Doctor of Philosophy, The Ohio State University, 2022, Physics

Quantum information science and engineering requires novel low-loss magnetic materials for magnon-based quantum-coherent operations. The search for low-loss magnetic materials, traditionally driven by applications in microwave electronics near room-temperature, has gained additional constraints from the need to operate at cryogenic temperatures for many applications in quantum information science and technology. Whereas yttrium iron garnet (YIG) has been the material of choice for decades, the emergence of molecule-based materials with robust magnetism and ultra-low damping has opened new avenues for exploration. Specifically, thin-films of vanadium tetracyanoethylene (V[TCNE]x) can be patterned into the multiple, connected structures needed for hybrid quantum elements and have shown room-temperature Gilbert damping (α = 4 x 10^(-5)) that rivals the intrinsic (bulk) damping otherwise seen only in highly-polished YIG spheres (far more challenging to integrate into arrays). However, while these properties clearly establish the potential of V[TCNE]x for new applications in traditional microwave electronics, very little is known about its low-temperature magnetization dynamics and therefore its potential for applications in quantum information science and technology. Presented in this thesis a comprehensive and systematic study of the low-temperature magnetization dynamics for V[TCNE]x thin films, with implications for their application in quantum systems. These studies reveal a temperature-driven, strain-dependent magnetic anisotropy that compensates the thin-film shape anisotropy, and the recovery of a magnetic resonance linewidth at 5 K that is comparable to room-temperature values (roughly 2 G at 9.4 GHz). We can account for these variations of the V[TCNE]x linewidth within the context of scattering from very dilute paramagnetic impurities, and anticipate additional linewidth narrowing as the temperature is further reduced. Additionally, ongoing work investigati (open full item for complete abstract)

Committee: Ezekiel Johnston-Halperin Professor (Advisor); Marc Bockrath Professor (Committee Member); Ciriyam Jayaprakash Professor (Committee Member); Christopher Hirata Professor (Committee Member) Subjects: Physics

Doctor of Philosophy (PhD), Wright State University, 2022, Electrical Engineering

Binary multipliers are ubiquitous in digital hardware. Digital multipliers along with the adders play a major role in computing, communicating, and controlling devices. Multipliers are used majorly in the areas of digital signal and image processing, central processing unit (CPU) of the computers, high-performance and parallel scientific computing, machine learning, physical layer design of the communication equipment, etc. The predominant presence and increasing demand for low-power, low-cost, and high-performance digital hardware led to this work of developing optimized multiplier designs. Two optimized designs are proposed in this work. One is an optimized 8 x 8 Booth multiplier architecture which is implemented using 32nm CMOS technology. Synthesis (pre-layout) and post-layout results show that the delay is reduced by 24.7% and 25.6% respectively, the area is reduced by 5.5% and 15% respectively, the power consumption is reduced by 21.5% and 26.6% respectively, and the area-delay-product is reduced by 28.8% and 36.8% respectively when compared to the performance results obtained for the state-of-the-art 8 x 8 Booth multiplier designed using 32nm CMOS technology with 1.05 V supply voltage at 500 MHz input frequency. Another is a novel radix-8 structure with 3-bit grouping to reduce the number of partial products along with the effective partial product reduction schemes for 8 x 8, 16 x 16, 32 x 32, and 64 x 64 signed multipliers. Comparing the performance results of the (synthesized, post-layout) designs of sizes 32 x 32, and 64 x 64 based on the simple novel radix-8 structure with the estimated performance measurements for the optimized Booth multiplier design presented in this work, reduction in delay by (2.64%, 0.47%) and (2.74%, 18.04%) respectively, and reduction in area-delay-product by (12.12%, -5.17%) and (17.82%, 12.91%) respectively can be observed. With the use of the higher radix structure, delay, area, and power consumption can be further reduced. (open full item for complete abstract)

Committee: Saiyu Ren Ph.D. (Advisor); Raymond E. Siferd Ph.D. (Committee Member); Henry Chen Ph.D. (Committee Member); Marian K. Kazimierczuk Ph.D. (Committee Member); Yan Zhuang Ph..D. (Committee Member); Michael Saville Ph.D., P.E. (Other); Barry Milligan Ph.D. (Other) Subjects: Computer Engineering; Electrical Engineering

Master of Science (MS), Ohio University, 2017, Environmental Studies (Voinovich)

