Rapid Ultrasonic Inspection of Army Projectiles

The electromagnetic acoustic transducer (EMAT) is a device of particular interest for rapid nondestructive evaluation (NDE) in assembly line applications because of its noncontact mode of operation. Speed is a crucial factor in the performance of an NDE system designed for the inspection of artillery projectiles where production rates may be on the order of several shells per minute. These requirements severely restrict the reliability of conventional ultrasonic techniques that use fluid couplants. A fully automated micro-processor based inpsection system utilizing multiple EMATs to launch shear vertical acoustic waves traveling at 30 degrees with respect to the surface normal is being assembled to inspect 155 mm projectiles for both ID and OD flaws. The system\u27s ability to detect small defects has been demonstrated by locating semi-elliptical EDM notches having surface lengths of 2.5 mm (0.1 in.) and maximum depths of 0.8 mm (0.03 in.)

Embedding Population Dynamics Models in Inference

Increasing pressures on the environment are generating an ever-increasing need to manage animal and plant populations sustainably, and to protect and rebuild endangered populations. Effective management requires reliable mathematical models, so that the effects of management action can be predicted, and the uncertainty in these predictions quantified. These models must be able to predict the response of populations to anthropogenic change, while handling the major sources of uncertainty. We describe a simple ``building block'' approach to formulating discrete-time models. We show how to estimate the parameters of such models from time series of data, and how to quantify uncertainty in those estimates and in numbers of individuals of different types in populations, using computer-intensive Bayesian methods. We also discuss advantages and pitfalls of the approach, and give an example using the British grey seal population.Comment: Published at http://dx.doi.org/10.1214/088342306000000673 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Atmospheric response in summer linked to recent Arctic sea ice loss

Since 2007 a large decline in Arctic sea ice has been observed. The large-scale atmospheric circulation response to this decline is investigated in ERA-Interim reanalyses and HadGEM3 climate model experiments. In winter, post-2007 observed circulation anomalies over the Arctic, North Atlantic and Eurasia are small compared to interannual variability. In summer, the post-2007 observed circulation is dominated by an anticyclonic anomaly over Greenland which has a large signal-to-noise ratio. Climate model experiments driven by observed SST and sea ice anomalies are able to capture the summertime pattern of observed circulation anomalies, although the magnitude is a third of that observed. The experiments suggest high SSTs and reduced sea ice in the Labrador Sea lead to positive temperature anomalies in the lower troposphere which weaken the westerlies over North America through thermal wind balance. The experiments also capture cyclonic anomalies over Northwest Europe, which are consistent with downstream Rossby wave propagatio

Dynamic GATA4 enhancers shape the chromatin landscape central to heart development and disease.

How stage-specific enhancer dynamics modulate gene expression patterns essential for organ development, homeostasis and disease is not well understood. Here, we addressed this question by mapping chromatin occupancy of GATA4--a master cardiac transcription factor--in heart development and disease. We find that GATA4 binds and participates in establishing active chromatin regions by stimulating H3K27ac deposition, which facilitates GATA4-driven gene expression. GATA4 chromatin occupancy changes markedly between fetal and adult heart, with a limited binding sites overlap. Cardiac stress restored GATA4 occupancy to a subset of fetal sites, but many stress-associated GATA4 binding sites localized to loci not occupied by GATA4 during normal heart development. Collectively, our data show that dynamic, context-specific transcription factors occupancy underlies stage-specific events in development, homeostasis and disease

Using density surface models to estimate spatio-temporal changes in population densities and trend

