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Infrared spectroscopy of volcanic gases at Masaya, NicaraguaHorrocks, Lisa January 2001 (has links)
Volcanic gases carry valuable information about processes occurring at active volcanoes, and so their accurate measurement and analysis are highly desirable. Masaya is a low-lying persistently active basaltic volcano, which is renowned for strong passive gas emission unaccompanied by lava extrusion, although it has also undergone plinian eruptions in the past. Its consistent behaviour sustains a reliable tropospheric plume, making it an ideal location at which to study volcanic degassing. During February-March 1998 and March 1999, Masaya's gas plume composition was investigated using the new ground-based remote sensing technique of open-path Fourier transform infrared spectroscopy. This technique meets criteria for safe and accurate quantitative characterisation of volcanic gases and on a temporal resolution previously impracticable. Flexibility of operation is the chief merit of OP-FTIR, since a range of infrared sources are available (e.g. an active lamp, the sun or hot volcanic vents). Laboratory calibration experiments using primary gas standards confirmed that the instrument and subsequent spectral analysis provide highly accurate concentration measurements for volcanic species, with errors typically around 5 %. Results showed that Masaya's plume composition was little changed between the field seasons. Average molar ratios for S0<sub>2</sub>/HCl, HCl/HF, C0<sub>2</sub>/S0<sub>2</sub> and H<sub>2</sub>0/S0<sub>2</sub> were 1.6, 4.9, 2.2 and 72, respectively, in 1998, and 1.6, 5.1, 2.3 and 66 in 1999. These ratios, coupled with simultaneous COSPEC-derived SO<sub>2</sub> data, indicated that emission rates, especially of HCl and HF, were high compared with other passively-degassing volcanoes. Measurements using the spectrometer with different infrared sources and at different locations downwind demonstrated that tropospheric scavenging processes had little discernible effect on plume composition. in the light of these new OP-FTIR gas data, possible physical mechanisms for the degassing behaviour at Masaya Volcano have been discussed. In order to account for all the observations, an integrated model, in which gas emission rates are primarily controlled by degassing-driven convection in the conduit, is proposed.
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Improving UK greenhouse gas emission estimates using tall tower observationsHowie, James Edward January 2014 (has links)
Greenhouse gases in the Earth’s atmosphere play an important role in regulating surface temperatures. The UK is signatory to international agreements that legally commit the UK to reduce its greenhouse gas emissions, and there is a scientific and political need to better understand greenhouse gas sources on regional scales. The current methods used to provide greenhouse gas emission inventories rely on ‘bottom-up’ techniques and have large associated errors. However, it is also possible to use observations of atmospheric concentrations of greenhouse gases and models of atmospheric transport to link the observations with source regions in order to estimate emissions in a ‘top-down’ approach. The key findings presented in this thesis are (a) UK emissions can be retrieved from the Angus tall tower in Scotland using the NAME inversion technique at a finer spatial resolution than has previously been reported using similar ‘top-down’ inverse methods; (b) atmospheric measurements from the Angus tall tower in Scotland have been used for the first time with the NAME inversion technique in order to estimate UK emissions of methane, nitrous oxide and sulfur hexafluoride for the years 2006 to 2009; (c) increasing the number of towers in UK network substantially increases the spatial resolution of greenhouse gas emission estimates. The errors and uncertainties associated with the NAME inversion over the UK domain are discussed and potential future improvements to this approach are presented. Overall, the work presented in this thesis has contributed to our understanding of the spatial and inter-annual variability of UK greenhouse gas emissions.
