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- Creators: Poulenc, Francis, 1899-1963
ContributorsPoulenc, Francis, 1899-1963 (Composer)
ContributorsPoulenc, Francis, 1899-1963 (Composer)
ContributorsPoulenc, Francis, 1899-1963 (Composer)
ContributorsPoulenc, Francis, 1899-1963 (Composer)
Description
This report analyzes the potential for accumulation of boron in direct potable reuse. Direct potable reuse treats water through desalination processes such as reverse osmosis or nanofiltration which can achieve rejection rates of salts sometimes above 90%. However, boron achieves much lower rejection rates near 40%. Because of this low rejection rate, there is potential for boron to accumulate in the system to levels that are not recommended for potable human consumption of water. To analyze this issue a code was created that runs a steady state system that tracks the internal concentration, permeate concentration, wastewater concentration and reject concentration at various rejection rates, as well as all the flows. A series of flow and mass balances were performed through five different control volumes that denoted different stages in the water use. First was mixing of clean water with permeate; second, consumptive uses; third, addition of contaminant; fourth, wastewater treatment; fifth, advanced water treatments. The system cycled through each of these a number of times until steady state was reached. Utilities or cities considering employing direct potable reuse could utilize this model by estimating their consumption levels and input of contamination, and then seeing what percent rejection or inflow of makeup water they would need to obtain to keep boron levels at a low enough concentration to be fit for consumption. This code also provides options for analyzing spikes and recovery in the system due to spills, and evaporative uses such as cooling towers and their impact on the system.
ContributorsDoidge, Sydney (Author) / Fox, Peter (Thesis director) / Perreault, Francois (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
There are many factors that influence the college decision process, but rural students face a unique set of challenges because of the environment in which they make the decision. This is a qualitative study that combines a review of previous literature on the subject with a survey of twelve students from the graduating class of 2011 in a rural area of Arizona. Results from the interviews found that the rural students consider the perception of importance of a college degree, parental influence, and self-discovery as important factors in the decision making process. In addition, not all non-college-going students felt that college was necessary for a better quality of living, but did express desire for more development opportunities while in high school. The findings resulted in the following recommendations for local educators to help students better navigate the college decision process: teach parents how to have more meaningful conversations, provide step-by-step assistance to students about the college application process, and provide more opportunities for self/educational/career development to students.
ContributorsCrow, Ellyse Diann (Author) / Wang, Lili (Thesis director) / Hollin, Michelle (Committee member) / Barrett, The Honors College (Contributor) / Division of Educational Leadership and Innovation (Contributor) / School of Community Resources and Development (Contributor) / W. P. Carey School of Business (Contributor) / Department of Management (Contributor)
Created2015-05
Description
The 8.1 magnitude earthquake that struck Mexico City in 1985 left 10,000 people dead, and over 400 buildings collapsed. The extent of the damage left behind by this powerful quake has been extensively studied to make improvements to engineering and architectural practices in earthquake-prone areas of the world. Thirty-two years later, on the exact anniversary of the devastating earthquake, Mexico City was once again jolted by a 7.1 magnitude earthquake. Although still significant, the 2017 earthquake collapsed only about a tenth of the buildings collapsed by the 1985 Earthquake, and in turn resulted in a lower death toll. Even though these earthquakes struck in the same seismic region, their effects were vastly different. This thesis completes a comparison between the two earthquakes focusing on the structural impacts including background on Mexico City's unique geology, basic concepts necessary to understand the response of structures to earthquake excitation, and structural failure modes observed in both earthquakes. The thesis will also discuss the earthquake's fundamental differences that led to the discrepancy in structural damage and ultimately in lower death tolls. Of those discussed, is the types of buildings that were targeted and collapsed. In 1985, buildings with 6 or more floors had the highest damage category. Resonance frequencies of these buildings were similar to the resonance frequencies of the subsoil, leading to amplified oscillations, and ultimately in failure. The 2017 earthquake did not have as much distance from the epicenter for the high frequency seismic waves to be absorbed. In contrast, the shorter, faster waves that reached the capital affected smaller buildings, and spared most tall buildings.
