Science.gov

Sample records for enhanced precipitation preliminary

  1. Performance of Evapotranspirative Covers Under Enhanced Precipitation: Preliminary Data

    SciTech Connect

    David C. Anderson, Lloyd T. Desotell, David B. Hudson, Gregory J. Shott, Vefa Yucel

    2007-02-01

    Since January 2001, drainage lysimeter studies have been conducted at Yucca Flat, on the Nevada Test Site, in support of an evapotranspirative cover design. Yucca Flat has an arid climate with average precipitation of 16.5 cm annually. The facility consists of six drainage lysimeters 3 m in diameter, 2.4 m deep, and backfilled with a single layer of native soil. The bottom of each lysimeter is sealed and equipped with a small drain that enables direct measurement of saturated drainage. Each lysimeter has eight time-domain reflectometer probes to measure moisture content-depth profiles paired with eight heat-dissipation probes to measure soil-water potential depth profiles. Sensors are connected to dataloggers which are remotely accessed via a phone line. The six lysimeters have three different surface treatments: two are bare-soil; two were revegetated with native species (primarily shadscale, winterfat, ephedra, and Indian rice grass); and two were allowed to revegetate naturally with such species as Russian thistle, halogeton, tumblemustard and cheatgrass. Beginning in October 2003, one half of the paired cover treatments (one bare soil, one invader species, and one native species) were irrigated with an amount of water equal to two times the natural precipitation to achieve a three times natural precipitation treatment. From October 2003 through December 2005, all lysimeters received 52.8 cm precipitation, and the four irrigated lysimeters received an extra 105.6 cm of irrigation. No drainage has occurred from any of the nonirrigated lysimeters, but moisture has accumulated at the bottom of the bare-soil lysimeter and the native-plant lysimeter. All irrigated lysimeters had some drainage. The irrigated baresoil lysimeter had 48.3 cm of drainage or 26.4 percent of the combined precipitation and applied irrigation for the entire monitoring record. The irrigated invader species lysimeter had 5.8 cm of drainage, about 3.2 percent of the combined precipitation and

  2. Preliminary analysis of regional-precipitation periodicity

    USGS Publications Warehouse

    Perry, Charles A.

    1980-01-01

    Precipitation variability plays a major role in nearly every aspect of the hydrologic cycle. Precipitation is not a random event, but it occurs after a sequence of prerequisites has been fulfilled. Recent investigations have shown that activity of the sun can affect atmospheric vorticity, an important factor in precipitation formation. Solar activity is known to be periodic; therefore, through a complex series of physical processes, precipitation variance is solar forced to a certain degree. A preliminary analysis of precipitation periodicity was made for eight regions scattered across the central United States. Each region contained 5 to 10 stations with long-term precipitation records that were averaged to obtain yearly regional-precipitation values. Graphic analysis shows 11-year and 22-year cycles that are nearly in phase with the solar cycles. An example of the effect of cyclic precipitation is presented for the Powder River basin in Wyoming and Montana. A cycle of 22 years exhibits fluctuations of approximately 22 to 27% for precipitation and 38 to 50% for runoff. A more detailed study that investigates solar-forced precipitation cycles and their relationship to hydrologic processes is needed. (USGS)

  3. Global precipitation measurement (GPM) preliminary design

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Kakar, Ramesh K.; Azarbarzin, Ardeshir A.; Hou, Arthur Y.

    2008-10-01

    The overarching Earth science mission objective of the Global Precipitation Measurement (GPM) mission is to develop a scientific understanding of the Earth system and its response to natural and human-induced changes. This will enable improved prediction of climate, weather, and natural hazards for present and future generations. The specific scientific objectives of GPM are advancing: Precipitation Measurement through combined use of active and passive remote-sensing techniques, Water/Energy Cycle Variability through improved knowledge of the global water/energy cycle and fresh water availability, Climate Prediction through better understanding of surface water fluxes, soil moisture storage, cloud/precipitation microphysics and latent heat release, Weather Prediction through improved numerical weather prediction (NWP) skills from more accurate and frequent measurements of instantaneous rain rates with better error characterizations and improved assimilation methods, Hydrometeorological Prediction through better temporal sampling and spatial coverage of highresolution precipitation measurements and innovative hydro-meteorological modeling. GPM is a joint initiative with the Japan Aerospace Exploration Agency (JAXA) and other international partners and is the backbone of the Committee on Earth Observation Satellites (CEOS) Precipitation Constellation. It will unify and improve global precipitation measurements from a constellation of dedicated and operational active/passive microwave sensors. GPM is completing the Preliminary Design Phase and is advancing towards launch in 2013 and 2014.

