Furnace System Improvements,
2018
California Polytechnic State University, San Luis Obispo
Furnace System Improvements, Kenji K. Anzai, Ethan Fedor, Patrick Zailaa
Mechanical Engineering
This Final Design Review (FDR) documents the work done by the group to manufacture the system to deliver improvements to the furnace in the Cal Poly microfabrication laboratory (better known as the cleanroom). The document describes the material covered in the Scope of Work (SOW), including background research, customer needfinding, and the problem statement, material associated with concept development and selection for Preliminary Design Review (PDR), material detailing the design and manufacturing plan of the system for Critical Design Review (CDR), and new material detailing the manufacture of the system for FDR.
Research done for the SOW resulted in a …
Exploration Of Radiation Damage Mechanism In Mems Devices.,
2018
University of Louisville
Exploration Of Radiation Damage Mechanism In Mems Devices., Pranoy Deb Shuvra
Electronic Theses and Dissertations
We explored UV, X-ray and proton radiation damage mechanisms in MEMS resonators. T-shaped MEMS resonators of different dimensions were used to investigate the effect of radiation. Radiation damage is observed in the form of resistance and resonance frequency shift of the device. The resistance change indicates a change in free carrier concentration and mobility, while the resonance frequency change indicates a change in mass and/or elastic constant. For 255nm UV radiation, we observed a persistent photoconductivity that lasts for about 60 hours after radiation is turned off. The resonance frequency also decreases 40-90 ppm during irradiation and slowly recovers at …
Stability Analysis Of A High-Power Microgrid,
2018
University of Arkansas, Fayetteville
Stability Analysis Of A High-Power Microgrid, David Manuel Carballo Rojas
Graduate Theses and Dissertations
The objective of this thesis is to perform the modeling and stability analysis of a high-power microgrid with multiple parallel-and grid connected voltage source converters using the system parameters from the high-power microgrid testbed at the National Center for Reliable Electric Power Transmission (NCREPT) at the University of Arkansas in order to identify, minimize, if not eliminate, the potential instabilities that can affect the proper operation of the microgrid testbed. To achieve this objective, the mathematical modeling of the high-power microgrid considering the adverse effects of resonances due to interactions among the converter LCL output filters is presented and analyzed. …
Exfoliation, Synthesis, And Characterization Of Nanoscale Te,
2018
University of Arkansas, Fayetteville
Exfoliation, Synthesis, And Characterization Of Nanoscale Te, Takayuki Hironaka
Graduate Theses and Dissertations
Since the experimental discovery of graphene, two dimensional materials have enjoyed more attention and emphasis in academic research than nanowires, but the latter are an important area of study for creating 1D materials, or single atom chains, the next generation materials for advancing electronic devices. Atomically thin layers can be generated from 2D materials with weak bonds in one direction, and by applying this concept to one dimensional weakly bonded materials, we hypothesize that single atom chains with atomic-scale diameters may be produced. Tellurium (Te) and selenium (Se) have lattices consisting of spiral chains oriented along the c-axis, and each …
Gesn Thin Film Epitaxy And Quantum Wells For Optoelectronic Devices,
2018
University of Arkansas, Fayetteville
Gesn Thin Film Epitaxy And Quantum Wells For Optoelectronic Devices, Perry Christian Grant
Graduate Theses and Dissertations
Group IV photonics is an effort to generate viable infrared optoelectronic devices using group IV materials. Si-based optoelectronics have received monumental research since Si is the heart of the electronics industry propelling our data driven world. Silicon however, is an indirect material whose optical characteristics are poor compared to other III-IV semiconductors that make up the optoelectronics industry. There have been major efforts to integrate III-V materials onto Si substrates. Great progress on the integration of these III-V materials has occurred but incompatibility with CMOS processing has presented great difficulty in this process becoming a viable and cost-effective solution. Germanium …
Growth And Behaviors Of Inn/Gan Multiple Quantum Wells By Plasma-Assisted Molecular Beam Epitaxy,
2018
University of Arkansas, Fayetteville
Growth And Behaviors Of Inn/Gan Multiple Quantum Wells By Plasma-Assisted Molecular Beam Epitaxy, Chen Li
Graduate Theses and Dissertations
Fully realizing the potential of InGaN semiconductors requires high quality materials with arbitrary In-content. To this date the growth of In-rich InGaN films is still challenging since it suffers from the low growth temperatures and many detrimental alloying problems. InN/GaN multiple quantum wells (MQWs) and super lattices (SLs) are expected to be promising alternatives to random InGaN alloys since in principle they can achieve the equivalent band gap of InGaN random alloys with arbitrarily high In-content and at the same time bypass many growth difficulties.
