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The effectiveness of grouted macadam at intersections. : A life-cycle cost analysisJacobsen, Sofie January 2012 (has links)
Intersections often experience severe rutting in the asphalt concrete layers due to slow moving, high loads, acceleration, deceleration and turning. This thesis aims to investigate the effectiveness of grouted macadam, open graded asphalt with its voids filled with cement grout, as a pavement material at intersections. This was done by investigating the properties of grouted macadam through a literature review and performing a life-cycle cost analysis comparing grouted macadam and asphalt concrete as pavement materials at an intersection. Grouted macadam is found to be similar to asphalt concrete concerning the relation between stiffness and temperature and frequency as well as fatigue behaviour. The main differences are that grouted macadam is stiffer, stronger and not prone to rutting. Thus it would be suitable to address rutting problems. The main drawbacks are that construction demands extra time and precision and that it is expensive compared to asphalt concrete. The life-cycle cost analysis showed that assuming that the grouted macadam has a service life of twenty years and rehabilitation of the asphalt concrete in the form of mill and refill takes place every fourth year the life-cycle costs are approximately the same. A sensitivity analysis was performed that showed that local variations can have large impact on the life-cycle costs. The main conclusion is that grouted macadam can be effective as a pavement material at intersections that experiences severe rutting and frequently reoccurring rehabilitations.
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A comparative analysis of road bound and drone-based parcel deliveries : – An ex-ante evaluation regarding environmental impact, life cycle cost and delivery timeJonsson, Greta, Hansson, Erika January 2022 (has links)
The increased demand for fast deliveries of goods have led to more costly and less environmentally friendly transports since many of the delivering trucks are not being fully loaded. The inefficiencies of deliveries have created a need for development of new freight systems. One alternative vehicle that has gained increasingly interest is usage of UAVs (unmanned arial vehicles), also known as drones. Several drones in varying sizes and configurations are being developed and applications within transports of both people and goods is seen as promising areas for the future. The study aims at investigating the performance of drone deliveries regarding time, cost, and environmental impact and to see what parameters are important for the performance. This have been made by comparing a UAV to two different vans (electric and HVO) for parcel deliveries in four chosen missions in both urban and rural settings. The evaluation takes a future perspective and are based on information received through both literature review and a market investigation. The result from this study indicates that UAVs are likely to be a competitive future option for parcel deliveries regarding time and cost. This is concluded since the results shows significant savings in both costs and delivery time and these results are not changed by the sensitivity analyses. The result regarding environmental performance shows that the UAVs competitiveness depends on the vehicle of comparison. The drone has a better environmental performance than vans with fossil-based propellants but given the energy intensity of the UAV, it is not favourable compared to an electric van. The energy requirement of the drone is one of the most important factors affecting the performance. The energy requirements per km for the UAV increases when the routes become shorter since different phases of the flight have different energy intensity. The most demanding phase is lifting and when the distance between the stops is reduced this phase becomes more prominent. Another important factor is the possibility to reduce the travelled distance by taking the straight path with the UAV compared to being bound by the road infrastructure. The shorter distance for the UAV contributes both to reduced time but also reduced energy requirements which in its turn affect both environmental and economic performance. The distances and energy requirements are thus not the most important factor for the economic sustainability but rather the cost of staff. Since the drones are unmanned, several UAVs could be controlled by the same operator contributing to reduced cost of staff. The low energy requirements for the UAV in the longer and more rural cases makes this type of applications the most beneficial regarding environmental performance. Urban missions are instead the most preferable regarding cost and time, since a bigger share of the distance can be saved and the difference in speed between the UAV and the van is larger.
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Bridge Life Cycle Cost Optimization : Analysis, Evaluation, & ImplementationAbed El-Fattah Safi, Mohammed January 2009 (has links)
No description available.
