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Description
Water scarcity is still an issue across the globe, so nonconventional desalination methods need to be developed to be able to get access to clean, safe water. One such method being studied is the pervaporation system, a membrane process that uses a vapor pressure differential to drive the system. There is a need to find the efficiency of the cold trap condenser that is used to collect the permeate so that a thermodynamic model can be fully developed to assist in the development of an industrial scale pervaporation system. An efficiency was not able to be confidently found, but it is believe to be between 95-100%.
ContributorsLuong, Kristina Jenny (Author) / Thomas, Mary Laura Lind (Thesis director) / Thomas, Elisabeth (Committee member) / Materials Science and Engineering Program (Contributor) / Chemical Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
In the past decade, the volume, variety, and velocity of amassed data relevant to healthcare have reached staggering levels. This data has come in the form of numerous sources such as electronic health records, genome sequencing, pharmaceutical research. This recent rise of big data in healthcare has enabled the rise of new healthcare research methods. One of these emerging methods is known as drug repositioning (also commonly known as drug repurposing) and is the process of finding new clinical applications for existing FDA-approved drugs that have previously been approved for a different indication (Naveja et al., 2016). This process often leverages big data sources containing information about specific drugs and diseases and utilizes specialized algorithms and bioinformatics techniques to find unknown connections between certain drugs and diseases.
The traditional drug discovery process often amasses substantial costs, faces high attrition rates, progress at an extremely slow pace, and has no guarantee of receiving FDA approval by the end of the process. On average, the total cost and timeframe of drug discovery are $2.6 billion and at least 10 years (PhRMA, 2015). Alternatively, drug repositioning has become an increasingly attractive approach to pharmaceutical development and drug discovery because it has the potential to circumvent these obstacles by utilizing “de-risked” FDA-approved compounds, employing lower-cost computational research methods, and necessitating shorter development timelines (Pushpakom et al, 2019). Used effectively, drug repositioning can save a lot of money, time, and lives.
One potential application of drug repositioning research is in neurodegenerative diseases, which are diseases that primarily affect neurons in the brain. Many of these diseases manifest themselves through complex mechanisms that can impair memory, cognition, and movement. Huntington’s Disease (HD) is a fatal genetic progressive neurodegenerative disease that causes the progressive breakdown of neurons in the brain. This disease is caused by a trinucleotide repeat disorder known as a CAG repeat. This means that, due to a mutation in a person’s DNA, a set of code in the DNA erroneously repeats itself an excessive number of times. These mutations lead to the production of deformed, highly reactive proteins that can cause neuronal dysfunction, degeneration, and death. The number of repetitions varies from person to person, and longer repeat chains tend to cause the onset of HD to occur earlier in life. Symptoms include loss in motor function, personality and behavioral changes, decline in cognitive function, severe weight loss, and suicidal ideation (Heemskerk and Roos, 2012). One unique facet of the disease is that symptoms generally do not begin to appear until ages 30-50 and worsen over the course of a 10-25-year period. HD is also an autosomal dominant hereditary disease, meaning that any parent who is a carrier of the genetic disorder has a 50% chance or higher of passing the gene to his/her child. The high transmission rate, coupled with the prolonged symptoms of the disease, makes HD a devastating disease for families, as individuals are often unaware of their HD disease until after they have already had offspring. Currently, there are approximately 30,000 symptomatic HD patients and more than 200,000 individuals at risk for developing HD. The disease is also significantly more frequent in Western countries. There is no known cure for the disease, and the only focus of treatment is managing symptoms.
The goal of this Honors Thesis project is to utilize basic drug repositioning methods to develop a disease profile for HD and curate a set of drugs that can be tested and validated for HD treatment in future experiments.
The traditional drug discovery process often amasses substantial costs, faces high attrition rates, progress at an extremely slow pace, and has no guarantee of receiving FDA approval by the end of the process. On average, the total cost and timeframe of drug discovery are $2.6 billion and at least 10 years (PhRMA, 2015). Alternatively, drug repositioning has become an increasingly attractive approach to pharmaceutical development and drug discovery because it has the potential to circumvent these obstacles by utilizing “de-risked” FDA-approved compounds, employing lower-cost computational research methods, and necessitating shorter development timelines (Pushpakom et al, 2019). Used effectively, drug repositioning can save a lot of money, time, and lives.