  4. Preliminary microphysical characterization of precipitation at ground over Antarctica coast

    NASA Astrophysics Data System (ADS)

    Roberto, Nicoletta; Adirosi, Elisa; Montopoli, Mario; Baldini, Luca; Dietrich, Stefano; Porcù, Federico

    2017-04-01

    processing PSD spectra. Software provided by disdrometer manufacturer assumes spherical shape to compute the size and the fall velocity of the particle. In the case of solid precipitation, this assumption can be unrealistic. However, averaging over a long time the influence of irregular shape of the particles can be reduced. Despite this limit, the Parsivel disdrometer has been used in several study to measure falling snow. In this work, some preliminary measurements from OTT Parsivel at MSZ are presented. In particular, the PSD collected during summer season 2016-2017 are analyzed in order to infer microphysical characteristics of snows in Antarctica. A specific methodology to estimate the reflectivity factor and the snow rate from snow size spectra collected by Parsivel is investigated. Microphysical properties of Antarctica precipitating clouds, in particular PSD, are compared to measurements collected by disdrometer during snow events in other regions, such as the data collected during the GPM Cold-season Precipitation Experiment (GCPEx) in Ontario, Canada.

  5. V and V Efforts of Auroral Precipitation Models: Preliminary Results

    NASA Technical Reports Server (NTRS)

    Zheng, Yihua; Kuznetsova, Masha; Rastaetter, Lutz; Hesse, Michael

    2011-01-01

    Auroral precipitation models have been valuable both in terms of space weather applications and space science research. Yet very limited testing has been performed regarding model performance. A variety of auroral models are available, including empirical models that are parameterized by geomagnetic indices or upstream solar wind conditions, now casting models that are based on satellite observations, or those derived from physics-based, coupled global models. In this presentation, we will show our preliminary results regarding V&V efforts of some of the models.

  6. Ionospheric density enhancement during relativistic electron precipitation

    NASA Technical Reports Server (NTRS)

    Foster, J. C.; Doupnik, J. R.; Stiles, G. S.

    1980-01-01

    The temporal evolution of the ionospheric density enhancement produced by a widespread relativistic electron precipitation (REP) has been observed with the Chatanika Radar. The REP was associated with a substorm particle energization event, and both the ionospheric absorption and density perturbation exhibited an approximately 90 min periodicity associated with the particles' longitudinal drift. A 80-keV characteristic energy for the precipitating electrons is deduced from ground-based and satellite data. At the maximum of the event, electrons deposited approximately 50 ergs/sq cm per sec in the ionosphere, producing a peak density of 500,000/cu cm at 89 km altitude. At that time the radar observed densities greater than 100,000/cu cm between 70 km and 110 km altitude and riometer absorption at 30 MHz was approximately 12 db.

  7. Enhancement of satellite precipitation estimation via unsupervised dimensionality reduction

    SciTech Connect

    Mahrooghy, Majid; Younan, Nicolas H.; Anantharaj, Valentine G; Aanstoos, James

    2012-01-01

    A methodology to enhance Satellite Precipitation Estimation (SPE) using unsupervised dimensionality reduction (UDR) techniques is developed. This enhanced technique is an extension to the Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Network (PERSIANN) and Cloud Classification System (CCS) method (PERSIANN-CCS) enriched using wavelet features combined with dimensionality reduction. Cloud-top brightness temperature measurements from Geostationary Operational Environmental Satellite (GOES-12) are used for precipitation estimation at 4 km 4 km spatial resolutions every 30 min. The study area in the continental United States covers parts of Louisiana, Arkansas, Kansas, Tennessee, Mississippi, and Alabama. Based on quantitative measures, root mean square error (RMSE) and Heidke skill score (HSS), the results show that the UDR techniques can improve the precipitation estimation accuracy. In addition, ICA is shown to have better performance than other UDR techniques; and in some cases, it achieves 10% improvement in the HSS.

  8. A Preliminary Analysis of Precipitation Properties and Processes during NASA GPM IFloodS

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence; Gatlin, Patrick; Petersen, Walt; Wingo, Matt; Lang, Timothy; Wolff, Dave

    2014-01-01

    The Iowa Flood Studies (IFloodS) is a NASA Global Precipitation Measurement (GPM) ground measurement campaign, which took place in eastern Iowa from May 1 to June 15, 2013. The goals of the field campaign were to collect detailed measurements of surface precipitation using ground instruments and advanced weather radars while simultaneously collecting data from satellites passing overhead. Data collected by the radars and other ground instruments, such as disdrometers and rain gauges, will be used to characterize precipitation properties throughout the vertical column, including the precipitation type (e.g., rain, graupel, hail, aggregates, ice crystals), precipitation amounts (e.g., rain rate), and the size and shape of raindrops. The impact of physical processes, such as aggregation, melting, breakup and coalescence on the measured liquid and ice precipitation properties will be investigated. These ground observations will ultimately be used to improve rainfall estimates from satellites and in particular the algorithms that interpret raw data for the upcoming GPM mission's Core Observatory satellite, which launches in 2014. The various precipitation data collected will eventually be used as input to flood forecasting models in an effort to improve capabilities and test the utility and limitations of satellite precipitation data for flood forecasting. In this preliminary study, the focus will be on analysis of NASA NPOL (S-band, polarimetric) radar (e.g., radar reflectivity, differential reflectivity, differential phase, correlation coefficient) and NASA 2D Video Disdrometers (2DVDs) measurements. Quality control and processing of the radar and disdrometer data sets will be outlined. In analyzing preliminary cases, particular emphasis will be placed on 1) documenting the evolution of the rain drop size distribution (DSD) as a function of column melting processes and 2) assessing the impact of range on ground-based polarimetric radar estimates of DSD properties.

