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INVESTIGATION OF TRIBOELECTRIC NANOGENERATORS IN SUBMERGED BODIES
No full textUnmanned underwater vehicles (UUVs) are often assigned unique missions that require the vessel to wait on station for long periods of time with minimal activity. In this case the small quantity of power required to perform basic vehicle functions is proposed to come from triboelectric nanogenerators (TENGs). Lightweight, inexpensive, and simple in design, TENG devices can provide adequate power by translating mechanical motion into electrical charge through the triboelectric effect, thus making submerged bodies in wave motion excellent candidates for energy harvesting. By using a series of rolling mode contact actuator models fabricated from Teflon and copper materials, this study focused on the investigation of parameters such as contact duration of electrode and actuator surfaces, and electrode design for charge. This study provided insight into understanding the specifics of the TENG operating principles and methods for optimizing them by using measurements of open circuit voltage and capacitor charge over time. It was found that a grating style of smaller electrodes with a larger ball diameter produced increased charge rates. Future research is needed to further explore performance of specific electrode designs in order to optimize design parameters for prototyping of the UUV test article.Distribution Statement A. Approved for public release: Distribution is unlimited.Ensign, United States Nav
DEVELOPMENT OF POLYETHYLENE COMPOSITES WITH BORON-NITRIDE NANOTUBES FOR HIGH PERFORMANCE NEUTRON RADIATION SHIELDING
No full textBoron is widely recognized and used as a reliable option to shield neutron radiation effectively. Boron-nitride nanotubes (BNNTs) offer the unique opportunity to combine boron’s shielding capability with the exceptional mechanical and thermal properties of nanotubes. This thesis investigates the synthesis and integration of BNNTs into polyethylene (PE) to create a composite material with enhanced neutron shielding performance without any significant weight increase compared to pure PE. The BNNT-PE composite was produced by melting high-density PE (HDPE) and dispersing an ultrasonicated BNNT solution via a high shear rate speed mixer. To assess the impact of BNNT content, five samples were prepared with BNNT concentrations of 0, 0.1, 0.5, and 1.0 wt.%, along with an additional control. Neutron shielding performance was evaluated using irradiation from a californium-252 source. Following irradiation, samples were machined into “dog bone” specimens for tensile testing to characterize their mechanical properties. The findings from this thesis demonstrate the potential of BNNT-PE composites as multifunctional materials that not only provide effective neutron shielding and slightly improved mechanical performance, but also lay the groundwork for future development of lightweight shielding solutions in aerospace, nuclear, and medical applications.Distribution Statement A. Approved for public release: Distribution is unlimited.Ensign, United States Nav
TURNING OFF THE TAPS: SOF SUPPORT TO ECONOMIC WARFARE
Get PDFIn this era of strategic competition, states are actively employing economic tools, realized through the execution of “economic warfare” aimed to weaken an adversary’s economy and, by extension, their political and military power. However, these economic tools have inherent limitations, are difficult to enforce, and are vulnerable to exploitation. The military instrument—specifically special operations forces (SOF)—can play a vital supporting role, enhancing the effectiveness of economic warfare. This thesis seeks to understand how SOF has historically contributed to economic warfare, under what conditions they were most effective, and what lessons can be applied to guide future operations. A qualitative, case-based methodology is employed, examining five examples: three from World War II and two from the ongoing Russo–Ukrainian war. The study finds that SOF is most effective when integrated within a broader economic warfare campaign, alongside diplomatic, informational, and conventional military efforts. Key enablers include centralized coordination, detailed economic intelligence, well-timed strikes during moments of peak pressure, and targeting truly strategic resources. Additionally, SOF provides several risk mitigations to improve strategic effectiveness in ways that conventional forces or other national instruments cannot. These findings highlight the need to institutionalize SOF’s role in economic warfare and improve interagency integration.Distribution Statement A. Approved for public release: Distribution is unlimited.Outstanding ThesisMajor, Canadian Arm
NPS, Cal State Monterey Bay Forge Partnership to Advance STEM Education and Regional Innovation
Get PDFFLOW CONTROL CHANNEL INSTRUMENTATION DESIGN AND MODELING
No full textPrimary causes of compressor stalls in gas turbines are tip leakage, casing corner leakage, and boundary layer separation flow over the rotor blades. With the fluctuation of static pressure, a self-recirculating flow channel can help increase the stall margin while still maintaining efficiency. To better visualize air flow in the recirculation passage, instrumentation will be added to the transonic compressor at Naval Postgraduate School. One aim of this study was to redesign the main structural casing that encompasses the casing insert with the flow channel to accommodate enhanced instrumentation. Another aim of this study is to create a new method that automates the development of the flow channel. Previous works have manually designed recirculating flow channels within a solid model that have proved to improve the stall margin of the transonic compressor. Using code, the flow channel was able to be changed according to the user's needs. The automated code developed allowed for multiple recirculation passages to be developed within the course of this study. Finally, the last aim of the study was to additively manufacture the two casing inserts with different flow channels. Both were tested in the transonic compressor. These were able to improve the stall margin while maintaining and improving the efficiency.Distribution Statement A. Approved for public release: Distribution is unlimited.Ensign, United States NavyONR 35, Arlington V
Automatic Extraction of Key Concepts from Commander-Intent Messages