Hydraulic fracturing is an industry that has expanded quickly in the United States and around the world. Over the past years, salt waste water from these operations has been injected to the ground. The salt water is not only containing a high amount of salt, it is also containing a mixture of proppants, and other harmful substances which have potential risks and are toxic to public health, wildlife, and the environment. Produced water or waste fluid that came from hydraulic fracturing should be properly handled and disposed to protect the environment and human health. This study is focused on a study of a water quality alert system able to detect brine spills by using a low-cost technology. The water quality alert system is being developed especially in remote areas where it is not always feasible to monitor the quality of the water. The brine spill alert system is based on using Atlas Scientific temperature and conductivity sensors and deploy them downstream of Class II injection wells. The data collection from the probes is transmitted to the Ohio Voinovich campus server using a cellular network to upload the data bundles into the Mongolab cloud database. Testing has demonstrated an accuracy within 5-10% of reading from the calibrated commercial meter in laboratory conditions. Calibration for the EC sensor is necessary for every 5 days; meanwhile, the temperature sensor required a weekly calibration based on field data; however, additional investigation is necessary. Modeling the mixing of fracking fluids with river water using PHREEQCi software demonstrated that a brine spill mixing with a stream in a ratio of 1:99 trigger the alert threshold of 1500 µS/cm during summer and winter seasons.

Committee: Natalie Kruse (Advisor); Dina Lopez (Committee Member); Hans Kruse (Committee Member) Subjects: Environmental Studies

BS, Kent State University, 2017, College of Education, Health and Human Services / School of Teaching, Learning and Curriculum Studies

Assistive technology devices are being utilized more frequently in classrooms for accommodations and modifications, especially for students with disabilities. These devices can be high technology devices containing batteries, or low technology devices which may be inexpensive and do not require batteries to be used. Throughout the thesis, the use of high technology devices and low technology devices is specified to introduce the idea of integrating devices into general education and special education classrooms. Furthermore, resources are provided regarding learning more about specific devices, how to further implement technology in the classroom, and catalogs to buy devices.

Committee: Robert Cimera Dr. (Advisor); Sloane Burgess Dr. (Committee Member); Annette Kratcoski Dr. (Committee Member); Natasha Levinson Dr. (Committee Member) Subjects: Special Education

PhD, University of Cincinnati, 2005, Engineering : Computer Science and Engineering

In the past few decades with advancement in VLSI technology, FPGA chip density has increased and FPGA devices now provide a large number of smaller feature size transistors and can support higher clock speeds. While this advancement is beneficial for implementing larger and faster designs within a single chip, it also leads to increased power consumption. With the remarkable growth of FPGA based battery-powered systems, such as personal computing devices, wireless equipment, space-borne systems, and consumer electronics, low power FPGA design is of increased importance. In this thesis, I investigate various FPGA design techniques to minimize dynamic power consumed by an FPGA design. The objective of this research is to minimize the power drawn by a design without altering its functionality and with minimal or no impact on its timing. The work focuses on the implementation of control logic within a design. Reduction of power consumption of an FPGA design is attempted at the following design stages: high-level synthesis, mapping and placement and routing stage. In addition, power consumed by fault tolerant finite state machines in FPGAs is also addressed, and it has been shown that power consumed by the proposed alternate design is significantly lower than a traditional fault tolerant design. The central idea behind all the design techniques proposed is to reduce the switching activity on the power hungry programmable interconnection network. Power consumed by the clock network which also consumes a considerable amount of power is also reduced by selective clocking of finite state machines. The techniques and algorithms presented in this thesis can be easily automated and can be incorporated in an existing FPGA design flow.

Committee: Dr. Karen Tomko (Advisor) Subjects:

PhD, University of Cincinnati, 2005, Pharmacy : Pharmaceutical Sciences

Process Analytical Technology (PAT) was utilized for on-line evaluation of drug hydration state and its effect on final product quality, as well as the effect of blending parameters on low dose blend and tablet uniformity. Experiments were conducted to elucidate the relationship between risedronate sodium (RS) hydration state and the physical stability of tablets containing RS. The RS crystal lattice contains channels occupied by water which is removed by drying processes at temperatures below the boiling point of water, causing a reversible contraction of the crystal lattice. In this study, RS was wet granulated followed by fluid bed drying and compression into tablets. During drying, RS solid-state form was continuously monitored using on-line Raman spectroscopy. It was determined that final granulation moisture had a significant effect on change in RS hydration state measured by Raman and on change in tablet thickness over time. In addition, change in RS hydration state during fluid bed drying, measured by on-line Raman, was correlated to the increase in tablet thickness and subsequent loss of tablet integrity. Evaluation of RS solid-state during drying with Raman enabled establishment of relationships between fundamental hydration dynamics associated with RS and final product performance attributes. On-line Raman was also used to evaluate the effect of blending parameters on uniformity of a low dose, 1%, blend of azimilide dihydrochloride. Parameters investigated were blend time, blender speed, azimilide placement in the blender, filler particle size and density, multiple tablet components, and sampling. At the 8qt scale used, there was no effect of azimilide placement in the blender on time to reach uniformity. However, there was an effect of filler particle size/density and blender speed on time to reach uniformity. On-line Raman analysis of blend uniformity provided more information about the blending process as compared to traditional thief sampling and off- (open full item for complete abstract)

Committee: Dr. Adel Sakr (Advisor) Subjects: