1 |
An Automated Script to Acquire Gas Uptake Data from Molecular Simulation of Metal Organic Frameworksvan Rijswijk, David G. 18 April 2012 (has links)
Attention worldwide has been placed towards reducing the global carbon footprint. To this end the scientific community has been involved in improving many of the available methods of carbon capture and storage (CCS). CCS involves scrubbing flue gases of greenhouse gases and safely storing them deep underground. MOFs, a
family of functionally tunable three dimensional nanoporous frameworks, have been
shown to adsorb gases with great selectivity and capacity. Investigating these frameworks using computational simulations, although faster than in-lab synthetic methods, involves a tedious and meticulous input preparation process which is subject to human error. This thesis presents Dave's Occupancy Automation Package (DOAP),a software which provides a means to automatically determine the gas uptake of many three dimensional frameworks. By providing atomic coordinates for a unit simulation cell, the software acts to performs the necessary calculations to construct and execute a Grand Canonical Monte Carlo simulation, determining the gas uptake in a metal organic framework. Additionally an analysis of different convergence assessment tests for describing the end point of the GCMC simulation is presented.
|
2 |
Energy use analysis and technology for electric transit busesHinse, Pierre R. 01 May 2010 (has links)
Electric vehicles offer a method of transportation where the energy generation process is moved from the on-board engine to the electrical generation system. The Canadian electrical generation mix has a significant portion of low carbon and renewable sources. This low environmental impact source of energy is then transferred to electric vehicles when they are charged from the grid. This thesis analyses the energy flow for such electric vehicles, particularly buses. Battery systems and charger technology, core to the vehicle operations, are examined; looking at energy flow from plug to wheels. Field data collected from on-board recordings and simultaneous Global Positioning System (GPS) signals were used to develop a new predictive model for an electric bus. The mathematical model for the electric bus was then compared with a similar sized diesel engine vehicle model using the Powertrain System Analysis Toolkit (PSAT). The operational energy cost of the electric bus is contrasted with a similarly sized Compression Ignition (CI) engine bus and was found to be very favourable. Also cost effective battery system upgrades to the present system were analysed for improved return on investment. / UOIT
|
3 |
To Act or Not to Act : Muncipial Authority over Green House Gas MitigationKikerpuu, Tiina January 2010 (has links)
The purpose of this study is twofold. Firstly, it is a feasibility study intended to contribute tofurther research on the municipal authority to mitigate green house gas emissions. This will bedone by studying the municipal authority on green house gas mitigation measures in threeSwedish municipalities. To fulfil the purpose the following questions are set to be answered.What is the municipal authority over green house gas mitigation measures in these threemunicipalities?- What is the formal ability of municipalities in Sweden to act on GHG mitigation?- What measures do these three municipalities use to mitigate GHG emissions?- How do the municipalities consider their climate authority?The study focused on measures within three sectors; traffic and transport; energy, andinformation and out-reaches. Transport and energy make up the main sources of GHGemissions in the municipalities, and information was a common measure.4 categories of authority were developed; Legal authority, Economic authority, Climatecompetence and Collaborations, this to get a picture of what influenced climate authority. Theidea for this came from previous research that involved aspects similar to the categories. Theresult showed that municipal climate authority is quite relative, the categories are relevant, butpolitical will and ambitions on tackling climate change are decisive. In the transport sector themunicipal authority was restricted due to the authority of other actors. The authority in theenergy sector was limited because national legislation had precedence.The municipal climate authority is considered strong within its own organisation, themunicipal role as wide and involving many responsibilities. The role was described as widerthan the municipal authority. Most of the climate measures are directed towards themunicipality’s own organisation, the premises of the municipality and the services it provides.Outside the municipal organisation and services, but within its geographic unit, in the specificmeasures developed in this study, the climate authority was weaker and mainly exercisedthrough collaborations. The municipalities are not using their climate authority in full. Byimplementing measures like climate considerations in public procurement, their authoritycould be improved.
