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Networked robotic systems, such as connected vehicle platoons, can improve the safety and efficiency of transportation networks by allowing for high-speed coordination. To enable such coordination, these systems rely on networked communications. This can make them susceptible to cyber attacks. Though security methods such as encryption or specially designed network topologies can increase the difficulty of successfully executing such an attack, these techniques are unable to guarantee secure communication against an attacker. More troublingly, these security methods are unable to ensure that individual agents are able to detect attacks that alter the content of specific messages. To ensure resilient behavior under such attacks, this paper formulates a networked linear time-varying version of dynamic watermarking in which each agent generates and adds a private excitation to the input of its corresponding robotic subsystem. This paper demonstrates that such a method can enable each agent in a networked robotic system to detect cyber attacks. By altering measurements sent between vehicles, this paper illustrates that an attacker can create unstable behavior within a platoon. By utilizing the dynamic watermarking method proposed in this paper, the attack is detected, allowing the vehicles in the platoon to gracefully degrade to a non-communicative control strategy that maintains safety across a variety of scenarios., Comment: 19 pages, 7 figures

2021 ASEE Virtual Annual Conference Content Access 17 USC 105 interim-entered record; under review. Addressing reliability issues is critical to the successful design and implementation of new semiconductor material systems proposed for next generation power electronic devices. For military systems, reliability is central to successful device designs, often outweighing other design factors. Several reliability testing schemes are central to validating power semiconductor device reliability. Of these, high temperature operating life (HTOL) and high temperature reverse bias (HTRB) testing are often used as go/no-go metrics for the success or failure of a fabricated lot of devices. To educate students in the importance of these testing regimens for devices, several undergraduate and graduate students have developed a custom, modular thermoelectrically cooled and controlled HTOL/HTRB system which allows for joint long term HTOL/HTRB testing at both institutions. Under constraints for cost, the system was designed to utilize a novel thermoelectric cooling scheme to provide a temperature range of 55 °C from 5 °C to 62 °C with less than 0.5 °C variation under 15 W heat load from devices-under-test (DUTs). A hermetic DUT environment was designed using nitrogen purging and active humidity sensing to control relative humidity (RH) within the environment to beneath 5% RH. Undergraduate students gained experience designing for manufacturability and machining with CAD tools not typically explored in typical electrical engineering design projects. An automated switch-matrix was designed and implemented to automate testing and allow for programming of complex stress-measure-stress reliability testing profiles. Control and automation was enabled using common MBED processors used throughout an undergraduate electrical engineering curriculum. To accomplish a unified design which could be installed at multiple locations, students investigated and implemented a server rack mounted design which uses commonly available banana and BNC connections for "plug-and-play" of the system. A control program was developed using a LabVIEW program which managed the system wide control and programming of different reliability testing regimens, such as stress-measure-stress, stepped-stress, and constant current, voltage, or power testing. Results for the fabricated system performance are shown demonstrating the successful achievement of the design metrics. To demonstrate the use of the system, results from recent undergraduate student led HTOL testing on novel GaN Schottky diode parts are presented. Current and future senior capstone and masters-level research projects using the novel system are reviewed.

UnlabelledEpithelial barrier dysfunction during human immunodeficiency virus (HIV) infection has largely been attributed to the rapid and severe depletion of CD4(+) T cells in the gastrointestinal (GI) tract. Although it is known that changes in mucosal gene expression contribute to intestinal enteropathy, the role of small noncoding RNAs, specifically microRNA (miRNA), has not been investigated. Using the simian immunodeficiency virus (SIV)-infected nonhuman primate model of HIV pathogenesis, we investigated the effect of viral infection on miRNA expression in intestinal mucosa. SIV infection led to a striking decrease in the expression of mucosal miRNA compared to that in uninfected controls. This decrease coincided with an increase in 5'-3'-exoribonuclease 2 protein and alterations in DICER1 and Argonaute 2 expression. Targets of depleted miRNA belonged to molecular pathways involved in epithelial proliferation, differentiation, and immune response. Decreased expression of several miRNA involved in maintaining epithelial homeostasis in the gut was localized to the proliferative crypt region of the intestinal epithelium. Our findings suggest that SIV-induced decreased expression of miRNA involved in epithelial homeostasis, disrupted expression of miRNA biogenesis machinery, and increased expression of XRN2 are involved in the development of epithelial barrier dysfunction and gastroenteropathy.ImportanceMicroRNA (miRNA) regulate the development and function of intestinal epithelial cells, and many viruses disrupt normal host miRNA expression. In this study, we demonstrate that SIV and HIV disrupt expression of miRNA in the small intestine during infection. The depletion of several key miRNA is localized to the proliferative crypt region of the gut epithelium. These miRNA are known to control expression of genes involved in inflammation, cell death, and epithelial maturation. Our data indicate that this disruption might be caused by altered expression of miRNA biogenesis machinery during infection. These findings suggest that the disruption of miRNA in the small intestine likely plays a role in intestinal enteropathy during HIV infection.