One potential application of drug repositioning research is in neurodegenerative diseases, which are diseases that primarily affect neurons in the brain. Many of these diseases manifest themselves through complex mechanisms that can impair memory, cognition, and movement. Huntington’s Disease (HD) is a fatal genetic progressive neurodegenerative disease that causes the progressive breakdown of neurons in the brain. This disease is caused by a trinucleotide repeat disorder known as a CAG repeat. This means that, due to a mutation in a person’s DNA, a set of code in the DNA erroneously repeats itself an excessive number of times. These mutations lead to the production of deformed, highly reactive proteins that can cause neuronal dysfunction, degeneration, and death. The number of repetitions varies from person to person, and longer repeat chains tend to cause the onset of HD to occur earlier in life. Symptoms include loss in motor function, personality and behavioral changes, decline in cognitive function, severe weight loss, and suicidal ideation (Heemskerk and Roos, 2012). One unique facet of the disease is that symptoms generally do not begin to appear until ages 30-50 and worsen over the course of a 10-25-year period. HD is also an autosomal dominant hereditary disease, meaning that any parent who is a carrier of the genetic disorder has a 50% chance or higher of passing the gene to his/her child. The high transmission rate, coupled with the prolonged symptoms of the disease, makes HD a devastating disease for families, as individuals are often unaware of their HD disease until after they have already had offspring. Currently, there are approximately 30,000 symptomatic HD patients and more than 200,000 individuals at risk for developing HD. The disease is also significantly more frequent in Western countries. There is no known cure for the disease, and the only focus of treatment is managing symptoms.
The goal of this Honors Thesis project is to utilize basic drug repositioning methods to develop a disease profile for HD and curate a set of drugs that can be tested and validated for HD treatment in future experiments.
ContributorsJategaonkar, Gaurav (Co-author) / Sulit, Christian (Co-author) / Readhead, Ben (Thesis director) / Dudley, Sean (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The development of stab-resistant Kevlar armor has been an ongoing field of research
since the late 1990s, with the ultimate goal of improving the multi-threat capabilities of
traditional soft-body armor while significantly improving its protective efficiency - the amount
of layers of armor material required to defeat threats. To create a novel, superior materials
system to reinforce Kevlar armor for the Norica Capstone project, this thesis set out to
synthesize, recover, and characterize zinc oxide nanowire colloids.
The materials synthesized were successfully utilized in the wider Capstone effort to
dramatically enhance the protective abilities of Kevlar, while the data obtained on the 14
hydrothermal synthesis attempts and numerous challenges at recovery provided critical
information on the synthesis parameters involved in the reliable, scalable mass production of the
nanomaterial additive. Additionally, recovery was unconventionally facilitated in the absence of
a vacuum filtration apparatus with nanoscale filters by intentionally inducing electrostatic
agglomeration of the nanowires during standard gravity filtration. The subsequent application of
these nanowires constituted a pioneering use in the production of nanowire-reinforced
STF-based Kevlar coatings, and support the future development and, ultimately, the
commercialization of lighter and more-protective soft armor systems.
since the late 1990s, with the ultimate goal of improving the multi-threat capabilities of
traditional soft-body armor while significantly improving its protective efficiency - the amount
of layers of armor material required to defeat threats. To create a novel, superior materials
system to reinforce Kevlar armor for the Norica Capstone project, this thesis set out to
synthesize, recover, and characterize zinc oxide nanowire colloids.
The materials synthesized were successfully utilized in the wider Capstone effort to
dramatically enhance the protective abilities of Kevlar, while the data obtained on the 14
hydrothermal synthesis attempts and numerous challenges at recovery provided critical
information on the synthesis parameters involved in the reliable, scalable mass production of the
nanomaterial additive. Additionally, recovery was unconventionally facilitated in the absence of
a vacuum filtration apparatus with nanoscale filters by intentionally inducing electrostatic
agglomeration of the nanowires during standard gravity filtration. The subsequent application of
these nanowires constituted a pioneering use in the production of nanowire-reinforced
STF-based Kevlar coatings, and support the future development and, ultimately, the
commercialization of lighter and more-protective soft armor systems.
