Reed Digital Collections (Reed College)
Not a member yet
8045 research outputs found
Sort by
An Experimental Investigation of Internal Solitary Waves
No full texthttps://rdc.reed.edu/v1/resources/221f7ebf-219f-4161-a589-f9003cd5f5ff/thumb/128.jpgThis thesis offers an investigation into fluid dynamics by studying internal solitary waves. We built a flume tank that is 243 cm long, 7.5 cm wide, and 12.5 cm tall out of acrylic plexiglas to generate internal solitary waves in a two-fluid system. We analyzed the speed of the waves generated. We used a particular solution to the Korteweg-de Vries Equation to fit and analyze our waves and found it to be a good generalization to understand solitary waves. The experimental speeds of the waves are consistent with the theoretical predictions. The particular solution did not account for the small, oscillating waves trailing behind the soliton
Experiments in Photon Propulsion: A Lab-Based Investigation Into the Mechanism Behind Solar Sailing
No full texthttps://rdc.reed.edu/v1/resources/956576b1-2725-4d03-85ba-db04d9add7bc/thumb/128.jpgIn this thesis, we use a commercial torsion pendulum with a capacitive sensor to test photon force. We used several different configurations of pendulum and light sources. First, the pendulum was used as received, where the small lead spheres necessary for the Cavendish experiment were repurposed as reflectors for light provided by small flashlights. We then modified the pendulum to replace the spheres with small Mylar reflective sheets, attached to lightweight mounts. Using lasers and neutral density filters, the optical power was varied systematically between 0 and 10 mW. The pendulum deflection changed linearly with the power. The Mylar reflectors yielded the best data, with a slope of 0.008 mrad/mW, which matched the theoretical slope exactly. We found that the minimum measurable optical force was −8.3×10−9±4×−9 N, corresponding to 2.5 mW of power, and 0.676±0.00004 mrad of twist. The maximum value of optical force we measured was 5.3 × 10−8, ±2 × 10−8, with a power of 10 mW, and a deflection of 0.738 ± 0.00008 mrad. The main sources of error we identified were adjustments to the apparatus made while experimenting causing the pendulum to shift position, as well as our timescales being too short to receive stable dampened data (less than 15 minutes). We also found that the K values in Nm/mrad changed with each trial due to tension on the tungsten wire
An Examination of Hinterleitner Doubly Special Relativity
No full texthttps://rdc.reed.edu/v1/resources/fdea0e41-8212-4f13-972c-21bf0f25c673/thumb/128.jpgIn the first part of this thesis, a 3+1 dimensional model of doubly special relativity is examined, expanding the model in [Hinterleitner (2005)] from 2 to 4 dimensions. The model is first defined by its energy-momentum and spacetime transformations. It is shown that the model is in fact doubly special relativistic, in the sense of having an invariant energy scale, but that it lacks an invariant length. A method for constructing the metric tensor from the transformations is found; this is then used to show that there is no metric for this transformation, even up to conformality. In the second part of this thesis, the geodesics of the 2D version of this model are examined, for the manner of quantizing space described in[Hinterleitner (2005)]. In the low-energy case, the equations of motion are found and solved exactly, and the behavior across an arbitrary continuum of energy-momentum distributions is described. In the high-energy case, the equations of motion are found, but not solved
Empires of the Minds
No full texthttps://rdc.reed.edu/v1/resources/09ef885b-894d-4f5b-a111-5203067d8358/thumb/128.jpgIn this thesis I argue that events in the electorate of Brandenburg-Prussia and the successor state of the Prussian Kingdom during the years 1648-1740 shifted Prussian understandings and attitudes towards the Holy Roman Emperor and the Empire itself by creating an environment in which initial Prussian territorial aims could be fulfilled by forces outside of the Emperor, lessening the need for cooperation. Furthermore, the post-Westphalian Reich, while still functioning on an administrative level, was open to internal and external manipulation, placing Prussia in a position to rival the Emperor as defender of the Empire even as Prussian rulers sometimes sided with the enemies of the Reich against the Emperor. In three sections corresponding to the reigns of three Brandenburg-Prussian/Prussian rulers I have tracked the developments that I argue fueled this shift. This thesis is important because it highlights a crucial point in Central European history where centralizing forces as represented by the Emperor were unable to fashion a state along the lines of France or England, leading to the infamous reputation as a "monstrous" construction that the Empire possesses
A Spectral Graph Theoretic Analysis of the Sign Flipping Sequence
No full texthttps://rdc.reed.edu/v1/resources/7fbefbb5-6db0-48b2-b66a-1a4260e4a36b/thumb/128.jpgThis thesis examines the structure of 4-regular graphs constructed from the elements of the Sign Flipping Sequence. This research was prompted by an open question in "Finding Structure in Sequences of Real Numbers via Graph Theory: A Problem List" by Korssjoen et al. In the first chapter, I introduce the foundations of spectral graph theory, including important terminology and theorems. In the second chapter, I provide the background information to understand the Cheeger Inequality and the Alon-Boppana Bound, as well as two proofs of each theorem, respectively. In the third chapter, I provide spectral embedding code by which to visualize the graphs I am discussing and present my original proof that the graphs of the Sign Flipping Sequence for bases b = 2,4,6,8,10 and even nodes n form an infinite family of bipartite graphs with perfect matchings
Characterizing electrical properties of 2D and 3D materials as Field-Effect Transistors
