Matching Items (296)
Description
Rotary equipment has been used widely in the processing of particulates for the last century, but low thermal efficiency and poor effluent uniformity continue to plague its performance. Consequently, these technologies contribute largely to modern energy waste, environmental pollution, and price inflation of products dependent on particulates in their manufacture. Large industries like pharmaceuticals and oil are impacted, yet minimal research has been conducted into optimizing the equipment because of costs associated with process shut-downs necessary to enable study. Recent works bypassed this constraint with simulations and scaled-down replicates to observe impact of common design parameters, fill level and rotation speed, on heating. This thesis supplanted these studies by investigating particle diameter as a control parameter to optimize heating. The thesis investigated methodologies to study a stainless-steel rotary drum model facilitating the conductive heating of a silica bed by external heat guns. Diameter was varied 2-4 mm at controlled fill levels and rotation speeds, and radial temperature profiles were measured with thermocouples. Heating performance was evaluated for efficiency and uniformity; the former by analyzing thermal time constants and average temperature progression across 70 minutes of operation, and the latter with corresponding radial temperature variances. It was theorized that the direct influence of size on transport properties would implicate an inverse correlation between diameter and performance, but results demonstrated no significance. The apparatus and methodology were still under development, so results were preliminary. From results, the study proposed setup modifications to refine results and future directions to guide follow-up research.
ContributorsDeBruin, Dylan (Author) / Emady, Heather (Thesis director) / Adepu, Manogna (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Genetic manipulation of human cell lines has widespread applications in biomedical research ranging from disease modeling to therapeutic development. Human cells are generally difficult to genetically engineer, but exogenous nucleic acids can be expressed by viral, chemical, or nonchemical means. Chemical transfections are simpler in practice than both viral and nonchemical delivery of genetic material, but often suffer from cytotoxicity and low efficiency. Novel aminoglycoside antibiotic-derived lipopolymers have been synthesized to mediate transgene delivery to human cells. These polymers are comprised of either paromomycin or apramycin crosslinked with glycerol diglycidylether and derivatized with stearoyl chloride in varying molar ratios. In this work, three previously identified target lipopolymers were screened against a library of human embryonic and induced pluripotent stem cell lines. Cells were transfected with a plasmid encoding green fluorescent protein (GFP) and expression was quantified with flow cytometry 48 hours after transfection. Transfection efficiency was evaluated between three distinct lipopolymers and four lipopolymer:DNA mass ratios. GFP expression was compared to that of cells transfected with commercially available chemical gene delivery reagent controls\u2014JetPEI, Lipofectamine, and Fugene\u2014at their recommended reagent:DNA ratios. Improved transgene expression in stem cell lines allows for improved research methods. Human stem cell-derived neurons that have been genetically manipulated to express phenotypic characteristics of aging can be utilized to model neurodegenerative diseases, elucidating information about these diseases that would be inaccessible in unmanipulated tissue.
ContributorsMehta, Frea (Author) / Brafman, David (Thesis director) / Rege, Kaushal (Committee member) / Chemical Engineering Program (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The objective of this research study is to assess the effectiveness of a poster-based messaging campaign and engineering-based activities for middle school and high school students to encourage students to explore and to pursue chemical engineering. Additionally, presentations are incorporated into both methods to provide context and improve understanding of the presented poster material or activity. Pre-assessments and post-assessments are the quantitative method of measuring effectiveness. For the poster campaign, ASU juniors and seniors participated in the poster campaign by producing socially relevant messages about their research or aspirations to address relevant chemical engineering problems. For the engineering-based activity, high school students participated in an Ira A. Fulton Schools of Engineering program "Young Engineers Shape the World" in which the students participated in six-hour event learning about four engineering disciplines, and the chemical engineering presentation and activity was conducted in one of the sessions. Pre-assessments were given at the beginning of the event, and the post-assessments were provided towards the end of the event. This honors thesis project will analyze the collected data.
ContributorsBueno, Daniel Tolentino (Author) / Ganesh, Tirupalavanam (Thesis director) / Parker, Hope (Committee member) / Chemical Engineering Program (Contributor) / School of Historical, Philosophical and Religious Studies (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Polymer modified tuning fork-based sensors were fabricated to assure reproducibility. The effect of system valve switching on the modified tuning fork-based sensors was studied at the different temperature. The response to Xylene gas sample on stabilized modified tuning fork-based sensors with temperature was defined while learning about the key analytical performance for chemical sensors to be used in the real-world application.
