Peatlands are multiservice ecosystems: they are the largest terrestrial store of carbon in the UK, unique habitats which provide a home for internationally important species and managed for forestry, farming and game management and shooting. This makes understanding the impact of management practices on their ecology important if they are to be sustainably managed for multi-benefits. Fire has long been used to manage peatlands in the UK to improve grazing and habitat provision for livestock and game. The effect of fire on carbon cycling in blanket bogs is of increasing concern as greenhouse gas emissions from land use is now an important management as well as political issue. Gaps however, still exist in our understanding of the controls on greenhouse emissions from blanket bogs and the impact fire may have on them both directly and indirectly by modifying vegetation composition and environmental conditions. The main objective of this research was to assess the effect of fire on greenhouse gas emissions by measuring methane and ecosystem respiration after burning at blanket bog sites across Scotland for a period of up to 3 years and relating changes in fluxes with changes in vegetation composition and abiotic conditions. In addition, the response of the Sphagnum layer to burning was assessed by looking at the recovery of Sphagnum capillifolium in the field and in a novel laboratory experiment. The indirect effects of fire on methane emissions were further investigated by a laboratory experiment devised to test if high temperatures would be fatal to methanotrophic bacteria in the Sphagnum layer, reducing methanotrophy, and thus a mechanism for fire to increase methane emissions in the short term. The results showed that methane emissions and ecosystem respiration were not significantly different in burnt plots when compared to adjacent unburnt plots at each of the three sites studies. Methane emissions were only weakly correlated to the position of the water table and neither methane fluxes or ecosystem respiration correlated with measures of vegetation composition and above ground biomass. Methanotrophy in Sphagnum was found to be difficult to detect, with a high temperature treatment having no significant effect on rates of methane oxidation. S. capillifolium was found to respond to fire by growing new auxiliary stems if the capitulum was consumed or irreversible damaged physiologically by temperatures experienced at the moss surface, with surface temperatures around 400oC with a temperature residency time of 30 seconds on artificially dried samples the most damaging, but not lethal, treatment. These results suggest that low severity fires which only consume the canopy vegetation, not penetrating the peat and leaving the moss layer mostly intact, do not have significant effects on methane emissions and ecosystem respiration in the short and medium term. In addition, it suggests that S.capillifolium can, under certain circumstances, survive a fire with the characteristics of those studied here. These findings reiterate that best practice burning guidelines must continue to ensure that burning is only carried out on blanket bog when conditions are conducive to fires with the characteristics studied here, which had little effect on important components of the carbon cycle and are survivable by at least one of the most common species of Sphagnum.

Call number: LD2668 .T4 1986 M35 / Master of Science / Physics

A dissertation submitted to the faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfilment of the requirements for the degree of Master of Science in Engineering – Chemical Engineering Johannesburg, 2017 / In this research, the C, H and O bond equivalent diagram was used to design processes for DME synthesis using natural gas as a feed. This research proposes alternative ways of producing DME using natural gas (a cleaner gas) compared to the traditional routes. The different feed combinations were assessed for the production of syngas. The crucial step is the H2:CO ratio in each feed which determines the DME synthesis process route and yield. The syngas process was developed under equilibrium and non-equilibrium conditions (assuming 100% methane conversion). The region of operation on the ternary bond diagram was limited by mass and energy balance and carbon deposition boundaries. The feed composition was as follows, (1) Feed 1: methane, steam and oxygen (2) Feed 2: methane, oxygen and carbon dioxide (3) Feed 3: methane, oxygen, carbon dioxide and water. Feed (2) had the highest DME yield. The most optimal reaction route produced DME via the JFE reaction route (H2:CO =1). The yield of DME was 0.67 moles of DME per mole methane processed under non-equilibrium conditions. The proposed route does not emit CO2, excess CO2 is recycled back to the reforming reactor. Under equilibrium, the yield of DME was 0.25 mole DME per mole methane processed. The results indicate that a combination of partial oxidation and dry reforming produces a syngas composition which results in a high DME yield compared to (1) and (3). / MT2017

This study investigates the laminar burning velocity of premixed methane-air mixtures, having controlled supply of micron-sized (75-90 ¥ìm) coal dust and sand particles over a range of gas phase equivalence ratios (0.9-1.2), dust concentrations (0-250 g/m3) and reactant temperatures (297, 350, 400 K) using a novel Bunsen-burner type experimental design. The experimental results show that, the laminar burning velocity is enhanced by the increase in the reactant temperature, irrespective of the equivalence ratio of the mixture due to enhanced reaction rates. Addition of coal particles in fuel lean (ϕ < 1) mixtures increases the laminar burning velocity initially up to a certain coal dust concentration, but after that, the trend is altered; either it remains constant or shows a decreasing trend. The dust concentration value, which produces the initial or local maximum, increases with increase in reactant temperature. In other words, the reactant temperature plays a significant role in the trend of increase in laminar burning velocity with dust addition. For ϕ > 1, at a given reactant temperature, a linear decay of burning velocity with dust addition is observed. When a combustible dust particle interacts with the flame zone, it extracts energy from the flame (heat sink effect) and releases volatiles, thereby changing the local equivalence ratio around the flame zone. Both, increase in the equivalence ratio and the heat sink effect, are influenced by the reactant temperature. A mathematical model including these effects is developed and the model predictions are compared with the experimental results. The results are in a good agreement for fuel lean and stoichiometric mixtures; whereas the model is found to under predict results for fuel rich cases, and needs further improvements.

