VictorJuiz/thesis huggingface dataset:
Numerical modeling of energy storage materials [electronic resource]

Lithium-ion batteries (LIBs) are important energy storage devices with applications ranging from portable electronics to electric vehicles. Their widespread applications persistently drive the advancement of LIB technologies. To improve energy density of LIBs, one approach is to use novel electrode materials, such as Silicon (Si), Germanium (Ge), Tin (Sn), or Sulfur (S), which have been investigated both experimentally and numerically. This work mainly focuses on the numerical modeling of Si anodes to understand the important role of mechanics in electrochemical systems. Si is considered to be a promising anode material for LIBs, characterized by a theoretical specific capacity as high as 4200 mAh/g, in comparison to 372 mAh/g for graphite, which currently is the most common commercial anode material. The charging/discharging process of Si anodes is highly complex, involving mass diffusion, electrochemical reaction, phase transformation, and large mechanical deformation (~300% volume change). The large volume change can cause fracture of both Si anodes and the solid electrolyte interphase (SEI) layer, which is a thin layer formed on the anode to prevent unwanted side reactions between the anode and the electrolyte, resulting in poor cyclic performance of Si-based LIBs. To better understand the diffusion and mechanical behavior of Si anodes, sophisticated computational models are needed to describe diffusion-induced elastoplastic deformation and fracture of Si anodes. In this work, a variational based electro-chemo-mechanical coupled computational framework is formulated to study diffusion-induced mechanical deformation of Si anodes, where a diffusive phase field fracture model is used to describe the crack formation and propagation. To account for the underlying phase transformation of Si anodes (crystalline Si to amorphous LixSi and amorphous Si to amorphous LixSi) during the initial charging process, a physically motivated reaction-controlled diffusion (RCD) model is proposed. The RCD model is incorporated into the newly proposed coupled variational framework to model diffusion-induced anisotropic deformation for crystalline Si. With this fully coupled computational framework, we investigate the stress state, Lithium (Li) concentration distribution, and phase boundary evolution during the lithiation process of Si anodes. We further investigate how electrode geometry and geometrical constraints affect the fracture behavior of Si anodes. This work can be extended to study the formation and fracture of the SEI layer on Si anodes and provides necessary computational tools for optimizing and designing high energy density Si anodes for LIBs with outstanding cyclic performance in the future.

Advisor: Linder Christian (Engineering professor) primary advisor. Thesis advisor
Borja Ronaldo I. (Ronaldo Israel)
Cai Wei
Oakland Warehouses: Where are they now?

The Ghostship fire on Dec. 2 stirred conversations surrounding safety and policies for the future of warehouses as the world mourned the tragic loss of 36 artists. The Ghostship was unique though, in its unsafe two-story structure and maze-like second floor. Specifically, there was only one known exit—the stairs.
Through further investigation, the stairs were pinpointed as one of the most dangerous parts of the house. In fact, many of the artists that perished were trapped on the second floor after the stairs collapsed. In early December, Oakland officials announced that not a single building enforcement inspector stepped foot in the warehouse in over 30 years. Further, the building was coded for only commercial use, meaning no one was legally allowed to live inside. If the building had been inspected, these issues would likely have been addressed.

This media explosion highlighting warehouses led to a nationwide crackdown on the live-work spaces as cities try to extinguish the problem by closing down the artist housing spaces. The effects of this crackdown are uncertain. On one hand, it could force artist to relocate, but it could have driven the warehouse deeper underground as artists hope to ensure their live-work spaces.
Mya Byrnes, 39, an American-rock singer songwriter who moved into a warehouse in the Lower Bottoms neighborhood in 2014. For her, the LoBot warehouse was a dream space that due to its shear size, allowed creativity on a new scale was always breaming with dancing and laughter. LoBot was a warehouse that did pass inspection and was up to code. However, the building owner stopped renting the space and evicted all 20 artists in Sept. 2016.
Afterward, Mya was forced to go back to New York and hopped from couch to couch and finally found housing after eight months. Other LoBot residents moved to New England or left the Bay Area.
Nihar Bhatt, 29, is a DJ and producer known professionally as Nine. He was at the party the night of the Ghostship fire, and though he survived, he lost multiple friends in the fire.
His main focus since the fire has been a remembrance project to help honor the close friends he lost and showcase the artists’ work. The artist community continues to feel the absence of those they lost, but has channeled that pain into creating stronger relationships with one another.
Bhatt has a small music studio in his home and he has started opening it up to more artists and sharing his resources with others. His hope is to continue to be a catalyst to help create more art

Keywords:  Department of Communication.
Oakland fire
Ghostship
Artists
Warehouses
Survivors
LoBot
Thesis
Advisor: Hamilton Jay
Phillips Cheryl
Observations, causes, and potential consequences of small-scale temperature and dissolved oxygen variability in a kelp forest system [electronic resource]