  9. Mesospheric Odd Nitrogen Enhancements During Relativistic Electron Precipitation Events

    NASA Technical Reports Server (NTRS)

    Aikin, A. C.; Smith, H. J. P.

    1999-01-01

    The behavior of mesospheric odd nitrogen species during and following relativistic and diffuse auroral precipitation events is simulated, Below 75 km nitric oxide is enhanced in proportion to the ion pair production function associated with the electron precipitation and the length of the event. Nitrogen dioxide and nitric acid are also enhanced. At 65 km the percentage of odd nitrogen for N is 0.1%, HNO3 is 1.6%, NO2 is 15%, and NO is 83.3%. Between 75 and 85 km NO is depleted during particle events due to the faster destruction of NO by N relative to the production of NO by N reacting with O2. Recovery of NO depends on transport from the lower thermosphere, where NO is produced in abundant amounts during particle events.

  10. Enhancing droplet deposition through in-situ precipitation

    NASA Astrophysics Data System (ADS)

    Damak, Maher; Mahmoudi, Seyed Reza; Hyder, Md Nasim; Varanasi, Kripa K.

    2016-08-01

    Retention of agricultural sprays on plant surfaces is an important challenge. Bouncing of sprayed pesticide droplets from leaves is a major source of soil and groundwater pollution and pesticide overuse. Here we report a method to increase droplet deposition through in-situ formation of hydrophilic surface defects that can arrest droplets during impact. Defects are created by simultaneously spraying oppositely charged polyelectrolytes that induce surface precipitation when two droplets come into contact. Using high-speed imaging, we study the coupled dynamics of drop impact and surface precipitate formation. We develop a physical model to estimate the energy dissipation by the defects and predict the transition from bouncing to sticking. We demonstrate macroscopic enhancements in spray retention and surface coverage for natural and synthetic non-wetting surfaces and provide insights into designing effective agricultural sprays.

  11. Enhanced droplet retention through in-situ precipitation

    NASA Astrophysics Data System (ADS)

    Damak, Maher; Mahmoudi, Seyed Reza; Hyder, Md Nasim; Varanasi, Kripa

    2016-11-01

    Poor retention of agricultural sprays on hydrophobic plants is an important issue, as large quantities of toxic chemicals end up in soils and groundwater after sprayed droplets bounce off leaves. Here we propose to increase liquid retention on hydrophobic surfaces by in-situ formation of hydrophilic surface defects that pin the impacting drops. Defects are formed through simultaneous spraying of solutions containing opposite polyelectrolyte, which combine on the surface and precipitate. We study individual drop-on-drop impact dynamics with high-speed imaging and analyze the surface after impact. Using these results, we elucidate the mechanism of precipitate formation and droplet retention. We derive a physical model to estimate the energy dissipation by the formed defects and predict the transition from bouncing to sticking, which can be used to design effective sprays. We finally show large macroscopic enhancements in retention of sprays on superhydrophobic synthetic surfaces as well as leaves.

  12. Enhancing droplet deposition through in-situ precipitation

    PubMed Central

    Damak, Maher; Mahmoudi, Seyed Reza; Hyder, Md Nasim; Varanasi, Kripa K.

    2016-01-01

    Retention of agricultural sprays on plant surfaces is an important challenge. Bouncing of sprayed pesticide droplets from leaves is a major source of soil and groundwater pollution and pesticide overuse. Here we report a method to increase droplet deposition through in-situ formation of hydrophilic surface defects that can arrest droplets during impact. Defects are created by simultaneously spraying oppositely charged polyelectrolytes that induce surface precipitation when two droplets come into contact. Using high-speed imaging, we study the coupled dynamics of drop impact and surface precipitate formation. We develop a physical model to estimate the energy dissipation by the defects and predict the transition from bouncing to sticking. We demonstrate macroscopic enhancements in spray retention and surface coverage for natural and synthetic non-wetting surfaces and provide insights into designing effective agricultural sprays. PMID:27572948

  13. Quantitative evaluation of bronchial enhancement: preliminary observations

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Godoy, Myrna C. B.; Schmidt, Bernhard

