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Physical mechanisms for delaying condensation freezing on grooved and sintered wicking surfaces
Get PDFHeat pipes are passive heat transfer devices crucial for systems on spacecraft; however, they can freeze when exposed to extreme cold temperatures. The research on freezing mechanisms on wicked surfaces, such as those found in heat pipes, is limited. Surface characteristics, including surface topography, have been found to impact freezing. This work investigates freezing mechanisms on wicks during condensation freezing. Experiments were conducted in an environmental chamber at 22 °C and 60% relative humidity on three types of surfaces (i.e., plain copper, sintered heat pipe wicks, and grooved heat pipe wicks). The plain copper surface tended to freeze via ice bridging—consistent with other literature—before the grooved and sintered wicks at an average freezing time of 4.6 min with an average droplet diameter of 141.9 ± 58.1 μm at freezing. The grooved surface also froze via ice bridging but required, on average, almost double the length of time the plain copper surface took to freeze, 8.3 min with an average droplet diameter of 60.5 ± 27.9 μm at freezing. Bridges could not form between grooves, so initial freezing for each groove was stochastic. The sintered wick's surface could not propagate solely by ice bridging due to its topography, but also employed stochastic freezing and cascade freezing, which prompted more varied freezing times and an average of 10.9 min with an average droplet diameter of 97.4 ± 32.9 μm at freezing. The topography of the wicked surfaces influenced the location of droplet nucleation and, therefore, the ability for the droplet-to-droplet interaction during the freezing process
Track Performance in Tunnels and Rail Transition Areas with Under Tie Pads and Under Ballast Mats
Get PDFRailroads have begun to use under tie pads (UTP) and under ballast mats (UBM) in rail track construction to reduce maintenance costs by better distributing loads, reducing the track modulus, and increasing ballast contact areas with ties. Locations such as tunnels, bridges, and bridge approaches are especially strong candidates for UTP and UBM use due to the high support stiffness they provide to the ballast. In this study, the University of Florida (UF) instrumented the Virginia Avenue Tunnel in Washington D.C., which uses UTP and UBM, during construction to monitor track pressure distribution, tie movement, and tunnel floor vibration during the first 20 months of use (July 2018 – February 2020). Track pressure distributions across ties were measured for hundreds of trains at the tunnel floor transition area and inside the tunnel. Measurements showed that the track settlement occurred over the first 6 months of measurement after track was opened, after which it stabilized to less than 0.157 in. (4 mm)
CRISPR-Cas9 ribonucleoprotein-mediated gene editing in the plant pathogenic fungus Magnaporthe oryzae
Get PDFMagnaporthe oryzae, the cause of rice blast disease, is a model fungus for studying plant-pathogen interactions and a major threat to global agriculture. From changes made to their DNA, pathogens like M. oryzae have evolved characteristics like aggressiveness, host range, and fungicide resistance. Once source of DNA variation, arises from DNA repair. There are many sources of DNA damage, with the most severe being double-strand breaks (DSBs) which can lead to genome instability if left unrepaired. Hence, eukaryotes have evolved complex repair mechanisms like microhomology-mediated-end-joining (MMEJ), non-homologous-end-joining (NHEJ) and homologous-recombination (HR) to repair DNA DSBs. Interestingly, these repair pathways have different rates of fidelity, meaning some pathways create more mutations than others. In filamentous fungi, the mechanism by which MMEJ repairs DSBs is not well molecularly characterized, so the purpose of this project is to identify genes controlling MMEJ. To facilitate this, we created knockouts for homologs of DNA repair genes. Five genes were selected for deletion, including ligase 1 A & B, and polymerases θ, 3, and 4. Two CRISPR-Cas9 ribonucleoproteins were used to make DNA DSBs surrounding our target genes. Donor DNA encoding resistance to G418 antibiotic was supplied for insertion into the DSB site, where it served as a selectable marker when plated on complete media containing G418 antibiotics. DNA was extracted from individual colonies and used in PCR genotyping to test for the target gene and correct G418 integration. These knockouts will be characterized in future work to determine their individual roles in MMEJ DSB repair
Variability of protease activity and growth rate in isolates of Macrophomina phaseolina from various hosts
