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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

Integrating Sustainability Grand Challenges and Active, Experiential Learning into Undergraduate Engineering Education

January 2015 (has links)
abstract: Engineering education can provide students with the tools to address complex, multidisciplinary grand challenge problems in sustainable and global contexts. However, engineering education faces several challenges, including low diversity percentages, high attrition rates, and the need to better engage and prepare students for the role of a modern engineer. These challenges can be addressed by integrating sustainability grand challenges into engineering curriculum. Two main strategies have emerged for integrating sustainability grand challenges. In the stand-alone course method, engineering programs establish one or two distinct courses that address sustainability grand challenges in depth. In the module method, engineering programs integrate sustainability grand challenges throughout existing courses. Neither method has been assessed in the literature. This thesis aimed to develop sustainability modules, to create methods for evaluating the modules’ effectiveness on student cognitive and affective outcomes, to create methods for evaluating students’ cumulative sustainability knowledge, and to evaluate the stand-alone course method to integrate sustainability grand challenges into engineering curricula via active and experiential learning. The Sustainable Metrics Module for teaching sustainability concepts and engaging and motivating diverse sets of students revealed that the activity portion of the module had the greatest impact on learning outcome retention. The Game Design Module addressed methods for assessing student mastery of course content with student-developed games indicated that using board game design improved student performance and increased student satisfaction. Evaluation of senior design capstone projects via novel comprehensive rubric to assess sustainability learned over students’ curriculum revealed that students’ performance is primarily driven by their instructor’s expectations. The rubric provided a universal tool for assessing students’ sustainability knowledge and could also be applied to sustainability-focused projects. With this in mind, engineering educators should pursue modules that connect sustainability grand challenges to engineering concepts, because student performance improves and students report higher satisfaction. Instructors should utilize pedagogies that engage diverse students and impact concept retention, such as active and experiential learning. When evaluating the impact of sustainability in the curriculum, innovative assessment methods should be employed to understand student mastery and application of course concepts and the impacts that topics and experiences have on student satisfaction. / Dissertation/Thesis / Doctoral Dissertation Engineering 2015
12

Sustainability studies in recycling post consumer carpet

Subbiah, Valli 25 August 2008 (has links)
This thesis presents some novel techniques to process Post Consumer Carpet waste and provides detailed cost comparisons between setting up and running small-scale decentralized units and large-scale centralized chemical facilities. The techniques presented include: a decentralized underlay manufacturing process which does not distinguish between the types of face fiber, a decentralized facility with twin screw extruder to depolymerize nylon 6 face fiber with a concurrent underlay manufacturing facility, a decentralized pallet production facility, and a centralized facility for chemically depolymerizing nylon 6, and nylon 6,6 with a concurrent underlay manufacturing facility The limiting factors to recycling are the collection of significant volumes of material and effective recycling techniques. This is illustrated in this study. The aim of this study is to enable recyclers to assess their recycling activities using various performance parameters, such as payback period of the venture, mass of carpet recycled, and energy used. Thus, this study aims to shed light on the impact of recycling on current carpet consumption per capita. The results indicate that decentralized facilities located in metropolitan areas with populations of over 2 million people have a lower payback period than the large scale centralized facilities that are sparsely distributed throughout the country. These decentralized facilities are also more efficient in reducing the current carpet consumption per capita. The reduced traveling distance for the post consumer carpet from the collection/disposal site to the processing facility should make a huge impact on energy consumption and the corresponding environmental emissions.
13

Incorporating sustainability into transportation planning and decision making definitions, performance measures, and evaluation /

Jeon, Mihyeon Christy. January 2007 (has links)
Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Adjo Amekudzi; Committee Member: Catherine Ross; Committee Member: Josias Zietsman; Committee Member: Michael Meyer; Committee Member: Randall Guensler.
14

Development and application of novel solvents for sustainable reactions and separations

Donaldson, Megan Elizabeth. January 2008 (has links)
Thesis (Ph.D.)--Chemical Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Charles A. Eckert; Committee Co-Chair: Charles L. Liotta; Committee Member: Christopher W. Jones; Committee Member: Facundo M. Fernandez; Committee Member: Thomas F. Fuller.
15

Development and application of novel solvents for sustainable reactions and separations

Donaldson, Megan Elizabeth 30 June 2008 (has links)
Environmentally benign alternatives for solvents and catalysts are essential for the development of sustainable chemical processes. Toward this end, we focused our research on the design of novel solvents and catalysts that reduce the environmental impact of these important materials. In this research, we develop switchable and tunable systems that couple reaction and separation to ease the processing requirements for product isolation and catalyst recovery. The switchable solvents use a ¡°switch¡± to transition from non-volatile, polar, aprotic solvents to volatile gases that can be easily separated. This allows us to facilitate reactions within the solvent and then enable easy separation through activation of the switch. We have used these materials for numerous reaction applications, including difficult reactions involving highly immiscible compounds. We also extended the work to acid-catalyzed reactions, in which we can avoid wasteful neutralization processes that are often associated with homogeneous acid catalysis. The tunable solvents use carbon dioxide pressure to ¡°tune¡± into desired solvent properties. We enable this through the dissolution of carbon dioxide into organic solvents, which generates gas-expanded liquids with solvent properties highly dependent on the carbon dioxide pressure. We can use this effect to couple homogeneous reaction with heterogeneous separation, allowing for recovery of expensive catalysts and ligands. In this work, we assess the possibilities of using liquid polyethylene glycol in the tunable systems, studying the phase behavior and industrial applications.
16

Design of hydrodynamic test facility and scaling procedure for ocean current renewable energy devices

