Matching Items (311)
Description
Hydrocephalus is a chronic neurological condition affecting an estimated 1 in every 500 infants born. The most common treatment method involves surgical implantation of a shunt system; however these systems have a high failure rate resulting in repeat invasive surgeries. A promising approach being researched to treat hydrocephalus is a miniaturized valve composed of silicon and a hydrogel material. The current chemical cross-linker used in the hydrogel, EGDMA, however is susceptible to hydrolytic cleavage due to the ester groups.
This thesis proposed a novel hydrogel composed of a HEMA backbone and methacrylated Jeffamines as the chemical cross-linker as a possible replacement for the HEMA and EGDMA hydrogel used currently in the hydrocephalus valve. Jeffamine EDR-148 was methacrylated through reaction with methacryloyl chloride and characterized using 1H NMR spectroscopy. Subsequently, hydrogels were synthesized, using both EGDMA and EDR-MA, and the properties were compared through swelling and rotational rheology. Finally, degradation tests were performed to compare the hydrolytic stability of the two cross-linkers.
Results of this work demonstrated that Jeffamine EDR-148 was able to be successfully methacrylated and used to synthesize a hydrogel. The new hydrogel was shown to have comparable mechanical behavior and robustness to the EGDMA hydrogel, with slightly increased swelling capabilities. Degradation tests did not confirm the theory that the EDR-MA gels would exhibit greater hydrolytic stability however. Future work includes perfecting the purification of the EDR-MA, conducting a longer-term degradation study at physiologically relevant conditions, and demonstrating the tunability of the Jeffamine hydrogels.
This thesis proposed a novel hydrogel composed of a HEMA backbone and methacrylated Jeffamines as the chemical cross-linker as a possible replacement for the HEMA and EGDMA hydrogel used currently in the hydrocephalus valve. Jeffamine EDR-148 was methacrylated through reaction with methacryloyl chloride and characterized using 1H NMR spectroscopy. Subsequently, hydrogels were synthesized, using both EGDMA and EDR-MA, and the properties were compared through swelling and rotational rheology. Finally, degradation tests were performed to compare the hydrolytic stability of the two cross-linkers.
Results of this work demonstrated that Jeffamine EDR-148 was able to be successfully methacrylated and used to synthesize a hydrogel. The new hydrogel was shown to have comparable mechanical behavior and robustness to the EGDMA hydrogel, with slightly increased swelling capabilities. Degradation tests did not confirm the theory that the EDR-MA gels would exhibit greater hydrolytic stability however. Future work includes perfecting the purification of the EDR-MA, conducting a longer-term degradation study at physiologically relevant conditions, and demonstrating the tunability of the Jeffamine hydrogels.
ContributorsTrimble, Kari Leigh (Author) / Green, Matthew (Thesis director) / Chae, Junseok (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Intellectual property law and the controversy surrounding its nuances, loopholes, and obscure definitions have existed and grown since the inception of the original U.S. Constitution. The original idea was to legislate a way so that innovators and inventors of every generation could be incentivised to create new products which could increase the efficiency and productivity in all aspects of American life. However, the generalizations placed in the law, perhaps for the purpose of giving inventors more leeway, has become, over time, a double-edged sword. Because lawsuits and the lucrative settlements that follow were attached to violating intellectual property law, other individuals have mischievously used this to their advantage, namely creating as many random ideas as possible and patenting them so that when someone ingeniously creates an actual product or physical manifestation, those individuals can sue that inventor for supposedly “stealing” their “idea”. These individuals are basically unable to bring their idea to life so they set traps for those who can. So the law, which originally was supposed to motivate Americans to create has now become a weapon that can be used against those true innovators. Our topic then is to look more in-depth at a specific aspect under the broad umbrella of intellectual property law: can intellectual property law apply to biotechnology? We want to look into different forms of biotechnology, medical devices, and pharmaceuticals, observe where patent law has deviated from its original path and where it is going.