Get PDFMacrophomina phaseolina is a necrotrophic fungal pathogen that causes charcoal rot, among other diseases, on over 500 plant hosts and economically important crops in Kansas such as soybean and sorghum. Because it thrives in hot, dry environments, global climate change threatens to make this pathogen increasingly difficult to manage. M. phaseolina has a relatively low number of genes encoding proteases, protein-lysing enzymes commonly employed by plant pathogens. Further, their effect on virulence has been understudied. Three-hundred thirteen isolates of M. phaseolina from a variety of hosts were cultured on potato dextrose agar (PDA) plates to measure growth rate over one week, then were cultured on casein agar (CNA) to assess proteolytic activity over one week. Clearing zones that formed around the colonies on CNA represent areas where protein had been lysed, thus distinguishing isolates by their proteolytic activity. We hypothesize that different isolates will demonstrate varying levels of protease activity. This would shed light on the role that proteases play as a virulence factor for M. phaseolina and how this role may shift depending on the host and genetic identity of the isolate. Better understanding of M. phaseolina virulence mechanisms is vital to manage this pathogen, especially as climate change exacerbates the environmental conditions that promote charcoal rot
The Sandy Hook Conspiracy Theories: A Case Study
No full textKirmser Undergraduate Research Award - Individual Freshman category, grand prizeRoger FriedmannThis project provides an in-depth exploration of the conspiracy theories that emerged after the 2012 school shooting at Sandy Hook Elementary School. As well as debunking these conspiracy theories, the project also explains how said theories have been used in subsequent mass-shootings to the same effect--that being, the prevention of reforming gun control laws. What happened at Sandy HookElementary School? Why did misinformation begin to spread? Who believed the conspiracy theories and why? How can future school shootings be avoided, and why are conspiracy theories standing in the way of a safe future for children? "The Sandy Hook Conspiracy Theories: A Case Study" attempts to answer all these questions and more by explaining important context, providing insight into the minds of both propagators and victims, and asking questions about the nature of conspiracy theories and how they spread on the internet
Growing Opportunities for Communitites
No full textSummary of the 2021-2022 actiivities of the Kansas PRIDE program and affiliated communities
Swell and magmatic fluxes along the Louisville hotspot chain. Data associated with Adam et al. (2022) published in Geochemistry, Geophysics, Geosystems
No full textColumn 1: longitude
Column 2: latitude
Column 3: distance from active volcanism (in meters)
Column 4: volcanism age (in Ma)
Column 5: magmatism flux (in m3s-1)
Column 6: swell flux (in m3s-1
Group Oral Policy Analysis Presentation
No full textKirmser Undergraduate Research Award - Group category, honorable mentionAmanda GaulkeFor this project, the main goal was to analyze one specific expenditure or tax policy from a nonpartisan position and then present it to the class. The oral presentation was required to be 10 minutes long with a visual and citations to back up the claims. Since it is nonpartisan, we were not allowed to sway our audience to think one way or another about the issue. Rather, we were to recite a plethora of research about the topic. After presenting, every group would be asked a number of questions about their research, such as research methods used or how systems work. Within the project, we were asked to cover topics such as economic theory, costs, benefits, published economic research about the topic, and how the policy works. We were required to have at least 10 sources used in the project, but it was recommended that you utilized more. We then had 1 and a half months to work on our projects
Building a Home
Get PDFMichael WeschThis supplemental paper provides insight into the process of using video production (planning, filming, editing) as an access point to a local community center, Be Able Community. I build on lessons that I’ve learned throughout my time at KSU, focusing on the anthropological perspectives I’ve gained and especially those that intersect with the other disciplines I’ve studied: psychology, trauma studies. I reflect not only on how these lessons have served me during my time at K-State, but also on how I plan to carry them forward into the next phase of life
Friend or Foe: The Importance of Identifying Bacteria with Biochemical Tests
Get PDFKirmser Undergraduate Research Award - Individual Non-Freshman category, grand prizeMartha CaldasBrett NaveDebolina DasguptaIdentifying bacteria by utilizing biochemical tests is important, as bacteria can have a great impact on humans. Some bacterial strains are helpful while others are harmful, and having the ability to precisely identify bacteria can be crucial in maintaining human health. Biochemical tests generally consist of both selective and differential medias. Selective media only allows particular organisms to grow on it, while differential media will produce differing results, like a change in color, with the growth of different species. In this report, two bacterial strains were identified by performing a Gram stain and a series of selective and differential tests. Using an expected results table, the strains were identified as _Enterococcus faecalis_, a probiotic, and _Proteus vulgaris_, a potentially pathogenic bacterium. Correctly identifying bacteria is important in determining further steps after discovering bacteria in area from the food industry to the medical field