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Department of Energy Engineering (Battery Science and Technology)The continuous throng in demand for high energy density rechargeable batteries innovatively drives technological development in cell design as well as electrochemically active materials. In that perspective metal-free batteries consisting of a flowing seawater as a cathode active material were introduced. However, the electrochemical performance of the seawater battery was restrained by NASICON (Na3Zr2Si2PO12) ceramic solid electrolyte. Here, we demonstrate a new class of fibrous nanomat hard-carbon (FNHC) anode/1D (one-dimensional) bucky paper (1DBP) cathode hybrid electrode architecture in seawater battery based on 1D building block-interweaved hetero-nanomat frameworks. Differently from conventional slurry-cast electrodes, exquisitely designed hybrid hetero-nanomat electrodes are fabricated through concurrent dual electrospraying and electrospinning for the anode, vacuum-assisted infiltration for the cathode. HC nanoparticles are closely embedded in the spatially reinforced polymeric nanofiber/CNT hetero-nanomat skeletons that play a crucial role in constructing 3D-bicontinuous ion/electron transport pathways and allow to eliminate heavy metallic aluminum foil current collectors. Eventually the FNHC/1DBP seawater full cell, driven by aforementioned physicochemical uniqueness, shows exceptional improvement in electrochemical performance (Energy density = 693 Wh kg-1), (Power density = 3341 W kg-1) removing strong stereotype of ceramic solid electrolyte, which beyond those achievable with innovative next generation battery technologies.ope

Examining the Link Between Diversity and Firm Performance: The Effects of Diversity Reputation and Leader Racial Diversity

Given the scarcity of empirical research on the impact of diversity on organizational performance, we used longitudinal data for 100 firms to test hypotheses related to the effects of diversity reputation and leader racial diversity on firm financial outcomes. The results showed a positive relationship between diversity reputation and book-to-market equity, and a curvilinear U-shaped relationship between leader diversity and revenues, net income and book-to-market equity. Our analyses suggest that economic benefits generated from diversity reputation may primarily derive from capital rather than product markets. Further, firm performance declines with increases in the representation of racial minorities in leadership up to a point, beyond which further increases in diversity are associated with increases in performance

Quantifying the Effects of Knee Joint Biomechanics on Acoustical Emissions

The knee is one of the most injured body parts, causing 18 million patients to be seen in clinics every year. Because the knee is a weight-bearing joint, it is prone to pathologies such as osteoarthritis and ligamentous injuries. Existing technologies for monitoring knee health can provide accurate assessment and diagnosis for acute injuries. However, they are mainly confined to clinical or laboratory settings only, time-consuming, expensive, and not well-suited for longitudinal monitoring. Developing a novel technology for joint health assessment beyond the clinic can further provide insights on the rehabilitation process and quantitative usage of the knee joint. To better understand the underlying properties and fundamentals of joint sounds, this research will investigate the relationship between the changes in the knee joint structure (i.e. structural damage and joint contact force) and the JAEs while developing novel techniques for analyzing these sounds. We envision that the possibility of quantifying joint structure and joint load usage from these acoustic sensors would advance the potential of JAE as the next biomarker of joint health that can be captured with wearable technology. First, we developed a novel processing technique for JAEs that quantify on the structural change of the knee from injured athletes and human lower-limb cadaver models. Second, we quantified whether JAEs can detect the increase in the mechanical stress on the knee joint using an unsupervised graph mining algorithm. Lastly, we quantified the directional bias of the load distribution between medial and lateral compartment using JAEs. Understanding and monitoring the quantitative usage of knee loads in daily activities can broaden the implications for longitudinal joint health monitoring.Ph.D

Imaging cholesterol metabolism and trafficking by stimulated Raman scattering microscopy

Cholesterol is an essential component of mammalian cells which is tightly regulated. However, our understanding of cholesterol transport and metabolism is still incomplete, partly due to lack of suitable tools for studying cholesterol dynamics in living cells and organisms with spatio-temporal information. My dissertation work applied spectroscopic imaging of cholesterol in human tissues, living cells, and model organisms to unravel new insights of cholesterol metabolism and trafficking. Using stimulated Raman spectroscopic analysis of lipid droplets in human prostate cancer patient tissues, we observed an aberrant accumulation of cholesteryl ester in metastatic lesions. Inhibition of cholesterol esterification in prostate cancer cells significantly suppresses the development and growth of metastatic cancer lesions in both orthotopic and intra-cardiac injection mouse models. Gene expression profiling shows that cholesteryl ester depletion suppresses the metastatic potential through upregulation of multiple regulators that negatively impact metastasis. Additionally, Wnt/β-catenin, one of vital pathways for metastasis, is downregulated upon cholesteryl ester depletion. Mechanistically, we found evidence suggesting that inhibition of cholesterol esterification significantly blocks secretion of Wnt3a through reduction of monounsaturated fatty acid levels, which limits Wnt3a acylation. These results collectively validate cholesterol esterification as a novel metabolic target for treating metastatic prostate cancer. My thesis work also developed a new biocompatible cholesterol analog, which enabled real-time imaging of cholesterol metabolism and trafficking in living cells and organisms. Based on quantum chemistry calculations, we designed and synthesized phenyl-diyne cholesterol (PhDY-Chol), which has an extremely large Raman scattering cross section. The phenyl-diyne group is biologically inert and provides a Raman scattering cross section that is 88 times larger than the endogenous C=O stretching mode. Stimulated Raman scattering microscopy offers an imaging speed that is faster than spontaneous Raman microscopy by three orders of magnitude, and a detection sensitivity of 31 μM PhDY-Chol (~1,800 molecules in the excitation volume). Inside living cells, PhDY-Chol mimics the behavior of cholesterol, including membrane incorporation and esterification. In a cellular model of Niemann-Pick type C disease, PhDY-Chol reflects the lysosomal accumulation of cholesterol, and shows relocation to lipid droplets after HPβCD treatment. In living C. elegans, PhDY-Chol mimics cholesterol uptake by intestinal cells and reflects cholesterol storage. Together, this work demonstrates an enabling platform for study of cholesterol trafficking in living cells and organisms

