L’Afrique de l'Ouest manque de ressources naturelles pour la production d'énergie. Les sous-produits agro-industriels comme les coques d’anacarde (CNS), les tourteaux de jatropha et de karité ont été identifiés comme des ressources disponibles et facilement mobilisables à des fins énergétiques. Ces biomasses se caractérisent par de fortes teneurs en extractibles (baume de cajou=CNSL ou triglycérides), sources de fumées toxiques en combustion. La thèse visait à évaluer la pertinence de la pyrolyse rapide comme procédé alternatif pour ces ressources, etplus particulièrement à établir l'impact des extractibles sur les rendements, la composition et la stabilité des bio-huiles. Les biomasses ont été dérivées en échantillons couvrant la gamme entière des teneurs en extractibles (tourteau déshuilé ~0% ; extractible purs 100%), lesquels ont été caractérisés et pyrolysés dans 2 dispositifs laboratoires (ATG et four tubulaire), puis en conditions réelles sur un pilote de pyrolyse rapide à lit fluidisé. On ne constate pas d'interaction significative entre la matrice solide et les extractibles lors de leur décomposition, mais des produits différents ont été identifiés. Le CNSL se volatilise entre 250 et 320°C ; plusieurs composés phénoliques ou typiques du CNSL brut se retrouvent dans l'huile de pyrolyse. En revanche, les triglycérides se décomposent entièrement entre 380 et 420°C en chaînes d’hydrocarbures linéaires. Quelques produits d'interaction avec les triglycérides et les protéines ont été identifiés. Par ailleurs, les essais sur pilote ont mis en évidence des difficultés opérationnelles dans le lit fluidisé liées aux spécificités des tourteaux, suggérant une optimisation des conditions opératoires. Pour pallier la séparation de phases constatée sur les bio-huiles, des formulations avec d'autres biocarburants ont été testées. Les émulsions obtenues sont plus homogènes, mais leur stabilité physique est encore insuffisante malgré l'ajout / Sub-Saharan West Africa lacks of natural resources, especially for energy production. By-products of agro-industry as cashew nut shells (CNS), jatropha (Jc) and shea (Sc) press cakes were identified as available resources for energetic valorisation. These biomasses are characterized by high extractive contents (cashew nut shell liquid/CNSL or triglycerides) which are the reason for toxic fumes during combustion. The thesis investigated the feasibility of flash pyrolysis as alternative process for these resources, more specifically the impact of the extractives on yields, the composition and the stability of flash pyrolysis oils. The feedstock were derived into samples covering the whole range of extractive contents (from de-oiled press cakes, ~0 wt%; to pure extractives, 100 wt%) which were characterized and pyrolysed in two laboratory devices (TGA and tubular furnace), then by applying flash pyrolysis conditions in a fluidized bed reactor. No significant interaction in-between the solid matrix and the extractives during pyrolysis were observed but different products were identified. CNSL volatises between 250 and 320°C, several phenolic compounds and typical compounds of crude CNSL were found to be present in the pyrolysis oil. In contrast, triglycerides are entirely decomposed at 380 to 420°C to give linear hydro-carbon chains. Some interaction products of the triglycerides with proteins were identified. Additionally, the experiments with the pilot plant have shown operational difficulties in the fluidized bed, which are linked to specific properties of the press cakes. Thus, further optimisations of process conditions are suggested. To overcome the observed phase separation of the pyrolysis oils mixtures with other biofuels were studied. The obtained emulsions are more homogeneous but the physical stability is still insufficient despite the addition of surfactants.