Funding – Centre for Research into Ecological and Environmental Modelling, University of St Andrews and U.S. Geological Survey provided funding for this analysis through a studentship to RJC.Precise measures of population abundance and trend are needed for species conservation; these are most difficult to obtain for rare and rapidly changing populations. We compare uncertainty in densities estimated from spatio–temporal models with that from standard design‐based methods. Spatio–temporal models allow us to target priority areas where, and at times when, a population may most benefit. Generalised additive models were fitted to a 31‐year time series of point‐transect surveys of an endangered Hawaiian forest bird, the Hawai'i ‘ākepa Loxops coccineus. This allowed us to estimate bird densities over space and time. We used two methods to quantify uncertainty in density estimates from the spatio–temporal model: the delta method (which assumes independence between detection and distribution parameters) and a variance propagation method. With the delta method we observed a 52% decrease in the width of the design‐based 95% confidence interval (CI), while we observed a 37% decrease in CI width when propagating the variance. We mapped bird densities as they changed across space and time, allowing managers to evaluate management actions. Integrating detection function modelling with spatio–temporal modelling exploits survey data more efficiently by producing finer‐grained abundance estimates than are possible with design‐based methods as well as producing more precise abundance estimates. Model‐based approaches require switching from making assumptions about the survey design to assumptions about bird distribution. Such a switch warrants carefully considered. In this case the model‐based approach benefits conservation planning through improved management efficiency and reduced costs by taking into account both spatial shifts and temporal changes in population abundance and distribution.Publisher PDFPeer reviewe