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WATER DISTRIBUTION SYSTEM DESIGN AND REHABILITATION UNDER CLIMATE CHANGE MITIGATION SCENARIOSRoshani, EHSAN 22 April 2013 (has links)
The water industry is a heavy consumer of electricity to pump water. Electricity generated with fossil fuel sources produce greenhouse gas (GHG) emissions that contribute to climate change. Carbon taxation and economic discounting in project planning are promising policies to reduce GHG emissions. The aim of this research is to develop novel single- and multi-objective optimization frameworks that incorporate a new gene-coding scheme and pipe ageing models (pipe roughness growth model, a pipe leakage model, and a pipe break model) to examine the impacts of a carbon tax and low discount rates on energy use, GHG emissions, and design/operation/rehabilitation decisions in water systems. Chapter 3 presents a new algorithm that optimizes the operation of pumps and reservoirs in water transmission systems. The algorithm was applied to the KamalSaleh transmission system near Arak, Iran. The results suggest that a carbon tax combined with a low discount rate produces small reductions in energy use and GHG emissions linked to pumping given the high static head of the KamalSaleh system. Chapter 4 presents a new algorithm that optimizes the design and expansion of water distribution networks. The algorithm was applied to the real-world Fairfield water network in Amherstview, Ontario, Canada. The results suggest that a carbon tax combined with a low discount rate does not significantly decrease energy use and GHG emissions because the Fairfield system had adequate installed hydraulic capacity. Chapters 5 and 6 present a new algorithm that optimizes the optimal rehabilitation type and timing of water mains in water distribution networks. In Chapter 5, the algorithm is applied to the Fairfield network to examine the impact of asset management strategies (quantity and infrastructure adjacency discounts) on system costs. The results suggest that applying discounts decreased capital and operational costs and favored pipe lining over pipe replacement and duplication. In Chapter 6, the water main rehabilitation optimization algorithm is applied to the Fairfield network to examine the impact of a carbon tax and low discount rates on energy use and GHG emissions. The results suggest that adopting a low discount rate and levying a carbon tax had a small impact in reducing energy use and GHG emissions and a significant impact in reducing leakage and pipe breaks in the Fairfield system. Further, a low discount rate and a carbon tax encouraged early investment in water main rehabilitation to reduce continuing leakage, pipe repair, energy, and GHG costs. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2013-04-21 13:58:08.302
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Integration of trigeneration and CO2 based refrigeration systems for energy conservationSuamir, I. Nyoman January 2012 (has links)
Food retail with large supermarkets consumes significant amounts of energy. The environmental impact is also significant because of the indirect effect from CO2 emissions at the power stations and due to the direct effect arising from refrigerant leakage to the atmosphere. The application of trigeneration (local combined heat, power and refrigeration) can provide substantial improvements in the overall energy efficiency over the conventional supermarket energy approach of separate provision of electrical power and thermal energy. The use of natural refrigerants such as CO2 offers the opportunity to reduce the direct impacts of refrigeration compared to conventional systems employing HFC refrigerants that possess high global warming potential. One approach through which the overall energy efficiency can be increased and the environmental impacts reduced, is through the integration of trigeneration and CO2 refrigeration systems where the cooling generated by the trigeneration system is used to condense the CO2 refrigerant in a cascade arrangement. This research project investigates experimentally and theoretically, through mathematical modelling and simulation, such a system and its potential application to supermarkets. A small size CO2 refrigeration system for low and medium food temperature applications was designed and constructed to enable it to be integrated with an existing trigeneration system in the refrigeration laboratory at Brunel University to form an integrated trigeneration and CO2 refrigeration test facility. Prior to the construction, the design of the system was investigated using mathematical models developed for this purpose. The simulations included the CO2 refrigeration system, CO2 evaporator coils and the integration of the trigeneration and CO2 refrigeration systems. The physical size of the design and component arrangement was also optimised in a 3D AutoCAD model. A series of experimental tests were carried out and the results showed that the medium temperature system could achieve a very good COP, ranging from 32 to 60 due to the low pumping power requirement of the liquid refrigerant. The low temperature system performed with average steady state COP of 4, giving an overall refrigeration system COP in the range between 5.5 and 6. Mathematical models were also developed to investigate the application of the integrated trigeneration and CO2 refrigeration system in a case study supermarket. The models were validated against test results in the laboratory and manufacturers’ data. The fuel utilisation efficiency and environmental impacts of different trigeneration and CO2 refrigeration arrangements were also evaluated. The results indicated that a system comprising of a sub-critical CO2 refrigeration system integrated with a trigeneration system consisting of a micro-turbine based Combined Heat and Power (CHP) unit and ammonia-water absorption refrigeration system could provide energy savings of the order of 15% and CO2 emission savings of the order of 30% compared to conventional supermarket energy systems. Employing a trigeneration system with a natural gas engine based CHP and Lithium Bromide-Water sorption refrigeration system, could offer energy savings of 30% and CO2 emission savings of 43% over a conventional energy system arrangement. Economic analysis of the system has shown a promising payback period of just over 3 years compared to conventional systems.