Digitized by Kansas Correctional Industries

Orientador: Telma Teresinha Berchielli / Coorientador: Juliana Duarte Messana / Banca: Marcia Helena Machado Rocha Fernandes / Banca: Rafael Canonenco de Araújo / Resumo: Este estudo objetivou avaliar o efeito da substituição da fonte de proteína verdadeira e da ureia por nitrato encapsulado (En) e enxofre (S) elementar sobre consumo, digestibilidade, parâmetros ruminais, eficiência de síntese de proteína microbiana e emissão de CH4 em bovinos Nelore. Foram utilizados cinco novilhos Nelore (352.7 ± 38.4 kg PV) canulados no rumen, e distribuídos em um delineamento em quadrado latino 5 × 5 (5 tratamentos e 5 períodos, 21 dias cada). O volumoso utilizado foi feno de Tifton 85 e o concentrado basal foi composto por milho, farelo de soja, e suplemento mineral comercial. Ureia, En e S foram adicionados para compor demais dietas. Os tratamentos foram: farelo de soja (SBM) como tratamento controle; ureia (U); U mais S elementar (US); nitrato encapsulado (EN); e EN mais S elementar (ENS). O En foi incluído nos tratamentos EN e ENS em 2% da MS (1,42% de NO3 - ânion), enquanto que a inclusão de ureia nos tratamentos U e US foi de 0,8% na MS da dieta. A inclusão de S nos tratamentos U e EN foi em 0,24% da MS, e a relação N:S foi reduzida de 8:1 para 4:1 com a adição de S. O En foi incluído gradualmente de 0,5% até 2% da MS da dieta. Os contrastes ortogonais para avaliar os efeitos de tratamento foram: SBM vs. EN + ENS; U + US vs. EN + ENS; U vs. US; e EN vs. ENS. Os novilhos apresentaram baixos níveis de MetHb (média de 1,1%) a medida em que a quantidade de En foi aumentada. O consumo de OM e NDF foram menores (P ≤ 0,01) para os animais alimentados com En... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to investigate the replacement of true protein source as well as the conventional NPN source (urea) by encapsulated NO3 - (En) plus elemental sulfur (S) on microbial protein synthesis efficiency, and CH4 emission in Nellore beef cattle. Five ruminally-cannulated Nellore steers (352.7 ± 38.4 kg BW) were used in a 5 × 5 Latin square design with 5 periods of 21 d each. Tifton 85 hay was used as forage and the basal concentrate consisted of corn, soybean meal, and commercial mineral supplement (50:50 wt/wt, forage:concentrate). Urea, En and S were added to compose the other diets. The treatments were: true protein from soybean meal as control (SBM); urea (U); U plus elemental S (US); encapsulated NO3 - (EN); and EN plus elemental S (ENS). En was included in 2% on dietary DM (1.42% NO3 - anion), while the inclusion of urea in U and US diets was 0.8% on dietary DM. The inclusion of S for U and EN diets was 0.24% on dietary DM, and the N:S ratio was reduced from 8:1 to 4:1 with the addition of S. En was gradually included from 0.5 to 2% on dietary DM by 0.5% every 4 d. The orthogonal contrasts for specific partitioning of treatment effects were: SBM vs. EN + ENS; U + US vs. EN + ENS; U vs. US; and EN vs. ENS. Steers displayed adequate MetHb levels as dietary En content increased. Organic matter and aNDF intake were smaller (P ≤ 0.01) for animals fed En diets compared to SBM. Digestibility of DM, OM, and GE were greater (P ≤ 0.01) when fed En diets com... (Complete abstract click electronic access below) / Mestre