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New Method Aiming at Comprehensive Evaluation of Low Impact Development:Case Study in Tianjin, China / 環境影響の少ない都市計画の新たな総合的評価モデルの開発:中国天津市を例としてLi, Yu 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21743号 / 工博第4560号 / 新制||工||1711(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 田中 茂信, 准教授 田中 賢治, 教授 中北 英一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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A strategy to reduce total cost of ownership of the U.S. Air Force’s airfield pavementsSynovec, Thomas 25 November 2020 (has links)
The U.S. Air Force (USAF) estimates it has a $33 billion (about 10 percent is airfield pavements) deferred maintenance backlog within its $263 billion infrastructure portfolio. Given the scope of this backlog and the importance of airfields, the USAF has a vested interest in finding strategies to help reverse this growing trend. Without an increase in funding, divestiture of excess infrastructure, or change in strategy, this backlog is estimated to climb to over $50 billion by 2030. Reversing the growing infrastructure backlog trend requires new methods and strategies to rethink how the USAF invests in its infrastructure. As such, the overall goal of this research is to develop a comprehensive and practical asset management approach to reduce the total cost of ownership of USAF airfield pavements. By reducing the cost of ownership, the goal is to reverse the growing maintenance backlog while maintaining a pavement portfolio capable of supporting USAF flying operations into the future. While this research is particularly relevant to the USAF, it seeks to fill research gaps within the current body of knowledge related to pavement management strategies for other agency types by presenting a practical, simulation-based methodology for work planning and budget allocation across a large pavement portfolio over a thirty-year period. The dissertation presents the development of the BEAST and RAMPSS algorithms. The BEAST algorithm is a simulation tool capable of modeling behaviors and decisions of 109 organizations managing a global network of airfield pavements over thirty years. Additionally, the BEAST is used to forecast outcomes of USAF investment decisions utilizing its current management strategies and historical behaviors. The RAMPSS is a simulation algorithm designed to select the most economical maintenance strategy for each pavement section in the USAF’s portfolio (i.e., individualized maintenance recommendation strategy for each pavement section). Analysis from the RAMPSS algorithm of the USAF’s pavement portfolio suggests that airfields are generally more cost-effective to maintain if kept in better conditions with strategies other than localized preventative maintenance. The USAF’s current maintenance strategy is unsustainable; however, switching to recommendations from RAMPSS (incorporated and modeled in the BEAST) provides a potentially significant course correction.
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Sustainable Design and Operation of the Cement IndustryAvetisyan, Hakob G. 19 December 2008 (has links)
No description available.
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Exploring the Intersection of Science and Policy: The Case Study of Installing Solar Panels and Energy Storage System at the University of OttawaElshorbagy, Eslam 14 September 2022 (has links)
Buildings account for up to a third of total world greenhouse gas GHG emissions, and this pattern is expected to persist. By 2050, cities will be home to 70 % of the world's population, demanding a significant number of buildings to be constructed. Efforts to reduce these emissions in the past had varied performance. However, several examples indicate that well thought and adequately executed mix of building technology coupled with environmental policies may reduce emissions. Therefore, cities worldwide are joining the race to decarbonize their buildings to become net-zero carbon and support green economies through a diversified bundle of policies. However, designing and selecting the appropriate mix of building technology and environmental policies is challenging to generate the most outlast net-zero carbon impacts. This research aims to uncover the intersection between science and policy's role in achieving a global net-zero energy building sector. First, an urban comparative analysis for ten environment-leading cities has been made to understand the latest progress in the building sector and draw on future recommendations. The findings are thematically grouped into five themes a) Building's energy efficiency (energy demand sector). (b) Electrified renewable grids (energy supply sector). (c) Green fiscal incentives (d) Education and capacity building. (e) Governance and collaboration. Second, the University of Ottawa has been utilized as a part of the campus as a living lab initiative to examine installing photovoltaic panels over the campus buildings as part of the university expansion program to achieve net-zero operations by 2040. The following parameters have been considered to address the PV systems viability, 1) the expected electricity output. 