Two Level Converter XML Format and Data
Two Level Converter XML Format and Data
Hasan, Shamim [ORNL] (ORCID:0000000262721562)↗
SEARCH · Engineering Papers
Results for “CONVERTER”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Electro-optic Analog-to-Digital Converter Using Spectral Interferometry
We demonstrate an optical analog-to-digital converter (ADC) leveraging spectral interferometry of an integrated electro-optic Mach-Zehnder interferometer on thin-film lithium niobate. The ADC features a high dynamic range of 118 dB/Hz with a 3-Vpp input range.
Shao, Linbo↗
Real-time jitter correction in a photonic analog-to-digital converter
A real-time jitter meter is used to measure and digitally sample the pulse-to-pulse timing error in a laser pulse train. The jitter meter is self-referenced using a single-pulse delay line interferometer and measures timing jitter using optical heterodyne detection between two frequency channels of the pulse train. Jitter sensitivity down to 3×10 -10 fs 2 /Hz at 500 MHz has been demonstrated with a pulse-to-pulse noise floor of 1.6 fs. Furthermore, as a proof of principle, the digital correction of the output of a high-frequency photonic analog-to-digital converter (PADC) is demonstrated with an emulated jitter signal. Up to 23 dB of jitter correction, down to the noise floor of the PADC, is accomplished with radio-frequency modulation up to 40 GHz.
47 OTHER INSTRUMENTATION↗
Telecom-to-visible quantum frequency converter on a silicon nitride chip
Quantum frequency conversion serves a key role in the realization of hybrid quantum networks by interfacing between wavelength-incompatible platforms. Here we present what is believed to be the first quantum frequency converter connecting visible and telecom domains on a silicon nitride (SiN) chip, using Bragg-scattering four-wave mixing to upconvert heralded single photons from 1260 to 698 nm, which covers a 192 THz span. We examine the noise sources in SiN and devise approaches to suppress noise photons at the source and target frequencies to enable measurements at the single-photon level. We demonstrate an on-chip conversion efficiency of 5% in photon flux and describe design modifications that can be implemented to significantly improve it. Our results pave the way for the implementation of complementary metal-oxide-semiconductor (CMOS)-compatible devices in quantum networks.
59 BASIC BIOLOGICAL SCIENCES↗
SARS-CoV-2 spike protein variant binding affinity to an angiotensin-converting enzyme 2 fusion glycoproteins
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the Coronavirus disease 2019 (Covid-19) pandemic, continues to evolve and circulate globally. Current prophylactic and therapeutic countermeasures against Covid-19 infection include vaccines, small molecule drugs, and neutralizing monoclonal antibodies. SARS-CoV-2 infection is mainly mediated by the viral spike glycoprotein binding to angiotensin converting enzyme 2 (ACE2) on host cells for viral entry. As emerging mutations in the spike protein evade efficacy of spike-targeted countermeasures, a potential strategy to counter SARS-CoV-2 infection is to competitively block the spike protein from binding to the host ACE2 using a soluble recombinant fusion protein that contains a human ACE2 and an IgG1-Fc domain (ACE2-Fc). Here, we have established Chinese Hamster Ovary (CHO) cell lines that stably express ACE2-Fc proteins in which the ACE2 domain either has or has no catalytic activity. The fusion proteins were produced and purified to partially characterize physicochemical properties and spike protein binding. Our results demonstrate the ACE2-Fc fusion proteins are heavily N-glycosylated, sensitive to thermal stress, and actively bind to five spike protein variants (parental, alpha, beta, delta, and omicron) with different affinity. Our data demonstrates a proof-of-concept production strategy for ACE2-Fc fusion glycoproteins that can bind to different spike protein variants to support the manufacture of potential alternative countermeasures for emerging SARS-CoV-2 variants.
60 APPLIED LIFE SCIENCES↗
Validation of simulated wave energy converter responses to focused waves
Focused waves are increasingly used as a design method to predict extreme loads for offshore structures, such as wave energy converters (WECs). However, the ability of computational methods to accurately simulate the prescribed focused waves and resulting wave structure interactions is not well validated. This study uses two computational fluid dynamic methods, WEC-Sim and STAR-CCM+, to evaluate the responses of two taut-moored WEC-like buoys to three different focused waves. WEC-Sim is a computationally efficient, mid-fidelity model, based on linearised potential flow theory. In contrast, STAR-CCM+ is a high-fidelity, three-dimensional, unsteady, Reynolds-averaged Navier–Stokes-based model. The two buoy geometries considered are a hemispherical-bottom cylinder and a truncated cylinder with a cylindrical moon pool. Three prescribed focused waves are generated in both codes, and the simulated displacements and mooring loads are obtained for each of the hydrodynamic bodies. The resulting STAR-CCM+ generated focused waves have approximately the same accuracy, in comparison with the analytic solution, as experimentally generated focused waves. The WEC-Sim simulated responses, when using viscous coefficients tuned to the measured displacements, are, on average, within 11.5% of experimentally measured values, whereas the STAR-CCM+ simulated responses are, on average, within 14.2% of the experimental values.
