INVESTIGATING PRE-BREAKDOWN CURRENTS IN POLYMER TANTALUM CAPACITORS

Poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer, has been used since the 1990s for the cathode of tantalum capacitors, which have a tantalum anode, and a layer of tantalum pentoxide as the dielectric. Such capacitors are referred to as Polymer Ta capacitors. The first method, an in situ polymerization technique, used to deposit the polymer resulted in capacitors with a significant leakage current and breakdown voltages near 50 V. The second method, a pre-polymerization (pre-poly) technique, resulted in capacitors that have a much lower leakage current and a higher breakdown voltage than the in situ capacitors. In this thesis, an accurate measurement technique for dielectric leakage current, also referred to as the pre-breakdown current, was established for capacitors. Current versus time measurements at constant voltage were performed at several voltages and the results were compiled to obtain the current-voltage (I-V) characteristics of both in situ and pre-poly types of capacitors. These characteristics were then modeled and analyzed, which led to the conclusion that the pre-breakdown current is controlled by the Poole-Frenkel mechanism in the in situ capacitors and by both the Poole-Frenkel and Schottky mechanisms in the pre-poly capacitors. Current versus time measurements were also performed at various temperatures to obtain the activation energy for the current in the capacitors and to verify the leakage mechanisms. Results suggest the presence of shallow 0.15 eV traps in the dielectric of the in situ capacitor and deeper 0.75 eV traps in that of the pre-poly capacitor. Additionally, pre-poly capacitors also have a 0.54 eV Schottky barrier that limits the electrons from being emitted into the dielectric from the electrode. Both the deep trap levels and the Schottky barrier explain the lower leakage current and higher breakdown voltage observed in the pre-poly capacitors as compared to the in situ capacitors

Earth Abundant Thin Film Technology for Next Generation Photovoltaic Modules

With a cumulative generation capacity of over 100 GW, Photovoltaics (PV) technology is uniquely poised to become increasingly popular in the coming decades. Although, several breakthroughs have propelled PV technology, it accounts for only less than 1% of the energy produced worldwide. This aspect of the PV technology is primarily due to the somewhat high cost per watt, which is dependent on the efficiency of the PV cells as well as the cost of manufacturing and installing them. Currently, the efficiency of the PV conversion process is limited to about 25% for commercial terrestrial cells; improving this efficiency can increase the penetration of PV worldwide rapidly. A critical review of all possibilities pursued in the public domain reveals serious shortcomings and manufacturing issues. To make PV generated power a reality in every home, a Multi-Junction Multi-Terminal (MJMT) PV architecture can be employed combining silicon and another earth abundant material. However, forming electronic grade thin films of earth abundant materials is a non-trivial challenge; without solving this, it is impossible to increase the overall PV efficiency. Deposition of Copper (I) Oxide, an earth abundant semiconducting material, was conducted using an optimized Photo assisted Chemical Vapor Deposition process. X-Ray Diffraction, Ellipsometry, Transmission Electron Microscopy, and Profilometry revealed that the films composed of Cu2O of about 90 nm thickness and the grain size was as large as 600 nm. This result shows an improvement in material properties over previously grown thin films of Cu2O. Measurement of I-V characteristics of a diode structure composed of the Cu2O indicates an increase in On/Off ratio to 17,000 from the previous best value of 800. These results suggest that the electronic quality of the thin films deposited using our optimized process to be better than the results reported elsewhere. Using this optimized thin film forming technique, it is now possible to create a complete MJMT structure to improve the terrestrial commercial PV efficiency

A Hiccup in the Road: OMM in the Medically Complex

Many patients in the hospital require multiple medications to treat their medical concerns. While medications may be highly effective, they can cause a variety of side effects. Osteopathic Manipulative Medicine (OMM) can be used as an adjuvant therapy, potentially decreasing the number of medications that patients are on and their side effects. We present a unique case of a patient with intractable hiccups who could not be solely managed with medications alone. OMM was used in this patient’s treatment plan, reducing the number of medications. The implications of this case demonstrate the need for OMM to be used more frequently in our medically complex patients

The Efficacy of Osteopathic Manipulative Treatment in Reducing Pain Medication Usage in Chronic Pain Patients: A Brief Literature Review

Chronic pain is one of the most common complaints for adult patients. Chronic pain almost always includes a pharmacological approach which can involve opioids and non opioids. Non-pharmacological approaches are less commonly used by patients with chronic pain, despite the significant misuse of opioids in the treatment of chronic pain. There is a need for nonpharmacological therapies in the treatment of chronic pain patients to lessen the misuse of opioids. One underused form of nonpharmacological therapy for chronic pain is OMT. There have been several studies demonstrating OMT to be effective in treating chronic pain conditions. In addition, there is an assortment of studies demonstrating how OMT has been effective in reducing the amount of non-opioid medications patients take. However, there is a lack of information in the field detailing if OMT can decrease the amount of opioids a patient with chronic pain may take

