Influence Of Naoh Concentration On Transfer Process Of Graphene, 2019 Singh Center for Nanotechnology
Influence Of Naoh Concentration On Transfer Process Of Graphene, Francisco Saldana, Chengyu Wen, George Patrick Watson
Protocols and Reports
The process of transferring a monolayer of graphene using two diﬀerent concentrations of sodium hydroxide (NaOH) solution unto a silicon dioxide (SiO2) coated Si chip using electrochemistry was performed. The transfer process is crucial for the delamination of a continuous graphene monolayer ﬁlm from copper foil. After examining and inspecting the integrity of the graphene monolayer, it was observed that the lower concentration to NaOH led to slower rate of hydrogen bubble generation; this condition was found to be less destructive and yielded a graphene ﬁlm with fewer visible tears.
Residential Electricity Management And Protection System, 2019 Afe Babalola University, Ado Ekiti (ABUAD), Nigeria
Residential Electricity Management And Protection System, Ejimonu Kosisochukwu Gabriel
Journal of International Technology and Information Management
The Residential Electricity Monitoring System is an electricity meter connected to the Internet to provide real time data on the power system in your home. The REMS is designed to replace the distribution board allowing it to conduct a series of tests on the quality of the electricity supply to your home/facility and, within your home detect basic wiring faults and allow owners and service providers to identify potential problems with the electrical systems.
The electrical monitoring system finally puts proper electrical control into the hands of the home owner by providing him with the ability to control power ...
Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, 2019 University of Arkansas, Fayetteville
Five-Level Flying Capacitor Converter Used As A Static Compensator For Current Unbalances In Three-Phase Distribution Systems, Rafael Franceschi
Theses and Dissertations
This thesis presents and evaluates a solution for unbalanced current loading in three-phase distribution systems. The proposed solution uses the flying capacitor multilevel converter as its main topology for an application known as Unbalanced Current Static Compensator. The fundamental theory, controller design and prototype construction will be presented along with the experimental results. The Unbalanced Current Static Compensator main objective is the balancing of the up-stream currents from the installation point to eliminate the negative- and zero-sequence currents originated by unbalanced single-phase loads.
Three separate single-phase flying capacitor converters are controlled independently using a d-q rotating reference frame algorithm to ...
Continuous Monitoring Of Soil Nitrate Using A Miniature Sensor With Poly(3-Octyl-Thiophene) And Molybdenum Disulfide Nanocomposite, Md. Azahar Ali, Xinran Wang, Yuncong Chen, Yueyi Jiao, Navreet K. Mahal, Satyanarayana Moru, Michael J. Castellano, James C. Schnable, Patrick S. Schnable, Liang Dong
There is an unmet need for improved fertilizer management in agriculture. Continuous monitoring of soil nitrate would address this need. This paper reports an all-solid-state miniature potentiometric soil sensor that works in direct contact with soils to monitor nitrate-nitrogen (NO3--N) in soil solution with parts-per-million (ppm) resolution. A working electrode is formed from a novel nanocomposite of poly(3-octyl-thiophene) and molybdenum disulfide (POT–MoS2) coated on a patterned Au electrode and covered with a nitrate-selective membrane using a robotic dispenser. The POT–MoS2 layer acts as an ion-to-electron transducing layer with high hydrophobicity and redox properties. The modification of the ...
Dc-Dc Converter For Electric Vehicle, 2019 California Polytechnic State University, San Luis Obispo
Dc-Dc Converter For Electric Vehicle, Jason Y. Zhou, Nicholas James Mah
In this work, a DC-DC converter is designed for an electric vehicle. The DC-DC converter is designed to provide 500W with a 200-400V input and a 12-15V adjustable output. Electric vehicle sales are beginning to increase in popularity and the need for DC-DC converters to siphon power from the tractive system is not yet fully satisfied, especially for single-seater class vehicles. Additionally, improving performance in efficiency without sacrificing wide input voltage range can benefit future DC-DC converter designs. In the end, a forward active clamp DC-DC converter is designed and tested. Additionally, spreadsheet calculators, LTSpice simulations, and Matlab scripts were ...
Designing A Low-Cost Ultrasound Pulser, 2019 Union College - Schenectady, NY
Designing A Low-Cost Ultrasound Pulser, Andrea Huey
Ultrasound imaging allows for those studying living beings to see inside a subject without causing it harm. This allows for real-time images to be taken, leading to ease of observational research. However, while this technology is beneficial to those who utilize it, the devices used to create and receive ultrasound pulses can be incredibly complex, allowing for precise adjustment of the output signal and various other functions, and therefore expensive. The focus of this senior project is the design of a low-cost pulser for use with an ultrasound transducer. While it does not have all the high-level functions of the ...
Structural Health Monitoring Of Composite Parts: A Review, 2019 Union College - Schenectady, NY
Structural Health Monitoring Of Composite Parts: A Review, Jacob Pessin
Structural health monitoring has the potential to allow composite structures to be more reliable and safer, then by using more traditional damage assessment techniques. Structural health monitoring (SHM) utilizes individual sensor units that are placed throughout the load bearing sections of a structure and gather data that is used for stress analysis and damage detection. Statistical time based algorithms are used to analyze collected data and determine both damage size and probable location from within the structure. While traditional calculations and life span analysis can be done for structures made of isotropic materials such as steel or other metals, composites ...
Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, 2019 University of New Mexico, Albuquerque
Symmetry And Dopant Diffusion In Inverted Nanopyramid Arrays For Thin Crystalline Silicon Solar Cells, Seok Jun Han
Chemical and Biological Engineering ETDs
In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal ...
Prototyping A Capacitive Sensing Device For Gesture Recognition, 2019 University of Arkansas, Fayetteville
Prototyping A Capacitive Sensing Device For Gesture Recognition, Chenglong Lin
Computer Science and Computer Engineering Undergraduate Honors Theses
Capacitive sensing is a technology that can detect proximity and touch. It can also be utilized to measure position and acceleration of gesture motions. This technology has many applications, such as replacing mechanical buttons in a gaming device interface, detecting respiration rate without direct contact with the skin, and providing gesture sensing capability for rehabilitation devices. In this thesis, an approach to prototype a capacitive gesture sensing device using the Eagle PCB design software is demonstrated. In addition, this paper tested and evaluated the resulting prototype device, validating the effectiveness of the approach.
Characterization Of High Temperature Optocoupler For Power Electronic Systems, 2019 University of Arkansas, Fayetteville
Characterization Of High Temperature Optocoupler For Power Electronic Systems, David Gonzalez
Electrical Engineering Undergraduate Honors Theses
High-temperature devices have been rapidly increas due to the implementation of new technologies like silicon carbide, high-temperature ceramic, and others. Functionality under elevated temperatures can reduce signal integrity reducing the reliability of power electronic systems. This study presents an ongoing research effort to develop a high-temperature package for optocouplers to operate at higher temperature compared with commercial devices. Low temperature co-fired ceramic (LTCC) was used as the substrate. Bare die commercial LED and photodetectors were attached to the substrate and tested for functionality. Preliminary results show enhanced performance at elevated temperatures compared to a commercial optocoupler device.
Model Development And Assessment Of The Gate Network In A High-Performance Sic Power Module, 2019 University of Arkansas, Fayetteville
Model Development And Assessment Of The Gate Network In A High-Performance Sic Power Module, William Austin Curbow
Theses and Dissertations
The main objective of this effort is to determine points of weakness in the gate network of a high-performance SiC power module and to offer remedies to these issues to increase the overall performance, robustness, and reliability of the technology. In order to accomplish this goal, a highly accurate model of the gate network is developed through three methods of parameter extraction: calculation, simulation, and measurement. A SPICE model of the gate network is developed to analyze four electrical issues in a high-speed, SiC-based power module including the necessary internal gate resistance for damping under-voltage and over-voltage transients, the disparity ...
Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, 2019 University of Arkansas, Fayetteville
Synchrophasor-Based Fault Location Detection And Classification, In Power Systems, Using Artificial Intelligence, Hemal Falak
Theses and Dissertations
With the introduction of sophisticated electronic gadgets which cannot sustain interruption in the provision of electricity, the need to supply uninterrupted and reliable power supply, to the consumers, has become a crucial factor in the present-day world. Therefore, it is customary to correctly identify fault locations in an electrical power network, in order to rectify faults and restore power supply in the minimum possible time. Many automated fault location detection algorithms have been proposed, however, prior art requires topological and physical information of the electrical power network. This thesis presents a new method of detecting fault locations, in transmission as ...
A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, 2019 University of Arkansas, Fayetteville
A Silicon Germanium Cmos Linear Voltage Regulator For Wireless Agricultural Applications, Aminta Naidili Castillo Robles
Theses and Dissertations
This thesis presents the design, simulation and test results of a silicon germanium (SiGe) complementary metal-oxide-semiconductor (CMOS) linear regulator. The objective of the circuit is to power other analog devices regardless of the load current and input voltage changes. The application of this regulator is to be part of a project developing a miniaturized semiconductor platform that can be inserted into stems of crops in order to measure data inside the plant and then send it wirelessly to the user. The linear regulator was designed on a BiCMOS SiGe 0.13µm which is a GlobalFoundries process. It has been tested ...
Investigation Of Critical Technologies Of Chemical Vapor Deposition For Advanced (Si)Gesn Materials, 2019 University of Arkansas, Fayetteville
Investigation Of Critical Technologies Of Chemical Vapor Deposition For Advanced (Si)Gesn Materials, Joshua Matthew Grant
Theses and Dissertations
The development of new materials for efficient optoelectronic devices from Group IV elements is the heart of Group IV photonics. This has direct ties to modern technology as the foundation for the electronics industry is silicon. This has driven the development of silicon-based optoelectronics using these other Group IV materials as silicon is a poor optical material due to its indirect band gap when compared to the III-V semiconductors that are used by most of the optoelectronics industry. While efforts have been made to integrate III-V materials onto silicon substrates, the incompatibility with the complementary metal oxide semiconductor process has ...
Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two ﬂuorocarbon Gases Chf3 And Cf4, 2019 Singh Center for Nanotechnology
Reactive Ion Etching Selectivity Of Si/Sio2: Comparing Of Two ﬂuorocarbon Gases Chf3 And Cf4, Meiyue Zhang, Pat Watson
Protocols and Reports
Two reactive ion etching (RIE) processes were studied to show the relative etch selectivity between SiO2 and Si using two ﬂuorocarbon gases, CF4 and CHF3. Results show that CHF3 gives better selectivity (16:1) over CF4 (1.2 :1). On the other hand, the etch rate of SiO2 of CF4 is approximately 52.8 nm/min, faster than CHF3 (32.4 nm/min).
Wearable Bluetooth Sensors For Capturing Relational Variables And Temporal Variability In Relationships: A Construct Validation Study, James G. Matusik, Ralph Heidl, John R. Hollenbeck, Andrew Yu, Hun W. Lee, Michael D. Howe
The advent of wearable sensor technologies has the potential to transform organizational research by offering the unprecedented opportunity to collect continuous, objective, highly granular data over extended time periods. Recent evidence has demonstrated the potential utility of Bluetooth-enabled sensors, specifically, in identifying emergent networks via colocation signals in highly controlled contexts with known distances and groups. Although there is proof of concept that wearable Bluetooth sensors may be able to contribute to organizational research in highly controlled contexts, to date there has been no explicit psychometric construct validation effort dedicated to these sensors in field settings. Thus, the two studies ...
Experimental Study And Modeling Of The Gm-I Dependence Of Long-Channel Mosfets, 2019 California Polytechnic State University, San Luis Obispo
Experimental Study And Modeling Of The Gm-I Dependence Of Long-Channel Mosfets, Michael Fong Cheng
Master's Theses and Project Reports
This thesis describes an experimental study and modeling of the current-transconductance dependence of the ALD1106, ALD1107, and CD4007 arrays. The study tests the hypothesis that the I-gm dependence of these 7.8 µm to 10 µm MOSFETs conforms to the Advanced Compact Model (ACM). Results from performed measurements, however, do not support this expectation. Despite the relatively large length, both ALD1106 and ALD1107 show sufficiently pronounced ‘short-channel’ effects to render the ACM inadequate. As a byproduct of this effort, we confirmed the modified ACM equation. With an m factor of approximately 0.6, it captures the I-gm dependence with sub-28 ...
Electromagnon Excitation In Cupric Oxide Measured By Fabry-Pérot Enhanced Terahertz Mueller Matrix Ellipsometry, 2019 University of Nebraska - Lincoln
Electromagnon Excitation In Cupric Oxide Measured By Fabry-Pérot Enhanced Terahertz Mueller Matrix Ellipsometry, Sean Knight, Dharmalingam Prabhakaran, Christian Binek, Mathias Schubert
Christian Binek Publications
Here we present the use of Fabry-Pérot enhanced terahertz (THz) Mueller matrix ellipsometry to measure an electromagnon excitation in monoclinic cupric oxide (CuO). As a magnetically induced ferroelectric multiferroic, CuO exhibits coupling between electric and magnetic order. This gives rise to special quasiparticle excitations at THz frequencies called electromagnons. In order to measure the electromagnons in CuO, we exploit single-crystal CuO as a THz Fabry-Pérot cavity to resonantly enhance the excitation’s signature. This enhancement technique enables the complex index of refraction to be extracted. We observe a peak in the absorption coefficient near 0.705 THz and 215 K ...
Fabrication And Characterization Of Nanofiber Nylon-6-Mwcnt As An Electrochemical Sensor For Sodium Ions Concentration Detection In Sweat, Kelsey Mills
Williams Honors College, Honors Research Projects
Fabrication and characterization nylon-6-MWCNT nanofiber as an electrochemical sensor to detect sodium ion concentrations specifically in sweat. Using contact angle to determine surface morphology and chronoamperometry testing to identify ideal sensor conditions, tests optimized parameters like weight percent of nylon or other polymers, carbon nanotube (CNT) isomer, and solution concentration to determine reproducibility of functional sensors. Utilizing the electric qualities of carbon nanotubes partnered with the sodium ion selectivity of calixarene treatment and polymers unique properties like flexibility and scalability create open an arena for optimizing sodium ion sensors for further development for functional prototypes. Morphology tests showed that the ...
S.A.V.E. M.E., 2019 The University of Akron
S.A.V.E. M.E., Taylor Davis, Kelly Nicole O'Neill, Adrianna M. Dunlap, Parsa Esshaghi Bayat
Williams Honors College, Honors Research Projects
S.A.V.E. M.E. stands for Submerged Automated Vehicular Elevation Minor Extraction or alternatively a Home Swimming Pool Rescue Device. The objective of this project is to design and prototype a system that will make unattended swimming pools through detecting a victim’s presence, deploying a means to save the victim, and alerting others nearby of the situation. This system encompasses sensors and devices within the pool and an alarm system outside of the pool. Upon detection of a sufficiently sized object entering the pool when the system is armed, a device will maneuver to the victim and ...