Orientador: Jorge de Lucas Junior / Coorientador: Ana Carolina Amorim Orrico / Banca: Adhemar Pitelli Milani / Banca: Mara Cristina Pessoa da Cruz / Banca: Mônica Sarolli Silva de Mendonça Costa / Banca: Maria Fernanda Ferreira Menegucci Praes / Resumo: Objetivou-se com a execução deste trabalho o estudo a respeito dos níveis recomendados de inclusão de óleo de descarte aos dejetos de suínos bem como a influencia da inclusão de níveis de lipase ou Biol®, com o intuito de avaliar o efeito do acréscimo de produção de biogás, metano e redução dos teores de sólidos. Foram realizadas duas etapas, sendo a primeira a respeito dos níveis recomendados de adição de óleo e a segunda utilizando os níveis de óleo que apresentaram efeito negativo adicionados à lipase ou Biol®. Para desenvolvimento do ensaio de co-digestão da primeira etapa foram preparados substratos contendo 4% de sólidos totais (ST), compostos por dejetos de suínos, óleo de descarte (nas proporções de 0, 2, 4, 6, 8, 10 e 12%) além de água para diluição destes resíduos e inóculo, para abastecimento de biodigestores batelada. Para desenvolvimento da segunda etapa foi realizado abastecimento de biodigestores batelada com substratos contendo 4% de ST, compostos por dejetos de suínos, óleo de descarte (nas proporções de 8, 10 e 12%), lipase (nas proporções de 0,05; 0,10; 0,15; 0,20 e 0,25%) ou Biol® (10 g/m3 ou 15 g/m3) além de água para diluição destes resíduos e inoculo. Com relação a influencia da adição de níveis de óleo verificou-se que as máximas reduções de ST e SV foram de 36,8 e 41,1% e ocorreram nos níveis de 5,2 e 5,8% de óleo aos substratos, as inclusões de 5,4 e 6,1% de óleo permitiram o alcance de potenciais de 222,9 e 263,6 litros de biogás por kg de ST e SV adicionados. Referindo-se a influencia da adição de níveis de óleo e lipase verificou-se que as reduções máximas de ST e SV foram de 56,13 e 64,49% e ocorreram nos níveis de inclusão 0,15 e 0,13% de lipase e 12% de óleo adicionado aos substratos e ainda que os maiores potenciais de produção de metano por g de ST e sólidos voláteis (SV) adicionados (0,23 e 0,29 litros) foram alcançados pela ... / Abstract: The objective of the implementation of this work the study on the recommended levels of disposal of oil addition to swine manure as well as the influence of the inclusion of lipase levels or Biol®, in order to evaluate the effect of increased production of biogas, methane and reduction of solids. Two steps were conducted, the first with respect to recommended levels of oil addition and using the second oil levels that were negative effect on lipase or Biol® added. For assay development co-digestion of the first stage substrates were prepared containing 4% total solids (TS), composed of swine manure disposal of oil (in the ratios of 0, 2, 4, 6, 8, 10 and 12 %) addition of water for dilution of this waste and inoculum to supply batch digesters. For development of the second stage was performed supply of batch digesters with substrates containing 4% TS, composed of swine manure disposal of oil (in the ratios of 8, 10 and 12%), lipase (in the proportions of 0.05; 0.10, 0.15, 0.20 and 0.25%) or Biol® (10 g/m3 to 15 g/m3) than water for dilution of these residues and inoculum. Regarding the influence of the oil addition levels found that the maximum TS and VS reductions were 36.8 and 41.1% and occurred at levels of 5.2% oil and 5.8 to substrates, the additions of 5.4 and 6.1% enabled the oil potential range of 222.9 and 263.6 liters of biogas per kg TS and VS added. Referring to influence of adding oil and lipase was found that reductions of TS and VS were 56.13 and 64.49% and were in inclusion levels of 0.15 and 0.13% lipase and 12% of oil added to the substrates and that the greatest potential of methane production per g of TS and volatile solids (VS) added (0.23 and 0.29 liters) were achieved by greater inclusion of oil (12%) was added when the levels of 0.12 and 0.11% lipase. Regarding the inclusion of Biol®, it was found that the higher potential production of methane per g TS and VS added (0.22 and 0.27 liters, respectively) were ... / Doutor

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains ix, 53 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 50-52).

Historically, Ukraine has been a net energy importer, needing oil and natural gas for the effective functioning of its industries and satisfaction of domestic needs. Ukraine's independence immediately followed the disintegration of the Soviet Union in 1991, resulting in its ultimate dependency on oil and natural gas imports from Russia. During the last few years, the parties had undergone a number of disagreements that led to the disruption of natural gas supply to Ukraine, and political instability within the country. The necessity to redevelop Ukraine's domestic energy industry and adjust it to an available domestic natural gas source became vitally important for the national government. The present project provides a summary of the Ukrainian energy policy dynamics from 2006-present time. It specifies current energy trends, renewable energy sources, alternatives, and provides recommendations for the Ukrainian government on how to integrate successful international experiences into the development of coalbed methane in the local environment. / McAnulty College and Graduate School of Liberal Arts; / Graduate Center for Social and Public Policy / MA; / Thesis;

Methane is the most abundant organic chemical in the earth's atmosphere. Its abundance in the atmosphere is increasing with time and has reached levels not seen in recent geological history. The methane is produced both naturally, and anthropogenically. One of the sources of anthropogenic methane is manure from domesticated animals. Casada and Safley (1990) estimated the amount of methane generated from this source. This was done by estimating the Methane Conversion Factor (MCF) typically achieved by various waste management systems. This study was done to evaluate those estimates of the MCF. The MCF's for the most dominant of disposal methods, rangeland/pasture disposal, were much lower than the earlier estimates. Other waste management systems, such as solid storage and liquid slurry storage had much higher MCF's, at 20° and 30° C. However, these waste management methods are more prevalent in parts of the world where the average annual temperature is closer to 10° C. At that temperature, the MCF is negligible in all waste management systems. This study showed that the previously reported estimates of MCF for some waste management systems were higher than what was actually the case. Consequently earlier estimates of the amount of methane generated from manures were higher than what this study found. / Graduation date: 1994