This work concerns the efficient treatment of wastewaters from pulp and paper mills by means of aerobic biological processes. For treatment processes there are many aspects of efficiency and the present study investigates both energy efficiency and purification efficiency during disturbances. Special focus is put on wood extractives, such as resin acids and fatty acids, since they can cause negative effects in fish and other organisms in the receiving waters. They can furthermore be toxic to microorganisms in a biological treatment plant. They also affect oxygen transfer, which is important for energy efficient aeration of aerobic biological treatment processes. This thesis includes five papers/studies and presents a strategy for efficient treatment of forest industrial wastewaters. The results should help creating resilient wastewater treatment strategies with efficient use of energy. One new strategy proposed here includes separation of extractives before the wastewater is treated biologically, and the use of the extra amount of sludge as an energy source, shifting the energy balance from negative to positive.

No description available.

Recent events in the business world have focused attention on the importance of high quality financial reporting. Of particular interest is where the collapse of prominent companies such as Baring Plc. was due to the company's involvement with derivative instruments. In Australia, some derivative instruments are not recognised in the balance sheet. However, the Australian accounting standard AASB 1033 Presentation and Disclosure of Financial Instruments requires extensive disclosures to overcome the lack of guidance with regard to the recognition and measurement. Therefore, AASB 1033 may be regarded as a high quality disclosure standard. This thesis investigates the transparency or information quality of derivative disclosures of Australian firms in the extractive industries using 1998 to 2001 financial reports. The extractive industries play a major role in the Australian economy, where they generated exports worth more than A$30billion in 2000 to 2002 (Department of Foreign Affairs and Trade, 2003a and 2003b). Further, firms in the extractive industries extensively use derivative instruments for hedging purposes (Berkman, Bradbury, Hancock and Innes, 1997). The objective of this study is, first, to examine the relationship between the transparency or disclosure quality of derivative information and firm characteristics. Second, this study investigates the value relevance of derivative disclosures in particularly hedge information, net fair value information and risk information. Quality is measured based on a disclosure index developed from AASB 1033 Presentation and Disclosure of Financial Instruments. A finding of concern is that the majority of firms in this study provide less than complete information and therefore enforcement power is required to ensure compliance (Kothari, 2000) Prior studies have related disclosure quality of accounting information with firm characteristics but no attempt has been made to relate those characteristics with the disclosure quality of derivative instruments. The current study contributes to the literature by examining the relationship between firm characteristics and the quality of derivative disclosures. Firm characteristics investigated are size, profitability, price-earnings ratio, market-to-book ratio, research and development activity, auditor, debt-to-equity ratio and type of extractive firm. This study finds that the variables, firm size, price-earnings and debt-to-equity ratios are associated with the disclosure quality of derivative information. To a lesser extent, the variables, market-to-book ratio and profitability, are also associated with disclosure quality. High disclosure quality has been argued to lead to a reduction in the cost of debt (Sengupta, 1998) and equity (Botosan, 1997), resulting in higher security prices (Miller and Bahnson, 2002). The results of this study indicate that high quality derivative information, as represented by the disclosure index, is value relevant. Market participants do consider hedge information and risk information components as important for decision-making. However, examining the specific information disclosed in the financial statements indicate that some of the disclosed information such as the unrealised gain or loss on financial assets and liabilities and off-balance sheet derivative financial instruments are not significant. These results contribute to the value relevance literature as this study focuses on the extractive industries which have been neglected in the literature. This study provides important information for standard setters and regulators for future directions in developing accounting standards and is particularly relevant for the impending adoption of International Accounting Standards.