Production of High Quality Syncrude from Lignocellulosic Biomass

[EN] Wood chips were hydrothermally treated in near critical point water in the presence of a catalyst to yield a raw biocrude, containing a wide range of organic components. This product was subsequently distilled to remove its heaviest fraction, which tends to yield chary products if heated above 350 degrees C. The biocrude obtained has an oxygen content of 12wt% and was subsequently hydrotreated to obtain a hydrocarbon stream. Varying the hydrotreatment operating conditions and catalyst yielded a deoxygenated syncrude which quality improved with operation severity. The hydroprocessed stream produced under very mild conditions can be further upgraded in conventional refinery operations while the stream produced after more severe hydrotreatment can be mixed with conventional diesel. This proof of concept was demonstrated with commercial hydrotreating catalysts, operating between 350 and 380 degrees C, 40 to 120bar pressure and 0.5 to 1h(-1) contact time.The authors thank Licella for material and financial support, as well as providing the biocrude used for the hydrotreating experiments. Licella gratefully acknowledges support from the Australian Government in the form of funding as part of the Advanced Biofuels Investment Readiness Program, received through the Australian Renewable Energy Agency (ARENA). Financial support by the Spanish Government-MINECO through program "Severo Ochoa" (SEV 2012-0267), CTQ2015-70126-R (MINECO/FEDER), and by the Generalitat Valenciana through the Prometeo program (PROMETEOII/2013/011) is also acknowledged.Mathieu, Y.; Sauvanaud, LL.; Humphreys, L.; Rowlands, W.; Maschmeyer, T.; Corma Canós, A. (2017). Production of High Quality Syncrude from Lignocellulosic Biomass. ChemCatChem. 9(9):1574-1578. https://doi.org/10.1002/cctc.201601677S1574157899Huber, G. W., & Corma, A. (2007). Synergies between Bio- and Oil Refineries for the Production of Fuels from Biomass. Angewandte Chemie International Edition, 46(38), 7184-7201. doi:10.1002/anie.200604504Huber, G. W., & Corma, A. (2007). Synergien zwischen Bio- und Ölraffinerien bei der Herstellung von Biomassetreibstoffen. Angewandte Chemie, 119(38), 7320-7338. doi:10.1002/ange.200604504U.S. Department of Energy 2016.2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy Volume 1: Economic Availability of Feedstocks. M. H. Langholtz B. J. Stokes L. M. Eaton (Leads) ORNL/TM-2016/160. Oak Ridge National Laboratory Oak Ridge TN. 448p. DOI:10.2172/1271651.Klein-Marcuschamer, D., & Blanch, H. W. (2015). Renewable fuels from biomass: Technical hurdles and economic assessment of biological routes. AIChE Journal, 61(9), 2689-2701. doi:10.1002/aic.14755Maitlis, P. M., & de Klerk, A. (2013). New Directions, Challenges, and Opportunities. Greener Fischer-Tropsch Processes for Fuels and Feedstocks, 337-358. doi:10.1002/9783527656837.ch16De Miguel Mercader, F., Groeneveld, M. J., Kersten, S. R. A., Geantet, C., Toussaint, G., Way, N. W. J., … Hogendoorn, K. J. A. (2011). Hydrodeoxygenation of pyrolysis oil fractions: process understanding and quality assessment through co-processing in refinery units. Energy & Environmental Science, 4(3), 985. doi:10.1039/c0ee00523aGoudriaan, F., & Peferoen, D. G. R. (1990). Liquid fuels from biomass via a hydrothermal process. Chemical Engineering Science, 45(8), 2729-2734. doi:10.1016/0009-2509(90)80164-aPeterson, A. A., Vogel, F., Lachance, R. P., Fröling, M., Antal, Jr., M. J., & Tester, J. W. (2008). Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies. Energy & Environmental Science, 1(1), 32. doi:10.1039/b810100kToor, S. S., Rosendahl, L., & Rudolf, A. (2011). 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Catalysis Communications, 12(6), 436-440. doi:10.1016/j.catcom.2010.11.001Monnier, J., Sulimma, H., Dalai, A., & Caravaggio, G. (2010). Hydrodeoxygenation of oleic acid and canola oil over alumina-supported metal nitrides. Applied Catalysis A: General, 382(2), 176-180. doi:10.1016/j.apcata.2010.04.035Kubička, D., & Kaluža, L. (2010). Deoxygenation of vegetable oils over sulfided Ni, Mo and NiMo catalysts. Applied Catalysis A: General, 372(2), 199-208. doi:10.1016/j.apcata.2009.10.034Huber, G. W., O’Connor, P., & Corma, A. (2007). Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures. Applied Catalysis A: General, 329, 120-129. doi:10.1016/j.apcata.2007.07.002Anthonykutty, J. M., Van Geem, K. M., De Bruycker, R., Linnekoski, J., Laitinen, A., Räsänen, J., … Lehtonen, J. (2013). Value Added Hydrocarbons from Distilled Tall Oil via Hydrotreating over a Commercial NiMo Catalyst. Industrial & Engineering Chemistry Research, 52(30), 10114-10125. doi:10.1021/ie400790vH. P.Ruyter J. H. J.Annee (Shell Oil Co) US Pat. no. 4670613A 1987.S. Jones et al. Process Design and Economics for the Conversion of Algal Biomass to Hydrocarbons: Whole Algae Hydrothermal Liquefaction and Upgrading PNNL report 23227 2014.Baker, E. G., & Elliott, D. C. (1988). Catalytic Hydrotreating of Biomass-Derived Oils. Pyrolysis Oils from Biomass, 228-240. doi:10.1021/bk-1988-0376.ch021Kubička, D., & Horáček, J. (2011). Deactivation of HDS catalysts in deoxygenation of vegetable oils. Applied Catalysis A: General, 394(1-2), 9-17. doi:10.1016/j.apcata.2010.10.03