16 TIDAL AND WAVE POWER↗
Identifying Direct SP -Converted Waves Constrains Local Induced Earthquake Depths
Abstract Seismicity in southern Kansas and northern Oklahoma in the past decade has been associated with fluid injections. In southcentral Kansas, the Wellington earthquake catalog is primarily composed of local, low-magnitude events. Approximately 22% of recorded earthquakes over a 2.5 yr period exhibit a seismic phase arriving between the direct P phase and direct S phase with particle motion similar to the P wave. This intermediate phase was identified as an S to P conversion (SP phase) occurring in the sedimentary rocks instead of the hypothesized basement to sedimentary section transition. We exploit the SP-converted phases to improve the depth accuracy of shallow earthquakes and to constrain VP/VS. The revised depth calculations further confirm that these local induced earthquakes are occurring in the shallow crystalline basement, below the sedimentary section in which fluids are injected.
Geochemistry & Geophysics↗
Investigation of Wave Energy Converter Effects on Wave Fields: A Modeling Sensitivity Study in Monterey Bay CA.
A n indust ry standard wave modeling tool was utilized to investigate model sensitivity to input parameters and wave energy converter ( WEC ) array deploym ent scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that b oth wave height and near - bottom orbital velocity we re subject to the largest pote ntial variations, each decreas ed in sensitivity as transmission coefficient increase d , as number and spacing of WEC devices decrease d , and as the deployment location move d offshore. Wave direction wa s affected consistently for all parameters and wave perio d was not affected (or negligibly affected) by varying model parameters or WEC configuration .
Roberts, Jesse D.↗
Investigation of Wave Energy Converter Effects on Near-shore Wave Fields: Model Generation Validation and Evaluation - Kaneohe Bay HI.
The numerical model, SWAN (Simulating WAves Nearshore) , was used to simulate wave conditions in Kaneohe Bay, HI in order to determine the effects of wave energy converter ( WEC ) devices on the propagation of waves into shore. A nested SWAN model was validated then used to evaluate a range of initial wave conditions: significant wave heights (H s ) , peak periods (T p ) , and mean wave directions ( MWD) . Differences between wave height s in the presence and absence of WEC device s were assessed at locations in shore of the WEC array. The maximum decrease in wave height due to the WEC s was predicted to be approximately 6% at 5 m and 10 m water depths. Th is occurred for model initiation parameters of H s = 3 m (for 5 m water depth) or 4 m (10 m water depth) , T p = 10 s, and MWD = 330deg . Subsequently, bottom orbital velocities were found to decrease by about 6%.
Roberts, Jesse D.↗
Wave Energy Converter (WEC) Array Effects on Wave Current and Sediment Circulation: Monterey Bay CA.
The goal s of this study were to develop tools to quantitatively characterize environments where wave energy converter ( WEC ) devices may be installed and to assess e ffects on hydrodynamics and lo cal sediment transport. A large hypothetical WEC array was investigated using wave, hydrodynamic, and sediment transport models and site - specific average and storm conditions as input. The results indicated that there were significant changes in sediment s izes adjacent to and in the lee of the WEC array due to reduced wave energy. The circulation in the lee of the array was also altered; more intense onshore currents were generated in the lee of the WECs . In general, the storm case and the average case show ed the same qualitative patterns suggesting that these trends would be maintained throughout the year. The framework developed here can be used to design more efficient arrays while minimizing impacts on nearshore environmen ts.
Roberts, Jesse D.↗
Wave Energy Converter Effects on Wave Fields: Evaluation of SNL-SWAN and Sensitivity Studies in Monterey Bay CA.
A modified version of an indust ry standard wave modeling tool was evaluated, optimized, and utilized to investigate model sensitivity to input parameters a nd wave energy converter ( WEC ) array deployment scenarios. Wave propagation was investigated d ownstream of the WECs to evaluate overall near - and far - field effects of WEC arrays. The sensitivity study illustrate d that wave direction and WEC device type we r e most sensitive to the variation in the model parameters examined in this study . Generally, the changes in wave height we re the primary alteration caused by the presence of a WEC array. Specifically, W EC device type and subsequently their size directly re sult ed in wave height variations; however, it is important to utilize ongoing laboratory studies and future field tests to determine the most appropriate power matrix values for a particular WEC device and configuration in order to improve modeling results .
Roberts, Jesse D.↗
Investigation of Wave Energy Converter Effects on the Nearshore Environment: A Month-Long Study in Monterey Bay CA.