|
4 |
An Automated Script to Acquire Gas Uptake Data from Molecular Simulation of Metal Organic Frameworksvan Rijswijk, David G. 18 April 2012 (has links)
Attention worldwide has been placed towards reducing the global carbon footprint. To this end the scientific community has been involved in improving many of the available methods of carbon capture and storage (CCS). CCS involves scrubbing flue gases of greenhouse gases and safely storing them deep underground. MOFs, a
family of functionally tunable three dimensional nanoporous frameworks, have been
shown to adsorb gases with great selectivity and capacity. Investigating these frameworks using computational simulations, although faster than in-lab synthetic methods, involves a tedious and meticulous input preparation process which is subject to human error. This thesis presents Dave's Occupancy Automation Package (DOAP),a software which provides a means to automatically determine the gas uptake of many three dimensional frameworks. By providing atomic coordinates for a unit simulation cell, the software acts to performs the necessary calculations to construct and execute a Grand Canonical Monte Carlo simulation, determining the gas uptake in a metal organic framework. Additionally an analysis of different convergence assessment tests for describing the end point of the GCMC simulation is presented.
|
5 |
An Automated Script to Acquire Gas Uptake Data from Molecular Simulation of Metal Organic Frameworksvan Rijswijk, David G. January 2012 (has links)
Attention worldwide has been placed towards reducing the global carbon footprint. To this end the scientific community has been involved in improving many of the available methods of carbon capture and storage (CCS). CCS involves scrubbing flue gases of greenhouse gases and safely storing them deep underground. MOFs, a
family of functionally tunable three dimensional nanoporous frameworks, have been
shown to adsorb gases with great selectivity and capacity. Investigating these frameworks using computational simulations, although faster than in-lab synthetic methods, involves a tedious and meticulous input preparation process which is subject to human error. This thesis presents Dave's Occupancy Automation Package (DOAP),a software which provides a means to automatically determine the gas uptake of many three dimensional frameworks. By providing atomic coordinates for a unit simulation cell, the software acts to performs the necessary calculations to construct and execute a Grand Canonical Monte Carlo simulation, determining the gas uptake in a metal organic framework. Additionally an analysis of different convergence assessment tests for describing the end point of the GCMC simulation is presented.
|
6 |
Constitutive Modeling of Hexagonal Close Packed PolycrystalsWang, Huamiao 09 1900 (has links)
<P> There is a growing interest in magnesium and its alloys due to their high strength
to weight ratio. Magnesium is of particular interest to the automotive industry as a
consequence of the current pressure to reduce green house gas emissions from the
transportation sector through vehicle weight reduction. However, there is a lack of
knowledge concerning the formability of magnesium. As a result, the application of
magnesium as a commercial material has not been fully exploited. Much has been learned
from the constitutive modeling of materials such as aluminum and steel. Therefore, this
thesis considers the constitutive modeling of magnesium and its alloys. </p> <p> Based on this motivation, polycrystal plasticity theories that have been established
and used to characterize aluminum and steel are studied. The validity of these theories is
examined with respect to magnesium and its alloys. The magnesium system is composed
of the hexagonal closed-packed (HCP) crystal structure. Therefore, a strong plastic
anisotropy is induced in magnesium crystals due to the limited number of slip systems
that may be activated with ease. The models proposed by Taylor and Sachs neglect strain
and stress heterogeneities respectively. As a result, the models are either too stiff or too
soft to study magnesium due to the anisotropic nature of the crystal structure. The
intermediate models; self-consistent models, which are able to consider the
heterogeneities among the grains in polycrystals, are believed to be more suitable to study
magnesium and its alloys. Therefore, a large strain elastic-viscoplastic self-consistent
(EVPSC) model is developed for polycrystalline materials. Both rate sensitive slip and
twinning are included as mechanisms of plastic deformation, while elastic anisotropy is
accounted for in the elastic modulus. The transition from single crystal plasticity to
polycrystal plasticity is based on a completely self-consistent approach. It is shown that
the differences in the predicted stress-strain curves and texture evolutions based on the