ContributorsRohit, Riddhi S (Author) / Forzani, Erica (Thesis director) / Tsow, Francis (Committee member) / Dean, W.P. Carey School of Business (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
The overall goal of this project is to use metallic nanoparticles to develop a thin, ductile amorphous film at room temperature. Currently bulk metallic glasses are mainly formed via quenching, which requires very high cooling rates to achieve an amorphous molecular structure. These formations often fail in a brittle manner. The advantages of using a bottom-up approach with amorphous nanoparticles at ambient conditions is that the ductility of the metal can be improved, and the process will be less energy intensive. The nanoparticles used are iron precursors with ATMP and DTPMP ligand stabilizers and dispersed in methanol. Three forms of experimentation were applied over the course of this project. The first was a simple, preliminary data collection approach where the particles were dispersed onto a glass slide and left to dry under various conditions. The second method was hypersonic particle deposition, which accelerated the particles to high speeds and bombarded onto a glass or silicon substrate. The third method used Langmuir-Blodgett concepts and equipment to make a film. Qualitative analyses were used to determine the efficacy of each approach, including SEM imaging. In the end, none of the approaches proved successful. The first approach showed inconsistencies in the film formation and aggregation of the particles. The results from the hypersonic particle deposition technique showed that not enough particles were deposited to make a consistent film, and many of the particles that were able to be deposited were aggregated. The Langmuir-Blodgett method showed potential, but aggregation of the particles and uneven film formation were challenges here as well. Although there are ways the three discussed experimental approaches could be optimized, the next best step is to try completely new approaches, such as convective assembly and 3D printing to form the ideal nanoparticle film.
ContributorsKline, Katelyn Ann (Author) / Lind, Mary Laura (Thesis director) / Cay, Pinar (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Zeolite thin films and membranes are currently a promising technology for pervaporation, gas separation and water purification. The main drawback with these technologies is that the synthesis is not consistent leading to varied and unreproducible results. The Langmuir-Blodgett technique is a robust method for transferring monolayers of molecules or crystals to a solid substrate. By measuring the surface pressure and controlling the area, reliable results can be achieved by transferring monolayers to different solid substrates. It has been shown previously that various types of zeolites can be functionalized and dispersed on the top of water. This is done by using an alcohol to form a hydrophobic coating on the surface of zeolite. The Langmuir-Blodgett can be used to create thin, compact films of zeolites for synthesizing and growing zeolite films. For the first reported time, cubic LTA Zeolites monolayers have been assembled with the Langmuir-Blodgett technique with multiple solvents and different sizes of zeolites. These films were characterized with Scanning Electron Microscopy and Pressure-Area Isotherms generated from the Langmuir-Blodgett. It was found that linoleic acid is a required addition to the zeolite dispersions to protect the mechanical stability during agitation. Without this addition, the LTA zeolites are broken apart and lose their characteristic cubic structure. This effect is discussed and a theory is presented that the interparticle interactions of the long alkane chain of the linoleic acid help reduce the shear stress on the individual zeolite particles, thus preventing them from being broken. The effect of size of the zeolites on the monolayer formation was also discussed. There seemed to be little correlation between the monolayer quality and formation as size was changed. However, to optimize the process, different concentrations and target pressures are needed. Lastly, the effect of the solvent was explored and it was found that there is a different between monolayer formations for different solvents likely due to differing interparticle interactions. Overall, LTA zeolites were successfully fabricated and the important factors to consider are the zeolite size, the solvent, and the amount of surfactant stabilizer added.
ContributorsDopilka, Andrew Michael (Author) / Lind, Mary Laura (Thesis director) / Cay, Pinar (Committee member) / Materials Science and Engineering Program (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Microbial dysbiosis is a condition where one’s gut bacteria colonies and species are imbalanced due to infection, antibiotics, and diet. Dysbiosis can lead to chronic illnesses like inflammatory bowel disease where current clinical treatments, such as probiotics and fecal matter transplant, have limitations from precisely delivering the right bacteria species in the right location in the gastrointestinal tract. With recent developments of magnetically actuated endoscopy bots which are precisely controlled and less invasive, magnetically-controlled robotic solutions can be applied to solving microbial dysbiosis. Two GI bot designs were developed, an accordion and concertina design, which differ in geometry. These designs involved a soft Ecoflex body, four ring magnets that are made of NdFeB and Ecoflex (in a 4:1 weight ratio) and magnetically actuated in the same direction, and a 3D-printed plastic capsule. The design rationale involved introducing the GI bot to external magnetic fields to deliver a payload, i.e. bacteria, for an application in solving microbial dysbiosis.
First, the design was optimized. Tensile and compression testing were used to determine an optimal Ecoflex coating combination with Ecoflex 00-10 making the first layer and Ecoflex 00-50 making the second layer. Afterward, two main functions were tested for in the robot: (1) precise magnetic control of the robot’s movement and direction and (2) magnetic control of the GI bot’s compression to trigger a payload release. Orientation control of the GI bot was demonstrated with a robot arm introducing a magnetic field of 4.08 mT. The test demonstrated proper control of the robot for five degrees of freedom. Lastly, delivery capabilities for the designs were established under a 173 mT external magnetic field with the accordion and concertina having dyed water (payload) release efficiencies of 35.33% and 40.16% respectively. From these results, a GI bot in the gut is achievable, and the accordion or concertina models provide a basis for further exploring and optimizing the safety and efficiency of this clinical robotic and magnetic solution. Moreover, the results showcase that magnetic actuation can be used for both orientation and delivery control as they are decoupled based on the external magnetic field strength.
