SEARCH · Engineering Papers
Results for “POLLUTION”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The Pollution Effect and Novel Methods to Reduce Its Influence in the Mid-Frequency Range.
Abstract not provided.
The genomic landscape of rapid repeated evolutionary adaptation to toxic pollution in wild fish
Not Available
Lithium pollution of a white dwarf records the accretion of an extrasolar planetesimal
Tidal disruption and subsequent accretion of planetesimals by white dwarfs can reveal the elemental abundances of rocky bodies in exoplanetary systems. Those abundances provide information on the composition of the nebula from which the systems formed, which is analogous to how meteorite abundances inform our understanding of the early Solar System. We report the detection of lithium, sodium, potassium, and calcium in the atmosphere of the white dwarf Gaia DR2 4353607450860305024, which we ascribe to the accretion of a planetesimal. Using model atmospheres, we determine abundance ratios of these elements, and, with the exception of lithium, they are consistent with meteoritic values in the Solar System. We compare the measured lithium abundance with measurements in old stars and with expectations from Big Bang nucleosynthesis.
Fire heat affects the impacts of wildfires on air pollution in the United States
Explore the source record for details and available documents.
Draft Genome Sequence of Nocardioides luteus Strain BAFB, an Alkane-Degrading Bacterium Isolated from JP-7-Polluted Soil
ABSTRACT Nocardioides luteus strain BAFB is a Gram-positive bacterium that efficiently degrades C 8 to C 11 alkanes aerobically. The draft genome of N. luteus BAFB is 5.76 Mb in size, with 5,358 coding sequences and 69.9% G+C content. The genes responsible for alkane degradation are present in this strain.
Structural Basis of the Enhanced Pollutant-Degrading Capabilities of an Engineered Biphenyl Dioxygenase
Biphenyl dioxygenase, the first enzyme of the biphenyl catabolic pathway, is a major determinant of which polychlorinated biphenyl (PCB) congeners are metabolized by a given bacterial strain. Ongoing efforts aim to engineer BphAE, the oxygenase component of the enzyme, to efficiently transform a wider range of congeners. BphAE II9 , a variant of BphAE LB400 in which a seven-residue segment, 335 TFNNIRI 341 , has been replaced by the corresponding segment of BphAE B356 , 333 GINTIRT 339 , transforms a broader range of PCB congeners than does either BphAE LB400 or BphAE B356 , including 2,6-dichlorobiphenyl, 3,3'-dichlorobiphenyl, 4,4'-dichlorobiphenyl, and 2,3,4'-trichlorobiphenyl. To understand the structural basis of the enhanced activity of BphAE II9 , we have determined the three-dimensional structure of this variant in substrate-free and biphenyl-bound forms. Structural comparison with BphAE LB400 reveals a flexible active-site mouth and a relaxed substrate binding pocket in BphAE II9 that allow it to bind different congeners and which could be responsible for the enzyme's altered specificity. Biochemical experiments revealed that BphAE II9 transformed 2,3,4'-trichlorobiphenyl and 2,2',5,5'-tetrachlorobiphenyl more efficiently than did BphAE LB400 and BphAE B356 . BphAE II9 also transformed the insecticide dichlorodiphenyltrichloroethane (DDT) more efficiently than did either parental enzyme (apparent k cat /K m of 2.2 ± 0.5 mM –1 s –1 , versus 0.9 ± 0.5 mM –1 s –1 for BphAE B356 ). Studies of docking of the enzymes with these three substrates provide insight into the structural basis of the different substrate selectivities and regiospecificities of the enzymes. Biphenyl dioxygenase is the first enzyme of the biphenyl degradation pathway that is involved in the degradation of polychlorinated biphenyls. Attempts have been made to identify the residues that influence the enzyme activity for the range of substrates among various species. In this study, we have done a structural study of one variant of this enzyme that was produced by family shuffling of genes from two different species. Comparison of the structure of this variant with those of the parent enzymes provided an important insight into the molecular basis for the broader substrate preference of this enzyme. Here, the structural and functional details gained in this study can be utilized to further engineer desired enzymatic activity, producing more potent enzymes.
Broadening of Adiabatic Droplet Spectra through Eddy Hopping: Polluted versus Pristine Environments
Explore the source record for details and available documents.