A modified version of an indust ry standard wave modeling tool, SNL - SWAN, was used to perform model simulations for hourly initial wave conditio ns measured during the month of October 2009. The model was run with an array of 50 wave energy converters (WECs) and compared with model runs without WECs. Maximum changes in H s were found in the lee of the WEC array along the angles of incident wave dire ction and minimal changes were found along the western side of the model domain due to wave shadowing by land. The largest wave height reductions occurred during observed typhoon conditions and resulted in 14% decreases in H s along the Santa Cruz shoreline . Shoreline reductions in H s were 5% during s outh swell wave conditions and negligible during average monthly wave conditions.
Roberts, Jesse D.↗
Characterization of U.S. Wave Energy Converter (WEC) Test Sites: A Catalogue of Met-Ocean Data.
This report presents met - ocean data and wave energy characteristics at three U.S. wave energy converter (WEC) test and potential deployment sites . Its purpose is to enable the compari son of wave resource characteristics among sites as well as the select io n of test sites that are most suitable for a developer's device and that best meet their testing needs and objectives . It also provides essential inputs for the design of WEC test devices and planning WEC tests, including the planning of deployment and op eration s and maintenance. For each site, this report catalogues wave statistics recommended in the (draft) International Electrotechnical Commission Technical Specification (IEC 62600 - 101 TS) on Wave Energy Characterization, as well as the frequency of oc currence of weather windows and extreme sea states, and statistics on wind and ocean currents. It also provides useful information on test site infrastructure and services .
Dallman, Ann Renee↗
Effects of Analog-to-Digital Converter Nonlinearities on Radar Range-Doppler Maps
Radar operation, particularly Ground Moving Target Indicator (GMTI) radar modes, are very sensitive to anomalous effects of system nonlinearities. These throw off harmonic spurs that are sometimes detected as false alarms. One significant source of nonlinear behavior is the Analog to Digital Converter (ADC). One measure of its undesired nonlinearity is its Integral Nonlinearity (INL) specification. We examine in this report the relationship of INL to GMTI performance.
47 OTHER INSTRUMENTATION↗
Advanced Direct-Drive Generator for Improved Availability of Oscillating Wave Surge Converter Power Generation Systems Final Technical Report
This report summarizes the activities conducted under the DOE-EERE funded project DE-EE0006400, where ABB Inc. (ABB), in collaboration with Texas A&M’s Advanced Electric Machines & Power Electronics (EMPE) Lab and Resolute Marine Energy (RME) designed, derisked, developed, and demonstrated a novel magnetically geared electrical generator for direct-drive, low-speed, high torque MHK applications The project objective was to investigate a novel and compact direct-drive electric generator and its system aspects that would enable elimination of hydraulic components in the Power Take-Off (PTO) of a Marine and Hydrokinetic (MHK) system with an oscillating wave surge converter (OWSC), thereby improving the availability of the MHK system. The scope of this project was limited to the development and dry lab demonstration of a low speed generator to enable future direct drive MHK systems.
16 TIDAL AND WAVE POWER↗
State estimation for wave energy converters
This report gives a brief discussion and examples on the topic of state estimation for wave energy converters (WECs). These methods are intended for use to enable real-time closed loop control of WECs.
16 TIDAL AND WAVE POWER↗
Analysis of Fixed Duty Cycle Hysteretic Flyback Converter for Firing Set Applications.
This paper analyzes several performance aspects of the fixed-duty-cycle, hysteretic flyback converter topology typically used in firing sets. Topologies with and without active pulse-by-pulse current limiting are considered, and closed-form expressions in terms of basic operating parameters are derived.
42 ENGINEERING↗
Resistively Graded Insulation System for Next-Generation Converter-Fed Motors
The objective of this project was to demonstrate the feasibility of a new insulation material system capable of withstanding 10 kV/μs switching voltage ramp rate (dV/dt) with operating frequencies and temperatures targeted at converter-fed motors. If successful, with additional development, this insulation material can enable 5%-10% electric machine energy savings from advanced silicon carbide (SiC) drive implementation. To accomplish these goals, we propose to eliminate partial discharge as a degradation mechanism in high voltage, taped insulation. This can be accomplished through the use of a two-sided coating on a polymer film system that will envelop any residual defects on all sides, effectively creating a Faraday cage around the defect. This project focused on demonstrating the proof of concept for the coating. It was shown that concept of providing a stress grading coating around voids can prevent partial discharge. Simulation and lab scale experiments showed that the design can be implemented in a practical layered structure without causing overheating of the insulation due to conduction. Short term testing and calculations show there is a reasonable likelihood to improved insulation life. A path to full scale production was demonstrated, with gaps in process optimization identified as needing to be closed for full scale implementation. Longer term testing and integration onto a conductor is required to fully quantify life and show benefits at an application level.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