Há 27 anos foi criada a RESEX Chico Mendes, no Acre, conquista histórica para o movimento dos seringueiros. Desde a década de 1970, os seringueiros vinham resistindo contra a expropriação causada pelo avanço da fronteira agropecuária na Amazônia e faziam frente a um modelo específico de desenvolvimento econômico que era fruto da aliança entre o capital monopolista e o Estado. Como reivindicação popular, no I Encontro Nacional dos Seringueiros (1985) foi proposta uma outra lógica de reforma agrária que mais adiante ganharia o nome de Reserva Extrativista (RESEX), onde a territorialidade e a (re)produção da família seringueira seriam contempladas e aliadas à conservação ambiental. Neil Smith (2008) aponta que, a partir da crise capitalista dos anos 1970, início do período neoliberal, houve uma intensificação do movimento de captura da natureza como estratégia de acumulação. A institucionalização da RESEX, em 1990, está inserida nesse quadro global e também marca o começo da guinada neoliberal no Brasil. Observa-se um processo de captura da proposta gestada pelo movimento social dos seringueiros para a constituição e concretização de um outro projeto, que contemplaria os interesses do capital monopolista e de novos atores sociais, onde se enquadram as ONGs. Na presente pesquisa, buscaremos compreender a produção capitalista da natureza a partir da RESEX Chico Mendes (1990-2017), por meio da qual o Estado e o mercado incorporam - de maneira contraditória e conflituosa - relações de produção não capitalistas, redefinindo os usos, a apropriação da natureza e as territorialidades dos seringueiros. / Extractive Reserve Chico Mendes in Acre was created 27 years ago and considered a historic step towards the rubber tappers movement. Since the 1970\'s they had been resisting the expropriation starting from the agriculture frontier in the Brazilian Amazon Region which was part of specific economic development frame fruit of the link between monopolistic capital and the State. The first National Rubber Tappers Conference (1985) covered the popular motion and proposed a new concept of an agrarian reform which later on would be known as the Extractive Reserve (RESEX), in which the territoriality and the family social reproduction would be assisted together with environmental conservation. Neil Smith (2008) points out that the capitalist crisis of the 1970s mainly during the neoliberal showed an intensification of nature\'s takeover as an accumulation strategy. The institutionalization of RESEX in 1990 is inserted in this global picture and with the start of the pivotal neoliberal in Brazil. A process for the so called takeover proposal which was initially developed by the rubber tappers social movement was observed and the constitution and the materialization of another project which would assist the interests of the monopolist capital and of new social players such as NGOs. This present research aims to better understand the capitalist production of the nature through the constitution and materialization of RESEX Chico Mendes (1990-2017) whereby the State and the market both incorporate in contractionary and conflicting manner the non-capitalist production relations redefining its uses, the appropriation of nature and the rubber tappers territoriality.

This thesis elaborates a decolonial international political economy (IPE) as a means of examining the condition of market emergence in Indonesia. It presents the term ‘emerging market’ as the contemporary organising grammar which positions Indonesia in relation to international capital flows. This condition of market emergence is further understood in historical colonial perspective as the latest mode of producing Indonesia as an investible site for international capital. My expansion of decolonial IPE is made in this thesis through the analysis of difference-based ‘exclusion’ and ‘translation’, both as vital elements of coloniality and as processes which relate to accumulation and dispossession in an ‘emerging market’ context. I go on to make the case for bringing urban and rural terminable sites of extraction into the same frame of analysis. These are understood similarly here as internal frontiers along which social groups are materially and discursively excluded from the national emerging market project and thus rendered expropriatable. I further analyse the repeated dispossession of these expropriatable groups along with other means of enacting ‘translations’, or enforced alterations in ways of being. These translations are by no means passively accepted and my analysis further demonstrates various means by which these are negotiated and contested. This thesis therefore makes contributions to the literature on decolonial thought and IPE, at the same time as presenting an original examination of Indonesia in its present moment of market emergence. / Doctorat en Sciences politiques et sociales / info:eu-repo/semantics/nonPublished