    2010-03-01

    It has been known for several years that airflow limitations in the small airways may be an important contributor to Chronic Obstructive Pulmonary Disease (COPD). Quantification of wall thickness has lately gained attention thanks to the use of high resolution CT, with novel approaches focusing on automated methods that can substitute for visual assessment [1, 2]. While increased thickening of the wall is considered evidence of inflammatory disease, we hypothesize that there may be additional ways to detect and quantify inflammation, specifically the uptake of contrast material. In this preliminary investigation, we selected patients with documented chronic airway inflammation, and for whom pre and post contrast datasets were available. On targeted reconstruction of right upper and lower lobes, we selected airways with no connections to surrounding structures, and used a modified Full-Width-Half-Max method for quantification of lumen diameter, wall thickness, and wall density. Matching airway locations on the pre- and postcontrast cases were compared. Airways from patients without airway disease served as a control. Results for the airway disease cases showed an average enhancement of 72 HU within the airway walls, with a standard deviation of 59 HU. In the control group the average enhancement was 16 HU with standard deviation of 22 HU. While this study is limited in number of cases, we hypothesize that quantification of contrast uptake is an additional factor to consider in assessing airway inflammation. At the same time we are currently investigating whether enhancement can be measured via a "contrast" map created with dual energy scanning, where a 3-value decomposition algorithm differentiates iodine from other materials. This technique would eliminate both the need for a pre-contrast scan, and the task of matching airway locations on pre- and post- scans.

  14. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    USDA-ARS?s Scientific Manuscript database

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present resul...

  15. The Chilean Coastal Orographic Precipitation Experiment Pilot Project (CCOPE-2015): Overview and Preliminary Results

    NASA Astrophysics Data System (ADS)

    Minder, J. R.; Massmann, A.; Fults, S.; Kingsmill, D. E.; Snider, J.; Garreaud, R. D.; Montecinos, A.; Valenzuela, R. A.

    2015-12-01

    The Nahuelbuta Mountains are a coastal range of modest height (peak elevation 1.3km ASL) in Southern Chile (38 deg. S). Rain gauge observations reveal a strong orographic enhancement of rainfall over the Nahuelbuta. The interior of the mountains receives about 3.5 m annual rainfall, in contrast to nearby lowland locations that receive about 1 m. The small horizontal scale of the Nahuelbuta (~40km) indicates that orographic precipitation enhancement is potentially sensitive to the effects of aerosol loading and shallow convection. The Chilean Coastal Orographic Precipitation Experiment Pilot Project (CCOPE-2015) was conducted over the Nahuelbuta during the Austral winter of 2015 (May-Aug). Field observations during CCOPE-2015 were collected to improve understanding of orographic precipitation processes over coastal mountain ranges, particularly the role of aerosols, shallow convection, and shallow "non-bright-band" rainfall. Observations collected included: (1) surface rainfall from a network of 10 data logging rain gauges, (2) vertical precipitation profiles from a pair of K-band Micro Rain Radars, (3) rain drop size distributions from an optical disdrometer, (4) aerosol number concentration and size distribution measurements from a condensation particle counter and an Ultra High Sensitivity Aerosol Spectrometer, and (5) upstream wind and thermodynamic profiles from radiosonde launches. Mesoscale model simulations and satellite remote sensing provided additional context. An overview of observations collected during CCOPE-2015 will be presented. The character of precipitation over the Nahuelbuta will be contrasted between different precipitation regimes (shallow warm rain, deep synoptically forced, and shallow convection). Additionally, the performance of satellite-based quantitative precipitation estimates over the Nahuelbuta will be assessed.

  16. Precipitation isoscapes for New Zealand: enhanced temporal detail using precipitation-weighted daily climatology.

    PubMed

    Baisden, W Troy; Keller, Elizabeth D; Van Hale, Robert; Frew, Russell D; Wassenaar, Leonard I

    2016-01-01

    Predictive understanding of precipitation δ(2)H and δ(18)O in New Zealand faces unique challenges, including high spatial variability in precipitation amounts, alternation between subtropical and sub-Antarctic precipitation sources, and a compressed latitudinal range of 34 to 47 °S. To map the precipitation isotope ratios across New Zealand, three years of integrated monthly precipitation samples were acquired from >50 stations. Conventional mean-annual precipitation δ(2)H and δ(18)O maps were produced by regressions using geographic and annual climate variables. Incomplete data and short-term variation in climate and precipitation sources limited the utility of this approach. We overcome these difficulties by calculating precipitation-weighted monthly climate parameters using national 5-km-gridded daily climate data. This data plus geographic variables were regressed to predict δ(2)H, δ(18)O, and d-excess at all sites. The procedure yields statistically-valid predictions of the isotope composition of precipitation (long-term average root mean square error (RMSE) for δ(18)O = 0.6 ‰; δ(2)H = 5.5 ‰); and monthly RMSE δ(18)O = 1.9 ‰, δ(2)H = 16 ‰. This approach has substantial benefits for studies that require the isotope composition of precipitation during specific time intervals, and may be further improved by comparison to daily and event-based precipitation samples as well as the use of back-trajectory calculations.