No full textNPS NRP Executive SummaryThis project explored automatically inferring “commander’s intent,” a key aspect of communications by orders or policies transmitted from a commander to subordinates. This generally includes (1) purpose (motivations or reasons), (2) actions and procedures to be followed, and (3) goals or conditions to be achieved (either positive or negative) by the actions and procedures. Commander’s intent is critical for subordinates to intelligently follow orders, yet it is hard to extract automatically because it is usually stated only indirectly. This project examined two ways to extract commander’s intent: generative artificial intelligence prompted to express the purpose in input text, and a search for particular sentences that express intent based on particular linguistic clues. The first approach used the large language model of ChatGP3.0 with a set of prompt inputs that attempted to prioritize statement of purpose or goals. The second approach used machine-learning methods which ranked words and word pairs trained on a comparison of examples of commander’s intent with other text describing military activities but not intent. We obtained text examples and nonexamples from scanning U.S. military Web sites. Rating of words and word pairs was based on the ratio of their count in the examples to their count in the nonexamples. Sentences with high ratings were then extracted from the example text and appended to create intent summaries. Surprisingly, the first approach was a failure: We got many summaries, but little content expressing purposes, procedures, and goals. The second approach was more successful because it did not try to paraphrase, but just to isolate sentences that were likely related to intent and could be excerpted to summarize a document. These can then be further processed to extract text tags that can be stored with the documents for indexing and further analysis of them.Approved for public release. Distribution is unlimited.This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)N9 - Warfare System
Improving High Frequency Voice Communications
Get PDFNPS NRP Executive SummaryThe goal of this project has been to investigate methods to improve high frequency (HF) voice communications such that operators can understand each other without having to repeat voice messages. Improved HF voice quality can save precious time that could significantly improve mission success. HF voice can also be a viable complement when other wireless voice systems are compromised. HF voice quality has always been inferior compared to many modern wireless and cellular telephone systems. It is time to replace decades-old single-sideband amplitude modulation with modern modulation techniques such as digital frequency modulation (FM), high-order digital modulation, and multiple input multiple output (MIMO) methods. Along with advanced digital signal processing and error correction, this analysis has shown that much-improved HF voice communications are possible.Approved for public release. Distribution is unlimited.This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)N2/N6 - Information Warfar
Automatic Extraction of Key Concepts from Commander-Intent Messages
Get PDFThis study explored automatically inferring “commander’s intent,” a key aspect of communications by orders or policies transmitted from a commander to subordinates. This generally includes (1) purpose (motivations or reasons), (2) actions and procedures to be followed, (3) goals or conditions to be achieved (either positive or negative) by the actions and procedures, and (4) opportunities for individual initiative.. Commander’s intent is critical for subordinates to intelligently follow orders, yet it is hard to extract automatically because it is usually stated only indirectly. The study examined two ways to extract commander’s intent: generative artificial intelligence prompted to express the purpose in input text, and a search for particular sentences that express intent based on particular linguistic clues. The first approach used the large language model of ChatGP3.0 with a set of prompt inputs that attempted to prioritize statement of purpose or goals. The second approach used machine-learning methods which ranked words and word pairs trained on a comparison of examples of commander’s intent with other text describing military activities but not intent. We obtained text examples and nonexamples from scanning U.S. military Web sites. Rating of words and word pairs was based on the ratio of their count in the examples to their count in the nonexamples. Sentences with high ratings were then extracted from the example text and appended to create intent summaries. Surprisingly, the first approach was a failure: We got many summaries, but little content expressing nonobvious purposes, procedures, and goals. The second approach was more successful because it did not try to paraphrase, but just to isolate sentences that were likely related to intent and could be excerpted to summarize a document. These can then be further processed to extract text tags that can be stored with the documents for indexing and further analysis.Approved for public release; distribution is unlimited.This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Naval Postgraduate School, Naval Research ProgramU.S. Navy N9 -- Warfare System
Maximizing Mission Success and Employee Work-Life Balance in Workplace. Dept. of Defense Management
No full textNPS NRP Executive SummaryMany employees in the Naval Education and Training Command (NETC) have a history of working some days in the office and some teleworking. This pattern was supported by the U.S. Office of Personnel Management to enhance employee performance, facilitate engagement, promote work-life balance, and bolster productivity. A recent return-to-office mandate has disrupted this pattern, presenting challenges to employees and managers. As the Navy transitions to in-office work, strategies are needed to maintain productivity, satisfaction, and morale. This study reviews literature related to managing teleworkers, hybrid workforces, and former teleworkers returning to work full-time in employers’ offices. Success factors and best practices are identified. Results of the Federal Employee Viewpoint Survey (FEVS) conducted in July 2024 are reviewed to identify strengths and weaknesses in NETC climate. Results of a subsequent survey indicate that return-to-office requirements negatively impacted morale and increased intention to leave, but also that managerial support can improve attitudes toward returning to the office. This, in turn, affects individual and team morale. Supervisors and employees had different perspectives on the pros and cons related to requiring everyone to be in the office, but in general both recognized the impact on work-life balance and employees' well-being. Results of the study inform recommendations to support mission success and employee well-being at NETC.This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)N1 - Manpower, Personnel, Training & Educatio
3D Printed Oxide Reinforced Titanium Composites and Methods
No full textThis disclosure, and the exemplary embodiments provided herein, include AM processed Ti-MMCs reinforced with either aluminum oxide or tantalum pentoxide. According to an exemplary embodiment, composite feedstock powders of Ti-6Al-4V (Ti64) with 1% and 3% (by volume) reinforcements of either nano-Al₂O₃ or Ta₂O₅ are prepared by high energy ball milling and then 3-D printed using SLM