ContributorsGonzalez, Diana Laura (Author) / Hjelmstad, Keith (Thesis director) / Ward, Kristen (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The loading provisions were compared between the ASCE 7-10 standard and ASCE 7-16 standard. Two different structural models were considered: an office building with a flat roof located in Tempe and a community center with a gable roof located in Flagstaff. The following load types were considered: dead, live, wind, and snow loads. The only major changes between the standards were found in the wind load calculations. The winds loads were reduced by approximately 22% for the office building in Tempe and 37% for the community center in Flagstaff. A structural design was completed for the frame of the Flagstaff community building. There was a 19% reduction in cost from the design using ASCE 7-10 provisions compared to the design utilizing ASCE 7-16 provisions, leading to a saving of $7,599.17. The reduction in loading, and subsequently more cost-effective design, is attributed to the reduction in basic wind speed for the region and consideration of the ground elevation factor. The introduction of the new ASCE 7-16 standard was met with criticism, especially over the increase in specific coefficients in the wind load and seismic load chapters. Proponents of ASCE 7-16 boast that the new chapter on tsunami loads, new maps for various environmental loads, and a new electronic hazard are some of the merits of the newest standard. Others still question whether the complexity of the provisions is necessary and call for further improvements for the wind and seismic provisions. While tension exists in the desire for a simple standard, ASCE 7-16 prioritizes in having its provisions provide economical and reliable results. More consideration could be devoted to developing a more convenient standard for users. Regardless, engineering professionals should be able to adapt alongside newly developed practices and newly discovered data.
ContributorsCajegas, Cyam Joshua Dato (Author) / Rajan, Subramaniam (Thesis director) / Neithalath, Narayanan (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Consumers purchase point-of-use (POU) devices to further improve the quality of water provided by the tap. As awareness increases of harmful contaminants, an emerging market of advanced POU with claims of removing beyond what a typical activated carbon filter is capable of, such as heavy metals. This research compares four commercially available pitcher filters; two that claim to remove arsenic and hexavalent chromium and two without such claims. Arsenate (As (V)) and hexavalent chromium (Cr (VI)) co-occur in natural geologic formations and are known to have harmful effects on humans when ingested. Pitcher filters Epic Water Filter and Aquagear had claims of removing both As (V) and Cr (VI) up to 99% with a capacity of nearly 200 gallons. In contrast, pitcher filters Brita and Pur had no claims for removal of As(V) and Cr(VI) with a 40-gallon lifespan. A series of experiments were conducted to first determine the efficiency of each filter, then to add the ability or improve removal of As(V) and Cr(VI) in one filter for future design implementations. Experiment 1 was conducted by treating 100 gallons of spiked tap water (50 ppb for As (V) and 100 ppb for Cr (VI)) with each filter. All four pitcher filters showed low performance, resulting in Pur with the lowest removal percentage of 2% and Aquagear with the highest percentage 16% for As (V). For Cr (VI) Pur performed the worst with a removal of 5% and Brita had the best performance of 15%. The functionality of Brita was improved by embedding a selective ion exchange media, which when nanotized successfully removed Cr (VI) in previous studies. The optimal mass of resin to add to the pitcher was experimentally determined as 18.9 grams through Experiment 2. Finally, Experiment 3 compared an alternative placement of the resin material using the same 18.9 grams. The performance in Experiment 3 was significantly worse than Experiment 2. The final recommendation for future design implementation was to add 18.9 grams of SIR-700 resin below the filter media for optimum performance. Overall, the results demonstrate the limited removal of As(V) and Cr(VI) by the four commercial pitcher filters and show that by adding selective ion exchange media, the POUs can be nano-enabled to effectively remove As(V) and Cr(VI) from water.
ContributorsDietrich, Lisa Keri (Author) / Westerhoff, Paul (Thesis director) / Perreault, Francois (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Asphalt pavements deteriorate over time and are subjected to various distresses like rutting, fatigue cracking, stripping, raveling, etc. In this study, an experiment to indirectly assess aggregate stripping was completed in order to evaluate the effect of type of binder, and aging on the binder-aggregate bond under dry conditioning. The asphalts used in the study are commonly used in the state of Arizona, which included both non-polymer modified and polymer modified asphalts. The phenomenon of stripping was simulated using the Bitumen Bond Strength Test (BBS) and evaluated for Arizona binders. The BBS test is a simple test that measures the "pull-off" tensile strength of the bond between asphalt and the aggregate. Polymer modified binders were found to have lower pull-off strength in comparison to the non-modified or neat binder which were found to possess greater pull-off strength, but lower elasticity, causing the failure to become brittle and spontaneous. However, when aged binder was used, the bond strength expectedly reduced for non-polymer modified asphalts but surprisingly increased for polymer modified asphalts. Both un-aged neat and polymer modified binders were observed to have a cohesive failure whereas only the aged polymer modified binders failed in cohesion. The aged non-polymer modified binders were seen to have an adhesive failure.
ContributorsPonce, Esai Jonathon (Author) / Kaloush, Kamil (Thesis director) / Gundla, Akshay (Committee member) / Civil, Environmental and Sustainable Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05