Abstract This thesis aims to increase our knowledge about the characteristics of chemical pulp process and wastewaters and how problematic substances, e.g. wood extractives, could be removed effectively and selectively by coagulation–flocculation with either internal or external water treatment. Characterization was performed by investigating kraft pulp bleaching filtrates, as well as wastewater, before (influent) and after (effluent) the activated sludge treatment by means of a range of chemical analyses and by carrying out size fractionation studies. Cationic polyelectrolytes were used to purify oxygen stage bleaching filtrate, and charge analyses (zeta potential, charge quantity) were carried out in order to understand the coagulation phenomenon. In activated sludge treatment, the enhancement of particle removal, either by filtration or using a chemical in the primary clarifier, would lead to savings in aeration costs and result in a more stable process. Microfiltration already with a large pore size (8 µm) removed 30–50% of the wood extractives from the influent. Separate treatment stages for certain wastewater fractions, e.g. debarking plant effluent, would ensure cost-efficiency. After the activated sludge process, the wood extractives were present as particles (18%) and < 3 kDa fraction (82%). β-sitosterol occurred only in particles in the effluent. The release of harmful components into the environment could be decreased by microfiltration (e.g. 0.45 µm) of the final effluent or using a chemical in the secondary clarifier. Interestingly a huge increase in BOD was realized in the 3 kDa fraction of both influent and effluent, which indicated the presence of toxic substances in the larger fractions. After passing the effluent into the water system, there might be a similar jump in the BOD because the effluent is diluted many-fold. This would contribute to the formation of areas with an oxygen deficit. In the coagulation–flocculation studies, effective and selective removal of wood extractives (92%) from the oxygen stage filtrate was obtained with a cationic polyelectrolyte of medium molecular weight and medium charge density at 72 °C and pH 5–6. The multimodal zeta potential distribution gave more information than the average zeta potential. Aggregation of colloidal particles occurred when only one zeta potential was observed. The number of different zeta potentials diminished with decreasing pH and after exceeding a certain polyelectrolyte dosage level.

Abstract Stickies refer to tacky contaminants in recovered paper, excluding wood extractives. Stickies originate from adhesives, ink binders and coating binders. Stickies able to pass a sieve of 100 or 150 μm (depending on standard) are called micro stickies, whereas the particles retained on the screen are called macro stickies. Dissolved and colloidal stickies are called secondary stickies. There are standard methods for macro stickies, but a standard method measuring the total amount of stickies is lacking. Furthermore, the size distribution, and nature of stickies in the sense if they are free particles or agglomerated with some other substances, has not been previously known. The information on the removal of stickies in different unit operations was also not known very well except for macro stickies. The aim of this thesis was thus to develop an analysis method for the total amount of stickies, determine the size distribution and nature of stickies, and find ways to better remove stickies in the deinking process. Extraction with tetrahydrofuran (THF) and High Pressure Liquid Chromatography (HPLC) with Size Exclusion Column (SEC) was used here to separate hydrophobic polymers (stickies) from the pulp suspension. An Evaporating solvent Light Scattering (ELS) detector was utilized to quantify the polymers after SEC. This analysis procedure was used in this thesis to measure stickies. Fractionation of pulp before the analysis was carried out if information of different-sized stickies was desired. The majority of stickies are micro stickies. A significant, although lower, portion of stickies are macrostickies, especially in the beginning of the deinking process. The dissolved and colloidal phase was found to contain wood extractives, and only trace amounts of stickies. Flotation is very effective in stickies removal. Ink and micro stickies were removed nearly equally in flotation, because they both are hydrophobic and are both in an optimal size range for removal in flotation. Ink measurements may be used for estimating the trends of stickies removal in flotation. The stickies removal in flotation may be enhanced by optimizing the pulper chemistry.

This study investigates modifications to AWPA Standard E18-06 to develop an above-ground field test for subterranean termites native to the eastern United States. AWPA Standard E18-06 was modified in two stages to progressively increase optimum conditions for subterranean termite feeding. Modification II, which incorporated the use of house bricks and feeder strips with a solid ventilated cover, had an increase in termite attack with less variation between tests. This study also investigates the effects of adding antioxidants, both natural and synthetic, and analogues which lack antioxidant properties, to test wood blocks on feeding by Reticulitermes flavipes Kollar using AWPA Standard E1-09. Antioxidants had feeding deterrence and mortality properties to R. flavipes. Conversely, the non-antioxidant analogues, with the exception of the heterocyclic flavanone, had little effect on R. flavipes. It is concluded that R. flavipes instinctively avoids wood which contains high levels of antioxidants, such as heartwood with phenolic extractives.

