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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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UAS operate today under many restrictions - Certificate of Authorization or Waiver (COA) for public use - Experimental certificate for civil use - Goal is to move toward more routine access UAS span a wide range of size and performance - Small UAS (<55 lbs.) will be covered by separate rulemaking - Our research interest is in larger UAS, interacting with air traffic services in non-segregated airspace
The NASA SIO demonstration flight of April 3, 2020 represents a successful culmination of 18 months of coordinated effort between GA-ASI, NASA, the FAA, Collins Aerospace, and Honeywell Aerospace to operate a Medium Altitude, Long Endurance (MALE) Unmanned Aircraft System (UAS) safely in the National Airspace System (NAS) using industry leading prototype technologies. The GA-ASI team consisted of technical experts, program managers, engineers, mechanics, flight technicians, flight crews, and numerous other subject matter experts. This final report describes the most significant and potentially impactful aspects of the planning, integration, test, and flight aspects of this effort. GA-ASI successfully integrated the key technologies needed for UAS to fly in the NAS onto our prototype SkyGuardian UAS, which was designed to meet the most stringent airworthiness standards applicable to an aircraft of its size category. A proven Detect and Avoid (DAA) system, developed by GA-ASI and utilizing Honeywell Aerospace technology was integrated onto SkyGuardian for the first time, along with datalink radios from Collins Aerospace that meet the new civil standard for Control and Non-Payload Communication (CNPC) links. GA-ASI also obtained approvals from the FAA and FCC to operate the reconfigured UAS. The SIO demonstration flight represented a commercial aerial surveying operation conducted at medium altitude (>10,000ft above mean sea level). The aircraft’s onboard sensors were used to capture photographic, infrared and radar imagery of public and commercial infrastructure and land, and to subsequently produce the types of data products that would provide business value to potential customers. These survey services would supplement or replace services currently provided by manned airplanes and helicopters, small drones or satellites. A “virtual” mission was also planned, to show what additional survey data could have been captured during the flight if additional sensors had been installed on the aircraft’s external hardpoints. This revision of the final report focuses on information of value to the wider UAS community, and avoids propriety data to facilitate broad dissemination. It also includes a description of GA-ASI’s engagement with the FAA following the SIO flight, which led to the award of an updated Special Airworthiness Certificate in the Experimental Category (SAC-EC) and a Certificate of Waiver or Authorization (COA) allowing operation of the SkyGuardian UAS using its DAA system to satisfy right-of-way rules, instead of a chase plane. The associated operational limitations are described to illustrate the further steps that would be needed to remove those limitations for unhindered commercial operations.
The most ancient processes for energy production in the evolution of life involve the reversible oxidation of molecular hydrogen by hydrogenase. Extant hydrogenase enzymes are complex, comprising hundreds of amino acids and multiple cofactors. We designed a 13 amino acid nickel-binding peptide capable of robustly producing molecular hydrogen from protons under a wide variety of conditions. The peptide forms a di-nickel cluster structurally analogous to a Ni-Fe cluster in [NiFe]-hydrogenase and the Ni-Ni cluster in acetyl-CoA synthase (ACS), two ancient, extant proteins central to metabolism. These experimental results clearly demonstrate that modern enzymes, despite their enormous complexity, likely evolved from simple peptide precursors on early Earth. One Sentence Summary: Small metal-binding peptides were the likely precursors of modern enzymes.
The present invention provides for a genetically modified yeast cell comprising at least six or more of the following modifications: increased expression of Mus musculus fatty acid reductase, acetyl-CoA carboxylase, fatty acid synthase 1, fatty acid synthase 2, a mutant of the bottleneck enzyme encoded by ACC1 insensitive to post-transcriptional and post-translational repression, and/or a desaturase encoded by OLE1, and reduced expression of DGA1, HFD1, ADH6, and/or GDH1. The present invention provides a method for constructing the genetically modified yeast cell, and a method for producing a fatty alcohol from the genetically modified yeast cell.