Opportunities in upgrading biomass crudes

[EN] An unconventional crude from biomass (biocrude) has been processed to yield a hydrocarbon stream that is not only fully processable in conventional refineries but is already close to the specification of commercial fuels such as transportation diesel. The upgrading of biocrude was carried out with a combination of hydrotreatment and catalytic cracking, yielding middle distillate as the main product.The authors thank Licella for material and financial support, as well as providing the biocrude used for the hydrotreating experiments. Licella gratefully acknowledges support from the Australian Government in the form of funding as part of the Advanced Biofuels Investment Readiness Program, received through the Australian Renewable Energy Agency (ARENA). Financial support by the Spanish Government-MINECO through program "Severo Ochoa" (SEV 2012-0267), CTQ2015-70126-R (MINECO/FEDER), and by the Generalitat Valenciana through the Prometeo program (PROMETEOII/2013/011) is also acknowledged.Mathieu, Y.; Sauvanaud, LL.; Humphreys, L.; Rowlands, W.; Maschmeyer, T.; Corma Canós, A. (2017). Opportunities in upgrading biomass crudes. Faraday Discussions. 197:389-401. https://doi.org/10.1039/c6fd00208kS389401197U.S. Department of Energy. 2016. 2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy, Volume 1: Economic Availability of Feedstocks. M. H. Langholtz, B. J. Stokes, and L. M. Eaton (Leads), ORNL/TM-2016/160. Oak Ridge National Laboratory, Oak Ridge, TN. 448ppP. M. Maitlis and A.de Klerk, Greener Fischer-Tropsch Processes for Fuels and Feedstocks, Wiley, 2013, ch. 16De Miguel Mercader, F., Groeneveld, M. J., Kersten, S. R. A., Geantet, C., Toussaint, G., Way, N. W. J., … Hogendoorn, K. J. A. (2011). Hydrodeoxygenation of pyrolysis oil fractions: process understanding and quality assessment through co-processing in refinery units. Energy & Environmental Science, 4(3), 985. doi:10.1039/c0ee00523aGoudriaan, F., & Peferoen, D. G. R. (1990). Liquid fuels from biomass via a hydrothermal process. Chemical Engineering Science, 45(8), 2729-2734. doi:10.1016/0009-2509(90)80164-aPeterson, A. A., Vogel, F., Lachance, R. P., Fröling, M., Antal, Jr., M. J., & Tester, J. W. (2008). Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies. Energy & Environmental Science, 1(1), 32. doi:10.1039/b810100kToor, S. S., Rosendahl, L., & Rudolf, A. (2011). Hydrothermal liquefaction of biomass: A review of subcritical water technologies. Energy, 36(5), 2328-2342. doi:10.1016/j.energy.2011.03.013Oasmaa, A., & Czernik, S. (1999). Fuel Oil Quality of Biomass Pyrolysis OilsState of the Art for the End Users. 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A. W. (2014). Production of green aromatics and olefins by catalytic cracking of oxygenate compounds derived from biomass pyrolysis: A review. Applied Catalysis A: General, 469, 490-511. doi:10.1016/j.apcata.2013.09.036Hughes, R., Hutchings, G. J., Koon, C. L., McGhee, B., Snape, C. E., & Yu, D. (1996). Deactivation of FCC catalysts using n-hexadecane feed with various additives. Applied Catalysis A: General, 144(1-2), 269-279. doi:10.1016/0926-860x(96)00106-8Huber, G. W., O’Connor, P., & Corma, A. (2007). Processing biomass in conventional oil refineries: Production of high quality diesel by hydrotreating vegetable oils in heavy vacuum oil mixtures. Applied Catalysis A: General, 329, 120-129. doi:10.1016/j.apcata.2007.07.002Anthonykutty, J. M., Van Geem, K. M., De Bruycker, R., Linnekoski, J., Laitinen, A., Räsänen, J., … Lehtonen, J. (2013). Value Added Hydrocarbons from Distilled Tall Oil via Hydrotreating over a Commercial NiMo Catalyst. Industrial & Engineering Chemistry Research, 52(30), 10114-10125. doi:10.1021/ie400790vS. Jones , Y.Zu, D.Anderson, R.Allen, D.Elliot, A.Schmidt, K.Albrecht, T.Hart, M.Butcher, C.Drennan, L.Snowden-Swan, R.Davis and C.Kinchin, PNNL report 23227, March 2014Corma, A., González-Alfaro, V., & Orchillés, A. . (2001). Decalin and Tetralin as Probe Molecules for Cracking and Hydrotreating the Light Cycle Oil. Journal of Catalysis, 200(1), 34-44. doi:10.1006/jcat.2001.3181CORMA, A., & ORTEGA, F. (2005). Influence of adsorption parameters on catalytic cracking and catalyst decay. Journal of Catalysis, 233(2), 257-265. doi:10.1016/j.jcat.2005.04.02