Reliable and inexpensive methods of in-situ stress measurement have been sought for more than 40 years. A number of non-destructive core-based methods of in-situ stress determination are currently available, among which Deformation Rate Analysis ' DRA ' and Acoustic Emissions ' AE ' method have the most promising potential due to their ability to measure stress as opposed to strain, which is measured by strain recovery techniques. The DRA and AE method are similar in their utilisation of a phenomenon termed Kaiser effect in the case of AE and deformation memory effect in the case of DRA. The KE/DME is defined as a recollection of a maximum stress a rock core had been subjected prior to its retrieval from the in-situ environment. The physical nature of this phenomenon has not however been universally established. In this study, interaction of microcracks as the most probable cause of the KE/DME, was investigated. To reproduce the damage that occurs to rock at the micro level, a discrete element modelling code was required, which enabled dynamic failure propagation to be modelled. Commercially available code PFC [ superscript 2D ] was found to be suitable for this purpose due to its ability to explicitly model mechanical damage in rocks. The numerical model was based on a real prototype - a sandstone rock core, which had also been previously subjected to the DRA. Although the bulk of the numerical tests were conducted on intact rock models, it was found that changes in the lithology and introduction of discontinuities did not have significant effect on the DME. Influence of the confining stress on the DME was confirmed. It was assumed that only the highest historical stress could be determined reliably using the DRA technique. The ability of the numerical model to reproduce the DME was validated. The link between the DME and development of microcracks was established. The results of the study encourage further use of the code for understanding the micromechanical behaviour of rocks under loading. / Thesis (M.Eng.Sc.)--Australian School of Petroleum, 2004.

This thesis investigates the impact of physical planning policy on combined transport and dwelling-related energy use by households. Separate analyses and reviews are conducted into dwelling-related and transport-related energy use by households, before a model is developed to investigate the city-wide implications of different land-use scenarios in Sydney, Australia. The analysis of household energy use in Chapter 3 suggests that medium density housing (i.e. lose-rise apartments, townhouses, and terraces) is likely to result in the lowest per-capita energy use, while also allowing for sufficient densities to make frequent public transport service viable. The analysis of transport energy in Chapter 4 confirms that increasing urban density is associated with decreased car ownership and use, independent of other factors. However, land use changes alone are likely to result in modest changes to travel behaviour. The results of the scenario modelling in Chapters 7-9 support the view that changes to land use alone can reduce household energy consumption, but the changes, even over a long time period (25 years) are small (~0-10%) for all but the most extreme land-use policies. Instead, a coordinated (land-use/transport and other policy levers) approach is much more effective. The results confirm that it is transport energy that is most sensitive to planning policy, but that a combined consideration of dwelling-related and transport-related energy use is still useful. The micro-simulation model developed to assess the impact of different land-use planning scenarios allows the establishment of a lower-bound estimate of the effect that housing policy has on household energy use, assuming ‘business as usual’ transport policy, household behaviour, and technology.

Arnold Winfred Reitze, Jr. / George Washington University, School of Law

<p>This paper investigates the environmental effectiveness of the Swedish energy taxes. That is, whether these have decreased the CO2 emissions and how they have changed the structure of the energy consumption. Time series data for the years 1960-2002 is used. The results show that the oil and coal taxes seem to favour a substitution towards less CO2 intensive energy sources. For the natural gas tax however, the opposite is true. An energy saving effect is found for the oil tax and the petrol tax, but the electricity tax seems to increase energy consumption. Regarding the total effect on CO2 emissions, the oil and coal taxes seem to decrease CO2 emissions while the natural gas tax seems to increase them.</p><p>Cross-country regressions are also made to examine if countries with a higher petrol tax have lower a lower rate of CO2 emissions on average. The results show that a higher petrol tax is significantly correlated to lower CO2 emissions.</p><p>The results thus indicate that energy taxes do decrease CO2 emissions. They also show that caution should be used before implementing a natural gas tax since it can have adverse effects on the CO2 emissions.</p>