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Gas Exchange over Aquatic Interfaces and its Importance for Greenhouse Gas EmissionKokic, Jovana January 2017 (has links)
Aquatic ecosystems play a substantial role in global cycling of carbon (C), despite covering only about 4% of the earth surface. They emit large amounts of greenhouse gases (GHG) to the atmosphere, comparable to the amount of C stored annually in terrestrial ecosystems. In addition, C can be buried in lake sediments. Headwater systems are located at the interface of the terrestrial and aquatic environment, and are first in line to process terrestrial C and throughout its journey through the aquatic continuum. The uncertainties in global estimates of aquatic GHG emissions are largely related to these headwater systems, as they are highly variable in time and space, and underrepresented in global assessments. The overall aim of this thesis was therefore to study GHG exchange between sediment, water and air in headwater systems, from both an ecosystem perspective and at the small scale of physical drivers of gas exchange. This thesis demonstrates that carbon dioxide (CO2) emission from headwater systems, especially streams, was the main pathway of C loss from surface waters from a lake catchment. Of the total aquatic CO2-emission of the catchment, 65% originated from stream systems that covered only 0.1% of the total catchment area. The gas transfer velocity (k) was the main driver of stream CO2-emission, but there was a high variability in k on small spatial scales (meters). This variability may have implications for upscaling GHG emissions, especially when using scaled k estimates. Lake sediments only contributed 16% to total lake C emission, but in reality, sediment C emission is probably even lower because experimentally determined sediment C flux returns high estimates that are biased since artificially induced turbulence enhances C flux rates beyond in-situ conditions. When sediment C flux is estimated in-situ, in natural bottom water turbulence conditions, flux rates were lower than those estimated experimentally. Conclusively, this thesis shows that GHG emissions from small aquatic ecosystems are dominant over other aquatic C fluxes and that our current knowledge regarding the physical processes controlling gas exchange from different small aquatic systems is limited, implying an inherent uncertainty of GHG emission estimates from small aquatic ecosystems.
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Inventário de gases de efeito estufa e emissões evitadas com o gerenciamento de resíduos e cobertura vegetal na Universidade do Vale do Rio dos SinosPreuss, Maicon Junior 23 February 2017 (has links)
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Previous issue date: 2017-02-23 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / PROSUP - Programa de Suporte à Pós-Gradução de Instituições de Ensino Particulares / As emissões de Gases de Efeito Estufa (GEE) têm sido uma das principais fontes de alterações climáticas na Terra desde o século XVII. Para conhecer o perfil das emissões e quantificar as fontes emissoras que mais contribuem para estas alterações, países, organizações e empresas têm desde o início do século XXI adotado a elaboração do Inventário de Gases de Efeito Estufa (IGEE) como ferramenta para compreenderem o perfil de suas emissões de GEE, o volume de emissões que suas atividades geram na atmosfera e direcionar ações para mitigar e controlar as emissões de tais gases. Frente a esta problemática, a presente pesquisa teve por objetivo realizar o Inventário de Gases de Efeito Estufa da Universidade do Vale do Rio dos Sinos, de acordo com todas as atividades e serviços realizados dentro do Campus de São Leopoldo. A metodologia adotada neste estudo utilizou a coleta de dados existentes no Sistema de Gestão Ambiental (SGA) da universidade, de acordo com os parâmetros do Programa Brasileiro GHG Protocol. O estudo demonstrou que no ano de 2015, a Unisinos emitiu 2.706 tCO2e, mensuradas através do seu IGEE. Os resíduos reciclados na universidade evitaram a emissão de 9,7 tCO2e na atmosfera, através do gerenciamento de resíduos da Unisinos. A cobertura vegetal da universidade absorveu 255 tCO2, através do sequestro de carbono dos 20,4 ha de área de preservação permanente (APP). O balanço de GEE mostrou uma compensação de 255 tCO2e pela manutenção da cobertura vegetal, sendo as emissões líquidas 2.451,44 tCO2e. Como conclusão o estudo sugere que ações para o futuro se baseiem na realização de inventários posteriores e na redução de emissões de GEE através da melhoria de eficiência nos processos de consumo de energia elétrica, manutenção de aparelhos de ar-condicionado e