  17. Enhanced precipitation variability decreases grass- and increases shrub-productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-10-13

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society.

  18. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    PubMed Central

    Gherardi, Laureano A.; Sala, Osvaldo E.

    2015-01-01

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  19. On an Enhanced PERSIANN-CCS Algorithm for Precipitation Estimation

    SciTech Connect

    Mahrooghy, Majid; Anantharaj, Valentine G; Younan, Nicolas H.; Aanstoos, James; Hsu, Kuo-Lin

    2012-01-01

    By employing wavelet and selected features (WSF), median merging (MM), and selected curve-fitting (SCF) techniques, the Precipitation Estimation from Remotely Sensed Imagery using an Artificial Neural Networks Cloud Classification System (PERSIANN-CCS) has been improved. The PERSIANN-CCS methodology includes the following four main steps: 1) segmentation of satellite cloud images into cloud patches, 2) feature extraction, 3) classification of cloud patches, and 4) derivation of the temperature rain-rate (T R) relationship for every cluster. The enhancements help improve step 2 by employing WSF, and step 4 by employing MM and SCF. For the study area herein, the results show that the enhanced methodology improves the equitable threat score (ETS) of the daily and hourly rainfall estimates mostly in the winter and fall. The ETS percentage improvement is about 20% for the daily (10% for hourly) estimates in the winter, 10% for the daily (8% for hourly) estimates in the fall, and at most 5% for the daily estimates in the summer at some rainfall thresholds. In the winter and fall, the area bias is improved almost at all rainfall thresholds for daily and hourly estimates. However, no significant improvement is obtained in the spring, and the area bias in the summer is also greater than that of the implemented PERSIANN-CCS algorithm.

  20. Preliminary planning for the Satellite Precipitation And Cloud Experiment (SPACE) Field Program

    NASA Technical Reports Server (NTRS)

    Williams, S. F.; Mcnider, R. T.

    1985-01-01

    Preliminary planning has been performed to support NASA/Marshall Space Flight Center (MSFC) in the coordination of the field experiment to be conducted in Central Tennessee, Northern Alabama, and Mississippi during the Spring/Summer of 1986. The goal of Satellite Precipitation and Cloud Experiments (SPACE) is to investigate mesoscale cloud/precipitation systems and development of associated satellite remote sensing technology. The field program will incorporate remote sensing observations from aircraft, satellite imagery, radar observations, ground based lightning measurements, rawinsonde observations, and various surface meteorological observations. The coordination of existing and special observation networks will provide a data base for analysis of precipitation events and provide ground truth comparisons for remote sensing capabilities. Existing surface-based observational networks include National Weather Service Meso/Alpha Scale Rawinsonde, radar, and surface measurements; the Tennessee Valley Authority automated and manual precpitation recording stations; and NASA/MSFC lightning measurement stations. Special observational features to be implemented include a meso/beta scale rawinsonde network, a special surface observational network within the rawinsonde network, and the installation of a RADAP II/ICRAD data processing unit on the National Weather Service radar at Nashville, TN. Initial coordination of these observational requirements to accomplish the goals of SPACE have been performed.

  1. Declining streamflows reveal nonstationary orographic precipitation enhancement driven by reduced westerly flows

    NASA Astrophysics Data System (ADS)

    Luce, Charles; Abatzoglou, John; Holden, Zachary

    2016-04-01

    Although orographic enhancement of precipitation lends mountains an important role in water resources, they are dramatically undersampled by long-term precipitation gages. This has led to the widespread practice of extrapolating trends in low-elevation precipitation gage networks to high elevations via simple climatological precipitation ratios developed from isohyetal maps. An implicit assumption in such a process is non-stationarity in orographic precipitation enhancement, an assumption that can lead to large errors in trend detection and attribution of climate change effects. We show an example from the Northwestern United States where streamflows from mountain watersheds show substantial declines over the last 60 years, even while long-term precipitation gage networks in the region show no trend. We demonstrate that these observed streamflow declines are driven by previously unexplored differential trends in precipitation. November to March westerly winds are strongly correlated with high-elevation precipitation but weakly correlated with low-elevation precipitation. Decreases in winter westerlies across the region from 1950 to 2012 are hypothesized to have reduced orographic precipitation enhancement, yielding differential trends in precipitation across elevations leading to the apparent paradox. Climate projections show continued weakening meridional pressure gradients and westerly flow across the region under greenhouse forcing, highlighting an additional stressor that is relevant for climate change impacts on water resources. This study also reveals the potential of wind speed data from circulation reanalysis products to better inform historical precipitation reconstructions.

