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NIST Atomic Spectra Database
No full textData describing NIST Levels, Lines, Ground States and Ionization Energies
Transit in Flux: Public Transportation in Chicago
No full textOn an average weekday, Chicago’s trains and buses provide over 750,000 rides. The city’s public transit system is its single most effective climate solution, displacing rides and emissions from automobiles. Public transportation also provides key access to jobs, education, and healthcare, which is especially important for low-income communities with fewer car owners. In 2020, researchers found that a unit increase in the percent of low-income residents corresponds to a decrease in average accessibility to jobs by 11,021 units. But the CTA underserves the South Side, continuing a history of underinvestment. Chicago has yet to realize an accessible, equitable, and sustainable transportation system. Currently, the CTA faces an existential budget deficit, with a predicted deficit of 771 million dollars for the 2026 fiscal year. The city is legally required to make back 50% of its budget from fares, which is an unattainable threshold. We recommend that the city remove this requirement and develop other funding sources to not only solve the CTA’s budgetary challenges, but also allow the CTA to invest in itself. We recommend that the Illinois State government “flex,” or redirect, some of its federal highway funding toward public transportation. The city has already taken advantage of this strategy to fund station improvements and other projects, but Illinois still flexes significantly less of its funding than comparable states. We additionally propose a congestion pricing scheme modelled on New York City’s successful policy. The most aggressive congestion zone would raise 750 million dollars a year while only charging a third of New York’s fare. In addition, Chicago’s transit system is structurally inefficient. Multiple transit agencies operate in the Chicago area, resulting in miscommunication. By either creating an RTA executive board or merging the transit agencies into one entity, Chicago can minimize the operational and structural inefficiencies its transit system currently faces. We also propose that the CTA optimize its bus routes and transit pricing schemes to improve ridership without needing to invest in new infrastructure. By designing routes and schedules for optimal use and adjusting prices, the CTA can boost ridership and avoid the cycle of decreased use and disinvestment. Long-term, we suggest that the city focus on transit-oriented design (TOD) by rezoning areas around transit stops for dense mixed-use development. The North Side is already densely developed around transit, with neighborhoods like Wicker Park boasting apartments, shopping, and amenities closely packed around its Blue Line stop. In contrast, sprawl surrounds stops on the South Side. Vacant lots and an expressway abut the Garfield Green Line station, for example, leaving untapped potential for new dense mixed-use projects. The CTA is a vital resource for making Chicago the most livable, equitable, and sustainable city it can be. In this report, we present a toolkit for confronting the challenges facing the CTA to build a robust future
Investigations into the Governing Factors of Performance for Redox Targeting Flow Batteries with Redox Active Polymers
No full textFlow batteries are a high potential technology for long duration energy storage through the use of modular design and low cost active materials. To date technology has seen moderate success in the commercial space but is limited in development. One hurdle flow batteries have faced is that of energy density due to solubility limits of active materials in the flowing solutions. One proposed solution to overcome this limitation is that of redox targeting flow batteries (RTFBs). These systems use soluble redox mediators to transfer charge between the electrode and a solid storage material (the redox target). By using a solid active material, there is potential to increase the energy density over the solubility limits of alternatives. This thesis looks to create a model system for polymeric based redox targeting flow batteries to study the design parameters and begin to highlight the necessary conditions to be met along the technological roadmap. To do this, in chapter 2 we first design, synthesize, and test a polymer based RTFB with a series of mediator systems. Next, a thermodynamic model is refined to provide insight into the most important variables for success in achieving high accessibility in an RTFB system: formal potential difference and mediator accessibility. The model system is next used to test the impact of lower flow rates and higher charge rates on the accessibility of the redox target in chapter 3. At both 2 mL/min and 20 mL/min the study finds that mediator accessibility is the dominant factor determining performance suggesting that the mediator-target kinetics in the storage tank are fast relative to electrochemical rates. To get an idea of the rate capabilities of the system a technique was developed to isolate the reaction rate between the redox mediator and solids in the storage tank suggesting the ability to reach near equilibrium in as little as 20 minutes. Chapter 4 takes a turn to look at alternative benefits that can be found from the open system concept of RTFBs in contrast to other architectures. By developing a reprocessing loop, we show that the redox targeting material can be isolated, recovered, and reused in 5 different flow cells with minimal change in performance. Finally, Chapter 5 investigates the performance of the same system using a different solvent: water. Water is attractive because of its high conductivity, low cost, and low flammability. In the chapter it is discovered that the rate capabilities of the water-based system are significantly reduced. After investigating multiple charge rates it is also found that very unique and repeatable behavior is seen in the voltage curves during initialization cycling. These odd profiles eventually go away to show a system capable of high accessibility, though at very low rates
Local Operations for Entangled States in Quantum Systems: Transfer, Tomography, and Manipulation
No full textIn addition to the quality of the controls, one factor that is often overlooked is the spectrum of available controls. This dissertation demonstrates how small differences in local operation capabilities can affect overall performance for entanglement generation, verification, and manipulation: in a photon capture process, how access to reflection permits perfect capture in the noiseless regime and improve efficiency in the noisy regime; how Pauli measurements are not suitable for verifying some simplest possible states; and how a single qudit gate can facilitate manipulation of entanglement with local Clifford gates in tripartite stabilizer states over qudits with nonsquarefree levels
