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This thesis concerns the role of geometric imperfections on assemblies in which the location of a target part is dependent on supports at two features. In some applications, such as a turbo-machine rotor that is supported by a series of parts at each bearing, it is the interference or clearance

This thesis concerns the role of geometric imperfections on assemblies in which the location of a target part is dependent on supports at two features. In some applications, such as a turbo-machine rotor that is supported by a series of parts at each bearing, it is the interference or clearance at a functional target feature, such as at the blades that must be controlled. The first part of this thesis relates the limits of location for the target part to geometric imperfections of other parts when stacked-up in parallel paths. In this section parts are considered to be rigid (non-deformable). By understanding how much of variation from the supporting parts contribute to variations of the target feature, a designer can better utilize the tolerance budget when assigning values to individual tolerances. In this work, the T-Map®, a spatial math model is used to model the tolerance accumulation in parallel assemblies. In other applications where parts are flexible, deformations are induced when parts in parallel are clamped together during assembly. Presuming that perfectly manufactured parts have been designed to fit perfectly together and produce zero deformations, the clamping-induced deformations result entirely from the imperfect geometry that is produced during manufacture. The magnitudes and types of these deformations are a function of part dimensions and material stiffnesses, and they are limited by design tolerances that control manufacturing variations. These manufacturing variations, if uncontrolled, may produce high enough stresses when the parts are assembled that premature failure can occur before the design life. The last part of the thesis relates the limits on the largest von Mises stress in one part to functional tolerance limits that must be set at the beginning of a tolerance analysis of parts in such an assembly.
ContributorsJaishankar, Lupin Niranjan (Author) / Davidson, Joseph K. (Thesis advisor) / Shah, Jami J. (Committee member) / Mignolet, Marc P (Committee member) / Arizona State University (Publisher)
Created2012
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Description
Haiti has witnessed high deforestation rates in recent decades, caused largely by the fuel needs of a growing population. The resulting soil loss is estimated to have contributed towards a decline in agricultural productivity of 0.5% -1.2% per year since 1997. Recent studies show the potential of biochar use through

Haiti has witnessed high deforestation rates in recent decades, caused largely by the fuel needs of a growing population. The resulting soil loss is estimated to have contributed towards a decline in agricultural productivity of 0.5% -1.2% per year since 1997. Recent studies show the potential of biochar use through pyrolysis technology to increase crop yields and improve soil health. However, the appropriateness of this technology in the context of Haiti remains unexplored. The three objectives of this research were to identify agricultural- and fuel-use-related needs and gaps in rural Haitian communities; determine the appropriateness of biochar pyrolyzer technology, used to convert agricultural biomass into a carbon-rich charcoal; and develop an action-oriented plan for use by development organizations, communities, and governmental institutions to increase the likelihood of adoption. Data were collected using participatory rural appraisal techniques involving 30 individual interviews and three focus-group discussions in the villages of Cinquantin and La Boule in the La Coupe region of central Haiti. Topics discussed include agricultural practices and assets, fuel use and needs, technology use and adoption, and social management practices. The Sustainable Livelihoods framework was used to examine the assets of households and the livelihood strategies being employed. Individual and focus group interviews were analyzed to identify specific needs and gaps. E.M. Rogers' Diffusion of Innovations theory was used to develop potential strategies for the introduction of pyrolysis technology. Preliminary results indicate biochar pyrolysis has potential to address agricultural and fuel needs in rural Haiti. Probable early adopters of biochar technology include households that have adopted new agricultural techniques in the past, and those with livestock. Education about biochar, and a variety of pyrolysis technology options from which villagers may select, are important factors in successful adoption of biochar use. A grain mill as an example in one of the study villages provides a model of ownership and use of pyrolysis technology that may increase its likelihood of successful adoption. Additionally, women represent a group that may be well suited to control a new local biochar enterprise, potentially benefiting the community.
ContributorsDelaney, Michael Ryan (Author) / Aggarwal, Rimjhim (Thesis advisor) / Chhetri, Nalini (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Mostly, manufacturing tolerance charts are used these days for manufacturing tolerance transfer but these have the limitation of being one dimensional only. Some research has been undertaken for the three dimensional geometric tolerances but it is too theoretical and yet to be ready for operator level usage. In this research,

