Investigating the build-up of precedence effect using reflection masking

The auditory processing level involved in the build‐up of precedence [Freyman et al., J. Acoust. Soc. Am. 90, 874–884 (1991)] has been investigated here by employing reflection masked threshold (RMT) techniques. Given that RMT techniques are generally assumed to address lower levels of the auditory signal processing, such an approach represents a bottom‐up approach to the buildup of precedence. Three conditioner configurations measuring a possible buildup of reflection suppression were compared to the baseline RMT for four reflection delays ranging from 2.5–15 ms. No buildup of reflection suppression was observed for any of the conditioner configurations. Buildup of template (decrease in RMT for two of the conditioners), on the other hand, was found to be delay dependent. For five of six listeners, with reflection delay=2.5 and 15 ms, RMT decreased relative to the baseline. For 5‐ and 10‐ms delay, no change in threshold was observed. It is concluded that the low‐level auditory processing involved in RMT is not sufficient to realize a buildup of reflection suppression. This confirms suggestions that higher level processing is involved in PE buildup. The observed enhancement of reflection detection (RMT) may contribute to active suppression at higher processing levels

Printed Energy Storage for Energy Autonomous Flexible Electronics

High-performance and efficient energy storage devices are a necessity for fulfilling the global demand of the growing market of distributed electronics, IoT, mobile electronic devices, electric vehicles, and many more. Supercapacitors and batteries are a priority for energy storage applications. In comparison with batteries, supercapacitors have longer cycle life and higher power density. In some cases, supercapacitors are integrated with batteries to increase electrical performance and efficiency. The aim of the research in this thesis is to develop and scale the design of a sustainable, low-cost, non-toxic, flexible, reliable, and eco-friendly energy storage device for energy-autonomous and distributed electronics platforms. The use of novel materials and a fabricating process for supercapacitor design were essential to achieve the goal of the research. With the use of low specific area electrode ink, the measured capacitance was 3–4 mF in dual cell supercapacitors. Similarly, a PET/Al laminated metal current collector has advantages due to high conductivity, low ESR, and the use of PC electrolyte (2.5 V/cell) to the target voltage range for low power BLE transmission applications. We also developed a PEDOT: PSS based polymer electrolytic capacitor as an alternative to supercapacitors, which demonstrated a way to print flexible capacitors of a few µF. This capacitor was modeled for low frequency applications such as smoothing and filtering. The second focus of the thesis was to perform a reliability study on the energy storage devices. This helps to observe the performance of the device in different situations, from normal to harsh environments. The supercapacitor’s electrical performance was stable over a wide temperature range from -40 °C to 100 °C. The supercapacitors maintain 100% retention for 10,000 bending cycles and a minimum bending radius of 0.41 cm, showing a high degree of flexibility. The device’s performance declined after thermal shock testing due to defects and cracks in the porous electrode because of rapid prolonged temperature cycling between -40 °C and 100 °C. The final part of the thesis is to harvest green energy from ambient surroundings using an organic photovoltaic (OPV) module or a piezoelectric transducer. The maximum indoor energy harvested with an OPV module and stored to the supercapacitor was 39 mJ. On the other hand, with a piezoelectric transducer, the maximum harvested energy was 1.1 mJ and peak power was 11.1 mW. The harvested energy was stored in our printed and flexible storage devices. We also demonstrated that the energy harvested was enough to power an LED driver circuit. Thus, these printed, low-cost, novel, and flexible devices open a door for the field of energy autonomous flexible electronics

Marshall Space Flight Center Research and Technology Report 2018

Many of NASAs missions would not be possible if it were not for the investments made in research advancements and technology development efforts. The technologies developed at Marshall Space Flight Center contribute to NASAs strategic array of missions through technology development and accomplishments. The scientists, researchers, and technologists of Marshall Space Flight Center who are working these enabling technology efforts are facilitating NASAs ability to fulfill the ambitious goals of innovation, exploration, and discovery

Technology 2003: Conference Proceedings from the Fourth National Technology Transfer Conference and Exposition, Volume 1

Proceedings from symposia of the Technology 2003 Conference and Exposition, December 7-9, I993, Anaheim, CA. Volume 1 features the Plenary Session and the Plenary Workshop, plus papers presented in Advanced Manufacturing, Biotechnology/Medical Technology, Environmental Technology, Materials Science, and Power and Energy

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018

Industrial-Scale Manufacture of Oleosin 30G for Use as Contrast Agent in Echocardiography

In ultrasound sonography, microbubbles are used as contrasting agents to improve the effectiveness of ultrasound imaging. Monodisperse microbubbles are required to achieve the optimal image quality. In order to achieve a uniform size distribution, microbubbles are stabilized with surfactant molecules. One such molecule is Oleosin, an amphiphilic structural protein found in vascular plant oil bodies that contains one hydrophobic and two hydrophilic sections. Controlling the functionalization of microbubbles is a comprehensive and versatile process using recombinant technology to produce a genetically engineered form of Oleosin called Oleosin 30G. With the control of a microfluidic device, uniformly-sized and resonant microbubbles can be readily produced and stored in stable conditions up to one month. Currently, Oleosin microbubbles are limited to the lab-scale; however, through development of an integrated batch bioprocessing model, the overall product yield of Oleosin 30G can be increased to 7.39 kg/year to meet needs on the industrial-scale. An Oleosin-stabilized microbubble suspension as a contrast agent is in a strong position to take a competitive share of the current market, capitalizing on needs unmet by current market leader, Definity®. Based on market dynamics and process logistics, scaled-up production of Oleosin 30G for use as a contrast agent is expected to be both a useful and profitable venture

Monoclonal Antibody Production and Purification

Monoclonal antibody (mAb) therapy is a form of immunotherapy that uses mAbs to bind mono-specifically to certain cells or proteins. This may then stimulate the patient\u27s immune system to attack those cells. MAbs are currently used to treat medical conditions such as cancer, diabetes, arthritis, psoriasis, and Crohn’s Disease, but have the potential to treat countless diseases and disorders. In 2015, the mAb market was valued at $85.4 billion, and is expected to reach$138.6 billion by 2024.1 In manufacturing, mAbs are typically produced in suspension in a series of fed-batch bioreactors using genetically engineered cells originally obtained from Chinese Hamster Ovaries (CHO).2 In this proposal, two upstream bioreactor designs were analyzed for economic comparison given an annual production goal of 100 kg of mAb, with the first design culminating in a 20,000 L volume at low mAb titer and the second design culminating with a 2,000 L volume at high mAb titer. Following upstream mAb production, the protein was purified to meet clinical FDA standards using a series of downstream purification techniques, including centrifugation, filtration, and chromatography. The two designs can be modeled for both an on-patent and off-patent mAb in order to ensure long-term economic viability. In this project, the drug was modeled based on Ocrevus (ocrelizumab), a humanized therapeutic mAb brought to market in 2017 that targets a CD20-positive B cell to treat the symptoms of both primary progressive and relapsing Multiple Sclerosis.3 For an off-patent drug, it is recommended that the mAb be priced at $35,000 per 1200 mg annual treatment in order to earn a 15$65,000 per 1200 mg treatment should be used to recover the R&D costs of developing a new drug and sunk cost of past unsuccessful drugs. After analyzing both designs, it was concluded that the second, smaller design scheme is more scalable, less risky, and more cost effective for the production of both the on- and off-patent drugs

Polymeric Foams

Postprint (published version