2) the initial and operational costs. 3) the GHG reductions in operational energy. 4) the PV system embodied carbons. RETScreen Expert software has been used to perform the Life Cycle Cost Analysis (LCCA) to assess PV system output and financial viability. One Click-LCA software to carry-out Life Cycle Assessment (LCA) to assess embodied carbons. The results indicate from analyzing 31 buildings that 20% - 107% of electricity can be offset depending on each building's energy use and solar collector area. Additionally, the 31 buildings analyzed for electricity generation collectively have the potential to save around 23% of the total campus electricity consumption with a production capacity of 18 million units (kWh) annually, including 21,108 solar panels. Also, the project shows financial viability only if the PV systems are installed as part of the whole campus with a Net Present Value (NPV) of $4,985,89 and an Internal Rate of Return (IRR) of 11.4%. The analysis shows 24% and 18% maximum sensitivity to increased initial cost and decreased electricity generation/rate. Finally, the GHG estimated reductions over 25 years from generated electricity are 14,445 tCO2, and the estimated increased embodied carbons from the Life Cycle Assessment are set to be 1,023 tCO2. Additionally, drawing upon urban analysis and the case study, the research highlights the dynamic nature of the building sector emissions reduction and city initiatives. Thirdly, a detailed analysis was carried out in the System Advisor Model (SAM) software to integrate the solar system with energy storage in the Advanced Research Complex (ARC) Building at the University of Ottawa. The study assesses the system viability and helps the university to reduce its monthly electricity bill and help Ontario to maintain its grid reliability by keeping the electricity demand low at peak times. The findings show that using an integrated solar system with an energy storage system by mitigating 100%, 90%, 75%, and 50% of the building electricity demand during the Ontario gird peak could lead to a Net Present Value of $2,01, $1.70, $1.30, and $0.864 million over 25 years the lifetime of the project through the Ontario Global Adjustment Program. The study also shows that with the absence of the Ontario Global Adjustment Program as a fiscal reform tool and relying only on the time of use electricity rates, the solar panels with an energy storage system could lead to a negative Net Present Value of $-550 thousand.
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Service Life Modeling of Virginia Bridge DecksWilliamson, Gregory Scott 09 April 2007 (has links)
A model to determine the time to the End of Functional Service Life (EFSL) for concrete bridge decks in Virginia was developed. The service life of Virginia bridge decks is controlled by chloride-induced corrosion of the reinforcing steel. Monte Carlo resampling techniques were used to integrate the statistical nature of the input variables into the model. This is an improvement on previous deterministic models in that the effect of highly variable input parameters is reflected in the service life estimations. The model predicts the time required for corrosion to initiate on 2% of the reinforcing steel in a bridge deck and then a corrosion propagation time period, determined from empirical data, is added to estimate the EFSL for a given bridge deck or set of bridge decks.
Data from 36 Virginia bridge decks was collected in order to validate the service life model as well as to investigate the effect of bridge deck construction specification changes. The bridge decks were separated into three distinct groups: 10 bare steel reinforcement decks â 0.47 water/cement (w/c), 16 Epoxy-Coated Reinforcement (ECR) decks â 0.45 w/c, and 10 ECR decks â 0.45 w/(c+pozzolan). Using chloride titration data and cover depth measurements from the sampled bridge decks and chloride corrosion initiation values determined from the literature for bare steel, service life estimates were made for the three sets of bridge decks. The influence of the epoxy coating on corrosion initiation was disregarded in order to allow direct comparisons between the three sets as well as to provide conservative service life estimates.
The model was validated by comparing measured deterioration values for the bare steel decks to the estimated values from the model. A comparison was then made between the three bridge deck sets and it was determined that bridge decks constructed with a 0.45 w/(c+p) will provide the longest service life followed by the 0.47 w/c decks and the 0.45 w/c decks, respectively. From this it can be inferred that the addition of pozzolan to the concrete mix will improve the long-term durability of a bridge deck while a reduction in w/c appears to be of no benefit. / Ph. D.