This dissertation focuses on studying the growth mechanisms, structural properties and energy structures of InN/GaN …
Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter,
2018
University of Arkansas, Fayetteville
Comparative Study Of Power Semiconductor Devices In A Multilevel Cascaded H-Bridge Inverter, Kenneth Mordi
Graduate Theses and Dissertations
This thesis compares the performance of a nine-level transformerless cascaded H-bridge (CHB) inverter with integrated battery energy storage system (BESS) using SiC power MOSFETs and Si IGBTs. Two crucial performance drivers for inverter applications are power loss and efficiency. Both of these are investigated in this thesis. Power devices with similar voltage and current ratings are used in the same inverter topology, and the performance of each device is analyzed with respect to switching frequency and operating temperature. The loss measurements and characteristics within the inverter are discussed. The Saber® simulation software was used for the comparisons. The power MOSFET …
Review Of Recent Nuclear Magnetic Resonance Studies Of Ion Transport In Polymer Electrolytes,
2018
CUNY Hunter College
Review Of Recent Nuclear Magnetic Resonance Studies Of Ion Transport In Polymer Electrolytes, Stephen Munoz, Steven Greenbaum
Publications and Research
Current and future demands for increasing the energy density of batteries without sacrificing safety has led to intensive worldwide research on all solid state Li-based batteries. Given the physical limitations on inorganic ceramic or glassy solid electrolytes, development of polymer electrolytes continues to be a high priority. This brief review covers several recent alternative approaches to polymer electrolytes based solely on poly(ethyleneoxide) (PEO) and the use of nuclear magnetic resonance (NMR) to elucidate structure and ion transport properties in these materials.
Vertical Transport Study Of Iii-V Type-Ii Superlattices,
2018
Center for High Technology Materials
Vertical Transport Study Of Iii-V Type-Ii Superlattices, Zahra Taghipour
Optical Science and Engineering ETDs
Type-II strained layer superlattice (T2SL) semiconductors hold great promise for mid- and long-wavelength infrared photodetectors. While T2SL-based materials have advanced significantly in the last three decades, an outstanding challenge to improve the T2SLs is to understand the carrier transport and its limitations, in particular along the superlattice growth layers.