In recent years, the military has been exploring the use of wide bandgap semiconductors (WBGS) such as gallium nitride (GaN) and silicon carbide (SiC) due to their promising material properties, as compared to silicon (Si). Understanding the reliability of these high-performance WBGS devices is paramount to their implementation in military systems. However, it remains to be tested because good-quality reliability data is needed, but it is difficult and expensive to produce. This thesis looks at the design and implementation of a modular reliability testing subsystem in the form of a novel data acquisition system. First, a system was designed to perform automated, in-situ leakage current measurements of up to four devices under test (DUT) with sub-nA resolution. Next, a wide sample of devices consisting of a resistor, two Zener diodes, a power diode, two GaN diodes, and a field effect transistor (FET) were subjected to various voltage sweep and reverse-bias tests that were recorded by the system. Finally, the results of those validation tests were processed and analyzed. The system achieved leakage current resolutions below 100 pA, demonstrating its ability to measure various devices. ONR Arlington, VA, 22217 Captain, United States Marine Corps Approved for public release. Distribution is unlimited.

This work demonstrates the very first implementation of electroluminescence from a gallium nitride vertical diode as a feedback mechanism for real-time current control of a power converter. Current estimation via electroluminescence provides a galvanically isolated sensor capability that is not susceptible to electromagnetic interference, which is inherently produced in switch mode power supplies. The light feedback is converted to an electrical signal that is further digitally filtered to construct a 3D current calibration surface. This surface converts duty cycle and light signal intensity into a real-time current estimation utilized as a feedback parameter in a buck converter control system. The accuracy of current estimation is shown to be within 5% of steady-state current over various load conditions. Transient-state response was also demonstrated for step changes in commanded current and voltage within the power converter. Methods of increasing accuracy and reducing current estimation delay time are discussed. Lieutenant, United States Navy Approved for public release. Distribution is unlimited.

Wide bandgap (WBG) semiconductor technology allows devices to be operated at higher voltages, currents, temperatures, and frequencies than does conventional silicon-based narrow bandgap semiconductors. These characteristics are advantageous to military applications, such as uses in power converters, weapons, and radar systems. Notably, WBG semiconductors have advantages where cooling and space availability for components are concerns, such as unmanned underwater platforms. The ability to monitor the health and performance of these devices passively and remotely would reduce the man-hours required for preventative maintenance; it would also reduce the needs for invasive troubleshooting and needless component replacement. This thesis demonstrates the abilities to measure and analyze the electroluminescence spectrum of WBG devices using a custom-built high-temperature operating life (HTOL) test setup incorporating the ability to sample light spectroscopy. Lieutenant, United States Navy Approved for public release. Distribution is unlimited.

Traditional silicon-based power electronics have approached their performance limits for high-power electronic applications. The U.S. Navy is actively pursuing the implementation of wide bandgap (WBG) semiconductor materials to realize reliable devices for use in high-power, high-current, and high-voltage applications. Gallium nitride (GaN) is a promising candidate for these applications due to its inherent material properties, and recent efforts to produce high quality bulk GaN have begun to enable the production of commercial-grade devices. However, much is still unknown regarding the reliability of GaN devices, especially Schottky diodes, which are often affected by issues involving barrier height inhomogeneity (BHI). First, a stress testing system capable of taking in-situ current-voltage-temperature (I-V-T) measurements while applying electrical stress was constructed. Next, a sample of commercial-grade vertical n-type palladium/gallium nitride (Pd/GaN) Schottky diodes were subjected to a series of step current and constant current stress tests. Current densities above 1.3 kA/cm^2 were achieved. Finally, the effects of electrical stress on material properties were observed through comparison of pre-, post-, and in-situ I-V-T data. The in-situ I-V-T measurements enabled degradation to be observed as a function of stress time. Results show that significant degradation to the material properties of the Schottky diodes occurs within the first few hours of stress testing. Lieutenant, United States Navy Approved for public release. Distribution is unlimited.