redução no número de viagens aéreas. / Greenhouse gas (GHG) emissions have been one of the main sources of climate change on the Earth since the 17th century. In order to know the emission´ profile and quantify the sources of emissions that contributed the most to these changes, countries, organizations and companies have since the beginning of the 21st century adopted the Greenhouse Gas Inventory (GHGI) as a tool to understand the profile of their GHG emissions, the volume of emissions their activities generate in the atmosphere and direct actions to mitigate and control emissions of those gases. Faced with this problem, the present research had as its goal accomplishing the Greenhouse Gas Inventory of the University of Vale do Rio dos Sinos according to all the activities and services carried out within the Campus of São Leopoldo. The methodology adopted in this study used data collection of the University's Environmental Management System (EMS), according to the parameters of the Brazilian GHG Protocol Program. The study showed that in 2015, Unisinos issued 2,706 tCO2e, measured through its GHGI. Recycled waste at the University prevented the emission of 9.7 tCO2e into the atmosphere through waste management at Unisinos. The university's vegetation cover absorbed 255 tCO2, through carbon sequestration in its 20.4 ha of permanent preservation area (PPA). The GHG balance showed a compensation of 255 tCO2e through the vegetal cover maintenance, showing net emissions of 2,451.44 tCO2e. In conclusion, this study suggests that future actions should be based on accomplishment of later inventories and reduction of GHG emissions through improvement of power consumption efficiency, air conditioners maintenance and reduction of air travels.
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A System Dynamics Approach to Integrated Water and Energy Resources ManagementZhuang, Yilin 01 May 2014 (has links)
Water and energy are two of the most important resources for societal prosperity and economic development. It is clear that water and energy are intrinsically linked together and depend on one another in modern society. To date, however, efforts on water-energy nexus concentrate on quantifying the energy use in water cycle or the water use in energy production. From management perspective, water and energy are still managed separately. Little work has been done to investigate the impacts of the management options associated with one resource on the other and examine the integrated water and energy management options. Accordingly, the overall goal of this study is to examine the integrated management options for long-term regional water and energy resources management with consideration of their interactions through a system dynamics approach.
System dynamics is based on systems thinking, which focuses on the system structure and offers a deeper insight into problems. It can link ecological, human, and social elements of water and energy systems in one modeling platform to investigate their interactions A four-step system dynamics modeling process was used in this study, which includes problem articulation, model formulation, model testing, and scenario design and simulation. Tampa Bay region was chosen as the study area, which is located on the west central coast of Florida and estuary along the Gulf of Mexico. This study considered a 100-year time scale with monthly interval, the first 30 years of which are used for model validation and the rest of which are for simulation.
In order to investigate the interrelationship between water and energy systems, two sub-models (i.e., water sub-model and energy sub-model) were developed first. The water sub-model is composed of sectoral water demand (agriculture, industry, municipality, and energy sector), water supply (surface water, groundwater, reclaimed water, and water imports), and water quality and energy consumption associated with water supply. The result shows that surface water level increases by 1.32~1.39% when considering water quality and 1.10~1.30% considering both water quality and energy consumption. There is a slight decrease in groundwater storage (0.02~0.08%) compared with the reference behavior. The result also reveals that water conservation education is the most effective option to reduce the freshwater withdrawals (~17.3%), followed by rebates on indoor water-efficient appliances (~15.4%). Water loss control has a high potential to reduce freshwater withdrawals but it is not effective currently due to limited budget. The implementation of minimum surface water level reduces the surface water withdrawal by 26 MGD (million gallons per day) and requires alternative water supply sources to meet the water demands.