No full texthttps://rdc.reed.edu/v1/resources/45af3cea-e4d9-4cab-9e84-3a35fbe19b2b/thumb/128.jpgThe objective of this one-semester undergraduate thesis is to make a 2D Field-Effect transistor (FET) from a graphene/h-BN/SiO2/Si wafer with evaporated gold contacts as the source and drain. A probing station was built to test the current-voltage (I-V) response of the drain current (Id) vs. voltage applied from drain-to-source (Vds) at varying gate-to-source voltages (Vg). The findings confirm proper operation of the 2D FET with linearly adjusting positive slopes at both positive and negative values of Vg and Vds. The conductivity (σ) vs. Vg was found to only be conducting holes with the Dirac point extending into positive voltage values of Vg that the probing station cannot supply, but an extrapolation of the linear fit suggests the Dirac point is in the range of Vg = 20 to 30V. A comprehensive overview of the electrodynamics involved in semiconducting physics related to this thesis is outlined first
Morality and Fidelity to Law: The Hart-Fuller Debate Reassessed
No full texthttps://rdc.reed.edu/v1/resources/9caef2ba-31ce-4b23-a856-7797a4fcb758/thumb/128.jpgThis thesis examines the important debate in the philosophy of law between the legal positivist H.L.A. Hart and the natural law theorist Lon L. Fuller. The Hart-Fuller debate centers on the relation between law, justice, and morality, and the source of our obligation to obey the law. This thesis argues that, contrary to Hart’s belief that morality is correlated but not necessarily connected to law and justice, Fuller’s natural law theory proves that law and justice require an intrinsic connection with morality for law to induce a just obligation in its legal subjects. In Chapter 1, I analyze Hart’s legal positivism and Fuller’s critiques of Hart’s jurisprudence. Subsequently, in Chapter 2, I turn to the Hart-Fuller debate as examined by Jennifer Nadler. According to Nadler’s prudent reinterpretation of Hart’s positivism, Hart’s view is much closer to Fuller’s, and the extent of their differences is exaggerated. In particular, Nadler argues that Fuller’s conception of an intrinsic connection between law and morality is compelling yet ultimately inconclusive. However, I argue that Fuller’s internal morality of law does provide a substantial and conclusive case that in order for law and justice to have the association that both he and Hart desire, morality external to law must be a factor in any good and sound legal order
A Higher-Order Network Analysis of Molecular Dynamics Simulations
No full texthttps://rdc.reed.edu/v1/resources/74d6fbdf-46a1-456e-94aa-0b4c234a8629/thumb/128.jpgMolecular dynamics simulations encode a massive amount of data which is often reduced into networks of stable residue-residue contacts. These contacts are analyzed using traditional graph algorithms to facilitate analysis at the cost of ignoring higher-order network structure and short-lived interactions. In this thesis we aim to use networks to analyze molecular dynamics simulations of the Kir2.2 inwardly rectifying potassium channel and its regulatory interactions with cholesterol. Patterns in the network, called graphlets and dynamic graphlets, can capture the minutiae of global and local network structure and short-lived contacts in the simulation. Using graphlets, we observe higher-order structural changes in the cytoplasmic domain, reinforcing the importance of residue V265 in the cholesterol regulation of Kir2.2. Our findings also draw attention to distinct stable equilibrium states in the bundle crossing gate which seemingly result from random initializations of simulations, rather than cholesterol concentration. In applying dynamic graphlets to the simulations, we find that the extreme sensitivity of dynamic graphlets yields large variance throughout the protein. By considering these network motifs, we engage with the higher-order dynamic network structure of the simulation and highlight structural interactions which merit further investigation
Testing Language Models for Code Vulnerability and Exploring Unlearning Algorithms as a Countermeasure
No full texthttps://rdc.reed.edu/v1/resources/73625574-670e-4ed4-bb51-3e680f318f53/thumb/128.jpgMachine learning is still a new field without many agreed upon best practices. Chances are, you have used some sort of AI, e.g., ChatGPT or GitHub Copilot, and the outputted response or recommendation is not expected, up to par, or completely accurate. In the case of code generation, some machine learning models may even generate code that would make a program vulnerable to security attacks---even more concerning is the possibility of private information being revealed. These less than desirable results are a consequence of machine learning models being trained on vast amounts of poorly written and maintained code. In this paper, I introduce a testing framework to measure code vulnerability, connect it to the model generation process, and explore the application of unlearning as a viable approach for tackling code vulnerabilities
Icelandic Formations of National Identity through the Ownership of Material Culture in a Post Colonial Context
No full texthttps://rdc.reed.edu/v1/resources/c324dcf6-c7d3-4afb-811a-7481f16a4ed3/thumb/128.jpgThe Icelandic independence movement drew upon 19th century Romantic Era nationalist philosophy to create an Icelandic national identity through material culture to legitimize their claim for independence from Denmark and to subsequently had to establish itself within the world as an independent nation. Through ethnographic and archival research, I seek to explore how Iceland created its cultural identity through material objects and how ownership of these objects contributes to understandings of sovereignty and identity. The repatriation of the Codex Regius and the Flateyjarbók manuscripts redefined what cultural heritage and cultural ownership means within the context of post-colonial Iceland. Both heritage and ownership signify claims about the relationship that exists between the individual, material cultural objects, and the intangible narratives that are intertwined with them. Cultural heritage and cultural ownership differ in how these claims are established. I would like to elaborate on this differentiation by proposing that cultural heritage is a temporally rooted system of kinship and knowledge while cultural ownership, the active engagement of an individual, community, or nation with material culture, with or without the prerequisite of temporal kinship. Engagement with these cultural materials, in addition to the legal right of ownership affirms the agency of the Iceland as an independent post-colonial agent as well as an individual and community’s agency to identify as culturally Icelandic. I will also explore how individuals interact with material culture items to authenticate their national identities through quotidian and ceremonial engagement