EVPSC and the viscoplastic self-consistent (VPSC) model proposed by Lebensohn and
Tome (1993) are negligible at large strains for monotonic loadings. For the deformations
involving unloading and strain path changes, the EVPSC predicts a smooth elasto-plastic
transition, while the VPSC model gives a discontinuous response because the model is
incapable of modeling elastic deformation. In addition, it is demonstrated that the EVPSC
model can capture some important experimental features which cannot be simulated by
using the VPSC model. </p> <p> Various self-consistent schemes exist for EVPSC and VPSC models. However,
the evaluations of these models are not complete. Therefore, an examination of various
polycrystal plasticity models is made, based on comparisons of the predicted and
experimental stress responses as well as the R values, to assess their validity. It is
established that, among the models examined, the self-consistent models with grain
interaction stiffuess values halfway between those of the limiting Secant (stiff) and Tangent (compliant) approximations give the best results. Among the available options,
the Affine self-consistent scheme results in the best overall performance. Furthermore, it
is demonstrated that the R values under uniaxial tension and compression within the sheet
plane show a strong dependence on the imposed strain. This suggests that the
development of anisotropic yield functions using measured R values, must account for
the strain. dependence. </p> <p> The recently developed large strain elastic visco-plastic self-consistent (EVPSC)
model, which incorporates both slip and twinning deformation mechanisms, is used to
study .the lattice strain evolution in extruded magnesium alloy AZ31 under uniaxial
tension and compression. The results are compared against in-situ neutron diffraction
measurements done on the same alloy. For the first time, the effects of stress relaxation
and strain creep on lattice strain measurements in respectively displacement controlled
and load controlled in-situ tests are numerically assessed. It is found that the stress
relaxation, has a significant effect on the lattice strain measurements. It is also observed
that although the creep does not significantly affect the trend of the lattice strain
evolution, a better agreement with the experiments is found if creep is included in the
simulations. </p> <p> In conjunction with the M-K approach developed by Marciniak and Kuczynski
(1967), the EVPSC model is applied to study the sheet metal formability of magnesium
alloys in terms of the forming limit diagram (FLO). The role of crystal plasticity models
and the effects of basal texture on formability of magnesium alloy AZ31 B sheet are
studied numerically. It is observed that formability in HCP polycrystalline materials is
very sensitive to the intensity of the basal texture. The path-dependency of formability is
examined based on different non-proportional loading histories, which are combinations
of two linear strain paths. It is found that while the FLO in strain space is very sensitive
to strain path changes, the forming limit stress diagram (FLSO) in stress space is much
less path-dependent. It is suggested that the FLSO is much more favourable than the FLO
in representing forming limits in the numerical simulation of sheet metal forming
processes. The numerical results are found to be in good qualitative agreement with
experimental observations. </p> / Thesis / Doctor of Philosophy (PhD)
|
7 |
How To Match The Green-House City Concept of City Marketing Research ¡V Kaohsiung Lantern FestivalChen, Hsin-yu 22 August 2007 (has links)
The near for several year Taiwan various metropolises city, steps out one after another footsteps of the city style transformation, simultaneously penetrates the successful city style transformation, not only causes the city transformation, to be reborn, also promotes the people to the city centripetal force and the honorable feeling.
But lets the city continue forever, the health development must penetrate the space, the landscape, the environment, the ecology, the economy, the society, the culture, educates each good government. Again by way of each way city marketing, establishes its image localization to this city with his city populace or the foreign
tourist.
In recent years the whole world climatic change fierce change, the cause continues discharging to hundred years coming person for the greenhouse gas which has not controlled, the humanity since 19th century Industrial Revolution until now, discharged in the atmosphere CO2 (carbon dioxide) to have absorbs the infrared which the surface diverged, enable to approach the surface the temperature rise, this
kind of approximate greenhouse increased the warm function to be called the greenhouse effect, but its function gas was the greenhouse gas.