The energy sub-model consists of sectoral energy demand (agriculture, industry, municipality, and water sector), energy supply (coal, natural gas, oil, and electricity), and greenhouse gas (GHG) emissions and water pollution associated with energy supply. The result finds that cost of fuels is the primary concern of determining the energy mix for power generation. The current electricity mix in the study area consists of 35.4% fuels from coal, 44.6% from natural gas, and 20% from oil. When considering the environmental impacts associated with energy supply, this percentage of coal reduces to 10.6%, and GHG emissions and water pollution can be reduced by 22% and 43% accordingly. The result also shows that energy price is most effect of reducing the demand (~16.3%), followed by energy conservation education (~10.6%). Rebates on household appliances are the least effective option (~3.6%) due to consumers' low willingness to pay. Combining the supply decision incorporating environmental impacts and the demand option of energy price increase, the reductions of GHG emissions and water pollution can reach 37% and 55%, respectively.
The integrated model is developed by linking the water and energy models through the interactions between water and energy systems identified by the system archetypes. The result shows that water demand is reinforced by energy demand, and vice versa. This growth, however, is limited by water and energy availability. The result also reveals that some decisions to solve the problems of one resource result in the problems of the other resource. The increase of water price is one of these, which decreases the water demand by 24.3% but leads to increase of the energy demand by 1.53% due to the use of reclaimed water. Rebates on indoor water-efficient appliances are effective to reduce both water and energy demands largely due to the household energy use in water heating. In addition, this study demonstrates that integrated management options can improve the uses of water and energy, but decisions without considering each other may lead to more issues. For example, reclaimed water, a supply management option considering the energy, can increase the water balance index by 27.3% and the energy balance index by 0.14%; it can also reduce the water pollution by 11.76% and the GHG emissions by 13.16%. Seawater desalination, a supply management option without integrated consideration, intends to decrease the water shortage but eventually increases the water balance index by 29.7%. It also causes the increases in water pollution and GHG emissions by 89.79% and 14.53%, respectively. Similarly, solar energy presents the advantage in increasing the balance indices and reducing the environmental impacts.
This study is an initial attempt to link water and energy systems to explore integrated management options. It is limited by the data availability, assumptions for model simplification, and lack of consideration of climate change. The recommendations for future study include (a) employing a more accurate projection or representation of precipitation, (b) testing the energy model with local data, (c) considering water and energy allocation between different users under shortages, (d) examining the environmental impacts associated with bay water withdrawal for power generation, (e) investigating the water and energy use under climate change, and (f) involving stakeholders early in model development and continuous participation in policy analysis.
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Environmental protection and energy conservation : Hybrid vehicles and combustion vehiclesBin, Lin, Cao, Yue, Liang, Li January 2013 (has links)
Purpose/aim This study is about environmental protection and energy conservation in the China vehicle market. Based on that, we focus on and comparison of combustion vehicles with hybrid vehicles.Design/method/approach Data was collected through questionnaire. The analysis includes a description of the sample and chi-square tests. We analyze two different particular engines (combustion engine vehicles and hybrid electric vehicles) and our single environment. We compare these two engine vehicles, and analyze the trends of the market. We use scientific data and existing theories to analyze the vehicles, including “lifecycle costs” “CO2 emissions”, “Greenhouse gas”, “Consumers perception”, “Full Costing”, “PPC (Production Possibilities Curve)”, “Supply Demand Curve”, and “Green Taxes”.Findings We conclude that hybrid engine vehicles are environmentally friendly and energy conserving, but they have higher lifecycle costs. The analysis also shows that different ages, education levels and regions affect the customers’ preferences for these two kinds of vehicles.Originality/value Our original idea is the problems of hybrid vehicles and how to support and popularize hybrid vehicles depends on the exact national conditions and policies implemented. However, consumers might not be able to accept the “environmental protection and energy conservation” concept immediately, because it’s difficult to change the consumption concept of a generation or culture. Therefore, the government should carry out policies that are suitable for their local region to update the consumption concepts of the consumers and promote the new energy vehicles. Thus, the goal of environmental protection and energy conservation can be reached.