Coastal hypoxia represents an important environmental change that has the potential to impact a wide range of species and communities in shallow subtidal habitats. While eutrophication-driven hypoxia has long been of concern in sheltered water bodies such as bays and estuaries, recently hypoxic events caused by advection of deep oceanic oxygen minimum zone waters into shallow shelf areas, have been observed. While a large component of this process is naturally occurring. Strong evidence exists which suggests that these events are also increasing due to climate change, through global deoxygenation and increases in coastal advective processes. While advective processes are commonly thought of as spatially uniform at the regional scale, this dissertation presents evidence throughout which, in fact, suggests that coastal advective processes (especially nearshore internal waves) are highly complex spatially, mostly due to their interactions with shallow topographic features such as rocky reefs. This observation is novel in two important ways. First, this small-scale spatial interaction between internal waves and rocky reefs represents novel complex habitat layer to the fluid environment, which has not been previously observed, nor considered for nearshore subtidal ecological studies. Secondly, when nearshore internal waves contain hypoxic water, the resulting small-scale spatial variability in the dissolved oxygen landscape may span super-saturated and severely hypoxic oxygen concentrations on the scale of meters within the reef. Together, the results from this dissertation suggest that small scale spatial variability in the fluid environment arising from internal wave/reef interactions, is a crucial, but poorly understood, component of nearshore habitats, which can complicate and extend hypoxic events. The results here also suggest variability at this scale may feasibly impact local organisms, especially through alterations to behavior. These dynamics are complicated, and much more work should be conducted in the future to better understand the whole impacts to shallow subtidal communities.

Keywords: Biology.
Advisor: Denny Mark W.
Micheli Fiorenza primary advisor. Thesis advisor
Carr Mark
Goldbogen Jeremy
Monismith Stephen Gene advisor. Thesis advisor
Woodson Brock advisor. Thesis advisor
Observing atomic layer deposition with scanning tunneling microscopy [electronic resource]

As modern device requirements move toward smaller and more complex architectures, ultra-thin films are playing an increasingly important role in device design and necessitate new fabrication methods. One technique that has gained prominence is atomic layer deposition (ALD) due to its surface conformality and control of material thickness and composition. But to fabricate the thinnest possible films via ALD, it is necessary to understand the early, non-uniform stage of ALD known as the nucleation phase. Because of instrument limitations, major frontiers remain both in the systematic characterization of ALD nucleation and in the degree of control of the nucleation process. This dissertation describes the utilization of a new scientific instrument that combines a nanoscale fabrication technique---ALD---with a nanoscale characterization technique---scanning tunneling microscopy (STM)---in a single vacuum chamber. The instrument has the capability to monitor individual nanostructures in situ as they are grown with ALD, tracking changes in their physical and electronic structure as they develop. It can be used to monitor the natural growth of extremely thin ALD films with sub-nanometer resolution, providing information about materials which are candidates for thin film devices. In addition, new silicon based substrates have been developed that are ideally suited for STM observation during ALD. The combination of these novel substrates and the STM-ALD instrument will allow for study of the nucleation phase of a wide range of ALD chemistries relevant for modern devices.

Keywords: Applied Physics.
Advisor: Mabuchi Hideo primary advisor. Thesis advisor
Prinz F. B. primary advisor. Thesis advisor
Kenny Thomas William advisor. Thesis advisor
On correlated x-ray scattering [electronic resource] : analysis of solution diffraction images using angular intensity correlations in both the hard matter and soft matter regimes

Correlated X-ray scattering (CXS) is a novel X-ray technique that utilizes angular intensity correlations in solution scattering patterns in order to extract a three-dimensional correlation function, which depends solely on the molecular structure factor. We report here on two of the first CXS experiments involving three-dimensional solutions of many molecules, at wide scattering angles. The first was done at a synchrotron facility, where we measured CXS arising from silver nanoparticles (NPs) embedded in a glycerol and agarose buffer. Crucially, a nitrogen jet was used to promote NP immobilization during each exposure. By averaging angular intensity correlations from on the order of 10 000 exposures, we were able to recover a CXS function that agreed well with atomic models. The second experiment was done at an X-ray free electron laser (XFEL) facility, where we measured CXS arising from gold NPs. There, we acquired on the order to 100 000 snapshots of gold NPs in solution, and were able to recover a CXS function indicating that the average NP was twinned, information that was previously unknown to us. Further, we are able to distinguish two populations of NPs present: small, twinned NPs and large, non-twinned NPs. Because CXS signal-to-noise is very low on a per-shot basis, great care must taken in order to minimize artifactual correlations that might arise during the image analysis. Artifactual correlations are a potential consequence of many experimental aspects, including sample-inhomogeneity, detector shadows, detector gain anisotropies, and beam polarization. In order to suppress these artifacts, we paired exposures that were similar in their anisotropy, and correlated their difference. By working with the difference intensities, we were able to significantly improve our signal-to-noise, and ultimately show that CXS is a viable way to extract atomic-level information from solution scattering measurements. As the technique continues to be explored, and data analysis methods are refined, CXS could reveal new pathways for studying ensemble statistics of small bio-molecules in solution, complimenting current state-of-the-art structural techniques, e.g. single particle imaging, cryo-electron microscopy, and serial femtosecond X-ray crystallography.