Silicon is commonly used in modern electronics; however, the technical specs are being maxed. Wide bandgap semiconductors such as gallium nitride (GaN) are being explored to further the development of better power electronics. This thesis continues testing conducted by Naval Postgraduate School student Burnell Clemmer, who designed a testing box capable of stressing wide bandgap semiconductors and found that they were failing quickly under stress. The objective of this thesis was to identify the range of operation for GaN Schottky diodes and their failure mechanisms under high current density stressing to allow for better designs for high voltage power diodes. In order to accomplish this, we conducted a series of high temperature operating life stress experiments by running an electrical current through representative bulk GaN power diodes for extended periods of time. We then documented their degradation by taking current-voltage-temperature characteristic plots throughout the test. The results generally showed that both time and current density increased the rate of degradation of the devices, but concrete conclusions could not be drawn due to limited amount of data and inconsistencies. Lieutenant, United States Navy Approved for public release. Distribution is unlimited.

This work explores previous research showing the correlation of light emission to current and temperature in a gallium nitride (GaN) vertical diode to predict current within a power converter circuit. Use of light emissions to measure current would offer an improvement over present sensors, since light would not be affected by the EMI found in most switched power converters. Matrices of the light emissions at 370, 380, 390, 400, 440, and 550 nm wavelengths over a range of 0.2 A to 4 A and 20 °C to 110 °C were used to develop best-fit polynomials for each matrix. Two of these polynomials can then be utilized to derive a unique solution of current and temperature based on the light output at the distinct wavelengths. Lock-in amplifiers allowed the amplification of weak light signals without gain bandwidth product limitations. Future efforts will be to duplicate the lock-in amplifier as well as the current and temperature prediction with use of a microcontroller. Lieutenant, United States Navy Approved for public release; distribution is unlimited.

In this work, Gallium Nitride Zirconium oxide metal oxide semiconductor capacitors were exposed to a 40MeV proton beam and a 15MeV Argon heavy ion beam of radiation. Characterization of each device was done using an Agilent B1500A, switch matrix, custom-printed circuit board while using a LabVIEW program to analyze the Capacitance-Voltage (C-V), Capacitance-Frequency (C-F), and Current-Voltage (I-V) measurement prior to and post exposure. Each reticle's C-V measurement and its hysteresis was then compared pre- and post-exposure for effects. Testing concluded with a time-dependent dielectric breakdown analysis. Results show that radiation exposure shifts the capacitance of the device and affects the hysteresis in its C-V measurement. Initial time-dependent dielectric breakdown data shows that devices exposed to certain fluences of radiation will extend the time it takes before oxide breakdown. Lieutenant, United States Navy Approved for public release. distribution is unlimited

The purpose of this research is to document further research into the optimization techniques investigated by James Walsh and applied to Multi-junction Solar Cells. Walsh performed his research with the Near Orthogonal Latin Hypercube (NOLH) in order to optimize the design specifications for each layer of solar cell thickness and doping concentration. Walsh at the same time evaluated cell performance under the radiation effects of the space environment. This research performed a similar analysis, except for the radiation effects, but focused more on producing an algorithm that could be executed from single user input and significantly reducing the selected design space. This research produced an efficient program that seamlessly operates between Ruby, MATLAB, and Silvaco ATLAS in order to produce an optimal designed dual-junction solar cell for space applications, in a much smaller design space than the technique utilized by Walsh. http://archive.org/details/optimizationofmu1094564137 Captain, United States Marine Corps Approved for public release; distribution is unlimited.