Electricity from a diversity of sources is increasingly utilized due to its low cost. However, since much of this energy is intermittently generated, there is a mismatch between energy demand and supply. Cheap intermittent energy offers opportunities to utilize this energy and generate value-added chemicals. Low-cost electricity can be used to chemically reduce CO2 to formate and methanol, which then can be upgraded to useful chemicals. To utilize formate for production of valuable chemicals, we decided to focus on Clostridium ljungdahlii as our host organism due to several advantages: it can already utilize formate under some conditions, it has the most developed genetic system for acetogens, and is a model organism for the Wood-Ljungdahl Pathway, the most efficient anaerobic carbon fixation pathway. Formate is a feedstock for a variety of bacteria and has several advantages to gaseous electrochemical products, including ease of storage and miscibility in liquid. Acetogens naturally take C1 compounds and convert them to higher chain products through acetyl-CoA, which is a precursor to many valuable products including carboxylic acids and alcohols. For this project, as a proof of concept, we are focusing on converting formate to butanol. This task primarily relies on two parts: improving formate utilization and installing a butanol pathway. First, we characterized the conditions of native formate utilization in C. ljungdahlii. We also have begun working on genetic tools to delete and express genes.
The present invention provides an expression cassette containing a polynucleotide coding sequence for a hydroxycinnamoyl-CoA hydratase-lyase (HCHL), which is operably linked to a heterologous promoter. Also provided are methods of engineering plants that have reduced lignification, as well as cells, plant parts, and plant tissues from such engineered plants.
The present invention provides for a genetically modified yeast cell comprising at least six or more of the following modifications: increased expression of Mus musculus fatty acid reductase, acetyl-CoA carboxylase, fatty acid synthase 1, fatty acid synthase 2, a mutant of the bottleneck enzyme encoded by ACC1 insensitive to post-transcriptional and post-translational repression, and/or a desaturase encoded by OLE1, and reduced expression of DGA1, HFD1, ADH6, and/or GDH1. The present invention provides a method for constructing the genetically modified yeast cell, and a method for producing a fatty alcohol from the genetically modified yeast cell.
A lens alignment system and method is disclosed. The disclosed system/method integrates one or more lens retaining members/tubes (LRM/LRT) and focal length spacers (FLS) each comprising a metallic material product (MMP) specifically manufactured to have a thermal expansion coefficient (TEC) in a predetermined range via selection of the individual MMP materials and an associated MMP manufacturing process providing for controlled TEC. This controlled LRM/LRT TEC enables a plurality of optical lenses (POL) fixed along a common optical axis (COA) by the LRM/LRT to maintain precise interspatial alignment characteristics that ensure consistent and/or controlled series focal length (SFL) within the POL to generate a thermally neutral optical system (TNOS). Integration of the POL using this LRM/LRT/FLS lens alignment system reduces the overall TNOS implementation cost, reduces the overall TNOS mass, reduces TNOS parts component count, and increases the reliability of the overall optical system.
Provided herein are compositions and methods for expression of functional bacterial type I fatty acid synthase in photosynthetic hosts for production of activated acyl-CoAs and for use in biofuel production.
Saccharomyces cerevisiae, Baker's yeast, is the industrial workhorse for producing ethanol and the subject of substantial metabolic engineering research in both industry and academia. S. cerevisiae has been used to demonstrate production of a wide range of chemical products from glucose. However, in many cases, the demonstrations report titers and yields that fall below thresholds for industrial feasibility. Ethanol synthesis is a central part of S. cerevisiae metabolism, and redirecting flux to other products remains a barrier to industrialize strains for producing other molecules. Furthermore, removing ethanol producing pathways leads to poor fitness, such as impaired growth on glucose. Here, we review metabolic engineering efforts aimed at restoring growth in non-ethanol producing strains with emphasis on relieving glucose repression associated with the Crabtree effect and rewiring metabolism to provide access to critical cellular building blocks. Finally, substantial progress has been made in the past decade, but many opportunities for improvement remain.