Keywords: Applied Physics.
Advisor: Doniach S. primary advisor. Thesis advisor
Brünger Axel T. advisor. Thesis advisor
Ratner Daniel
On the compressive strength and sustainability of protein bound concretes [electronic resource]

This thesis focuses on the study of protein and its use as a binder for Civil Engineering applications in material constrained construction systems. More specifically this thesis is intended to provide an understanding and quantification of the strength gained by soils with the addition of globular unfractionated blood proteins. At the same time, the thesis examines the potential materials use and environmental impact of using proteins compared to the use of Ordinary Portland Cement Concrete (OPCC) on earth. This thesis distinguishes itself from previous work as it identifies and determines the relevant mechanical properties of proteins taken out of their natural environments and used specifically for a construction composite in a material constrained system. In doing so, a mixture design methodology is developed focusing on the compressive strength of the composite. Building upon that work, the thesis uses a mechanistic model to extend the mixture design theory to enable sample design for targeted compressive strength. And finally, the thesis combines the strength and material mixture methodologies to create a functional unit for a life cycle assessment, which models the environmental impacts of 10,000 pavers made from proteins in comparison to Ordinary Portland Cement. The result is a coherent set of contributions to this novel class of materials that explores both its strength and environmental impact. The decision to study material constrained construction systems is two fold: The first is to provide an alternative that can reduce the environmental impact associated with OPCC manufacture. The second is to provide an alternative technique for extraterrestrial construction. In the field of planetary construction, considerations of binders are regarded with skepticism due to launch mass constraints. Instead, much of the focus in this field is placed on heat sintering methods, an energy intensive proposition. Proponents of these energy based methods have suggested that given enough time, the power requirements for sintering can become manageable. While correct in theory, the assumption of having ample time to charge batteries (\textit{i.e.}, through solar power) breaks down in the cases of maintenance and repair. This author also argues that a building is not made up of a single material, but many materials; and that the addition of new materials, such as Protein Bound Concrete, is necessary.

Advisor: Lepech Michael primary advisor. Thesis advisor
Billington Sarah L. (Sarah Longstreth)
Loftus David (David John) advisor. Thesis advisor
On the development of the direct flux reconstruction scheme for high-order fluid flow simulations [electronic resource]

In the past few years, there have been several emerging challenges facing the advancement of computational fluid dynamics (CFD) for aerospace design applications. Firstly, there is an growing interest in simulating unsteady, vortex-dominated flows over complex geometries, a problem for which existing second-order Reynolds-averaged Navier-Stokes (RANS) methods have had limited success. In addition to this, shifts in modern computing hardware towards highly data-parallel architectures, such as graphics processing units (GPU) and similar accelerators, have created another hurdle, as many existing CFD applications and methods are not well suited to draw compute performance efficiently from these increasingly dominant computing technologies. To address these challenges, there has been an increased interest in high-order CFD methods, in particular those based within a discontinuous finite element (DFE) framework. The high-order nature of these methods makes them well-suited to simulating vortex-dominated flows due to a limited introduction of numerical dissipation. Furthermore, the element-wise discretizations found within DFE methods result in tightly-coupled degrees of freedom within each element, a trait that maps well to modern computing hardware due to an increased potential for data reuse and high arithmetic intensity. A popular DFE method that is particularly suitable for solving the compressible Navier-Stokes equations is the flux reconstruction (FR) method. The FR method is based on the differential form of the governing equations and provides a general framework that can recover other similar high-order schemes, such as the nodal discontinuous Galerkin (DG) scheme and the spectral difference (SD) scheme. While existing FR methods are commonly touted as simple relative to comparable DFE methods, they still remain fairly complex relative to existing lower order alternatives. In this thesis, a simplified variation of the flux reconstruction scheme, named the direct flux reconstruction (DFR) scheme is developed which streamlines the existing flux reconstruction procedure, on tensor-product and simplex elements. The first part of the thesis contains the development of the DFR scheme in 1D and its extension to tensor-product elements for advection-diffusion type problems. The DFR formulation in this context is proven to be linearly stable and shown to recover the nodal DG method for 1D and tensor product elements. In latter chapters, an extension of the DFR scheme to simplex elements is developed beyond this which provides a new approach for FR on simplices that naturally extends many of the ideas from the 1D scheme. In addition to theoretical developments, this thesis includes details of a GPU implementation of the DFR scheme that achieves high-performance on modern computing hardware.