ContributorsLai, Edward (Co-author) / Goudamanis, Christy (Co-author) / Takahashi, Timothy (Thesis director) / VanAuker, Michael (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Fossil fuels have been the primary source of energy in the world for many decades. However, they are among the top contributors of the greenhouse gas emissions in the atmosphere. The objective of this research was to produce a more environmentally friendly biofuel from Algae-Helix and Salicornia biomasses. Experiments were conducted using a hydrothermal liquefaction (HTL) technique in the HTL reactor to produce biofuel that can potentially replace fossil fuel usage. Hydrothermal Liquefaction is a method used to convert the biomass into the biofuels. HTL experiments on Algae-Helix and Salicornia at 200°C-350°C and 430psi were performed to investigate the effect of temperature on the biocrude yield of the respective biomass used. The effect of the biomass mixture (co-liquefaction) of Salicornia and algae on the amount of biocrude produced was also explored. The biocrude and biochar (by-product) obtained from the hydrothermal liquefaction process were also analyzed using thermogravimetric analyzer (TGA). The maximum biocrude yield for the algae-helix biomass and for the Salicornia biomass were both obtained at 300°C which were 34.63% and 7.65% respectively. The co-liquefaction of the two biomasses by 50:50 provided a maximum yield of 17.26% at 250°C. The co-liquefaction of different ratios explored at 250°C and 300°C concluded that Salicornia to algae-helix ratio of 20:80 produced the highest yields of 22.70% and 31.97%. These results showed that co-liquefaction of biomass if paired well with the optimizing temperature can produce a high biocrude yield. The TGA profiles investigated have shown that salicornia has higher levels of ash content in comparison with the algae-helix. It was then recommended that for a mixture of algae and Salicornia, large-scale biofuel production should be conducted at 250℃ in a 20:80 salicornia to algae biocrude ratio, since it lowers energy needs. The high biochar content left can be recycled to optimize biomass, and prevent wastage.
ContributorsLaideson, Maymary Everrest (Co-author) / Luboowa, Kato (Co-author) / Deng, Shuguang (Thesis director) / Nielsen, David (Committee member) / Chemical Engineering Program (Contributor) / Economics Program in CLAS (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Titanium dioxide (TiO2) is a photocatalytic material which has made its way into the European market for use within building materials (e.g. in photocatalytic cement). The air-cleaning and self-cleaning properties of TiO2 make it an attractive material for development. TiO2 has been widely studied to determine the mechanism by which it catalyzes reactions, but research into its use in photocatalytic cement has focused only on the percent pollutant removed and not the composition of the resulting gas. The current research focuses on examining the oxidation of methanol over the solid materials and the development of a methodology to study the formation of intermediates in the removal of the pollutant molecule. The initial methanol oxidation studies over the photocatalytic cement resulted in a reduction in the concentration of methanol and an increase in potential products. However, these studies identified several system challenges that led to a focus on the system design. It is recommended that future reactor systems optimize the transfer of material through the use of agitation and minimize the path length between the reactor cell and the FTIR gas cell. Furthermore, creating an air-tight system is paramount to the success of future studies.
ContributorsBenov, Emil Plamenov (Author) / Andino, Jean (Thesis director) / Schoepf, Jared (Committee member) / Chemical Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This project evaluates the success that a Food Waste assignment had on reducing food waste by exploring factors that suggest waste minimization. Previous ASB 370/394: Ethics of Eating students were surveyed regarding their thoughts on their current food waste behavior and what food waste strategies they implemented to reduce their waste. The success of the assignment was determined using SPSS statistical software. Respondents reported that foods that they waste the most were vegetables, fruits, and bread and most respondents indicated that they threw away 1-2 cups of food per week, typically only when they clean out their fridge and/or pantry. Participants revealed the main reasons for their food waste were “I buy too much,” followed by “do not have time to prepare the food I buy,” and “my produce didn’t look appealing anymore.” Based on the results from the survey, over 60% of respondents indicated that they had changed their food waste behavior to produce less waste. The Food Waste Assignment was deemed a success in encouraging students to limit their food waste due to the majority of students indicating they change their behavior after completing the assignment. The three main tactics students implemented to reduce their food waste were: “eating more leftovers,” “proper food storage,” and, “meal planning.” While the Food Waste Assignment was successful, ways to improve the assignment were still identified. To help students address their food waste behavior, reading or videos on ways to prevent food waste or suggestions for students to improve their food waste could be provided.
ContributorsMicksch, Jessica Lee (Co-author, Co-author) / Stotts, Rhian (Thesis director) / Bidner, Laura (Committee member) / Industrial, Systems & Operations Engineering Prgm (Contributor) / Environmental and Resource Management (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The algal fuel industry has existed since the 1980s without fully commercializing a product. Algal fuels are potentially viable replacements for fossil fuels due to their fast cultivation, high oil content, carbon dioxide sequestration during growth, and ability to be grown on non-arable land. For this thesis, six companies from 61 investigated were interviewed about their history with biofuels, technological changes they have gone through, and views for the future of the industry. All companies interviewed have moved away from fuel production largely due to high production costs and have moved primarily toward pharmaceuticals and animal feed production as well as wastewater treatment. While most do not plan to return to the biofuel industry in the near future, a return would likely require additional legislation, increased technological innovation, and coproduction of multiple products.