ContributorsDurso, Michael Nathan (Author) / Tongay, Sefaattin (Thesis director) / Zhuang, Houlong (Committee member) / Materials Science and Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Titanium dioxide is an essential material under research for energy and environmental applications, chiefly through its photocatalytic properties. These properties allow it to be used for water-splitting, detoxification, and photovoltaics, in addition to its conventional uses in pigmentation and sunscreen. Titanium dioxide exists in several polymorphic structures, of which the most common are rutile and anatase. We focused on anatase for the purposes of this research, due to its promising results for hydrolysis.
Anatase exists often in its reduced form (TiO2-x), enabling it to perform redox reactions through the absorption and release of oxygen into/from the crystal lattice. These processes result in structural changes, induced by defects in the material, which can theoretically be observed using advanced characterization methods. In situ electron microscopy is one of such methods, and can provide a window into these structural changes. However, in order to interpret the structural evolution caused by defects in materials, it is often necessary and pertinent to use atomistic simulations to compare the experimental images with models.
In this thesis project, we modeled the defect structures in anatase, around oxygen vacancies and at surfaces, using molecular dynamics, benchmarked with density functional theory. Using a “reactive” forcefield designed for the simulation of interactions between anatase and water that can model and treat bonding through the use of bond orders, different vacancy structures were analyzed and simulated. To compare these theoretical, generated models with experimental data, the “multislice approach” to TEM image simulation was used. We investigated a series of different vacancy configurations and surfaces and generated fingerprints for comparison with TEM experiments. This comparison demonstrated a proof of concept for a technique suggesting the possibility for the identification of oxygen vacancy structures directly from TEM images. This research aims to improve our atomic-level understanding of oxide materials, by providing a methodology for the analysis of vacancy formation from very subtle phenomena in TEM images.
Anatase exists often in its reduced form (TiO2-x), enabling it to perform redox reactions through the absorption and release of oxygen into/from the crystal lattice. These processes result in structural changes, induced by defects in the material, which can theoretically be observed using advanced characterization methods. In situ electron microscopy is one of such methods, and can provide a window into these structural changes. However, in order to interpret the structural evolution caused by defects in materials, it is often necessary and pertinent to use atomistic simulations to compare the experimental images with models.
In this thesis project, we modeled the defect structures in anatase, around oxygen vacancies and at surfaces, using molecular dynamics, benchmarked with density functional theory. Using a “reactive” forcefield designed for the simulation of interactions between anatase and water that can model and treat bonding through the use of bond orders, different vacancy structures were analyzed and simulated. To compare these theoretical, generated models with experimental data, the “multislice approach” to TEM image simulation was used. We investigated a series of different vacancy configurations and surfaces and generated fingerprints for comparison with TEM experiments. This comparison demonstrated a proof of concept for a technique suggesting the possibility for the identification of oxygen vacancy structures directly from TEM images. This research aims to improve our atomic-level understanding of oxide materials, by providing a methodology for the analysis of vacancy formation from very subtle phenomena in TEM images.
ContributorsShindel, Benjamin Noam (Author) / Crozier, Peter (Thesis director) / Anwar, Shahriar (Committee member) / Singh, Arunima (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
This paper discusses the possibility of utilizing 2D molybdenum disulfide (MoS2) as a nanozyme to detect dopamine colorimetric assays, first by detecting color change in liquid solutions due to oxidation and then second on paper-based assays. MoS2 samples dispersed in methylcellulose (MC) solution were prepared using liquid-phase exfoliation through sonication. The dopamine (DOPA) and hydrogen peroxide (H¬¬2O2) solutions were prepared separately in specific concentrations. The solutions were mixed in a well plate and colorimetric results were analyzed by a plate reader, revealing a quantitative relationship between dopamine concentration and absorbance. Subsequent testing was conducted using paper assays, where combined solutions of DOPA and H2O2 were dropped onto paper with printed wax wells that contained dried MoS2. An analysis of the color change was conducted using a smartphone application called Color Grab to detect the red, green, and blue (RGB) values. Plotting the RGB results across the dopamine concentrations revealed a positively correlated relationship between the two factors, suggesting that a predictive model could be developed to predict dopamine concentrations based on measured colorimetric values.