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Assessment of densified biomass for fuels and chemicalsSultana, Arifa Unknown Date
No description available.
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Klimato kaitą skatinančių ir aplinką teršiančių dujų emisijų iš mėšlo mažinimo priemonių efektyvumas / The effectiveness of implements on mitigation of greenhouse gas emission and pollution reduction from manureMatulaitis, Raimundas 22 December 2014 (has links)
Darbo tikslas – nustatyti kiaulių ir galvijų mėšlui būdingas maksimalaus metano susidarymo (Bo), ir teorinio metano susidarymo (Bu) reikšmes, bei ištirti klimato kaitą skatinančių, ir aplinką teršiančių dujų emisijų mažinimo iš mėšlo priemonių taikymo efektyvumą.
Darbo uždaviniai: 1) nustatyti maksimalų metano dujų kiekį galintį išsiskirti iš kiaulių ir galvijų mėšlo. 2) ištirti priedų įtaką NH3, CO2, CH4, H2S, NO ir CO dujų emisijoms iš skysto ir pusiau skysto galvijų ir kiaulių mėšlo. 3) nustatyti įvairių plaukiojančių dangų poveikį NH3, CO2, CH4, H2S, NO ir CO dujų emisijoms skysto ir pusiau skysto mėšlo laikymo metu. 4) ištirti priedų ir plaukiojančių dangų kompleksinio naudojimo įtaką NH3, CO2, CH4, H2S, NO ir CO dujų emisijoms iš skysto ir pusiau skysto galvijų ir kiaulių mėšlo.
Tyrimai vykdyti dviejų kiaulių tvartų aplinkoje ir laboratorinėmis sąlygomis. Bandymams laboratorinėmis sąlygomis atlikti buvo panaudoti mėšlo mėginiai surinkti iš 28 gyvulininkystės ūkių. Tyrimų metu nustatytas maksimalus metano dujų kiekis galintis išsiskirti iš kiaulių ir galvijų mėšlo. Taip pat ištirtas mikrobiologinio preparato ir sieros rūgšties priedų, plaukiojančių dangų, t. y., keramzito, natūralių durpių, valgomojo saulėgrąžų aliejaus, medžio pjuvenų, šiaudų, polietileno plėvelės, bei priedų kompleksinio naudojimo su polietileno plėvele poveikis NH3, CO2, CH4, H2S, NO ir CO dujų emisijoms iš mėšlo.
Atliki tyrimai, kuriuose įvertintas priedų bei įvairių plaukiojančių dangų poveikis... [toliau žr. visą tekstą] / The aim of the present study – to study the ultimate (Bo) and theoretical (Bu) methane yield from pig and cattle manure, and to investigate the effectiveness of implements on the emission reduction of polluting and greenhouse gases from manure.
Tasks of the present study: 1. To measure the ultimate methane yield from pig and cattle manure. 2. To investigate the effect of the additives on the reduction of emission of the NH3, CO2, CH4, H2S, NO and CO gases from liquid and semi-liquid manure of cattle and pigs. 3. To determine the effect of different floating covers on the reduction of emission of the NH3, CO2, CH4, H2S, NO and CO gases from liquid and semi-liquid manure during the storage. 4. To investigate the effect of the complex of additives and floating covers on the reduction of emission of the NH3, CO2, CH4, H2S, NO and CO gases from liquid and semi-liquid manure of cattle and pigs.
The investigations were performed in two piggeries and a laboratory. To carry out the experiments in the laboratory, the manure was collected from 28 farms. During the investigation period, the ultimate methane yield from pig and cattle manure was determined. Also, the effect of the microbial-based and sulphuric acid additives, floating covers, i. e., leca (light expanded clay aggregate), natural peat, sunflower oil, sawdust, straw and plastic film, and furthermore, the complex of additives and a plastic film cover on the emission of NH3, CO2, CH4, H2S, NO and CO gases from manure were... [to full text]
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