Silicon (Si) and gallium arsenide (GaAs) solar cells have shown success in back-contact designs. However, solar cells with back contacts have not been implemented on copper indium gallium diselenide (CIGS). To show the advantages of using this type of solar cell on unmanned aircraft, data from the Puma 3 AE was used. Our objective was to model 144 staggered back contact (SBC) CIGS cells onto a Puma and prove that it would extend the flight time, all at a minimal cost to the U.S. military. There are four tasks to achieving this objective: calculate maximum efficiency the solar cell could achieve, simulate a real CIGS cell, simulate the SBC CIGS cell, and model 144 SBC CIGS cells on a Puma while doing a cost analysis. Using a MATLAB script, this research calculated the ideal efficiency for a CIGS cell to be 26.72%. Using Silvaco, an accurate CIGS cell was simulated, based on a 3% difference in output performance from the real cell. A simulated SBC CIGS cell was successfully designed, which had a 23% efficiency. The new design had an 18% increase in power output from the real NREL model. Modeling 144 SBC CIGS cells on the Puma improved its standard 1–2 hour flight time to 8–17 hours, depending on location and temperature. To install 144 cells and equipment, the total cost was estimated at $926. This thesis determined that a simulated SBC CIGS cell can be made to help extend the Puma flight time, at minimal cost to the U.S. military. Lieutenant, United States Navy Approved for public release; distribution is unlimited.

With the growing complexity of high-power converters, it has never been more important to have accurate sensors for optimal control and stability. With significantly better power handling than silicon materials, bulk gallium nitride–based devices can withstand high voltages and current while simultaneously emitting a unique light spectrum, the characteristics of which are a function of the current and temperature of the device. Using bulk GaN PN junctions, preliminary measurements of the emitted light showed a distinct multi-peak spectrum corresponding to excitonic and impurity-assisted optical processes. Optical filters and photodiodes are utilized to measure the light intensity of each spectral peak for up to 5 A applied current at a temperature range of 20 °C – 100 °C. Linear polynomial models fitted to the filter output show a strong relationship between the light intensity, current, and temperature, as well as a significant energy shift in light emitted through exciton annihilation. The experimental data is then used to fit a linear polynomial model estimating current from temperature and filter output. Mean errors of 2.5%, 2.7%, and 3.7% are achieved for three of the four current models. Recommendations are made for future work in utilizing the sensor data for real-time current and temperature measurements. Ensign, United States Navy Approved for public release; distribution is unlimited.

Dual junction solar cells are used in space applications for their high efficiency. In this thesis, we model an indium gallium phosphide/gallium arsenide dual-junction solar cell. The solar cell is modeled using Silvaco ATLAS software. Solar cell layer thicknesses and doping concentrations were varied to find optimum efficiency parameters for the solar cell under a variety of radiation conditions. These radiation conditions mimic the damage done at various orbits around Earth for an arbitrary mission length of 12 years. The optimization process resulted in an improved efficiency of 15.1% to 22.4%. http://archive.org/details/optimizationofmu1094559615 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The electrical power supplied to satellites will continue to be provided by solar cells for the foreseeable future and new technologies and better methods of production for these cells will continue to be developed. Additionally, the space environment within the Earth’s radiation belts and the effect of the radiation on solar cells within this environment is well documented. The effects of radiation on solar cells outside this environment with the use of an 8-MeV electron beam was investigated. Thin-film high-efficiency gallium arsenide test devices were characterized, and an analysis of the thin-film devices’ performance post-irradiation was conducted via illuminated DC current-voltage and external quantum efficiency measurements. The results of this analysis showed a drastic reduction in device short circuit current of over 95% by a total electron fluence of 1016 cm-2. http://archive.org/details/highenergyelectr1094559561 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Gallium Arsenide (GaAs) solar cells are proven lightweight and high power density photovoltaic devices that offer significant performance improvements over conventional silicon solar cells; however, only a handful of commercial companies currently produce GaAs cells due to manufacturing costs. The objective of this thesis is to investigate the combined performance of several uncommonly used methods of fabricating thin-film GaAs solar cells, which show promise in reducing the cost of cell fabrication. Using Silvaco ATLAS Technology Computer Aided Design (TCAD), we simulated and optimized the performance of back-side contact thin-film solar cells. In such a design, both anode and cathode contacts are placed on the same side of a device, resulting in no shadowing of incoming light. The replacement of the AlGaAs emitter with a Schottky junction was simulated and evaluated and compared to the original back-side contact design. Finally, a method of improving the Schottky barrier height of the Schottky design was simulated and evaluated. http://archive.org/details/modelingschottky1094559575 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Multi-junction solar cells have given rise to compact high-efficiency photovoltaic devices, which offer significant improvements over conventional single-junction solar cell designs. This research uses an existing five-junction solar cell design by Fraunhofer ISE to provide the baseline structure for a simulation model based on published cell characteristics. This structure is then optimized by varying doping concentration and material thickness in each active cell layer in order to increase overall photocurrent generation and maximize efficiency. Optimization of solar cell efficiency is carried out via nearly orthogonal balanced design of experiments methodology. Silvaco ATLAS is utilized to simulate the behavior of the multi-junction solar cells’ configurations sampled in the design space. The results of the simulations of points within the sampled design space are loaded into statistical analysis software to construct a stepwise linear regression model to predict the optimum input parameter values to maximize output power and efficiency. The predicted optimum design point is then simulated in the Silvaco ATLAS model. Simulation results are compared to the baseline to analyze improvements such as external quantum efficiency, recombination rate, and current generation. The results following the optimization raised the multi-junction cell output power efficiency from 26.2166% to 37.3682%, while the external quantum efficiencies of the second, third, and fourth junctions were raised 8% to 20%. http://archive.org/details/fivejunctionsola1094556146 Lieutenant Commander, United States Navy Approved for public release; distribution is unlimited.