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High-Intensity Discharge Industrial Lighting Design Strategies for the Minimization of Energy Usage and Life-Cycle CostFlory, Isaac L. IV 13 October 2008 (has links)
Worldwide, the electrical energy consumed by artificial lighting is second only to the amount consumed by electric machinery. Of the energy usage attributed to lighting in North America, approximately fifteen percent is consumed by those lighting products that are classified as High-Intensity Discharge (HID). These lighting products, which are dominated by Metal-Halide and High-Pressure Sodium technologies, range in power levels from 35 to 2000 watts and are used in both indoor and outdoor lighting applications, one category of which is the illumination of industrial facilities. This dissertation reviews HID industrial lighting design techniques and presents two luminaire layout algorithms which were developed to provide acceptable lighting performance based upon the minimum number of required luminaires as determined by the lumen method, regardless of the aspect ratio of the target area. Through the development of lighting design software tools based upon the Zonal Cavity Method and these layout algorithms, models for the quantification of energy requirements, lighting project life-cycle costs, and environmental impacts associated with conventional industrial lighting installations are presented. The software tools, which were created to perform indoor HID lighting designs for the often encountered application of illuminating general rectangular areas with non-sloped ceilings utilizing either High-Bay or Low-Bay luminaires, provide projections of minimal lighting system costs, energy consumption, and environmental impact based upon lamp selection, ballast selection, luminaire selection and lighting system maintenance practices. Based upon several industrial lighting application scenarios, lighting designs are presented using both the new software tools and a commercially available lighting design software package. For the purpose of validating this research, analyses of both designs for each scenario are presented complete with results of illuminance simulations performed using the commercially available software. / Ph. D.
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Modeling of Bioenergy ProductionLerkkasemsan, Nuttapol 06 June 2014 (has links)
In this dissertation we address three different sustainability concepts: [1] modeling of biodiesel production via heterogeneous catalysis, [2] life cycle analysis for pyrolysis of switchgrass for using in power plant, and [3] modeling of pyrolysis of biomass. Thus we deal with Specific Aim 1, 2 and 3.
In Specific Aim 1, the models for esterification in biodiesel production via heterogeneous catalysis were developed. The models of the reaction over the catalysts were developed in two parts. First, a kinetic study was performed using a deterministic model to develop a suitable kinetic expression; the related parameters were subsequently estimated by numerical techniques. Second, a stochastic model was developed to further confirm the nature of the reaction at the molecular level. The deterministic and stochastic models were in good agreement.
In Specific Aim 2, life cycle analysis and life cycle cost for pyrolysis of switchgrass for using in power plant model were developed. The greenhouse gas (GHG) emission for power generation was investigated through life cycle assessment. The process consists of cultivation, harvesting, transportation, storage, pyrolysis, transportation and power generation. Here pyrolysis oil is converted to electric power through co- combustion in conventional fossil fuel power plants. The conventional power plants which are considered in this work are diesel engine power plant, natural gas turbine power plant, coal-fired steam-cycle power plant and oil-fired steam-cycle power plant. Several scenarios are conducted to determine the effect of selected design variables on the production of pyrolysis oil and type of conventional power plants.
In Specific Aim 3, pyrolysis of biomass models were developed. Since modeling of pyrolysis of biomass is complex and challenging because of short reaction times, temperatures as high as a thousand degrees Celsius, and biomass of varying or unknown chemical compositions. As such a deterministic model is not capable of representing the pyrolysis reaction system. We propose a new kinetic reaction model, which would account for significant uncertainty. Specifically we have employed fuzzy modeling using the adaptive neuro-fuzzy inference system (ANFIS) in order to describe the pyrolysis of biomass. The resulting model is in better agreement with experimental data than known deterministic models. / Ph. D.
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