Effectiveness of Residue and Tillage Management on Runoff Pollutant Reduction from Agricultural Areas
Highlights No-till and no-till residue systems were effective in reducing runoff particulate and total nutrients but increased dissolved nutrients. Maintaining >30% residue cover reduced most runoff constituents, irrespective of no-till or tillage. No-till-residue prevented runoff nutrient losses and benefitted farm revenue by avoiding tillage. Abstract. Reduced tillage management conservation practices (No-till and Reduced-till) are widely adopted in agriculture; however, understanding their overall effectiveness for water quality protection is challenging. A meta-analysis was conducted to understand and quantify the effectiveness of residue and tillage management on runoff, sediment, and nutrient losses from agricultural fields. Annual runoff and the associated sediment, and nutrient (nitrogen and phosphorus) loads were compiled from 60 peer reviewed research articles published across the United States and Canada. A total of 1575 site-years of data were categorized into tillage (<30% surface cover), no-tillage (<30% surface cover), tillage with residue (>30% surface cover), no-tillage with residue (>30% surface cover), and pasture management. No-tillage, no-tillage-residue, and tillage-residue managements were evaluated for their effectiveness in reducing runoff, nutrients, and sediment loads compared to tillage. Synthesized and surveyed corn yield data were used to evaluate the economic cost effectiveness of no-tillage-residue management with respect to tillage. Across the site years (1968-2019) studied, median runoff depth for no-tillage and no-tillage-residue were 84% and 70% greater than tillage and tillage-residue management, respectively. No-tillage-residue management had up to 86% less sediment losses than tillage systems, on average, for both >30% and <30% surface cover. No-tillage-residue management was most effective, with a positive performance effectiveness of 65% to 90% in controlling sediments, particulate, and total nutrient losses in runoff compared to tillage. Cost effectiveness analysis revealed the benefits of no-tillage-residue management in reducing nutrient loads and increasing net-farm revenue by avoiding tillage operational costs. Except for dissolved phosphorus, no-tillage-residue management cost effectiveness for sediments and nutrient loads ranged from negative $6 to negative $102 per every Mg or kg of load reduction, indicating it had both economic and environmental benefits compared to tillage management. Overall, these results indicate that over the long-term, no-tillage and tillage, combined with greater than 30% residue cover, can effectively reduce sediment and nutrient losses. This work highlights the importance of crop residues on the soil surface to reduce runoff losses, even in no-tillage systems. Keywords: Conservation tillage, No-tillage, Residue cover, Tillage, Water quality.
A genome-scale metabolic model for the denitrifying bacterium Thauera sp. MZ1T accurately predicts degradation of pollutants and production of polymers
The denitrifying bacterium Thauera sp . MZ1T, a common member of microbial communities in wastewater treatment facilities, can produce different compounds from a range of carbon (C) and nitrogen (N) sources under aerobic and anaerobic conditions. In these different conditions, Thauera modifies its metabolism to produce different compounds that influence the microbial community. In particular, Thauera sp . MZ1T produces different exopolysaccharides with floc-forming properties, impacting the physical disposition of wastewater consortia and the efficiency of nutrient assimilation by the microbial community. Under N-limiting conditions, Thauera sp . MZ1T decreases its growth rate and accelerates the accumulation of polyhydroxyalkanoate-related (PHA) compounds including polyhydroxybutyrate (PHB), which plays a fundamental role as C and energy storage in this β-proteobacterium. However, the metabolic mechanisms employed by Thauera sp . MZ1T to assimilate and catabolize many of the different C and N sources under aerobic and anaerobic conditions remain unknown. Systems biology approaches such as genome-scale metabolic modeling have been successfully used to unveil complex metabolic mechanisms for various microorganisms. Here, we developed a comprehensive metabolic model (M-model) for Thauera sp . MZ1T ( i Thauera861), consisting of 1,744 metabolites, 2,384 reactions, and 861 genes. We validated the model experimentally using over 70 different C and N sources under both aerobic and anaerobic conditions. i Thauera861 achieved a prediction accuracy of 95% for growth on various C and N sources and close to 85% for assimilation of aromatic compounds under denitrifying conditions. The M-model was subsequently deployed to determine the effects of substrates, oxygen presence, and the C:N ratio on the production of PHB and exopolysaccharides (EPS), showing the highest polymer yields are achieved with nucleotides and amino acids under aerobic conditions. This comprehensive M-model will help reveal the metabolic processes by which this ubiquitous species influences communities in wastewater treatment systems and natural environments.
Predominance and high diversity of genes associated to denitrification in metagenomes of subantarctic coastal sediments exposed to urban pollution
The aim of this work was to characterize the microbial nitrogen cycling potential in sediments from Ushuaia Bay, a subantarctic environment that has suffered a recent explosive demographic growth. Subtidal sediment samples were retrieved in triplicate from two urban points in the Bay, and analyzed through metagenomic shotgun sequencing. Sequences assigned to genes related to nitrification, nitrate reduction and denitrification were predominant in this environment with respect to metagenomes from other environments, including other marine sediments. The nosZ gene, responsible for nitrous oxide transformation into di-nitrogen, presented a high diversity. The majority of NosZ sequences were classified as Clade II (atypical) variants affiliated to different bacterial lineages such as Bacteroidetes, Chloroflexi, Firmicutes, Proteobacteria, Verrucomicrobia, as well as to Archaea. The analysis of a fosmid metagenomic library from the same site showed that the genomic context of atypical variants was variable, and was accompanied by distinct regulatory elements, suggesting the evolution of differential ecophysiological roles. This work increases our understanding of the microbial ecology of nitrogen transformations in cold coastal environments and provides evidence of an enhanced denitrification potential in impacted sediment microbial communities. In addition, it highlights the role of yet overlooked populations in the mitigation of environmentally harmful forms of nitrogen.