In this dissertation, an overview of the current state-of-the-art InAs/GaSb T2SLs is presented. Fundamental semiconductor device equations and transport properties, including miniband conduction and the drift-diffusion parameters, are reviewed, and the fundamental limiting factors in carrier's transport are discussed. Furthermore, the standard method of electron-beam-induced current technique to measuring these parameters …
Genetic Algorithm Design Of Photonic Crystals For Energy-Efficient Ultrafast Laser Transmitters,
2018
University of New Mexico
Genetic Algorithm Design Of Photonic Crystals For Energy-Efficient Ultrafast Laser Transmitters, Troy A. Hutchins-Delgado
Shared Knowledge Conference
Photonic crystals allow light to be controlled and manipulated such that novel photonic devices can be created. We are interested in using photonic crystals to increase the energy efficiency of our semiconductor whistle-geometry ring lasers. A photonic crystal will enable us to reduce the ring size, while maintaining confinement, thereby reducing its operating power. Photonic crystals can also exhibit slow light that will increase the interaction with the material. This will increase the gain, and therefore, lower the threshold for lasing to occur. Designing a photonic crystal for a particular application can be a challenge due to its number of …
Vortex Structures Inside Spherical Mesoscopic Superconductor Plus Magnetic Dipole,
2018
Embry-Riddle Aeronautical University
Vortex Structures Inside Spherical Mesoscopic Superconductor Plus Magnetic Dipole, A. Ludu
Publications
We investigate the existence of multivortex states in a superconducting mesoscopic sphere with a magnetic dipole placed at the center. We obtain analytic solutions for the order parameter inside the sphere through the linearized Ginzburg-Landau (GL) model, coupled with mixed boundary conditions, and under regularity conditions and decoupling coordinates approximation. The solutions of the linear GL equation are obtained in terms of Heun double confluent functions, in dipole coordinates symmetry. The analyticity of the solutions and the associated eigenproblem are discussed thoroughly. We minimize the free energy for the fully nonlinear GL system by using linear combinations of linear analytic …
Spacecraft Charging In The Lunar Plasma Environment: An Analysis Of The Gateway Mission,
2018
University of Alabama in Huntsville
Spacecraft Charging In The Lunar Plasma Environment: An Analysis Of The Gateway Mission, Gwyer Sinclair
Von Braun Symposium Student Posters
No abstract provided.
Thermal And Mechanical Energy Harvesting Using Lead Sulfide Colloidal Quantum Dots,
2018
Louisiana State University and Agricultural and Mechanical College
Thermal And Mechanical Energy Harvesting Using Lead Sulfide Colloidal Quantum Dots, Taher Ghomian
LSU Doctoral Dissertations
The human body is an abundant source of energy in the form of heat and mechanical movement. The ability to harvest this energy can be useful for supplying low-consumption wearable and implantable devices. Thermoelectric materials are usually used to harvest human body heat for wearable devices; however, thermoelectric generators require temperature gradient across the device to perform appropriately. Since they need to attach to the heat source to absorb the heat, temperature equalization decreases their efficiencies. Moreover, the electrostatic energy harvester, working based on the variable capacitor structure, is the most compatible candidate for harvesting low-frequency-movement of the human body. …
Investigating The Effect Of Detecting And Mitigating A Ring Oscillator-Based Hardware Trojan,
2018
Southern Methodist University
Investigating The Effect Of Detecting And Mitigating A Ring Oscillator-Based Hardware Trojan, Lakshmi Ramakrishnan
Electrical Engineering Theses and Dissertations
The outsourcing of the manufacturing process of integrated circuits to fabrications plants all over the world has exposed these chips to several security threats, especially at the hardware level. There have been instances of malicious circuitry, such as backdoors, being added to circuits without the knowledge of the chip designers or vendors. Such threats could be immensely powerful and dangerous against confidentiality, among other vulnerabilities.