<p>  </p> <p>The potential of lignocellulose for producing fermentable sugars as feedstock to manufacture fuels, chemicals, and materials for decarbonization remains untapped due to costly logistics and conversion processes. Pelleting technology offers a solution by addressing logistical issues and impacting downstream conversion, though it comes with its own costs. An overview of recent advances in pelleting technologies and their impact on bioconversion highlights the importance of understanding variables and product attributes. The interplay between pelleting and pretreatment processes, considering various feedstocks, is crucial for future design. Practical considerations such as energy consumption, costs, and environmental impacts must not be overlooked, along with exploration of cutting-edge technologies and strategies in this field. This work further presents a comprehensive investigation into the recalcitrance of pelleted corn stover to enzymatic digestion prior to any pretreatment.</p> <p>The potential of lignocellulose for producing fermentable sugars as feedstock to manufacture fuels, chemicals, and materials for decarbonization remains untapped due to costly logistics and conversion processes. Pelleting technology offers a solution by addressing logistical issues and impacting downstream conversion, though it comes with its own costs. An overview of recent advances in pelleting technologies and their impact on bioconversion highlights the importance of understanding variables and product attributes. The interplay between pelleting and pretreatment processes, considering various feedstocks, is crucial for future design. Practical considerations such as energy consumption, costs, and environmental impacts must not be overlooked, along with exploration of cutting-edge technologies and strategies in this field. </p> <p>This dissertation further presents a comprehensive investigation into the recalcitrance of pelleted corn stover to enzymatic digestion prior to any pretreatment. One aspect focuses on the role of high moisture pelleting in enhancing the enzymatic digestibility of corn stover before pretreatment, along with the relevant substrate characteristics. The pelleting process increases the digestibility of unpretreated corn stover, resulting in a glucan conversion increase from 8.2% to 15.5% at a 5% solid loading using 1 FPU Cellic® CTec2 per gram of solids. Under the same enzymatic hydrolysis conditions, the conversion of glucan remains higher for pelleted corn stover compared to its non-pelleted counterpart, even though both samples underwent identical milling processes and passed through the same screen to minimize particle impact. Compositional analysis reveals that loose and pelleted corn stover have similar non-dissolvable compositions, albeit with differences in their extractives. Using microcrystalline cellulose (Avicel) as a substrate, the presence of corn stover extractives results in a lower sugar yield compared to using citrate buffer instead, particularly for extractives from pelleted corn stover. This indicates a more negative impact of pelleted corn stover extractives on the activity of employed enzyme, CTec2. However, pelleted corn stover still shows increased overall glucan conversion compared to loose corn stover, suggesting improved digestibility of non-dissolvable components after milling and washing. The improvement in digestibility of pelleted material can be attributed to factors such as reduced particle size, enhanced substrate accessibility, and hydrolysis of cross-linking structures induced by the pelleting process. These findings offer valuable insights for the development of processing strategies aimed at sustainable and efficient utilization of lignocellulose.</p> <p>Furthermore, this dissertation delves into the profound impact of extractives on enzymatic hydrolysis, prompting a thorough examination of the composition and characteristics of extractives derived from pelleted corn stover, as well as their effects on enzymatic conversion. In contrast to previous reports, it is discovered that water extractable materials actually enhance the enzymatic hydrolysis of extractive-free stover, while the enzyme activities diminish when using microcrystalline cellulose as a substrate. This divergent behavior of extractives is attributed to the presence of lignin, which may interact with inhibitory compounds like phenolics, thereby mitigating the detrimental effects of soluble inhibitors or insoluble lignin, or both. These findings significantly advance our fundamental understanding of the intrinsic behavior of extractives and contribute to the optimization of schemes for efficient and cost-competitive enzymatic conversion of lignocellulose. </p>