Updates to Acne Vulgaris Treatment: A Review of a Topical Androgen Receptor Inhibitor

Acne Vulgaris is an inflammatory skin disorder that is common among adolescents and young adults. Acne is defined as a chronic inflammatory dermatosis which consists of open comedones (blackheads), closed comedones (whiteheads) and inflammatory lesions.1 There are many ways to combat acne, one of which is to stop the effects of androgens on androgen receptors. Here we will review Clascoterone, a medication approved for the treatment of acne. Clascoterone is the first topical medication to target the hormonal pathogenesis of acne. It was approved by the FDA in 2020 and is effective in treatment of acne vulgaris in patients 12 years of age and older.

Janus Kinase (JAK) Inhibitors: A New Frontier in the Treatment of Vitiligo

Up to 70 million people worldwide suffer from vitiligo, an autoimmune disease characterized by the destruction of melanin. Current treatment options vary in efficacy. The disease manifests clinically as white circular macules of depigmentation seen primarily on the face and appendages.1 The pathophysiology of vitiligo is multifactorial and still being studied. One proposed mechanism behind the pathophysiology of vitiligo involves the upregulation of interferon gamma (IFN-γ) with downstream effects on JAK/STAT pathways resulting in CXCL10 transcription.1,2 Here we discuss Ruxolitinib, a topical JAK inhibitor, that recently passed its clinical trial phase, and Ritlecitinib, an oral JAK inhibitor which is currently undergoing clinical trials.3,4 These drugs are a reflection of the recent increase in targeted therapies for dermatologic diseases. The promising results of these drugs are widening the possible treatment options for patients that suffer from vitiligo

Factors Influencing the Need for and Access to IVF Treatment

Infertility is defined as the inability for a couple to become pregnant after 12 months of regular unprotected sexual intercourse. Infertility can stem from an issue with the female reproductive tract, the male reproductive tract, or both. Individuals struggling with infertility seek medical assistance for a successful reproductive course. However, there are many aspects outside of pathology that may encourage or deter an individual to elect for medical assistance such as in vitro fertilization (IVF). In vitro fertilization is defined as a medical procedure in which an egg is fertilized outside the body. The increased usage of IVF demonstrates the need for equitable access to IVF care. The purpose of this literature review is to consider all the factors and challenges involved in one’s decision to utilize IVF

Optimizing Latent Graph Representations of Surgical Scenes for Zero-Shot Domain Transfer

Purpose: Advances in deep learning have resulted in effective models for surgical video analysis; however, these models often fail to generalize across medical centers due to domain shift caused by variations in surgical workflow, camera setups, and patient demographics. Recently, object-centric learning has emerged as a promising approach for improved surgical scene understanding, capturing and disentangling visual and semantic properties of surgical tools and anatomy to improve downstream task performance. In this work, we conduct a multi-centric performance benchmark of object-centric approaches, focusing on Critical View of Safety assessment in laparoscopic cholecystectomy, then propose an improved approach for unseen domain generalization. Methods: We evaluate four object-centric approaches for domain generalization, establishing baseline performance. Next, leveraging the disentangled nature of object-centric representations, we dissect one of these methods through a series of ablations (e.g. ignoring either visual or semantic features for downstream classification). Finally, based on the results of these ablations, we develop an optimized method specifically tailored for domain generalization, LG-DG, that includes a novel disentanglement loss function. Results: Our optimized approach, LG-DG, achieves an improvement of 9.28% over the best baseline approach. More broadly, we show that object-centric approaches are highly effective for domain generalization thanks to their modular approach to representation learning. Conclusion: We investigate the use of object-centric methods for unseen domain generalization, identify method-agnostic factors critical for performance, and present an optimized approach that substantially outperforms existing methods.Comment: 7 pages, 3 figures, Accepted to IPCAI 202

WHY AND HOW PHOTOVOLTAICS WILL PROVIDE CHEAPEST ELECTRICITY IN THE 21ST CENTURY

With the advent of solar panels and windmills, and our ability to generate and use electrical energy locally without the need for long-range transmission, the world is about to witness transformational changes in energy infrastructure. The use of photovoltaics (PV) as source of direct current (DC) power reduces the cost and improves the reliability of PV system. DC microgrid and nanogrid based on PV and storage can provide sustainable electric power to all human beings in equitable fashion. Bulk volume manufacturing of batteries will lead to cost reduction in a manner similar to the cost reduction experience of PV module manufacturing. Future manufacturing innovations and R & D directions are discussed that can further reduce the cost of PV system. If the current trends of PV growth continue, we expect PV electricity cost with storage to reach $0.02 per kWh in the next 8-10 years