Keywords: Aeronautics and Astronautics.
Advisor: Jameson Antony
Alonso Juan José
Farhat Charbel advisor. Thesis advisor
On the emergence of spacetime and semi-classical dynamics [electronic resource]

The quantum physics of black holes and advances in string theory indicate that our contemporary notion of space—a continuous dynamical geometry obeying Einstein's equations—is an emergent concept. Gravitational physics appears instead as an effective description of a lower-dimensional quantum mechanical theory. This idea is called the holographic principle. In this thesis, we make steps towards developing a mathematical language for describing the emergence of geometry in the AdS/CFT correspondence, a string-theoretic realization of the holographic principle. The key idea we exploit is the curious relation between spacetime geometry and quantum entanglement discovered by Ryu and Takayanagi. We import mathematical tools from the field of integral geometry to connect questions such as "What is a point?" and "What is a distance?" in AdS space with the entanglement pattern of the CFT wavefunction. We then utilize the previous formalism to propose a new way of linking the degrees of freedom on the two sides of the AdS/CFT duality.

Keywords: Physics.
Advisor: Susskind Leonard primary advisor. Thesis advisor
Hayden Patrick (Patrick M.)
Shenker Stephen Hart
On the front lines of mental crisis: Dealing with mentally ill a growing challenge for SFPD

This reporting examines San Francisco Police Department interactions with mentally ill people. The department receives dozens of calls for service related to mental health each day, making these encounters a major part of its workload. An incident in early 2017 in which an officer shot mentally ill San Francisco resident Sean Moore highlights the challenges of handling mental-crisis encounters as well as some of the department’s shortcomings.
A growing homeless population and a shortage of mental health services have contributed to a rise in serious mental-crisis incidents. Incidents where officers conclude a person is a danger to himself or others have increased nearly 50 percent since 2003. The police department’s approach to interacting with the mentally ill revolves around the Crisis Intervention Team model, and protocols for dispatching CIT-certified officers are still evolving.

Keywords:  Department of Communication and Journalism
Department of Communication
mental health
San Francisco Police Department
5150
CIT
Thesis
Advisor: Nguyen Dan
On the mod p derived Hecke algebra of a p-adic group [electronic resource]

In this thesis we explore the structure of the derived Hecke algebra of a p-adic group, a graded associative algebra whose degree 0 subalgebra is the classical Hecke algebra. Working with Z/p^a coefficients, we will establish a Satake homomorphism relating the degree 1 component of this algebra, and the corresponding component for the algebra of a maximal torus. Generalizations and extensions of this construction are also discussed.

Keywords: Mathematics.
Advisor: Venkatesh Akshay
Bump Daniel
Conrad Brian
On Treaties and Taboos: US Responses to the Norms in the NPT and Genocide Convention (1946-1999)

Tens of millions of people perished during the Second World War. The deaths caused by the Holocaust and the nuclear bombing of Hiroshima and Nagasaki, however, attained a special prominence in the collective memory of humanity. The leader of the post-war international order, the United States, was simultaneously liberator of the Nazi concentration camps and the state that had used atomic weapons against Japanese civilians. Nevertheless, during the remainder of the 20th century, United States responded very differently to the norms that developed around nuclear weapons and genocide—specifically the nuclear nonproliferation norm and the international prohibition against genocide. This thesis investigates the reasons behind the difference in the United States’ responses to the nuclear nonproliferation norm and the international prohibition against genocide during the 20th century. Four case studies are examined: the drafting of the Genocide Convention (1944-1948); the drafting of the NPT (1958-1968); the United States’ response to India's nuclearization (1947 - 1999); US intervention during the Kosovo War (1998-1999). The results of this research find that the norm against nuclear proliferation reinforces the post-war international order—one led by the United States and organized under the United Nations system. In contrast, the international prohibition against genocide highlights contradictions embedded in the UN Charter and threatens to disrupt the foundation of the UN society of states. The implications of these findings suggest that there are limits to the kinds of international norms that can be constructed and endorsed by the United States within the structure of the current UN society of states.

Keywords: Center for International Security and Cooperation
International Relations Program
genocide
Genocide Convention
nuclear weapons
Nuclear Nonproliferation Treaty
norms
international norms
international order
international society
Thesis
Advisor: Holloway David