NNSA Pollution Prevention Awards Nominations for 2013
Abstract Not Provided.
2012 Update to the Site Discharge Pollution Prevention Plan (Rev. 1): Los Alamos/Pueblo Watershed (Vol. 1)
One historical industrial activity area is associated with R001, R-SMA-0.5: Site C-00-020. Area of Concern (AOC) C-00-020 is a suspected mortar impact area located along the north valley wall of Rendija Canyon on General Services Administration (GSA) and U.S. Forest Service (USFS) land. The 30-acre site also includes a tributary of Rendija Canyon. Most of the site lies within the Santa Fe National Forest, except for a small area on the southeastern edge that is private property. AOC C-00-020 was suspected to be a former mortar-impact area because of a “U.S. Property—No Trespassing” sign and a nearly illegible bilingual sign posted in the area. The signs no longer remain. Extensive archival searches have revealed no documentation regarding the use of this site as a munitions impact area. In addition, no field evidence of operations (e.g., munitions debris [MD], munitions and explosives of concern [MEC], unexploded ordnance [UXO], or impact scars) has ever been found at AOC C-00-020. Resource Conservation and Recovery Act (RCRA) facility investigation (RFI) activities conducted in 1993 included conducting an ordnance sweep followed by a geophysical sweep. No ordnance, MD, MEC, or UXO was located. In addition, no ordnance was found during the 2007 investigation or during the 2009 ordnance survey. The site is located within an area burned by the 2000 Cerro Grande fire. The stream channel that runs through the center of the site has been widened by flooding. Currently, there are burned and live trees on the steep slopes next to the stream. Ordnance surveys at the site resulted in no findings except for scrap metal such as bailing wire. The complete absence of ordnance and explosives waste (OEW) confirmed that the site was never used as an ordnance-impact area. In accordance with the approved investigation work plan, no further investigation was conducted at AOC C-00-020. The New Mexico Environment Department (NMED) concurred with the conclusion that no additional ordnance surveys need to be conducted at this site and issued a corrective action complete without controls for AOC C-00-020 on May 16, 2012. No industrial materials were historically managed at this Site; therefore, no potential contaminants are associated with the Site.
Nominations for the 2017 NNSA Pollution Prevention Awards
In the field of nuclear forensics, one of the biggest challenges is to dissolve postdetonation debris for analysis. Debris generated after a nuclear detonation is a glassy material that is difficult to dissolve with chemicals. Traditionally, concentrated nitric acid, hydrofluoric acid, or sulfuric acid are employed during the dissolution. These acids, due to their corrosive nature, are not suitable for in-field/on-site sample preparations. Uranium oxides are commonly present in nuclear fuel processing plants and nuclear research facilities. In uranium oxides, the level of uranium isotope enrichment is a sensitive indicator for nuclear nonproliferation and is monitored closely by the International Atomic Energy Agency (IAEA) to ensure there is no misuse of nuclear material or technology for nuclear weapons. During an IAEA on-site inspection at a facility, environmental surface swipe samples are collected and transported to the IAEA headquarters or network of analytical laboratories for further processing. Uranium oxide particles collected on the swipe medium are typically dissolved with inorganic acids and are then analyzed for uranium isotopic compositions. To improve the responsiveness of on-site inspections, in-field detection techniques have been recently explored. However, in-field analysis is bottlenecked by time-consuming and hazardous dissolution procedures, as corrosive inorganic acids must be used. Corrosive chemicals are difficult to use in the field due to personnel safety considerations, and the transportation of such chemicals is highly regulated. It was therefore necessary to develop fast uranium oxide dissolution methods using less hazardous chemicals in support of the rapid infield detection of anomalies in declared nuclear processes.
National Emission Standards for Hazardous Air Pollutants - Radionuclide Emissions Calendar Year 2015
Annual report submitted to regulators (State of Nevada and EPA Region IV) to document compliance with the Clean Air Act, specifically through 40 CFR 61 Subpart H.
MSGP Stormwater Pollution Prevention Plan for: TA-60-02 Salvage/Warehouse, Triad National Security, LLC (Triad), Los Alamos National Laboratory, January 2019, Revision 0
This SWPPP applies to discharges of stormwater from the operational areas of the TA-60-02 Salvage/Warehouse at Los Alamos National Laboratory. Los Alamos National Laboratory (also referred to as LANL or the “Laboratory”) is owned by the Department of Energy (DOE), and is operated by Triad. Throughout this document, the term “facility” refers to the TA-60-02 Salvage/Warehouse. The current MSGP expires at midnight on June 4, 2020.
Remediation of recalcitrant and emerging organic pollutants using bacteria and their extracted enzymes (CRADA FP00007386)
Researchers at the LBNL Advanced Biofuels Process Development Unit (ABPDU) engaged in a collaborative research agreement with Allied Microbiota, to demonstrate improved cultivation of thermophilic organisms known to secrete thermally stable enzymes suitable for bioremediation applications. During the course of the project, ABPDU researchers demonstrated a fed batch bioreactor cultivation method that improved process intensity and process consistency, helping to reduce the production cost of these promising enzymes.