1,092 research outputs found

    APPROACHES TO INNOVATION IN THE NAVAL CONSTRUCTION FORCE “SEABEES”

    Get PDF
    The increasing competition from China and the resurgence of Russian aggression has emphasized the need for innovation. The naval construction force (NCF) provides general engineering to the United States Navy and similarly needs to innovate to remain relevant and provide value to the warfighter. Innovation can be categorized as small incremental improvements (exploitation) or major disruptive shifts (exploration). This paper looks to define what exploitation and exploration mean to the NCF and what intangible assets and resources will be required to meet those innovation goals. This paper uses principles from literature in business academia and applies them to the research questions to establish a best practice recommendation for the NCF. In order to apply rigor to the paper, it uses metrics of effectiveness to determine which approach to innovation provides the greatest value to the Navy. Based on an evaluation of five measures of effectiveness, the NCF would be best served by pursuing the exploration approach to innovation. To do this, the NCF should create a dedicated Development Company to develop and validate new concepts for wider adoption.Lieutenant Commander, United States NavyApproved for public release. Distribution is unlimited

    Component test program for variable-cycle engines

    Get PDF
    Variable cycle engine (VCE) concepts for a supersonic cruise aircraft were studied. These VCE concepts incorporate unique critical components and flow path arrangements that provide good performance at both supersonic and subsonic cruise and appear to be economically and environmentally viable. Certain technologies were identified as critical to the successful development of these engine concepts and require considerable development and testing. The feasibility and readiness of the most critical VCE technologies, was assessed, a VCE component test program was initiated. The variable stream control engine (VSCE) component test program, tested and evaluated an efficient low emission duct burner and a quiet coannular ejector nozzle at the rear of a rematched F100 engine

    Role of the host cell in bacteriophage T4 development. II. Characterization of host mutants that have pleiotropic effects on T4 growth

    Get PDF
    Mutant host-defective Escherichi coli that fail to propagate bacteriophage T4 and have a pleiotropic effect on T4 development have been isolated and characterized. In phage-infected mutant cells, specific early phage proteins are absent or reduced in amount, phage DNA synthesis is depressed by about 50%, specific structural phage proteins, including some tail and collar components, are deficient or missing, and host-cell lysis is delayed and slow. Almost all phage that can overcome the host block carry mutantions that map in functionally undefined 'nonessential' regions of the T4 genome, most near gene 39. The mutant host strains are temperature sensitive for growth and show simultaneous reversion of the ts phenotype and the inability to propagate T4+. The host mutations are cotransduced with ilv (83 min) and may lie in the gene for transcription termination factor rho

    Impact of ERTS-1 images on management of New Jersey's coastal zone

    Get PDF
    The thrust of New Jersey's ERTS investigation is development of procedures for operational use of ERTS-1 data by the Department of Environmental Protection in the management of the State's coastal zone. Four major areas of concern were investigated: detection of land use changes in the coastal zone; monitoring of offshore waste disposal; siting of ocean outfalls; and allocation of funds for shore protection. ERTS imagery was not useful for shore protection purposes; it was of limited practical value in the evaluation of offshore waste disposal and ocean outfall siting. However, ERTS imagery shows great promise for operational detection of land use changes in the coastal zone. Some constraints for practical change detection have been identified

    NASA research in supersonic propulsion: A decade of progress

    Get PDF
    A second generation, economically viable, and environmentally acceptable supersonic aircraft is reviewed. Engine selection, testbed experiments, and noise reduction research are described

    The effect of sample preparation on uranium hydriding

    Get PDF
    AbstractThe influence of sample cleaning preparation on the early stages of uranium hydriding has been examined, by using four identical samples but concurrently prepared using four different methods. The samples were reacted together in the same corrosion cell to ensure identical exposure conditions. From the analysis, it was found that the hydride nucleation rate was proportional to the level of strain exhibiting higher number density for the more strained surfaces. Additionally, microstructure of the metal plays a secondary role regarding initial hydrogen attack on the highly strained surfaces yet starts to dominate the system while moving to more pristine samples

    Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

    Get PDF
    The author has identified the following significant results. Rapid access to ERTS data was provided by NASA GSFC for the February 26, 1974 overpass of the New Jersey test site. Forty-seven hours following the overpass computer-compatible tapes were ready for processing at EarthSat. The finished product was ready just 60 hours following the overpass and delivered to the New Jersey Department of Environmental Protection. This operational demonstration has been successful in convincing NJDEP as to the worth of ERTS as an operational monitoring and enforcement tool of significant value to the State. An erosion/ accretion severity index has been developed for the New Jersey shore case study area. Computerized analysis techniques have been used for monitoring offshore waste disposal dumping locations, drift vectors, and dispersion rates in the New York Bight area. A computer shade print of the area was used to identify intensity levels of acid waste. A Litton intensity slice print was made to provide graphic presentation of dispersion characteristics and the dump extent. Continued monitoring will lead to the recommendation and justification of permanent dumping sites which pose no threat to water quality in nearshore environments