Unknown Date (has links)
Simulations have been carried out to validate a hydrokinetic energy system non-dimensional scaling procedure. The requirements for a testing facility intended to test such devices will be determined from the results of the simulations. There are 6 simulations containing 3 prototype systems and 2 possible model facility depths to give a range of results. The first 4 tests are conducted using a varying current profile, while the last 2 tests use a constant current profile of 1.6 m/s. The 3 prototype systems include a: 6 m spherical buoy, a 12 m spherical buoy and a turbine component system. The mooring line used for the simulations is a 6x19 Wire Rope Wire Core of diameter 100 mm and length 1000 m. The simulations are implemented using Orcaflex to obtain the dynamic behavior of the prototype and scaled system. / by William Valentine. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.
17

Finite safety models for high-assurance systems

Unknown Date (has links)
Preventing bad things from happening to engineered systems, demands improvements to how we model their operation with regard to safety. Safety-critical and fiscally-critical systems both demand automated and exhaustive verification, which is only possible if the models of these systems, along with the number of scenarios spawned from these models, are tractably finite. To this end, this dissertation ad dresses problems of a model's tractability and usefulness. It addresses the state space minimization problem by initially considering tradeoffs between state space size and level of detail or fidelity. It then considers the problem of human interpretation in model capture from system artifacts, by seeking to automate model capture. It introduces human control over level of detail and hence state space size during model capture. Rendering that model in a manner that can guide human decision making is also addressed, as is an automated assessment of system timeliness. Finally, it addresses state compression and abstraction using logical fault models like fault trees, which enable exhaustive verification of larger systems by subsequent use of transition fault models like Petri nets, timed automata, and process algebraic expressions. To illustrate these ideas, this dissertation considers two very different applications - web service compositions and submerged ocean machinery. / by John C. Sloan. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
18

Designing switchable solvents for sustainable process development

Hart, Ryan J. 01 December 2010 (has links)
Novel solvents utilizing a reversible CO₂ induced property switch are presented. The synthetic procedure for designing the solvents is discussed, along with detailed characterizations on both solvent forms to serve as a tool for optimal solvent identification as well as future solvent design. A reflectance infrared spectroscopic technique is introduced to allow for the examination of CO₂ and solvent composition under high pressures and temperatures. The magnitude of solvent property changes afforded by this "switch" creates opportunities for sustainable processing; discussed are the application to coupling reactions and separations, and CO₂ capture. The switchable solvents are shown to serve as effective media for running reactions, with the switch providing facile recovery of products and catalysts for solvent recycling. Lastly, the switch itself is exploited to provide for the separation of CO₂ from low partial pressure feed streams, and structure-property relationships were successfully used to develop next generation materials with enhanced absorption capacities. The viscosity of the solvents, as a function of temperature and composition, is also presented.
19

Adaptable, scalable, probabilistic fault detection and diagnostic methods for the HVAC secondary system

Li, Zhengwei 30 March 2012 (has links)
As the popularity of building automation system (BAS) increases, there is an increasing need to understand/analyze the HVAC system behavior with the monitoring data. However, the current constraints prevent FDD technology from being widely accepted, which include: 1)Difficult to understand the diagnostic results; 2)FDD methods have strong system dependency and low adaptability; 3)The performance of FDD methods is still not satisfactory; 4)Lack of information. This thesis aims at removing the constraints, with a specific focus on air handling unit (AHU), which is one of the most common HVAC components in commercial buildings. To achieve the target, following work has been done in the thesis. On understanding the diagnostic results, a standard information structure including probability, criticality and risk is proposed. On improving method's adaptability, a low system dependency FDD method: rule augmented CUSUM method is developed and tested, another highly adaptable method: principal component analysis (PCA) method is implemented and tested. On improving the overall FDD performance (detection sensitivity and diagnostic accuracy), a hypothesis that using integrated approach to combine different FDD methods could improve the FDD performance is proposed, both deterministic and probabilistic integration approaches are implemented to verify this hypothesis. On understanding the value of information, the FDD results for a testing system under different information availability scenarios are compared. The results show that rule augmented CUSUM method is able to detect the abrupt faults and most incipient faults, therefore is a reliable method to use. The results also show that overall improvement of FDD method is possible using Bayesian integration approach, given accurate parameters (sensitivity and specificity), but not guaranteed with deterministic integration approach, although which is simpler to use. The study of information availability reveals that most of the faults can be detected in low and medium information availability scenario, moving further to high information availability scenario only slightly improves the diagnostic performance. The key message from this thesis to the community is that: using Bayesian approach to integrate high adaptable FDD methods and delivering the results in a probability context is an optimal solution to remove the current constraints and push FDD technology to a new position.
20

Role of carbon dioxide in gas expanded liquids for removal of photoresist and etch residue

Song, Ingu 08 October 2007 (has links)
Progress in the microelectronics industry is driven by smaller and faster transistors. As feature sizes in integrated circuits become smaller and liquid chemical waste becomes an even greater environmental concern, gas expanded liquids (GXLs) may provide a possible solution to future device fabrication limitations relative to the use of liquids. The properties of GXLs such as surface tension can be tuned by the inclusion of high pressure gases; thereby, the reduced surface tension will allow penetration of cleaning solutions into small features on the nanometer scale. In addition, the inclusion of the gas decreases the amount of liquid necessary for the photoresist and etch residue removal processes. This thesis explores the role of CO2-based GXLs for photoresist and etch residue removal. The gas used for expansion is CO2 while the liquid used is methanol. The cosolvent serving as the removal agent is tetramethyl ammonium hydroxide (TMAH) which upon reacting with CO2 becomes predominantly tetramethyl ammonium bicarbonate (TMAB).

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