ContributorsNguyen, Sophie (Author) / Marvi, Hamidreza (Thesis director) / Ceylan, Hakan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-12
Description
Shear-thinning hydrogels can be combined with other components to enable multi-functionality, including short fibers or particles [1]. For the inclusion of fibers, electrospinning has gained momentum as a simple technique to create tissue engineered scaffolds that mimic the fibrous nature of the extracellular matrix [2]. Combining electrospun fibers with a shear-thinning hydrogel has the potential to provide cells with essential physical cues while retaining injectability [3]. Cells do not adhere well to hyaluronic acid alone, thus, peptides or fibers can be incorporated into the hydrogel mixture to improve cell adherence and facilitate better cell-material interactions [1,4]. In the future, hydrogel composite systems including fibers and/or peptides can be manufactured using shear-thinning hydrogels as an ideal multi-functional, injectable hydrogel for tissue repair applications. To establish the effect of these components on composite injectability, injection force experiments were conducted to quantify break and glide force. There was no statistically significant difference in break force of Ad-MeHA + CD-HA guest-host hydrogels of 5 wt%, 6 wt%, 6 wt% with peptides, and 7 wt% HA. A significant difference (p < 0.001) in glide force of Ad-MeHA + CD-HA guest-host hydrogels between 5wt% and 7wt% was observed. There was no statistically significant difference in break force or glide force of Ad-MeHA + CD-HA 7 wt% guest-host hydrogels of 0, 0.5, or 1 wt% fibers (40 µm, 15% SPIONs).
ContributorsKhandelwal, Juhi (Author) / Holloway, Julianne (Thesis director) / Stabenfeldt, Sarah (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2025-05
Description
The gold standard of treatment for large bone defects remains autograft bone, which suffers from limited availability and donor-site morbidity. As an alternative, bone tissue engineering seeks to use a combination of cells, biomolecules, and biomaterials to regenerate functional bone tissue. Hydroxyapatite is a key component of bone tissue and is particularly important for its function. Here, we developed an approach to mineralize electrospun fibers to mimic native bone mineralization and serve as a scaffold for bone repair. Two types of electrospun fiber systems were investigated: polycaprolactone (PCL) and norbornene-functionalized cellulose acetate (nor-CA). PCL fiber surfaces were activated with sodium hydroxide and calcium phosphate. Next, the fibrous scaffolds were incubated in simulated body fluid (SBF) for seven days. Three types of SBF were chosen for incubation: conventional (C-SBF), revised (R-SBF), and 4x revised (4x R-SBF). Mineralization was assessed using energy-dispersive X-ray spectroscopy, Alizarin Red S staining, and scanning electron microscopy. Calcium phosphate and sodium chloride-based mineralization were observed for all SBF formulations for PCL. 4x R-SBF resulted in a calcium-to-phosphorus molar ratio most like native hydroxyapatite. R-SBF also had a calcium-to-phosphorus ratio similar to that of hydroxyapatite. R-SBF and 4x R-SBF resulted in lower values of sodium deposition on PCL when compared to C-SBF and had distinct regions of calcium-phosphate and sodium-chloride mineralization. Nor-CA was synthesized using a Boc2O esterification reaction between 5-norbornene-2-carboxylic acid and cellulose acetate, and analysis revealed the norbornene functionalization to be 60.02%. A fluorescent dye, 7-mercapto-4-methylcoumarin, was also successfully bound to the surface of nor-CA fibers using a UV-mediated thiol-ene reaction. The selectivity of the reaction between samples exposed to UV and kept in the dark requires improvement in future work.
ContributorsKupfer, Joshua (Author) / Holloway, Julianne (Thesis director) / Schwarz, Grace (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2025-05
Description
The process of wet granulation is a widely used process in which fine particles are agglomerated into a larger particle using a liquid binder. Understanding this process can help to standardize powder properties and improve transport efficiency. The practice of granulation is really influenced by various particle properties, powder properties, and specifications of equipment design. Determining how to predict the formation and breakage of granules in a consistent and predictable manner are important for its industrial applications and future research studies.
This study first looked at how penetration time of a drop into a powder bed depends on the impact velocity of the drop for several different viscosity liquid binders. A high-speed camera captured the impact time at several different height values of single-drop granulation. For lower viscosity liquids, penetration time decreases with increasing impact velocity. However, the trend reverses when using very high viscosity liquid binders. Another aim of this study was to look at granule breakage as a function of rotational speed in a granulator with several liquid binders with varying properties. 20 single-drop granules were made separately and placed in a high-shear granulator, where after 1 minute of mixing the final breakage fraction was recorded. Breakage rate generally increases with higher rotational speeds, however several factors such as viscosity, surface tension, and granule saturation also affect this breakage.
ContributorsMomeyer, Jason (Author) / Emady, Heather (Thesis director) / Kumar, Diana (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2025-05