Mostly, manufacturing tolerance charts are used these days for manufacturing tolerance transfer but these have the limitation of being one dimensional only. Some research has been undertaken for the three dimensional geometric tolerances but it is too theoretical and yet to be ready for operator level usage. In this research, a new three dimensional model for tolerance transfer in manufacturing process planning is presented that is user friendly in the sense that it is built upon the Coordinate Measuring Machine (CMM) readings that are readily available in any decent manufacturing facility. This model can take care of datum reference change between non orthogonal datums (squeezed datums), non-linearly oriented datums (twisted datums) etc. Graph theoretic approach based upon ACIS, C++ and MFC is laid out to facilitate its implementation for automation of the model. A totally new approach to determining dimensions and tolerances for the manufacturing process plan is also presented. Secondly, a new statistical model for the statistical tolerance analysis based upon joint probability distribution of the trivariate normal distributed variables is presented. 4-D probability Maps have been developed in which the probability value of a point in space is represented by the size of the marker and the associated color. Points inside the part map represent the pass percentage for parts manufactured. The effect of refinement with form and orientation tolerance is highlighted by calculating the change in pass percentage with the pass percentage for size tolerance only. Delaunay triangulation and ray tracing algorithms have been used to automate the process of identifying the points inside and outside the part map. Proof of concept software has been implemented to demonstrate this model and to determine pass percentages for various cases. The model is further extended to assemblies by employing convolution algorithms on two trivariate statistical distributions to arrive at the statistical distribution of the assembly. Map generated by using Minkowski Sum techniques on the individual part maps is superimposed on the probability point cloud resulting from convolution. Delaunay triangulation and ray tracing algorithms are employed to determine the assembleability percentages for the assembly.
ContributorsKhan, M Nadeem Shafi (Author) / Phelan, Patrick E (Thesis advisor) / Montgomery, Douglas C. (Committee member) / Farin, Gerald (Committee member) / Roberts, Chell (Committee member) / Henderson, Mark (Committee member) / Arizona State University (Publisher)
Created2011
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Description
"Seventy five percent of the world's poor live in rural areas of developing countries, where most people's livelihoods rely directly on agriculture." (USAid, 2014) Reduced levels of crop production and the accompanying problems of malnourishment exist all over the world. In rural Peru, for example, 11 percent of the population

"Seventy five percent of the world's poor live in rural areas of developing countries, where most people's livelihoods rely directly on agriculture." (USAid, 2014) Reduced levels of crop production and the accompanying problems of malnourishment exist all over the world. In rural Peru, for example, 11 percent of the population is malnourished. (Global Healthfacts.org, 2012) Since the success in agriculture relies importantly on the fertility of the soil, it is imperative that any efforts at reversing this trend be primarily directed at improving the existing soils. This, in turn, will increase crop yields, and if done properly, will also conserve natural resources and maximize profits for farmers. In order to improve the lives of those at the bottom of the pyramid through agriculture, certain tools and knowledge must be provided in order to empower such persons to help themselves. An ancient method of soil improvement, known as Terra Preta do Indio (Indian dark earth), was discovered by Anthropologists in the 1800's. These dark, carbon-rich, soils are notable for their high fertility, high amounts of plant available nutrients, and their high moisture retention rates. The key to their long-lasting fertility and durability is the presence of high levels of biochar, a highly stable organic carbon \u2014 produced when organic matter (crop residues, food waste, manure, etc.) is burned at low temperatures in the absence of oxygen. Research has shown that when charcoal (biochar) and fertilizers are combined, it can yield as much as 880 percent more than when fertilizers are used by themselves. (Steiner, University of Bayreuth, 2004)
ContributorsStefanik, Kathleen Ann (Author) / Henderson, Mark (Thesis director) / Johnson, Nathan (Committee member) / Barrett, The Honors College (Contributor) / Human Systems Engineering (Contributor)
Created2014-12
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Description
In Nepal, a viable solution for environmental management, food and water security is the production of biochar, a carbon material made of plants burned in low oxygen conditions. Currently, the biochar is manufactured into charcoal briquettes and sold on the market for energy usage, however this may not provide the