ContributorsMassey, Alexandria Rae (Author) / Parker, Nathan (Thesis director) / Agusdinata, Buyung (Committee member) / Chemical Engineering Program (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Engineering has historically been dominated by White men. However, in modern history, engineering is becoming more diverse as the opportunity to pursue engineering has become accessible to people of all races and genders. Yet, college ready high school students from nontraditional backgrounds—women, ethnic minorities, first-generation-to-college students, and those with financial need—often lack exposure to engineering, thus reducing their likelihood to pursue a career in this field. To create engineering learning experiences that can be expanded to a traditional high school science classroom, the Young Engineers Shape the World program at Arizona State University was consulted. The Young Engineers Shape the World program encourages women, notably the most underrepresented group in the engineering field, as well as other students of diverse backgrounds, to pursue engineering. The goal of this effort was to create a 3-contact hour chemical engineering based learning experience to help students in grades 10-11 learn about an application of chemical engineering. Using knowledge of chemical engineering, a soil pH testing activity was created, simulating a typical high school chemistry science experiment. In addition to measuring pH, students were asked to build a modern garden that contained a physical barrier that could protect the garden from acid rain while still allowing sunlight to reach the plant. Student feedback was collected in the form of an experience evaluation survey after each experience. Students found that the soil-moisture quality testing and design of a protective barrier was engaging. However, an iterative curriculum redesign-implement-evaluate effort is needed to arrive at a robust chemical engineering based design learning experience.
ContributorsOtis, Timothy Kevin (Author) / Ganesh, Tirupalavanam (Thesis director) / Schoepf, Jared (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Lithium-ion batteries that employ an electrolyte consisting of LiFSI and TMP are shown to have better cycle performance than conventional carbonate electrolyte batteries at elevated temperatures. Additionally, an inorganic alumina or silica separator also improves cycling performance at high temperatures. Half-cells of Li metal and Li2TiO3 were constructed with LiFSI/TMP electrolyte and inorganic separators and cycled at increasing temperatures. Their cycle performance was compared to batteries with the same anode and cathode material that were prepared with conventional components. Half-cells using either the novel electrolyte or inorganic separators were able to continue cycling at temperatures up to 80 ℃, long after the conventionally prepared batteries had failed. A cell with a combination of the LiFSI/TMP electrolyte and silica separator still showed 75% capacity retention after 10 cycles at 85 ℃ as well.
ContributorsHait, Liam Bennett (Author) / Lin, Jerry (Thesis director) / Rafiz, Kishen (Committee member) / Chemical Engineering Program (Contributor) / Computing and Informatics Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Improvement in carbon capture percentage was calculated as most effective in 10 mg/L-MEA BG-11 media, with improvement in carbon capture of 1.012% over the control. In studying the effect of agitation at 150 revolutions-per-minute (RPM) with a magnetic stir bar, it was found that mass transfer actually decreased. Future investigations are warranted to fully characterize the effect of different alkanolamine types, concentrations, and mixing regimens on mass transfer of CO2. In this thesis, emphasis was placed on experimental setup to allow for a discussion of the unexpected characteristics of the findings of the mass transfer experiments. Understanding the effect of experimental setup on mass transfer will be important in designing more effective methods of CO2 absorption for improving growth of cyanobacteria.
ContributorsMcallister, Cameron William (Author) / Nielsen, David (Thesis director) / Nannenga, Brent (Committee member) / School of Sustainability (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
A Study of the gasification of municipal solid waste (MSW) for hydrogen production was completed through research and statistical design of experiment. The study was done for general syngas production with conditions of high temperature and pressure. Waste samples from kitchen waste including rice, avocado, and egg shells were used. Dry orange blossom tree leaves were included and a very minimal fraction of used paper and Styrofoam. One of the components of the syngas predicted was hydrogen, but this study does not discuss techniques for the separation of the hydrogen from the syngas. A few suggestions, however, such as the use of gas chromatography and membranes are made for the study of the syngas and separation of the hydrogen from the syngas. A three level, three factors-half factorial design was used to analyze the impact of pressure, residence time and temperature on the gasification of MSW through a hydrothermal gasification approach. A series 4590 micro stirred reactor of 100mL was used to gasify MSW, but first, it was established through a TGA approach that the waste was about 5% moisture content and 55% organic content (OC). The TGA device used was the TG 209 F1 Libra. Results of the gasification indicated that the most important factor in the gasification of MSW is temperature, followed by residence time and that the syngas yield increases with a decreasing pressure of the system. A thermodynamic model relating the three factors and the syngas yield was developed.
ContributorsBuyinza, Allan Smith (Author) / Deng, Shuguang (Thesis director) / Nannenga, Brent (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05