ContributorsNalla, Akshay (Co-author, Co-author) / Wang, Qing Hua (Thesis director) / Green, Alexander (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
In this research, the effect of the crystal structure of the parent phase on the morphology of nanoporous gold is explored. Specifically, Cu-Au alloys are studied. For this experiment, Cu0.75Au0.25 is heat treated to achieve an ordered phase Cu3Au and a disordered random solid solution, face centered cubic, Cu0.75Au0.25 phase, which are then dealloyed to form nanoporous gold (NPG). Using a morphology digital image analysis software called AQUAMI, SEM images of the NPG morphology were characterized to collect data on the ligament length, ligament diameter, porosity size, etc. of the samples. It was determined that the NPG formed from the ordered parent phase had an average ligament diameter that was 10 nm larger than the NPG formed from the disordered parent phase. This may be due to the ordered crystal structure allowing for faster gold diffusion and coarsening resulting in an increased average ligament size. Further future work is needed in order to obtain further evidence to support this hypothesis.
ContributorsTse, Ariana Yusof (Author) / Sieradzki, Karl (Thesis director) / Wang, Qing Hua (Committee member) / Materials Science and Engineering Program (Contributor) / Walter Cronkite School of Journalism & Mass Comm (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Immigrant families expect their children to go above and beyond since they have access to better facilities and opportunities in comparison to their home land. In my autobiographical works of art for my Barrett Honors Thesis project, I explore how my family has become more Americanized, yet still holds traditional values. I’ve focused on how differences in culture have molded different sets of morals between my parents, me, and my sibling. My series of graphite drawings on paper are a collection of milestones in my life. It may not be a completely fluid timeline but all the important points are present and the viewer can ponder what happened in snapshots of my life. The difference in culture is depicted through representations of clothing, posture, praying, religion, and subjects.
ContributorsChu, Amanda R (Author) / Hogden, Heidi (Thesis director) / Green, Heather (Committee member) / Materials Science and Engineering Program (Contributor) / School of Life Sciences (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The investigation into wide band gap semiconductors for use in tandem solar cells has become an increasingly more researched area with many new absorbers outlining the landscape. Pairing silicon with another cheap wide band gap semiconductor absorber can generate more efficient solar cell, which could continue to drive up the energy output from solar. One such recently researched wide band gap absorber is ZnSnN2. ZnSnN2 proves too difficult to form under most conditions, but has the necessary band gap to make it a potential earth abundant solar absorber. The deposition process for ZnSnN2 is usually conducted with Zn and Sn metal targets while flowing N2 gas. Due to restrictions with chamber depositions, instead ZnO and SnO2 targets were sputtered with N2 gas to attempt to form separate zinc and tin oxynitrides as an initial single target study prior to future combinatorial studies. The electrical and optical properties and crystal structure of these thin films were analyzed to determine the nitrogen incorporation in the thin films through X-ray diffraction, UV-Vis spectrophotometry, and 4-point probe measurements. The SnO2 thin films showed a clear response in the absorption coefficient leading but showed no observable XRD peak shift. Thus, it is unlikely that substantial amounts of nitrogen were incorporated into SnO¬2. ZnO showed a clear response increase in conductivity with N2 with an additional shift in the XRD peak at 300 °C and potential secondary phase peak. Nitrogen incorporation was achieved with fair amounts of certainty for the ZnO thin films.
ContributorsTheut, Nicholas C (Author) / Bertoni, Mariana (Thesis director) / Holman, Zachary (Committee member) / Materials Science and Engineering Program (Contributor) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Obtaining access to clean water is a global problem that is becoming more important with increasing population and advancing technology. Desalination through reverse osmosis (RO) is a promising technology takes advantage of the global supply of saline water to augment its limited freshwater reservoirs. To increase RO membrane performance, the feedwater is pretreated to take any excess pollutants out before the desalination. These pretreatment membranes are susceptible to fouling, which reduces efficiency and drives up costs of the overall process. Increasing the hydrophilicity of these membranes would reduce fouling, and electrospinning is a production method of pretreatment membranes with the capability to control hydrophilicity. This work explores how the composition of electrospun fibrous membranes containing blends of hydrophilic and hydrophobic polymers affects membrane characteristics such as wettability as well as filtration performance. Nonwoven, nanoscale membranes were prepared using electrospinning with a targeted application of pretreatment in water filtration. Using a rotating collector, electrospun mats of hydrophobic poly(vinyl chloride) (PVC) and hydrophilic poly(vinyl alcohol) (PVA) were simultaneously deposited from separate polymer solutions, and their polymer compositions were then characterized using Fourier Transform Infrared (FTIR) spectra. The data did not reveal a reliable correlation established between experimental control variables like flow rate and membrane composition. However, when the membranes' hydrophilicity was analyzed using static water contact angle measurements, a trend between PVA content and hydrophilicity was seen. This shows that the hypothesis of increasing PVA content to increase hydrophilicity is reliable, but with the current experimental design the PVA content is not controllable. Therefore, the primary future work is making a new experimental setup that will be able to better control membrane composition. Filtration studies to test for fouling and size exclusion will be performed once this control is obtained.