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ABSTRACT Members of the genus Mesorhizobium, which are core components of the rhizosphere and specific symbionts of legume plants, possess genes for acyl-homoserine lactone (AHL) quorum sensing (QS). Here we show Mesorhizobium japonicum MAFF 303099 (formerly M. loti ) synthesizes and responds to N -[(2 E , 4 E )-2,4-dodecadienoyl] homoserine lactone (2 E, 4 E- C 12:2 -HSL). We show that the 2 E, 4 E- C 12:2 -HSL QS circuit involves one of four luxR-luxI -type genes found in the sequenced genome of MAFF 303099. We refer to this circuit, which appears to be conserved among Mesorhizobium species, as R1-I1. We show that two other Mesorhizobium strains also produce 2 E, 4 E- C 12:2 -HSL. The 2 E, 4 E- C 12:2 -HSL is unique among known AHLs in its arrangement of two trans double bonds. The R1 response to 2 E, 4 E- C 12:2 -HSL is extremely selective in comparison with other LuxR homologs, and the trans double bonds appear critical for R1 signal recognition. Most well-studied LuxI-like proteins use S -adenosylmethionine and an acyl-acyl carrier protein as substrates for synthesis of AHLs. Others that form a subgroup of LuxI-type proteins use acyl-coenzyme A substrates rather than acyl-acyl carrier proteins. I1 clusters with the acyl-coenzyme A-type AHL synthases. We show that a gene linked to the I1 AHL synthase is involved in the production of the QS signal. The discovery of the unique I1 product enforces the view that further study of acyl-coenzyme A-dependent LuxI homologs will expand our knowledge of AHL diversity. The involvement of an additional enzyme in AHL generation leads us to consider this system a three-component QS circuit. IMPORTANCE We report a Mesorhizobium japonicum quorum sensing (QS) system involving a novel acyl-homoserine lactone (AHL) signal. This system is known to be involved in root nodule symbiosis with host plants. The chemistry of the newly described QS signal indicated that there may be a dedicated cellular enzyme involved in its synthesis in addition to the types known for production of other AHLs. Indeed, we report that an additional gene is required for synthesis of the unique signal, and we propose that this is a three-component QS circuit as opposed to the canonical two-component AHL QS circuits. The signaling system is exquisitely selective. The selectivity may be important when this species resides in the complex microbial communities around host plants and may make this system useful in various synthetic biology applications of QS circuits.
Lignification of secondary cell walls is a major factor conferring recalcitrance of lignocellulosic biomass to deconstruction for fuels and chemicals. Genetic modification can reduce lignin content and enhance saccharification efficiency, but usually at the cost of moderate-to-severe growth penalties. We have developed a method, using a single DNA construct that uses CRISPR–Cas9 gene editing to knock-out expression of an endogenous gene of lignin monomer biosynthesis while at the same time expressing a modified version of the gene’s open reading frame that escapes cutting by the Cas9 system and complements the introduced mutation in a tissue-specific manner. Expressing the complementing open reading frame in vessels allows for the regeneration of Arabidopsis plants with reduced lignin, wild-type biomass yield, and up to fourfold enhancement of cell wall sugar yield per plant. The above phenotypes are seen in both homozygous and bi-allelic heterozygous T1 lines, and are stable over at least four generations. The method provides a rapid approach for generating reduced lignin trees or crops with one single transformation event, and, paired with a range of tissue-specific promoters, provides a general strategy for optimizing loss-of-function traits that are associated with growth penalties. This method should be applicable to any plant species in which transformation and gene editing are feasible and validated vessel-specific promoters are available.
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A study was conducted, as part of the integrated National Aeronautics and Space Administration Space Life Sciences 1 mission flown in June of 1991, to ascertain the effects of 9 days of exposure to zero gravity on the capacity of rodent skeletal muscle fiber types to oxidize either [14C]pyruvate or [14C]palmitate under state 3 metabolic conditions, i.e., nonlimiting amounts of substrate and cofactors. In addition, activity levels of marker enzymes of the tricarboxylic acid cycle, malate shuttle, and beta-oxidation were measured. Results showed that significant differences in muscle weight occurred in both the predominantly slow vastus intermedius and predominantly fast vastus lateralis of flight vs. control groups (P < 0.05). Total protein content of the muscle samples was similar between groups. Both pyruvate oxidation capacity and the marker oxidative enzymes were not altered in the flight relative to control animals. However, the capacity to oxidize long-chain fatty acids was significantly reduced by 37% in both the high- and low-oxidative regions of the vastus muscle (P < 0.05). Although these findings of a selective reduction in fatty acid oxidation capacity in response to spaceflight are surprising, they are consistent with previous findings showing 1) an increased capacity to take up glucose and upregulate glucose transporter proteins and 2) a marked accumulation of triglycerides in the skeletal muscles of rats subjected to states of unloading. Thus, skeletal muscle of animals exposed to non-weight-bearing environments undergo subcellular transformations that may preferentially bias energy utilization to carbohydrates.