Engineering Papers⌕ Search

Engineering topics

Weiss, Gregory

Publications and source records attributed to Weiss, Gregory.

Continuous Flow Biocatalytic Generation of Green Propellant Fuels

Propulsion technologies have focused on monopropellant hydrazine systems for the past four decades. However, hydrazine is both highly toxic and highly flammable, requiring expensive cold storage and specialized handling and disposal protocols. Alternative propellant fuels for supporting satellites and spacecraft are required, and greener, on-demand approaches for manufacturing denser, less dangerous rocket fuels are essential. This project will ensure that humans in extreme environments such as space can sustainably access renewable fuel resources from biomass waste streams via continuous biocatalytic manufacturing using microfluidic reactor systems. Demonstration of our sustainable and recyclable processes for manufacturing greener propellants from biomass waste will advance further applications in future space missions. There remains a continued need to develop more sustainable, environmentally-responsible pathways for manufacturing fuels in general and propellants in particular. This project, building upon known biocatalytic processes, will provide astronauts with renewable propellant fuel sources that can be manufactured in situ. Thus, “on-demand” access to propellants that perform more efficiently than hydrazine is enabled by this proposed work.

09 BIOMASS FUELS↗

CSI4 Analysis to Inform California Grid Integration Rules for PV

Sandia National Laboratories (Sandia) and Electric Power Research Institute, Inc. (EPRI) are collaborated to develop guidelines for effective use of smart inverters given the unique hosting capacity of the California grid. A key outcome of this project will be recommended settings for the smart inverter functions currently being considered as part of the modification to Rule 21. Additionally, this project will provide thresholds of smart inverter set points for which manufacturers can specify their equipment and suggested default settings that are applicable for most utility needs and feeder configurations in California. These results will directly contribute to the goals of the California Public Utilities Commission (CPUC) to enable and enhance integrating PVs on the electric grid.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Sensor Commercialization

The objective of this CRADA was the transfer the BaDx technology to a commercial partner, Aquila Technologies, to develop BaDx for medium-scale production. BaDx is a stand-alone, diagnostics cartridge for use in resourcelimited and challenging environments to sense low concentrations (<100 spores) of virulent pathogenic bacteria. The fully sealed cartridge also contains a “self-destruct” feature in which the device contents are sterilized post-assay. The ultimate goal of this CRADA was realized as validated and full-functioning BaDx cartridges are currently available for purchase and acquisition from Aquila. This project also resulted in significant and prestigious recognitions including, a R&D100 Award (2014), a Federal Laboratory Consortium (FLC) Excellence in Technology Transfer Award (2015), Popular Science Magazine naming BaDx ‘One of the Greatest Innovations of 2015,” and a TechConnect National Innovation Award (2015). Further, this CRADA resulted in a commercially viable bioagent detection platform transitioned from a national laboratory to industry that may significantly enhance national security by reducing the threat from biological agents that are stored and maintained in laboratories with poor safety and security protocols. Hospital, health clinic and at-home healthcare could also be revolutionized by this technology. This work has already lead to two follow-on projects, one funded by the US Department of Homeland Security (DHS), and the other by the US State Department.

47 OTHER INSTRUMENTATION↗

Spatially-dependent Hybridization of Potentials in LAMMPS

The purpose of the project was to facilitate joint Sandia/ExxonMobil collaborative research activities of mutual interest in the area of atomistic simulation of materials behavior using Sandia's LAMMPS molecular dynarnics software package. Work began in late 2013 and ended in early 2017. Initially, the main focus was on the development of a spatially-dependent hybridization capability for interatomic potentials in LAMMPS. Later, attention shifted to modeling and simulation of phase transformation kinetics in iron. Other research activities involved a variety of LAMMPS functionality, including interatomic potentials, Monte Carlo sampling, and energy minimization.

36 MATERIALS SCIENCE↗

X-Ray Phase Contrast Imaging (XPCI) System

Sandia National Laboratories (Sandia) and Carestream Health, Inc. (CHI) collaborated on the development of a grating-based X-ray Phase Contrast Imaging (XPCI) system at Sandia. The purpose of the agreement was to share research and development knowledge, resources, and capabilities in the advancement of XPCI that would be mutually beneficial to CHI and Sandia. In the course of this agreement Sandia designed and built an XPCI apparatus including opto-mechanical design, source and x-ray detector selection, software interface, hardware assembly, and system alignment. Data acquisition and image reconstruction were demonstrated at both CHI and Sandia. XPCI is a new imaging modality that enables non-destructive inspection of low density materials not previously possible with conventional x-ray. The technique fills a capability gap valuable to both the industry partner in their technical portfolio and in national security applications important to Sandia and the DOE mission space.

47 OTHER INSTRUMENTATION↗

A Micro-Thermionic Ionization Source for Chemical Detection

The major goal of this project was to develop an ionization-based detector that could be integrated into the portable gas chromatography systems currently produced by Defiant Technologies. This new detector would allow Defiant to analyze a broader range of analytes and enter new markets. There was also an interest in testing the new ionization source in an ion mobility spectrometer (IMS) that is produced by Sandia National Laboratories. Not only could this eliminate the need for a radioactive material in the IMS, it would offer Defiant the opportunity to add a whole new product line to their chemical analysis systems. Significant progress was made in the development of a thermionic ionization source (TIS) and detector. Using a MEMs heater was an attractive concept, but it proved to be an unfruitful approach because of the fragility of the devices at elevated temperatures. A rugged alternative heater was developed using nichrome wire and alumina tubes. These heaters are simple to make, and, for low quantity production, will be considerably cheaper to construct than MEMs devices. This work has provided a firm basis for follow-on projects. There is now a solid concept for constructing heater elements where, prior to this work, there was only the hope that MEMs heaters would work. In addition, the electrometer that was developed works better than the commercial rack-mounted system that was originally used in this study. Overcoming these two obstacles provides a clear technical approach for product development. There will be follow on efforts at Defiant Technologies to refine the development of the thermal ionization detector. Designs are being made to combine the TIS and electrometer electronics into a single package with a simple-to-replace TIS element. Further work will also focus on integrating this new detector into portable gas chromatography products and testing to optimize the performance.

47 OTHER INSTRUMENTATION↗