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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Study of Possible Applications of Currently Available Building Information Modeling Tools for the Analysis of Initial Costs and Energy Costs for Performing Life Cycle Cost Analysis

Mukherji, Payal Tapandev 2010 December 1900 (has links)
The cost of design, construction and maintenance of facilities is on continual rise. The demand is to construct facilities which have been designed by apply life cycle costing principles. These principles have already given strong decision making power to the manufacturing industry. The need to satisfy the environmental sustainability requirements, improve operational effectiveness of buildings and apply value engineering principles has increased the dependency on life cycle costing analysis. The objective is to obtain economically viable solutions by analyzing the alternatives during the design of a building. Though the LCCA process is able to give the desired results, it does have some problems which have stood as hindrances to the more widespread use of the LCCA concept and method. The literature study has highlighted that the problem areas are the lack of frameworks or mechanisms for collecting and storing data and the complexity of LCCA exercise, which involves the analysis of a thousand of building elements and a number of construction-type options and maintenance activities for each building element at detailed design stages. Building Information Modeling has been able to repeatedly answer the questions raised by the AEC industry. The aim of this study is to identify the areas where BIM can be effectively applied to the LCCA process and become a part of the workflow. In this study, initially four LCCA case studies are read and evaluated from the point of view of understanding the method in which the life cycle costing principles have been applied. The purpose, the type alternatives examined, the process of analysis, the type of software used and the results are understood. An attempt has been carried out to understand the workflow of the LCCA process. There is a confidence that Building Information Modeling is capable of handling changes during the design, construction and maintenance phases of the project. Since applying changes to any kind of information of the building during LCC analysis forms the core, it has become necessary to use computer building models for examining these changes. The building modeling softwares are enumerated. The case studies have highlighted that the evaluation of the alternatives are primarily to achieve energy efficient solutions for the buildings. Applying these solutions involves high initial costs. The return on investment is the means by which these solutions become viable to the owners of the facilities. This is where the LCCA has been applied. Two of the important cost elements of the LCC analysis are initial costs and the operating costs of the building. The collaboration of these modeling tools with other estimating software where the initial costs of the building can be generated is studied. The functions of the quantity take-off tools and estimating tools along with the interoperability between these tools are analyzed. The operating costs are generated from the software that focuses on sustainability. And the currently used tools for performing the calculations of the life cycle costing analysis are also observed. The objective is to identify if the currently available BIM tools and software can help in obtaining LCCA results and are able to offset the hindrances of the process. Therefore, the software are studied from the point of view of ease of handling data and the type of data that can be generated. Possible BIM workflows are suggested depending on the functions of the software and the relationship between them. The study has aimed at taking a snapshot the current tools available which can aid the LCCA process. The research is of significance to the construction industry as it forms a precursor to the application of Building Information Modeling to the LCCA process as it shows that it has the capacity of overcoming the obstacles for life cycle costing. This opens a window to the possibility of applying BIM to LCCA and furthering this study.
12

The Sustainability of Ion Exchange Water Treatment Technology

Amini, Adib 04 April 2017 (has links)
This research investigated using a life cycle environmental and economic approach to evaluate IX technology for small potable water systems, allowing for the identification and development of process and design improvements that reduce environmental impacts and costs. The main goals were to evaluate conventional IX in terms of life cycle environmental and economic sustainability, develop a method for improving designs of IX systems from a environmental and economic sustainability standpoint, evaluate potential design improvements, and make the research findings accessible to water professionals through user-friendly tools and frameworks that take into account their feedback. This research provides an understanding, from the perspective of life cycle environmental impacts and costs, of the tradeoffs between various reactor designs of IX, the effects of scale, key contributors to impact and cost, design trends that improve sustainability, and how combined cation anion exchange compares to conventional IX. Furthermore, tools were developed that can be used to identify design choices that improve sustainability of IX systems. These tools were made into a user-friendly format to better bridge the gap between research and practice.
13

The effectiveness of grouted macadam at intersections. : A life-cycle cost analysis

Jacobsen, 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.
14

Bridge Life Cycle Cost Optimization : Analysis, Evaluation, & Implementation

Abed El-Fattah Safi, Mohammed January 2009 (has links)
No description available.
15