Pseudouridylation of 7SK by PUS7 regulates Pol II transcription elongation
No full textPseudouridine (Ψ) is a widespread RNA modification in various RNA species, including rRNA, tRNA, snRNA and mRNA. Ψ plays a crucial role in RNA metabolism, where it regulates pre-mRNA splicing and affects protein translation. Whether and how Ψ may regulate transcription have not been adequately studied. Here, we report that pseudouridine synthase 7 (PUS7) can mediate pseudouridylation of 7SK small nuclear RNA (snRNA), a regulator of RNA polymerase II (Pol II) promoter-proximal pausing. PUS7 loss leads to hypo-pseudouridylation of 7SK, which promotes dissociation of the positive transcription elongation factor b (P-TEFb) complex from 7SK. The release of P-TEFb from 7SK increases serine 2 phosphorylation (Ser2P) in the RNA Pol II C-terminal domain and enhances transcription elongation. In colorectal cancer (CRC) cells, the Ψ level of 7SK can be modulated by PUS7, or by site-specifically targeted pseudouridylation through dCas13b-guided system. Hypo-pseudouridylation on 7SK upon PUS7 depletion promotes KLF6/DDIT3-mediated cell apoptosis and sensitizes CRC cells to 5-FU.</p
Changes in bubble-cloud dissolution throughout the application of histotripsy pulses
No full textMaterial damage is a consideration for any applications where pressure fields may initiate cavitation. Histotripsy is a focused ultrasound therapy that exploits the destructive property of bubble clouds to disrupt viscoelastic tissue. The resulting effect achieves the same outcomes as surgery without the need for an invasive procedure. This study investigated the relationship between changes in bubble clouds throughout focused ultrasound exposure. Specifically, the dissolution period of bubbles generated in water and agarose gel was tracked with ultrafast ultrasound imaging. This imaging marker was found to increase in agarose during the initial stages of exposure, and maintained steady-state values after 555 ± 64 applied histotripsy pulses. The relative change in damage area of the gel and bubble-dissolution period with exposure duration were found to be equivalent ( > 0.05). Acoustic emissions tracked with passive acoustic imaging were also evaluated and were found to have a different functional form with exposure duration than the bubble-dissolution period or area of damage to the gel. In contrast, there were no noted changes in these imaging markers throughout histotripsy exposure when bubble clouds were generated in water. A previously validated bubble-dynamics model was extended to calculate the anticipated changes to bubble expansion during histotripsy exposure under the assumption that the agarose elastic modulus approached 0 kPa (i.e., total fractionation). The calculations predicted larger changes in the bubble dynamics than was observed, which might reflect complicated dynamics of the bubble cloud during the final stages of treatment.</p
Feedback: Media Parasites and the Circuits of Communication (Dada and Burroughs)
No full textThe twentieth century saw a tremendous change in modes of mass communication. The circuits of social exchange were predominantly enhanced and amplified through the new circuitry that electrical engineering provided. From that point on, the hegemonies of communication shifted from writing and aurality to the ether of electromagnetic transmission, where messages did not only become transmittable over vast distances, but where they also could be modified and amplified. The key technology that should even increase the dominance of electromagnetic transmission, the vacuum tube, did not only improve the transmission and reception technologies of the radio, but also enabled the construction of unique sonic events as well as the amplification through feedback, where a signal became repeatedly fed back into the circuit that it produced in the first place. In the age of feedback, messages do not have to be an original product, but they have to resonate infinitely through the echo chambers of discourse. This nature of modern means of communication brings us directly to the topic of the parasite. The French theorist and historian of science Michel Serres identified feedback as a parasitical structure; it does not create an own performance but takes its own mirror image as a place of departure. In this article I discuss two examples from the twentieth century avant-garde to show how feedback was employed as an aesthetic strategy for social manipulation. I first outline the parasitical strategies of Dada performances in the early twentieth century and then, second, I focus on the project of a subversive media tactics as suggested by the famous experimental writer William S. Burroughs in his text The Electronic Revolution
Mathematics and Its Ideologies (An Anthropologist's Observations)
No full textStarting from the profound impact of Kenneth Arrow's Impossibility Theorem on the social sciences of the postwar twentieth century, this essay engages with the ways in which mathematics can be seen as a language-ideologically inflated notational system. In the mid-twentieth century, a profound belief in mathematics as a purely objective and non-ideological organization of knowledge took hold, and mathematical proof became the most authoritative type of statement on reality. When something was ruled 'logically impossible', real-world occurences could be seen as transgressions and exceptions. Hidden inside this belief is a set of irrational, metaphysical assumptions about humans and social behavior that can be laid bare by means of linguistic-anthropological analysis
Mere Noise or More than Noise?: The Interactional Entextualization of Signs in a Rural Encounter
No full textThis paper starts off from ethnographic data collected in the still diglossic rural hinterlands known as the Bourbon Mountains (Montagne bourbonnaise) in Central France. Looking at what goes on interactionally during a seemingly liminal and marginal sequence when an elderly speaker misreads a reminder note for our next informal meeting, it shows how through interactionally identifying some signs as being irrelevant (mere noise) and others as deserving attention (more than noise), speakers also define what is going on in the broader social context, i.e., interactional text-in-context. To do so I draw from Paris School semiotics’ concepts of “modes of existence” and particularly potentialization (Greimas and Fontanille 1991), as well as analytics from semiotically informed linguistic anthropology, particularly entextualization (Silverstein and Urban 1996)