ContributorsTronstad, Zachary (Author) / Green, Matthew (Thesis director) / Holloway, Julianne (Committee member) / Epps, Thomas (Committee member) / Chemical Engineering Program (Contributor) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
The story of graphene truly began in what was simply a stub in the journal Physical Review not two years after the end of World War II. In 1947, McGill University physicist P.R. Wallace authored “The Band Theory of Graphite” and attempted to develop a foundation on which the structure-property relationship of graphite could be explored; he calculates the number of free electrons and conductivity of what he describes as “a single hexagonal layer” and “suppos[es] that conduction takes place only in layers” in bulk graphite to predict wave functions, energies at specific atomic sites in the hexagonal lattice, and energy contours using a tight binding approximation for a hypothesized version of what we now call ‘armchair-style’ graphene. While Wallace was the first to explore the band structure and Brillouin Zones of single-layer graphite, the concept of two-dimensional materials was not new. In fact, for years, it was dismissed as a thermodynamic impossibility.
Everything seemed poised against any proposed physical and experimental stability of a structure like graphene. “Thermodynamically impossible”– a not uncommon shutdown to proposed novel physical or chemical concepts– was once used to describe the entire field of proposed two-dimensional crystals functioning separately from a three-dimensional base or crystalline structure. Rudolf Peierls and Lev Davoidovich Landau, both very accomplished physicists respectively known for the Manhattan Project and for developing a mathematical theory of helium superfluidity, rejected the possibility of isolated monolayer to few-layered crystal lattices. Their reasoning was that diverging thermodynamic-based crystal lattice fluctuations would render the material unstable regardless of controlled temperature. This logic is flawed, but not necessarily inaccurate– diamond, for instance, is thermodynamically metastable at room temperature and pressure in that there exists a slow (i.e. slow on the scale of millions of years) but continuous transformation to graphite. However, this logic was used to support an explanation of thermodynamic impossibility that was provided for graphene’s lack of isolation as late as 1979 by Cornell solid-state physicist Nathaniel David Mermin. These physicists’ claims had clear and consistent grounding in experimental data: as thin films become thinner, there exists a trend of a decreasing melting temperature and increasing instability that renders the films into islands at somewhere around ten to twenty atomic layers. This is driven by the thermodynamically-favorable minimization of surface energy.
Everything seemed poised against any proposed physical and experimental stability of a structure like graphene. “Thermodynamically impossible”– a not uncommon shutdown to proposed novel physical or chemical concepts– was once used to describe the entire field of proposed two-dimensional crystals functioning separately from a three-dimensional base or crystalline structure. Rudolf Peierls and Lev Davoidovich Landau, both very accomplished physicists respectively known for the Manhattan Project and for developing a mathematical theory of helium superfluidity, rejected the possibility of isolated monolayer to few-layered crystal lattices. Their reasoning was that diverging thermodynamic-based crystal lattice fluctuations would render the material unstable regardless of controlled temperature. This logic is flawed, but not necessarily inaccurate– diamond, for instance, is thermodynamically metastable at room temperature and pressure in that there exists a slow (i.e. slow on the scale of millions of years) but continuous transformation to graphite. However, this logic was used to support an explanation of thermodynamic impossibility that was provided for graphene’s lack of isolation as late as 1979 by Cornell solid-state physicist Nathaniel David Mermin. These physicists’ claims had clear and consistent grounding in experimental data: as thin films become thinner, there exists a trend of a decreasing melting temperature and increasing instability that renders the films into islands at somewhere around ten to twenty atomic layers. This is driven by the thermodynamically-favorable minimization of surface energy.
ContributorsShulman, Neal Arthur (Author) / Adams, James (Thesis director) / Islam, Rafiqul (Committee member) / Materials Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05