In Nepal, a viable solution for environmental management, food and water security is the production of biochar, a carbon material made of plants burned in low oxygen conditions. Currently, the biochar is manufactured into charcoal briquettes and sold on the market for energy usage, however this may not provide the best value for community members who make less than a dollar a day and sell the biochar for as little as 16 cents per kilogram. This thesis seeks to improve the price of biochar and help their livelihoods as well as explore innovative solutions. One way to improve biochar while addressing water security problems is to create activated carbon, which uses its heightened porosity to adsorb contaminants from water or air. Activated carbon is also worth 100x the price of biochar. This thesis evaluates the mass content of biochar produced in Nepal, comparing it to literature values, and performed gravimetric and thermogravimetric analysis, comparing it to Activated Charcoal. Analysis of the biochar system used in Nepal reveals that the byproduct of biochar, biofuels, is highly underutilized. The higher heating value of biochar is 17.95 MJ/kg, which is much lower than other charcoals which burn around 30 MJ/kg. Low volatile content, less than 5% in biochar, provides a smokeless briquette, which is favorable on the market, however low heating value and misutilizations of biofuels in the solution indicate that creating a briquette is not the best use for biochar. Ash content is really high in this biochar, averaging around 12% and it may be due to the feedstock, a composite between Mikania and Lantana, which have 5.23% and 10.77% ash content respectively. This does not necessarily indicate a poor quality biochar, since ash values can vary widely between charcoals. Producing activated charcoal from this biochar is a favored solution; it will increase the price of the biochar, provide water security solutions, and be an appropriate process for this biochar, where heating value and underutilization of biofuel byproducts pose a problem.
ContributorsCayer, Joelle Marie Caroline (Author) / Chhetri, Netra (Thesis director) / Henderson, Mark (Committee member) / Deng, Shuguang (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
After visiting Nepal and seeing the problem of potable drinking water, there needed to be a solution to purify it. Simultaneously, local national forests have been overrun with two invasive plant species: Mikania micrantha and Lantana camara. Both a very fast-growing species and can be turned into biochar. If the

After visiting Nepal and seeing the problem of potable drinking water, there needed to be a solution to purify it. Simultaneously, local national forests have been overrun with two invasive plant species: Mikania micrantha and Lantana camara. Both a very fast-growing species and can be turned into biochar. If the resulting is made through an effective process, then the community would be able to work less making each batch of biochar and make more money per batch, whereby the market already exists. The community could grow their profits even further by activating the created charcoal, which fetches an even better price. Most Importantly, among other important uses, the activated charcoal could also be used in clean drinking water systems. The prospect of using activated charcoal as water purifying agents can be tested in a future design of experiments. This design of experiments would assess the effectiveness of the activated charcoal, to determine which pore size is the most cost effective at filtering out pollutants. This thesis focuses on researching different types of biochar kilns, clean drinking water systems, and the use of charcoal in clean drinking water systems.
ContributorsBarron, Timothy (Author) / Chhetri, Netra (Thesis director) / Henderson, Mark (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
This thesis sought to better understand the process of creating biochar in kilns representative of those used in current biochar processes in Chitwan National Park, Nepal and surrounding areas. The project had two main objectives: First, design and build a scale kiln representative of those in Nepal. This will allow

This thesis sought to better understand the process of creating biochar in kilns representative of those used in current biochar processes in Chitwan National Park, Nepal and surrounding areas. The project had two main objectives: First, design and build a scale kiln representative of those in Nepal. This will allow a multitude of future projects to have access to a well-built kiln in which to run experiments, probe conditions and overall understand the process of pyrolysis. After approval of the plan and construction the second phase of the project began. Second, using the scaled kiln, pyrolyze quantities of biomass and capture the temperature profiles as the burn is started through until it is completed. Using qualitative methods the biochar was then analyzed and this quality compared against the temperature profiles captured. Using these profiles it was hoped that a relationship between how the temperature profiles behave and the quality of the biochar can be produced. The maximum temperature was also be analyzed to find useful correlations to the behavior of the process within the kiln. The project did not find any useful correlation between the maximum temperatures, but it did find useful correlations between temperature profiles and the resulting biochar. A description of how to analyze biochar in the field was also established to help researchers and farmers rate biochar quality while in the field. The kiln itself is housed on the Polytechnic Campus of Arizona State University in the Global Resolve outside storage area at the time of writing.
ContributorsCluff, Dallin Michael (Author) / Henderson, Mark (Thesis director) / Roger, Brad (Committee member) / Engineering Programs (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12