Mayoral Political Ideology and Affordable Housing: A Comparative Analysis of the Koch and Bloomberg Administrations in the City of New York

This paper examines the relationship between mayoral political ideology and siting decisions for affordable housing during two different periods in New York City. On the overarching goal of housing programs—the supply of housing affordable to low-income families and thus sustainable development—the United States government had endeavored to meet two trends: (1) the geographical and social integration of communities composed of households of varying incomes and other socio-economic traits, and (2) the encouragement of private investment, with the aim of reducing reliance on public subsidies. From the political-economic standpoint of urban theory, “distributive justice” maintains an emphasis on the development of affordable housing without residential segregation, whereas the concept of “economic efficiency” refers to promoting the economic development of a community in order to attract private investment. This conflict between distinct purposes of housing developments has been apparent in New York City. Given such conditions, two different mayors in office at two different times, Edward I. Koch and Michael R. Bloomberg, both confronted housing crises and presented large plans for addressing them. Koch, who was mayor during the 1980s, as a Democrat was concerned with distributive justice, whereas Bloomberg was a Republican whose political ideology was oriented towards economic efficiency. In this paper, I test whether the political ideology of the two mayors had an impact on placements in affordable housing, and the extent to which the housing developments that were built were oriented towards social integration or encouragement for private investment. Using regression analysis, I compare the characteristics of neighborhoods where the two administrations developed affordable housing units, focusing on racial composition, socio-economic factors, and property attributes

A state of transcendence in dance: An autoethnographic analysis

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis maps and analyses a dancer’s journey and as that dancer is myself the research investigates the limits and possibilities of self-observation as a methodology. I have taken a term commonly used in dance – transcendence – and used it as a gateway to explore the invisible experience that is the dancer’s personal process, configuring its key characteristic as a creative tension between restriction and infinite possibility, further explored as the dialogue between embodied technique and the sense of freedom in dance. I explore how my body and experience in dance can be theorised, and what methodological tools are useful in the attempt to better understand the embodied work and invisible inner experience of the dancer. I place myself as the subject of the research and argue for the significance of my lived experience as a cross-cultural journey in the development of my own body’s intelligence. The research addresses specifically a dancer’s body as a site for the interweaving of two different forms of dance, namely Korean dance and Western ballet, and explores the impact of this on the dancer in question. The aesthetic and technical implications of this inter-cultural practice are analysed alongside a study of the culturally inscribed body that in this research draws specifically on a Korean woman's upbringing in Korea. Included with the written thesis are accompanying creative material in the form of a spoken address and films of original choreography danced by the researcher. An appendix is attached for those interested in knowing more of the choreographic process involved in the dance works

Pulsed Laser Deposition of Rocksalt Magnetic Binary Oxides

Here we systematically explore the use of pulsed laser deposition technique (PLD) to grow three basic oxides that have rocksalt structure but different chemical stability in the ambient atmosphere: NiO (stable), MnO (metastable) and EuO (unstable). By tuning laser fluence, an epitaxial single-phase nickel oxide thin-film growth can be achieved in a wide range of temperatures from 10 to 750 {\deg}C. At the lowest growth temperature, the out-of-plane strain raises to 1.5%, which is five times bigger than that in a NiO film grown at 750 {\deg}C. MnO thin films that had long-range ordered were successfully deposited on the MgO substrates after appropriate tuning of deposition parameters. The growth of MnO phase was strongly influenced by substrate temperature and laser fluence. EuO films with satisfactory quality were deposited by PLD after oxygen availability had been minimized. Synthesis of EuO thin films at rather low growth temperature prevented thermally-driven lattice relaxation and allowed growth of strained films. Overall, PLD was a quick and reliable method to grow binary oxides with rocksalt structure in high quality that can satisfy requirements for applications and for basic research