Our Milky Way’s neighbor, the Large Magellanic Cloud (LMC), is a galaxy significantly shaped by powerful explosions from massive, dying stars that drive gas outflows. These explosions release gas and heavy elements, enriching the galaxy's outskirts and contributing to the formation of stars and planets. Understanding these processes is crucial for studying galactic evolution and the mechanisms that drive it. Our research uses observations from the Hubble Space Telescope to characterize the properties of the outflows from the LMC. Our observations are of light from background stars that pass through the LMC’s gas clouds. These clouds block some of the incoming light, and we analyze the missing features to study the physical properties of the outflows. To compare complex stellar spectra on a similar scale, we fit regions of the light that are free from major features blocking it with a best-fit polynomial. This process helps us differentiate components that either belong to the background star or the LMC’s outflowing gas. By examining the missing light, we gain a deeper understanding of how bursts of star formation impact the galactic environment and ultimately connect our existence to the explosive deaths of distant stars.

As stars begin to die, their surface chemistry changes over time. This is due to the combined effect of two competing processes: (1) gravitational settling that causes heavier elements to sink below the stellar surface and (2) radiative acceleration from photons that push gas upward. Although diffusion is a primary physical process in stellar interiors, its impact on surface chemical abundances is often overlooked in large-scale spectroscopic surveys, leading to systematic biases in stellar age estimates. This project investigates the onset (`turn-on') and suppression (`turn-off') signatures of atomic diffusion as dying stars transition into giants. Using high-resolution optical spectra, we will analyse open-cluster stars across various evolutionary stages to identify the age (or mass) threshold at which diffusion becomes detectable and shuts off. The resulting measurements will constrain the magnitude of diffusion-driven abundance changes, the stellar age (or mass) at which diffusion becomes observable, and the efficiency of abundance restoration during the first dredge-up. It will improve stellar age determinations and enhance the precision of Galactic archaeology and chemical-tagging studies.

ZnO is a wide-bandgap semiconductor with applications spanning optoelectronics, photovoltaics, pharmaceuticals, and related technologies. At the micro- and nanoscale, its functional properties are strongly governed by by surface structure, defect chemistry, and electronic states associated with the crystalline free surface. Targeted lattice doping therefore represents an effective strategy for tailoring surface energetics and enabling new functionalities. Fe incorporation has been proposed to stabilize ZnO nano- and microparticle surfaces by mitigating the internal surface dipoles and passivating dangling bonds. Such provides a controlled materials platform for probing the fundamental bactericidal mechanisms of ZnO. Although the origin of ZnO-induced cytotoxicity remains under debate, our recent findings indicate that surface-mediated interactions with bacteria and/or growth media components facilitate Zn²⁺ ion release from reactive surface defect sites. Surface stabilization through Fe doping is expected to reduce the density of these active sites, thereby limiting Zn²⁺ ion release. In this study, we systematically investigate the bulk and surface characteristics of hydrothermally synthesized Fe-doped ZnO across varying doping dopant concentrations. The antibacterial activity of both pure and Fe-doped ZnO is evaluated against Escherichia coli and Staphylococcus aureus assays. Structural and chemical analyses are performed using X-ray diffraction and X-ray photoelectron spectroscopy, whereas Raman spectroscopy is employed to probe dopant-induced modifications in lattice dynamics and bonding, providing further insight into the relationship between surface states and antibacterial performance.

Zinc oxide (ZnO) is a versatile, inexpensive semiconductor material with unique characteristics. ZnO is particularly known for its inhibitory effects on bacterial growth. ZnO can reduce bacterial growth through mechanisms such as oxidative stress, the deterioration of crucial proteins in the bacterial cell, and the release of Zn²⁺ ions that affect bacterial cell function. The exact mechanism behind ZnO’s antibacterial properties remains unclear. It has been seen that changing the surface and morphology of the particles changes their effectiveness for bacterial inhibition. An additional lesser explored branch of ethanol-based synthesis is solution pH pertaining to ZnO morphology. Our research aims to explore this by doing a wholistic investigation of an ethanol-based synthesis, especially pertaining to how pH affects particle morphology. To produce these materials, we used ethanol-based solvothermal synthesis to create ZnO micro- and nanocrystals. We performed a thorough characterization of these materials to observe changes to the ZnO lattice. This was done by employing scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) spectroscopy.

Graphene quantum dots GQDs possess broad potential in bioimaging and optoelectronics due to their unique optical properties, tunable structure, aqueous solubility, and minimal in vivo and in vitro toxicity. However, despite their solubility, GQD fluorescence may be quenched through interactions with water molecules and aggregation via non radiative decay pathways that reduce emission efficiency. Inspired by the ability of surfactants to prevent quenching interactions for single walled carbon nanotubes, we investigate their utility in preserving GQD fluorescence. Five structurally distinct surfactants, sodium dodecyl sulfate SDS, sodium dodecylbenzene sulfonate SDBS, sodium deoxycholate SDC, sodium cholate SC, and Pluronic F127, are tested across a range of concentrations for preserving fluorescence of top down and bottom up synthesized GQDs to determine optimal conditions. This work reveals that surfactant structure and concentration can non-linearly affect GQD emission in the visible and near-infrared, with SC and SDC providing maximum concentration dependent fluorescence increase. Zeta potential and dynamic light scattering measurements are conducted for each surfactant and GQD system to quantify interfacial charge, colloidal stability, and aggregate size distributions. The present study provides mechanistic understanding of how surfactants influence GQD photophysics, offering strategies to optimize GQD based probes for biomedical imaging and photonic applications establishing a structure-to-function framework that links solution phase organization to fluorescence emission.