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Dissertations / Theses on the topic 'Composition of biomass'

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