Exploring the Intersection of Science and Policy: The Case Study of Installing Solar Panels and Energy Storage System at the University of Ottawa

Elshorbagy, 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.
16

Service Life Modeling of Virginia Bridge Decks

Williamson, 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.
17

Economic Performance Assessment of Three Renovated Multi-Family Houses with Different HVAC Systems

Khadra, Alaa January 2018 (has links)
Since the building sector is responsible for 40% of the energy consumption and 36% of CO2 emissions in the EU, the reduction of energy use has become a priority in this sector. The EU has adopted several policies to improve energy efficiency. One of these policies aims to achieve energy efficient renovations in at least 3% of buildings owned and occupied by governments annually. In Sweden, a large part of existing buildings was built between 1965 and 1974, a period commonly referred to as ‘miljonprogrammet’. Stora Tunabyggen AB, the public housing company in Borlänge municipality, begun a renovation project in the Tjärna Ängar neighborhood within the municipality with the greatest share of its buildings stock from this period. The pilot project started in 2015. The aim of this project was to renovate three buildings with similar measures, that is, by adding 150 mm attic insulation, replacing windows with higher performing ones (U-value 1 W/m ²K), by adding 50 mm of insulation to the infill walls and by the installation of flowreducing taps. The essential difference between the three renovation packages is the HVAC systems. The selected HVAC systems are (1) exhaust air heat pump, (2) mechanical ventilation with heat recovery and (3) exhaust ventilation. Life cycle cost analysis was conducted for the three building and sensitivity analysis for different values of discount rate and energy price escalation was performed. The study found that the house with exhaust ventilation has the lowest life cycle cost and the highest energy cost. The house with exhaust air heat pump has 3% higher life cycle cost and 18% lower energy use at 3% discount rate and 3% energy price escalation. The study found that mechanical ventilation with heat recovery is not profitable, although it saves energy. The sensitivity analysis has shown that the possible increment of price energy and lower discount rate give higher value for the future costs in life cycle cost analysis. This lead to the main finding of this thesis, which is that exhaust air heat pump is the best choice for the owner according to the available data and the assessed parameters.
18

LIFE-CYCLE COST ANALYSIS OF REINFORCED CONCRETE BRIDGES REHABILITATED WITH CFRP

Smith, Jeffrey L. 01 January 2015 (has links)
The deterioration of highway bridges and structures and the cost of repairing, rehabilitating, or replacing deteriorated structures is a major issue for bridge owners. An aging infrastructure as well as the need to upgrade structural capacity for heavier trucks adds to problem. Life-cycle cost analysis (LCCA) is a useful tool for determining when the deployment of fiber-reinforced polymer (FRP) composite components is an economically viable alternative for rehabilitating deteriorated concrete bridges. The use of LCCA in bridge design and rehabilitation has been limited. The use of LCCA for bridges on a project level basis has often been limited to the non-routine design of major bridges where the life-cycle cost model is customized. LCCA has historically been deterministic. The deterministic analysis uses discrete values for inputs and is fairly simple and easy to do. It does not give any indication of risk, i.e. the probability that the input values used in the analysis and the resulting life-cycle cost will actually occur. Probabilistic analysis accounts for uncertainty and variability in input variables. It requires more effort than a deterministic analysis because probability distribution functions are required, random sampling is used, and a large number of iterations of the life-cycle cost calculations are carried out. The data needed is often not available. The significance of this study lies in its identification of the parameters that had the most influence on life-cycle costs of concrete bridge and how those parameters interacted. The parameters are: (1) Time to construct the new bridge; (2) traffic volume under bridge (when applicable); (3) value of time for cars; and (4) delay time under the bridge during new bridge construction (when applicable). Using these parameters the analyst can now “simulate” a probabilistic analysis by using the deterministic approach and reducing the number of iterations. This study also extended the use of LCCA to bridge rehabilitations and to bridges with low traffic volumes. A large number of bridges in the United States have low traffic volumes. For the highway bridge considered in the parametric study, rehabilitation using FRP had a lower life-cycle cost when compared to the new bridge alternative.
19

Evaluation of low-quality recycled concrete pavement aggregates for subgrade soil stabilization