This thesis describes the development of a new type of sensor for nitric oxide (NO) that can be used in a variety of combustion diagnostics and control applications. The sensor utilizes the absorption of ultraviolet (UV) radiation by the NO molecule to determine the concentration via optical absorption spectroscopy. UV radiation at 226.8 nm is generated by sum frequency mixing the outputs from a 395-nm external cavity diode laser (ECDL) and a 532-nm diode-pumped, intracavity frequency doubled Nd:YAG laser in a beta-barium borate (BBO) crystal. This radiation is used to probe the (v'=0, v"=0) band of the Α*Σ+ - Χ*π electronic transition of NO. The ECDL is tuned so that the UV radiation is in resonance with a specific energy level transition, and it is then scanned across the transition to produce a fully resolved absorption spectrum. Preliminary experiments were performed in a room-temperature gas cell in the laboratory to determine the accuracy of the sensor. Results from these experiments indicated excellent agreement between theoretical and experimental absorption line shapes as well as NO concentrations. Further experiments were performed at two actual combustion facilities to demonstrate the operation of the sensors in realistic combustion environments. Tests on a gas turbine auxiliary power unit (APU) at Honeywell Engines and Systems and on a well-stirred reactor (WSR) at Wright-Patterson Air Force Base produced excellent results despite the harsh temperatures and vibrations present. Overall, the sensitivity was estimated to be 0.8 parts per million (ppm) of NO (at 1000 K) for a 1 meter path length and the measurement uncertainty was estimated to be ±10%.

This paper investigates the environmental effectiveness of the Swedish energy taxes. That is, whether these have decreased the CO2 emissions and how they have changed the structure of the energy consumption. Time series data for the years 1960-2002 is used. The results show that the oil and coal taxes seem to favour a substitution towards less CO2 intensive energy sources. For the natural gas tax however, the opposite is true. An energy saving effect is found for the oil tax and the petrol tax, but the electricity tax seems to increase energy consumption. Regarding the total effect on CO2 emissions, the oil and coal taxes seem to decrease CO2 emissions while the natural gas tax seems to increase them. Cross-country regressions are also made to examine if countries with a higher petrol tax have lower a lower rate of CO2 emissions on average. The results show that a higher petrol tax is significantly correlated to lower CO2 emissions. The results thus indicate that energy taxes do decrease CO2 emissions. They also show that caution should be used before implementing a natural gas tax since it can have adverse effects on the CO2 emissions.

Vegetable oils have been researched as alternative source of energy for many years because they have proven themselves as efficient fuel sources for diesel engines when used in the form of biodiesel, vegetable oil–diesel blends, vegetable oil-water-diesel blends and mixtures thereof. However, very few studies involving the use of emulsified low grade alcohols in straight vegetable oils, as fuels for combustion have been published. Even, the published literature involves the use of emulsified fuels only for compression ignition diesel engines. Through this project, an attempt has been made to suggest the use of alcohol-in-vegetable oil emulsions (AVOE) as an alternate fuel in stationary burners like electric utility boiler producing steam for electricity generation and more dynamic systems like diesel engines. The main goal of this study is to understand the effect of the combustion of different methanol-in-canola oil emulsions, swirl angle and equivalence ratio on the emission levels of NOx, unburned hydrocarbons (UHC), CO and CO2. The 30 kW furnace facility available at Coal and Biomass Energy Laboratory at Texas A & M University was modified using a twin fluid atomizer, a swirler and a new liquid fuel injection system. The swirler blades were positioned at 60° and 51° angles (with respect to vertical axis) in order to achieve swirl numbers of 1.40 and 1.0, respectively. The three different fuels studied were, pure canola oil, 89-9 emulsion [9 percent methanol – in – 89 percent canola oil emulsion with 2 percent surfactant (w/w)] and 85-12.5 emulsion [12.5 percent methanol – in – 85 percent canola oil (w/w) emulsion with 2.5 percent surfactant]. All the combustion experiments were conducted for a constant heat output of 72,750 kJ/hr. One of the major findings of this research work was the influence of fuel type and swirl number on emission levels. Both the emulsions produced lower NOx, unburned (UHC) hydrocarbon and CO emissions than pure canola oil at both swirl numbers and all equivalence ratios. The emulsions also showed higher burned fraction values than pure oil and produced more CO2. Comparing the performance of only the two emulsions, it was seen that the percentage amount of methanol added to the blend had a definite positive impact on the combustion products of the fuel. The higher the percentage of methanol in the emulsions, the lesser the NOx, UHC and CO emissions. Of all the three fuels, 85-12.5 emulsion produced the least emissions. The vorticity imparted to the secondary air by the swirler also affected the emission levels. Increased vorticity at higher swirl number led to proper mixing of air and fuel which minimized emission levels at SN = 1.4. The effect of equivalence ratio on NO_x formation requires a more detailed analysis especially with regards to the mechanism which produces nitrogen oxides during the combustion of the studied fuels.

