Matching Items (3)
Filtering by
- All Subjects: engineering
- All Subjects: Polymers--Deterioration.
- All Subjects: Thermoplastic composites
- Genre: Academic theses
- Member of: Theses and Dissertations
Description
Front end planning (FEP) is an essential and valuable process that helps identify risks early in the capital project planning phases. With effective FEP, risks can potentially be mitigated through development of detailed scope definition and subsequent efficient project resource use. The thesis describes the FEP process that has been developed over the past twenty years by the Construction Industry Institute (CII). Specifically, it details the FEP tools developed for early project planning and the data gathered to analyze the tools used within the CII community. Data from a March 2011 survey are given showing the tools commonly used, how those tools are used and the common barriers faced that prohibit successful FEP implementation. The findings from in-depth interviews are also shared in the thesis. The interviews were used to gather detail responses from organizations on the implementation of their FEP processes. In total, out of the 116 CII organizations, 59 completed the survey and over 75 percent of the respondents used at least one CII tool in their front end planning processes. Of the 59 survey respondents, 12 organizations participated in the in-depth interviews. The thesis concludes that CII organizations continue to find value in CII FEP tools due to the increase tool usage. Also the thesis concludes that organizations must have strong management commitment, smart succession planning and a standardized planning process to increase the likelihood of successful FEP strategies.
ContributorsBosfield, Roberta Patrice (Author) / Gibson, G.Edward (Thesis advisor) / Wiezel, Avi (Committee member) / Ernzen, James (Committee member) / Arizona State University (Publisher)
Created2012
Description
With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that mimic the strength characteristics of a comparable part of the same design and materials created using injection molding. In achieving this goal the production cost can be reduced by eliminating the initial investment needed for the creation of expensive tooling. This initial investment reduction will allow for a wider variant of products in smaller batch runs to be made available. This thesis implements the use of ultraviolet (UV) illumination for an in-process laser local pre-deposition heating (LLPH). By comparing samples with and without the LLPH process it is determined that applied energy that is absorbed by the polymer is converted to an increase in the interlayer temperature, and resulting in an observed increase in tensile strength over the baseline test samples. The increase in interlayer bonding thus can be considered the dominating factor over polymer degradation.
ContributorsKusel, Scott Daniel (Author) / Hsu, Keng (Thesis advisor) / Sodemann, Angela (Committee member) / Kannan, Arunachala M (Committee member) / Arizona State University (Publisher)
Created2017
Description
The solar energy sector has been growing rapidly over the past decade. Growth in renewable electricity generation using photovoltaic (PV) systems is accompanied by an increased awareness of the fault conditions developing during the operational lifetime of these systems. While the annual energy losses caused by faults in PV systems could reach up to 18.9% of their total capacity, emerging technologies and models are driving for greater efficiency to assure the reliability of a product under its actual application. The objectives of this dissertation consist of (1) reviewing the state of the art and practice of prognostics and health management for the Direct Current (DC) side of photovoltaic systems; (2) assessing the corrosion of the driven posts supporting PV structures in utility scale plants; and (3) assessing the probabilistic risk associated with the failure of polymeric materials that are used in tracker and fixed tilt systems.
As photovoltaic systems age under relatively harsh and changing environmental conditions, several potential fault conditions can develop during the operational lifetime including corrosion of supporting structures and failures of polymeric materials. The ability to accurately predict the remaining useful life of photovoltaic systems is critical for plants ‘continuous operation. This research contributes to the body of knowledge of PV systems reliability by: (1) developing a meta-model of the expected service life of mounting structures; (2) creating decision frameworks and tools to support practitioners in mitigating risks; (3) and supporting material selection for fielded and future photovoltaic systems. The newly developed frameworks were validated by a global solar company.
As photovoltaic systems age under relatively harsh and changing environmental conditions, several potential fault conditions can develop during the operational lifetime including corrosion of supporting structures and failures of polymeric materials. The ability to accurately predict the remaining useful life of photovoltaic systems is critical for plants ‘continuous operation. This research contributes to the body of knowledge of PV systems reliability by: (1) developing a meta-model of the expected service life of mounting structures; (2) creating decision frameworks and tools to support practitioners in mitigating risks; (3) and supporting material selection for fielded and future photovoltaic systems. The newly developed frameworks were validated by a global solar company.
ContributorsChokor, Abbas (Author) / El Asmar, Mounir (Thesis advisor) / Chong, Oswald (Committee member) / Ernzen, James (Committee member) / Arizona State University (Publisher)
Created2017