  2. Enhanced precipitation variability effects on water losses and ecosystem

    USDA-ARS?s Scientific Manuscript database

    Climate change will result in increased precipitation variability with more extreme events reflected in more frequent droughts as well as more frequent extremely wet conditions. The increase in precipitation variability will occur at different temporal scales from intra to inter-annual and even long...

  3. Modeling Landscape Evolution and Climate: How Erosion and Precipitation are Linked in Active Orogens (Preliminary Results)

    NASA Astrophysics Data System (ADS)

    Lynch, B.; Yanites, B.; Shen, H.; Poulsen, C. J.

    2016-12-01

    The tectonic history and the climate driven erosional processes acting in a region are the primary controls on the evolution of a landscape. Quantifying these controls is essential to our understanding of uplift and erosion histories in mountain ranges. Our understanding of how landscapes respond to tectonic forcings is generally well constrained but the influence of climate on landscape evolution remains unclear. This uncertainty is especially apparent when comparing field experiments; some studies have demonstrated a positive feedback between climate and erosion, while others have not. To complement the field experiments and gain important quantitative insight into what climatic properties influence landscape evolution, we implement a numerical modeling approach. We investigate climate-landscape interactions by coupling a high-resolution climate model, Weather Research and Forecasting Model (WRF), and a landscape evolution model, Landlab. The Andes act as the climatic setting for this study, due to the variation in climate along the length of the orogen, and serve as a natural laboratory to test controls on erosion. Discharge is quantified across the landscape with the WRF Hydro model. Discharge and topography are passed between the models, allowing for a feedback relationship to form between topography and precipitation. We will present our preliminary model runs that result from an asynchronous model coupling approach. These results will allow us to run further experiments to test feedbacks between topography and climate by monitoring topographic metrics and erosion histories. This work provides a necessary next step in landscape evolution modeling by using an actively evolving climate to model real precipitation dynamics. This next step allows for modeling more accurate representations of precipitation through the development of an orogen. This will result in an improved understanding of the co-evolution of climate and topography in these settings.

  4. An Enhanced Global Precipitation Measurement (GPM) Validation Network Prototype

    NASA Technical Reports Server (NTRS)

    Schwaller, Matthew R.; Morris, K. Robert

    2009-01-01

    A Validation Network (VN) prototype is currently underway that compares data from the Precipitation Radar (PR) instrument on NASA's Tropical Rainfall Measuring Mission (TRMM) satellite to similar measurements from the U.S. national network of operational weather radars. This prototype is being conducted as part of the ground validation activities of NASA's Global Precipitation Measurement (GPM) mission. GPM will carry a Dual-frequency Precipitation Radar instrument (DPR) with similar characteristics to the TRMM PR. The purpose of the VN is to identify and resolve significant discrepancies between the U.S. national network of ground radar (GR) observations and satellite observations. The ultimate goal of such comparisons is to understand and resolve the first order variability and bias of precipitation retrievals in different meteorological/hydrological regimes at large scales. This paper presents a description of, and results from, an improved algorithm for volume matching and comparison of PR and ground radar observations.

  5. Drop Size Distribution Measurements Supporting the NASA Global Precipitation Measurement Mission: Infrastructure and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Petersen, Walter A.; Carey, Lawerence D.; Gatlin, Patrick N.; Wingo, Matthew; Tokay, Ali; Wolff, David B.; Bringi, V. N.

    2011-01-01

    seasons and for different rain system types. Preliminary results suggest that seasonal variations in the DSD parameters do occur, but are most pronounced when comparing tropical PSDs to either winter or summer convective precipitation. For example the previously documented shift to relatively smaller drop diameters in higher number concentrations for equivalent rain rate bins was observed in tropical storm rainbands occurring over Huntsville. On a more inter seasonal basis empirical fits between parameters such as D0 and ZDR do not appear to exhibit robust seasonal biases- i.e., one fit seems to work for all seasons within acceptable standard error (O[10%]) for estimates of D0. In polarimetric retrievals of the vertical variability in PSD (rain layer) for a tropical rainband we find that the Do varies with height when partitioned by specified precipitation categories (e.g., convective or stratiform, heavy and light stratiform etc.) but this variation is of order 10-20% and is smaller than the difference in D0 observed between the basic delineation of convective and stratiform precipitation types. Currently we are expanding our analysis of the vertical structure of the PSD to include several seasonally and/or dynamically-different storm system types (e.g., winter convection and stratiform events; summer mid-latitude convective etc.) sampled by ARMOR. The study will present the results of our combined analyses.

  6. Nitrogen oxides removal by pulsed corona enhanced wet electrostatics precipitation

    SciTech Connect

    Tseng, C.H.; Keener, T.C.; Khang, S.J.