    Integration of metabolite with transcript and enzyme activity profiling during diurnal cycles in Arabidopsis rosettes

    Get PDF
    ABSTRACT: BACKGROUND: Genome-wide transcript profiling and analyses of enzyme activities from central carbon and nitrogen metabolism has shown that transcript levels undergo marked and rapid changes during diurnal cycles and after transfer to darkness, whereas changes of enzyme activities are smaller and delayed. In the starchless pgm mutant, where sugars are depleted every night, there are accentuated diurnal changes of transcript levels. Enzyme activities do not show larger diurnal changes; instead they shift towards the levels found in wild-type after several days of darkness. These results indicate that enzyme activities change slowly, integrating the changes of transcript levels over several diurnal cycles. RESULTS: To generalize this conclusion, 137 metabolites were profiled using GC-MS and LC-MS. Amplitudes of the diurnal changes of metabolites in pgm were (with the exception of sugars) similar or smaller than in wild-type. The average levels shifted towards those found after several days of darkness in wild-type. Examples include increased levels of many amino acids due to protein degradation, decreased levels of many fatty acids, increased tocopherol and decreased myo-inositol. Many metabolite-transcript correlations were found and the proportion of transcripts correlated with sugars increased dramatically in the starchless pgm mutant. CONCLUSION: Rapid diurnal changes of transcripts are integrated over time to generate quasi-stable changes across large sectors of metabolism. The slow response of enzyme activities and metabolites implies that correlations between metabolites and transcripts are due to regulation of gene expression by metabolites, rather than metabolites being changed as a consequence of a change in gene expression

    Global transcript levels respond to small changes of the carbon status during progressive exhaustion of carbohydrates in Arabidopsis rosettes

    Get PDF
    The balance between the supply and utilization of carbon (C) changes continually. It has been proposed that plants respond in an acclimatory manner, modifying C utilization to minimize harmful periods of C depletion. This hypothesis predicts that signaling events are initiated by small changes in C status. We analyzed the global transcriptional response to a gradual depletion of C during the night and an extension of the night, where C becomes severely limiting from 4 h onward. The response was interpreted using published datasets for sugar, light, and circadian responses. Hundreds of C-responsive genes respond during the night and others very early in the extended night. Pathway analysis reveals that biosynthesis and cellular growth genes are repressed during the night and genes involved in catabolism are induced during the first hours of the extended night. The C response is amplified by an antagonistic interaction with the clock. Light signaling is attenuated during the 24-h light/dark cycle. A model was developed that uses the response of 22K genes during a circadian cycle and their responses to C and light to predict global transcriptional responses during diurnal cycles of wild-type and starchless pgm mutant plants and an extended night in wild-type plants. By identifying sets of genes that respond at different speeds and times during C depletion, our extended dataset and model aid the analysis of candidates for C signaling. This is illustrated for AKIN10 and four bZIP transcription factors, and sets of genes involved in trehalose signaling, protein turnover, and starch breakdown

    Understanding the generation of methanol synthesis and water gas shift activity over copper-based catalysts – A spatially resolved experimental kinetic study using steady and non-steady state operation under CO/CO<sub>2</sub>/H<sub>2</sub> feeds

    Get PDF
    AbstractUnderstanding the mechanism and generation of activity for methanol synthesis and the water gas shift reactions over copper-based catalysts remains a significant area of study in heterogeneous catalysis. In this work, steady and non-steady state experimental and kinetic modelling methods are presented to demonstrate changes in functionality of a Cu/ZnO/Al2O3 catalyst based on gas composition.Steady-state testing of a Cu/ZnO/Al2O3 catalyst, using experimental spatial discretisation approaches with fixed-bed, integral-operation micro reactors, has generated performance data over a range of PCO/PCO2 ratios (1–10). The data showed a mixture of observations where forward or reverse water gas shift was kinetically favourable, and also where the reaction was significantly limited by thermodynamic equilibrium. A steady state Langmuir–Hinshelwood model based on micro kinetics was most appropriate which includes kinetic descriptions of both directions of the water gas shift reaction. Using this method, the entire dataset could be predicted and an internal consistency within the kinetic model of the key adsorption constants was demonstrated.Non-steady state, ‘reactor start-up’, testing of a Cu/ZnO/Al2O3 catalyst marked a novel approach to further understanding the functionality of the catalyst. Initial changes in surface carbon and oxygen populations were quantified and linked to subsequent dynamic changes in methanol synthesis and water gas shift activity. Cu/ZnO and Cu/Al2O3 formulations were also evaluated and tested using kinetic models, permitting a structural and compositional comparison with Cu/ZnO/Al2O3
    corecore