Defense mechanisms against such attacks have been probed and defense techniques have been developed. But with the passage of time, attack techniques have improved immensely as well. From directly observing the inputs or outputs, adversaries …
Spice Based Compact Model For Electrical Switching Of Antiferromagnet,
2018
Purdue University
Spice Based Compact Model For Electrical Switching Of Antiferromagnet, Xe Jin Chan, Jan Kaiser, Pramey Upadhyaya
The Summer Undergraduate Research Fellowship (SURF) Symposium
A simulation framework that can model the behavior of antiferromagnets (AFMs) is essential to building novel high-speed devices. The electrical switching of AFMs allows for high performance memory applications. With new phenomena in spintronics being discovered, there is a need for flexible and expandable models. With that in mind, we developed a model for AFMs which can be used to simulate AFM switching behavior in SPICE. This approach can be modified for adding modules, keeping pace with new developments. The proposed AFM switching model is based on the Landau-Lifshitz-Gilbert equation (LLG). LLG along with an exchange coupling module is implemented …
Si-Based Germanium Tin Photodetectors For Short-Wave And Mid-Wave Infrared Detections,
2018
University of Arkansas, Fayetteville
Si-Based Germanium Tin Photodetectors For Short-Wave And Mid-Wave Infrared Detections, Thach Pham
Graduate Theses and Dissertations
The demand of light-weight and inexpensive imaging system working in the infrared range keeps increasing for the last decade, especially for civil applications. Although several group IV materials such as silicon and germanium are used to realize detectors in the visible and near infrared region, they are not the efficient approach for imaging system in the short-wave infrared detection range and beyond due to bandgap limit. On the other hand, this market is heavily relied upon mature technology from III-V and II-VI elements over years, which are costly to growth and incompatible with available Si complementary metal-oxide-semiconductor (CMOS) foundries. This …
High-Sn-Content Gesn Alloy Towards Room-Temperature Mid Infrared Laser,
2018
University of Arkansas, Fayetteville
High-Sn-Content Gesn Alloy Towards Room-Temperature Mid Infrared Laser, Wei Dou
Graduate Theses and Dissertations
Si photonics is a rapidly expanding technology that integrates photonic circuits onto a Si substrate. The integration of Si electronics and photonics has been a successful technology for a wide range of applications. Group-IV alloy GeSn has drawn great attentions as a complementary metal–oxide–semiconductor compatible optoelectronic material for Si photonics. The devices based on GeSn alloy could be monolithically integrated into well-established and high-yield Si integrated circuits, which is favorable for chip-scale Si photonics featuring smaller size, lower cost, and higher reliability.
The relaxed GeSn with high material quality and high Sn composition is highly desirable to cover mid-infrared wavelength. …
Hybrid Perovskite Characterization And Device Applications.,
2018
University of Louisville
Hybrid Perovskite Characterization And Device Applications., Kasun Fernando
Electronic Theses and Dissertations
Hybrid perovskites are a group of materials that has shown a great impact in the field of scientific research in the past decade due to the efficiency gain within a short period of time. Hot casting is one technique that has been producing high efficient and stable solar cells. Electrical transportation of lateral device structure by such film is explored to understand basic properties and predict possible device applications using it. Under dark, memristive ability of the film was explored using various experiments. Unique uni-polar memristor ability was observed. Using the experimental results, a model is hypothesized using the concepts …
Tunneling In Si Mos Nanostructures,
2018
University of New Mexico
Tunneling In Si Mos Nanostructures, Amir Shirkhorshidian
Electrical and Computer Engineering ETDs
In this dissertation, split-gate tunnel barriers in enhancement-mode silicon metal- oxide-semiconductor (MOS) device structures are characterized electrically at liquid helium temperatures (T = 4.2 K) using transport spectroscopy. Tunnel barriers with different gate geometries and barriers implanted with a small number of antimony donor atoms are characterized. Low disorder MOS tunnel barriers are demonstrated and compared to the implanted cases. The ”clean” MOS tunnel barriers are an important proof of principle that disorder free tunnel barriers can be achieved in MOS. The implanted cases provide an important reference for the effects of donors and shallow traps on a MOS tunnel …
Selected Applications Of Silicon Nanopillar Arrays.,
2018
University of New Mexico
Selected Applications Of Silicon Nanopillar Arrays., Behnam Kheyraddini Mousavi
Electrical and Computer Engineering ETDs
Interaction of optical waves with nanostructures made of various material systems has been the subject of intensive research for many years. These researches have been mainly driven by the need to make smaller optical devices and exploiting the functionalities offered by light-matter interaction in nanoscale. Majority of the nanostructures are fabricated using electron beam (e-beam) lithography that is slow and expensive. As such alternative methods have been developed to enable nanoscale fabrication faster and less expensive. Among these interferometric lithography (IL) is a relatively simple method for quick fabrication of nanostructures. As IL method generates periodic patterns, exploring the potential …