    1999-07-01

    This paper presents the results of a bench-scale pulsed-corona enhanced wet electrostatic precipitator (wESP) application for removal of nitrogen oxides. This wESP is designed to operate wet/dry, positive/negative, and pulsed/non-pulsed conditions. The applied pulsed voltage is varied from 0 to 60 kV at 70 Hz. Gas flow rate is a nominal 7 m{sup 3}/hr and the collecting electrode area is 0.20 m{sup 2}. A simulated flue gas with NO concentration up to 1,200 ppm{sub v} has been used to determine the feasibility of NO{sub x} removal in the wESP. NO has to be oxidized to N{sub 2} before any removal takes place. NO{sub x} removal efficiency increased with gas residence time, inlet NO concentration and applied corona power. In the air stream with 10 seconds gas residence time, up to 20% of 1,000 ppm NO (or 22% NO{sub x}) was removed from an air stream of 1.9x10{sup {minus}3} m{sup 3}/s with a water flow of 6.3 x 10{sup {minus}5} m{sup 3}/sec and 20 W, 70 Hz pulsed corona. Both ammonia and ozone injections improve the NO{sub x} removal for both the corona and non-corona cases. With the inclusion of NH{sub 3} (NH{sub 3}/NO{sub x} ratio 1.3) and 25 watts corona power, NO removal efficiency was increased from 28% to 57%. The amount of in-situ ozone is not enough to be considered as a major NO{sub x} removal mechanism in this wESP. However, the additional injection of ozone improves the NO removal from 29% to 38% for both the corona and non-corona cases. When the oxygen concentration is dropped to 3% in a simulated flue gas with 12% CO{sub 2} and 800 ppm NO and 70% relative humidity at 11.5 s of gas residence time, the removal efficiency of NO is only 5%. Adding NH{sub 3} (NH{sub 3}/NO{sub x} ratio 1) at 76 watts corona power, NO removal is increased to 13%.

  7. Enhanced diffusion of boron by oxygen precipitation in heavily boron-doped silicon

    NASA Astrophysics Data System (ADS)

    Torigoe, Kazuhisa; Ono, Toshiaki

    2017-06-01

    The enhanced diffusion of boron has been investigated by analyzing out-diffusion profiles in the vicinity of the interface between a lightly boron-doped silicon epitaxial layer and a heavily boron-doped silicon substrate with a resistivity of 8.2 mΩ cm and an oxide precipitate (O.P.) density of 108-1010 cm-3. It is found that the boron diffusion during annealing at 850-1000 °C is enhanced with the increase of the oxide precipitate density. On the basis of a model for boron diffusion mediated by silicon self-interstitials, we reveal that the enhanced diffusion is attributed to self-interstitials supersaturated as a result of the emission from oxide precipitates and the absorption by punched-out dislocations. In addition, the temperature dependence of the fraction of the self-interstitial emission obtained analyzing the diffusion enhancement well explains the morphology changes of oxide precipitates reported in literature.

  8. Sensitivity of historical orographically enhanced extreme precipitation events to idealized temperature perturbations

    NASA Astrophysics Data System (ADS)

    Sandvik, Mari Ingeborg; Sorteberg, Asgeir; Rasmussen, Roy

    2017-03-01

    Using high resolution convective permitting simulations, we have investigated the sensitivity of historical orographically enhanced extreme precipitation events to idealized temperature perturbations. Our simulations were typical autumn and winter synoptic scale extreme precipitation events on the west coast of Norway. The response in daily mean precipitation was around 5%/K for a 2 °C temperature perturbation with a clear topographical pattern. Low lying coastal regions experienced relative changes that were only about 1/3 of the changes at higher elevations. The largest changes were seen in the highest elevations of the near coastal mountain regions where the change was in order of +7.5%/K. With a response around 5%/K, our simulations had a precipitation response that was around 2%/K lower than Clausius-Clapeyron scaling and 3%/K lower than the water vapor change. The below Clausius-Clapeyron scaling in precipitation could not be explained by changes in vertical velocities, stability or relative humidity. We suggest that the lower response in precipitation is a result of a shift from the more efficient ice-phase precipitation growth to less effective rain production in a warmer atmosphere. A considerable change in precipitation phase was seen with a mean increase in rainfall of 16%/K which was partly compensated by a reduction in snowfall of around 23%/K. This change may have serious implications for flooding and geohazards.

  9. Observations of Ionospheric Langmuir-waves Enhanced by Electron Precipitation

    NASA Astrophysics Data System (ADS)

    Gustavsson, Bjorn; Gunell, Herbert; Lamy, Hervé

    2017-04-01

    Incoherent scatter radar observations during auroral events regularly show strongly enhanced back-scatter from Langmuir-waves. In this presentation we show observations of significantly enhanced power in E-region plasma-lines. The observations show the altitude variation of the plasma-line power and frequency with 3 km altitude-resolution. One novel observation is that the back-scatter is just above a multiple of the electron gyro-frequency. This novel finding cannot be explained by the standard incoherent-scatter and electron transport theories. However, this frequency dependency is similar to the ionospheric responses to HF-radio-wave pumping. Electron-beam excited UH-waves converting to Langmuir-waves are suggested as a plausible explanation.