Gallium Nitride(GaN) is known for its wide-energy bandgap of 3.4 eV and its high-efficiency as a semiconductor, which makes it a prime material for high-power, high-frequency, and low-noise systems. Specifically, GaN high electron-mobility transistors (HEMTs) have seen an increase in popularity due to its two-dimensional electron gas (2DEG) that allows for increased mobility of un-doped GaN. In this work, GaN HEMTs were irradiated with a fluence of 2x1016n cm2 while maintaining a 99 percent fast-to-thermal neutron ratio. There were three phases to this work, the first was the design and fabrication of a photoneutron converter. The second was the design and implementation of a device testing suite in order to characterize the GaN HEMTs before, during, and after the experiment. The last was the analysis of the data showing the relationship of the electrical and physical characteristics of the devices with respect to the fast neutron fluence. The damage was also analyzed using a total displacement calculation for each layer of the device. The GaN HEMTs linearly degraded due to the high energy neutron displacements within the heterojunction layers. http://archive.org/details/designndimplemen1094555551 Ensign, United States Navy Approved for public release; distribution is unlimited.

In this work, a physics-based simulation of non-ionizing proton radiation damage effects at different energy levels on a GaN-on-silicon high electron mobility transistor was created. Based on physical results of 2.0-MeV protons irradiation to fluence levels of 6 1014 protons cm2, the simulation was tuned to match electron mobility n and then compared to threshold voltage Vth on state resistance Ron and transconductance gm. A Monte Carlo simulator was used to model two particle interactions utilizing the Kinchin and Pease model. The model was developed in Silvaco ATLAS, but the Athena and Victory Stress modules were also utilized. After comparison of changing characteristics between the model and the physical device at 2.0-MeV proton irradiation, predictions were made for 5.0, 10.0, 20.0 and 40.0-MeV proton irradiation. The model generally overpredicted damage in the lattice when compared to the physical results seen in prior work. http://archive.org/details/analysisofproton1094552977 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Silicon- and silicon carbide-based power devices have dominated the power electronics industry. For many emerging high-current and high-power applications, vertical transport gallium nitride (GaN)-based devices are more desirable. In this study, a series of reduced-defect, vertical n-type GaN Schottky contacts were fabricated and subjected to high-current density accelerated lifetime tests to understand the physics of contact degradation and compare the reliability of different metallization types and process cleans. Tested Schottky metals included molybdenum, molybdenum-gold, and chromium-gold. Process cleans compared were a piranha etch and a hydrofluoric acid etch. Pre-stress electrical characterization confirmed functioning Schottky contacts and determined device electrical performance parameters. Using a stress-measure- stress system, we obtained results of high-current density accelerated lifetime testing of 170 hours at current densities of 2.3 kAcm-² that showed both catastrophic and non-catastrophic failures across all metallization types and process cleans. While comparative analysis showed that molybdenum was the most reliable, identified experimental testing and non-ideal fabrication issues limited the conclusivity of the results. The identified constraints and initial comparative results serve to inform future Schottky contact structural design and fabrication for future optimized testing http://archive.org/details/characterization1094550551 Major, United States Marine Corps Approved for public release; distribution is unlimited.