The central aim of this thesis is to support the efforts to counteract certain environmental problems caused by emissions of volatile organic compounds. The purpose of this work was (1) to develop a method to establish the amount of emitted substances from dryers, (2) to determine the effect of drying medium temperature and end moisture content of the processed material on emissions of monoterpenes and other hydrocarbons, (3) to examine the emissions of monoterpenes during production of pellets, and (4) to examine the natural emissions from forests with an eye to implications for modelling. The measurement method (1) resolves the difficulties caused by diffuse emissions, and also solves the problems associated with high moisture content of the drying medium. The basic idea is to use water vapour to determine the exhaust flow, while a dry ice trap is used both to preconcentrate emitted volatile organic compounds and to determine the moisture content of the drying medium. The method as used in this paper has an uncertainty of 13% using a 95% confidence interval. Emissions from a spouted bed (2) in continuous operation drying Norway spruce sawdust at temperatures of 140°C, 170°C or 200°C was analysed with FID and GC-MS. When the sawdust end moisture content was reduced below 10%wb, emissions of terpenes and volatile organic compounds per oven dry weight increased rapidly. Increased temperature of the drying medium increased the amounts of emitted monoterpenes when sawdust moisture content was below the fibre saturation point. Examination of sawdust and wood pellets from different pellets producers (3) revealed that most of the terpene emissions happened during the drying step, with rotary dryers causing higher emissions than steam dryers. Almost all of the volatile terpenes remaining in wood after drying were released during pelleting. When sawdust with higher moisture content was used in the pellets press, the terpene emissions were increased. Terpenes emitted naturally from vegetation can have an adverse environmental impact. Factors affecting terpene emissions from tree species in Sweden were reviewed (4). Models for prediction of terpene fluxes should include not only temperature but also light intensity, seasonal variation, and a base level of herbivory and insect predation. Prediction of high concentrations of ambient terpenes demand sufficient resolution to capture emission peaks e.g. those caused by bud break.

De senaste åren har utsläppsreglerna för sjöfarten blivit allt hårdare och under de kommande åren skärps de ännu mer. För att svaveldirektiven för sjöfarten ska fungera effektivt så krävs det också att de efterlevs. Syftet med den här studien var därför att undersöka hur länderna i Europeiska SECA områdena agerar och kommer att agera i framtiden för att se till att svaveldirektiven efterlevs. Studien syftar också till att undersöka hur efterlevnadskontroller genomförs, samt se om länderna har infört sanktioner mot överträdelser och vad dessa innebär. För att få svar på detta studerades lagar och förordningar, men framförallt skickades frågeformulär ut till de ansvariga myndigheterna i flera olika länder kring SECA områdena. Slutsatsen av det här arbetet är att samtliga länder anser att efterlevnadskontroll sker i tillräcklig omfattning och alla länder använder sig av samma metod. I Sverige pågår utveckling av en optisk mätmetod för att mäta svavelhalt i avgaserna ifrån luften, men än är metoden inte tillräckligt säker för att kunna användas. Det framkom också att i flera länder anses det på grund av flera faktorer vara svårt att fälla någon ifall de bryter mot gällande svavelförordningar, därför anses det också finnas en risk för överträdelser. Detta trots att det i andra länder faktiskt sker ingripande mot överträdelser och samtliga länder använder sig av samma metoder för efterlevnadskontroll. Det saknas i dagsläget även sanktioner mot överträdelser i flera länder.

The production of food is responsible for large share of the anthropogenic greenhouse gas emissions. There is a wide range of emissions associated with different food-groups. In particular the production of meat from ruminants causes higher emissions compared to plant-based food. This study compared two different types of meat-free diets (ovo-lacto-vegetarian and vegan) in Sweden and the emission of greenhouse gases that are connected to the aliment and beverages that are consumed in these diets. Dietary records were used to obtain real data on what food is consumed on a weekly basis. On average the food consumed by the vegan sample caused lower emissions that the food consumed by the vegetarian sample. The average vegan diet caused 591 kg CO2e per year whereas the average vegetarian diet caused 761 kg CO2e. The annual difference is thus 170 kg. These findings are in line with existing research although recent studies often used hypothetical diets instead of real data.