|
8 |
Clean development Mechanism (CDM) Policy and Implementation in ChinaZeng, Lei January 2006 (has links)
<p>China is the second largest emitter of greenhouse gases (GHG) in the world. Since 68% of its primary energy is from coal, China’s average energy intensity is 7.5 times higher than the EU and 4.3 times higher than the US (EU, 2003). Therefore, introducing advanced clean technologies and management to China represents opportunities for Annex I countries to obtain low-cost CERs through CDM projects, and access to one of the largest energy conservation markets in the world.</p><p>The Chinese government considers that the introduction of CDM projects can bring advanced energy technologies and foreign investment to China, thereby helping China’s sustainable development. As energy efficiency is generally low and carbon intensity is high in both China’s energy supply and demand sectors, numerous options exist for cost-effective energy conservation and GHG mitigation with CDM.</p><p>This study has focused on the following areas:</p><p> Clean development Mechanism (CDM) Policy and Implementation in ChinaClean development Mechanism (CDM) Policy and Implementation in ChinaChina’s energy development strategy and climate change, how to make CDM work for sustainable development in China?</p><p> CDM projects in China: policies assessment and recommendations for improvement.</p><p> Energy efficiency CDM projects and renewable CDM projects in China: case studies</p><p>Firstly, this thesis reviewed the current CDM developments in China, attentions were given to the renewable energy, energy efficiency and methane capture project opportunities in China.</p><p>Secondly, this study introduced China’s current policy on CDM implementation, and reviewed its permission requirements, institutional arrangements and project procedures. Based on the observations, this study analyzed the current problems and pointed out the shortfalls of the existing Chinese CDM policies and institutional settings. Options to remove these barriers were given as recommendations. This thesis also looked at the problem of that CDM was designed to have double dividends, to reduce the compliance cost of the Annex I countries and to contribute to sustainable development in Non Annex I Parties, but in reality, CDM has caused concerns about whether it could really support sustainable development in host countries. This study analyzed the reasons underpin this problem.</p><p>Thirdly, based on the analysis made on energy efficiency and renewable CDM project development in China, case study was given on China’s landfill gas to energy project. This study analyzed the perspective of GHG mitigation through landfill gas capture and utilization in China, its opportunities and challenges. Moreover, this study demonstrated how CDM can add value to landfill gas-to-energy projects in China.</p>
|
9 |
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.
|
10 |
Clean development Mechanism (CDM) Policy and Implementation in ChinaZeng, Lei January 2006 (has links)
China is the second largest emitter of greenhouse gases (GHG) in the world. Since 68% of its primary energy is from coal, China’s average energy intensity is 7.5 times higher than the EU and 4.3 times higher than the US (EU, 2003). Therefore, introducing advanced clean technologies and management to China represents opportunities for Annex I countries to obtain low-cost CERs through CDM projects, and access to one of the largest energy conservation markets in the world. The Chinese government considers that the introduction of CDM projects can bring advanced energy technologies and foreign investment to China, thereby helping China’s sustainable development. As energy efficiency is generally low and carbon intensity is high in both China’s energy supply and demand sectors, numerous options exist for cost-effective energy conservation and GHG mitigation with CDM. This study has focused on the following areas: Clean development Mechanism (CDM) Policy and Implementation in ChinaClean development Mechanism (CDM) Policy and Implementation in ChinaChina’s energy development strategy and climate change, how to make CDM work for sustainable development in China? CDM projects in China: policies assessment and recommendations for improvement. Energy efficiency CDM projects and renewable CDM projects in China: case studies Firstly, this thesis reviewed the current CDM developments in China, attentions were given to the renewable energy, energy efficiency and methane capture project opportunities in China. Secondly, this study introduced China’s current policy on CDM implementation, and reviewed its permission requirements, institutional arrangements and project procedures. Based on the observations, this study analyzed the current problems and pointed out the shortfalls of the existing Chinese CDM policies and institutional settings. Options to remove these barriers were given as recommendations. This thesis also looked at the problem of that CDM was designed to have double dividends, to reduce the compliance cost of the Annex I countries and to contribute to sustainable development in Non Annex I Parties, but in reality, CDM has caused concerns about whether it could really support sustainable development in host countries. This study analyzed the reasons underpin this problem. Thirdly, based on the analysis made on energy efficiency and renewable CDM project development in China, case study was given on China’s landfill gas to energy project. This study analyzed the perspective of GHG mitigation through landfill gas capture and utilization in China, its opportunities and challenges. Moreover, this study demonstrated how CDM can add value to landfill gas-to-energy projects in China.
|
Page generated in 0.1334 seconds