Tavakol, Masoumeh January 1900 (has links)
Doctor of Philosophy / Department of Civil Engineering / Mustaque A. Hossain / Stacey E. Kulesza / Recycled concrete aggregate (RCA) is the byproduct of the demolition of concrete structures and pavements. An estimated 140 million tons of concrete waste is produced annually in the United States, most of which ends up in landfills. The use of RCA to replace quarried aggregates in paving projects is one way to utilize these materials and alleviate concerns regarding this increasing waste stream. RCA usage prevents waste concrete disposal into landfills, resulting in more sustainable use of mineral aggregate sources, and may further reduce costs associated with paving projects. However, the inferior physical properties of RCA, such as the presence of recycled mortar, complicate the incorporation of RCA into new concrete mixtures. State highway agencies such as the Kansas Department of Transportation are facing further issues with RCA from D-cracked pavements, raising the question if D-cracked aggregates should be used in paving operations. No known work has evaluated the effect of RCA from D-cracked pavements in subgrade soil stabilization. This study stabilized a low-plasticity clay in Kansas using RCA and three stabilizing materials (lime, Class C fly ash, and a combination of Portland cement and fly ash). Candidate mixtures with varying proportions of chemical stabilizers and D-cracked aggregates were evaluated using the standard Proctor, unconfined compressive strength, linear shrinkage, and California Bearing Ratio tests. Microstructure characteristics of selected mixtures were explored using scanning electron microscopy (SEM) and energy dispersive X-ray tests. Laboratory test results indicated that RCA, in conjunction with all cementitious materials except lime, improved clay strength, stiffness, and shrinkage properties. SEM results indicated that RCA caused a low void space and a dense arrangement of soil particles. RCA effectively improved evaluated mixture properties when an adequate soil-RCA bond was reached using chemical agents. The long-term performance of full-depth flexible pavements with stabilized mixtures as subgrade was assessed in the AASHTOWare Pavement ME Design (commonly known as MEPDG) software. The life-cycle cost of flexible pavements with stabilized mixtures was estimated for a 40-year design period. Economic analysis results indicated that RCA was cost effective only if it was used with a combination of fly ash and Portland cement.
20

A Model for Assessing Cost Effectiveness of Applying Lean Tools

Al-Hamed, Heba, Qiu, Xiaojin January 2007 (has links)
The purpose of this thesis is to develop a model for assessing cost effectiveness of applying lean tools. The model consists of eight phases: it starts by understanding customers' requirements using Voice of Customer (VOC) and Quality Function Deployment (QFD) tools. In phase 2, the current state of plant is assessed using lean profile charts based on Balanced Scorecard (BSC) measures. In phase 3 and phase 4, identification of critical problem(s) and generating of improvement suggestion(s) are performed. Phase 5 provide evaluation of the cost effectiveness of implementing the suggested lean methods based on life cycle cost analysis (LCCA) and phase 6 prefers the right alternative based on multiple criteria decision making (MCDM). In phase 7 the selected alternative is supposed to be implemented and finally the user should monitor and control the process to make sure that the improvement is going as planned. The model was verified successfully using a case study methodology at one Swedish sawmill called Södra Timber in Ramkvilla, one part of Södra group. Results obtained from the study showed that the production and human resources perspectives are the most critical problem areas that need to be improved. They got the lowest scores in the lean profile, 63% and 68%, respectively. Using value stream mapping (VSM) it was found that the non value added (NVA) ratios for the core and side products are 87.4% and 90.4%, respectively. Using the model, three improvement alternatives were suggested and evaluated using LCCA and MCDM. Consequently, implementing 5S got the highest score, second came redesigning the facility layout. However, it was estimated that 4.7 % of NVA for the side product would be reduced by redesigning the facility layout. The recommendations were suggested for the company to improve their performance. The novelty of the thesis is based on the fact that it addresses two main issues related to lean manufacturing: firstly, suggesting lean techniques based on assessment of lean profile that is based on BSC and QFD, and secondly assessing the cost effectiveness of the suggested lean methods based on LCCA and MCDM. This thesis provides a generalized model that enables the decision-maker to know and measure, holistically, the company performance with respect to customer requirements. This will enable the company to analyze the critical problems, suggest solutions, evaluate them and make a cost effective decision. Thus, the company can improve its competitiveness.

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