This research examines the potential for the conjunction between photovoltaic (PV) and thermophotovoltaic (TPV) technologies for spacecraft power production. There is sufficient overlap between the sources of energy used for these devices and the function of the devices themselves that either PVs or TPVs could gain improvements in efficiency from the integration of the other type of device, or that a hybrid device could be developed. As a proof of concept, a GaAs PV cell and GaSb TPV cell were modeled in a tandem design using Silvaco ATLAS, with varying PV cell substrate thicknesses, and simulated under the AM0 spectrum to determine the potential range of efficiency gains for a PV device integrated with a TPV device. The same design was then tested under a 2000 K blackbody spectrum—to approximate use in a radioisotope thermoelectric generator (RTG)—to determine if similar efficiency gains could be seen for a TPV device integrated with a PV device. The possible gains with a PV-TPV design under AM0 are clear, potentially resulting in cells with a 30–34% overall efficiency. The possible gains for a PV-TPV device utilizing a blackbody spectrum are less clear, and would benefit from further design and investigation. http://archive.org/details/conjunctionofpho1094547338 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The objective of this thesis was to simulate a new way to create high efficiency Copper Indium Gallium Selenide (Cu(InGa)Se2) cells. This was accomplished by creating a model in Silvaco’s technology computer aided design ATLAS program. A baseline model was tested to confirm functionality of the software, and a stepwise approach was used to include additional features. The first addition was the inclusion of a multi-layer absorber layer with graded Ga concentrations. This layer showed increased internal electric fields, which helped to increase the output of the cell. This was followed by the replacement of the traditional n-type CdS buffer layer with a n-type ZnO buffer layer. The ZnO buffer layer was found to have better band alignment than CdS and resulted in a significant improvement in device performance. Finally, a top grid was included which reduced the output of the cell as a result of shading. The final simulation resulted in a Cu(InGa)Se2 cell which operated at 21.14% efficiency, a 21.9% increase from the baseline cell. http://archive.org/details/designndoptimiza1094547285 Captain, United States Marine Corps Approved for public release; distribution is unlimited.

The Silvaco Atlas semiconductor modeling software was used to simulate an interdigitated back-surface-contact solar cell. The cell is modeled after the silicon-based Sunpower Corporation A-300 solar cell, which contains a number of unique features that give it advantages over conventional solar cells. This simulation attempted to match as closely as possible the results measured by the National Renewable Energy Laboratory from the A-300 cell in order to validate the model. This model was then used to investigate the effects of making the A-300 thinner, which would permit its use in military solar blanket applications. A thin and flexible solar cell is ideal for this application due to its lighter weight, making it portable and flexible, which increases its ruggedness. The ability to simulate an interdigitated back-surface-contact cell also allows future work using computer algorithms to improve power output results as well as investigations into using materials other than silicon, which may further improve power output. http://archive.org/details/interdigitatedba1094545861 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

The purpose of this thesis is to streamline the sample preparation procedure to maximize the yield of successful samples to be analyzed chemically in an energy dispersive spectrometry detector. The secondary objective of this work is to identify the specific chemical elements needed to ascertain trends in stressing nickel/gold and platinum/gold gated high electron mobility transistors (HEMT). We analyze unstressed devices near the hetero-epitaxial layers to ascertain any inconsistencies due to processing defects. Results show it is possible to identify areas of electrical stress-induced diffusion and point defect creation. Identification of these trends will assist in the improvement of gallium nitride HEMT fabrication processes leading to the development of more reliable devices. http://archive.org/details/imaginggalliumni1094541457 Lieutenant, United States Navy Approved for public release; distribution is unlimited.

Alternative energy products are an increasingly common sight on military bases in the United States. Energy product reliability affects the sustainability and cost-effectiveness of these systems, which must be tested by outside entities to ensure quality. The purpose of this thesis is to perform component level reliability testing on a high voltage power capacitor used in an electrical vehicle solar charging system. A component level characterization was performed to better understand the physical attributes of these capacitors. This investigation identified the expected component lifetime and conditions in which this component will become less reliable. Results are compared to those published by the manufacturer. http://archive.org/details/reliabilityndcha1094541346 Lieutenant, United States Navy Approved for public release; distribution is unlimited.