  10. Controlled precipitation for enhanced dissolution rate of flurbiprofen: development of rapidly disintegrating tablets.

    PubMed

    Essa, Ebtessam A; Elmarakby, Amira O; Donia, Ahmed M A; El Maghraby, Gamal M

    2017-09-01

    The aim of this work was to investigate the potential of controlled precipitation of flurbiprofen on solid surface, in the presence or absence of hydrophilic polymers, as a tool for enhanced dissolution rate of the drug. The work was extended to develop rapidly disintegrated tablets. This strategy provides simple technique for dissolution enhancement of slowly dissolving drugs with high scaling up potential. Aerosil was dispersed in ethanolic solution of flurbiprofen in the presence and absence of hydrophilic polymers. Acidified water was added as antisolvent to produce controlled precipitation. The resultant particles were centrifuged and dried at ambient temperature before monitoring the dissolution pattern. The particles were also subjected to FTIR spectroscopic, X-ray diffraction and thermal analyses. The FTIR spectroscopy excluded any interaction between flurbiprofen and excipients. The thermal analysis reflected possible change in the crystalline structure and or crystal size of the drug after controlled precipitation in the presence of hydrophilic polymers. This was further confirmed by X-ray diffraction. The modulation in the crystalline structure and size was associated with a significant enhancement in the dissolution rate of flurbiprofen. Optimum formulations were successfully formulated as rapidly disintegrating tablet with subsequent fast dissolution. Precipitation on a large solid surface area is a promising strategy for enhanced dissolution rate with the presence of hydrophilic polymers during precipitation process improving the efficiency.

  11. The influence of topography on the isotopic composition of orographically enhanced precipitation in an idealized baroclinic wave: Implications for isotope-based paleoaltimetry

    NASA Astrophysics Data System (ADS)

    Wheeler, L.; Galewsky, J.

    2016-12-01

    Isotope-based paleoaltimetry is based on the idea that as surface elevation increases, the isotopic composition of rainwater decreases and is recorded in geologic deposits. One of the main assumptions used in isotope-based paleoaltimetry is that pure orographic precipitation is the primary mechanism generating precipitation and the driver of isotopic fractionation. In pure orographic precipitation an air mass traveling perpendicular to the range front is lifted along the windward side and as the water vapor condenses the heavier isotopes are preferentially rained out. There is essentially no precipitation as an air mass travels down the leeside, which would leave no record of elevation on the leeside of mountain ranges. Pure orographic precipitation is rare though, and more commonly precipitation is derived from the orographic enhancement of a pre-existing storm system. Using an idealized baroclinic wave simulation in the Weather Research and Forecasting model (WRF), which is representative of a typical wintertime storm that affects the western United States, we test how changes in elevation and topographic configuration affect the distribution of orographically enhanced precipitation and the resulting isotopic composition. We modified the WRF model to include simple isotope physics in the microphysics scheme and the addition of a smooth topographic ridge. Tracers for the heavy isotopologues of water are incorporated into a Perfect Precipitation Model (PPM) and modified within the full microphysics scheme. In the PPM, precipitation is generated when a grid cell exceeds saturation. No condensate is retained in the atmosphere and all excess water vapor is condensed and falls out as precipitation. The isotopic fractionation takes place upon condensation based on the temperature dependent equilibrium factors for 18O and D. Our preliminary results show that for a low ridge, unlike in pure orographic precipitation, there is leeside precipitation. We also find that there

  12. The Cloud Aerosol Interactions and Precipitation Enhancement Experiment (CAIPEEX): overview and prominent results

    NASA Astrophysics Data System (ADS)

    Kulkarni, J. R.; Maheskumar, R. S.; Konwar, M.; Deshpande, C. G.; Morwal, S. B.; Padma Kumari, B.; Joshi, R. R.; Pandithurai, G.; Bhalwankar, R. V.; Mujumdar, V. R.; Goswami, B.; Rosenfeld, D.

    2009-12-01

    “Cloud-Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX)”, an Indian national program, funded by Ministry of Earth Sciences, (MoES), Govt. of India is being conducted by Indian Institute of Tropical Meteorology (IITM), Pune during the period 2009-2012. CAIPEEX has two phases. Phase I is devoted for intensive cloud and aerosol observations over different parts of India using an instrumented aircraft. Phase II is devoted for randomized precipitation enhancement experiment. The phase I is being carried out during the period May-September 2009. The main scientific objectives of Phase I are : To measure background concentrations of aerosols and cloud condensation nuclei (CCN) during pre-monsoon and monsoon seasons over different parts of the country. Measurements of the associated differences in convective cloud microstructure and precipitation forming processes. The important preliminary results from the observational studies are: 1) During the pre-monsoon thick layer of brown haze extends to height of about 5-6 km at the foothills of the Himalaya, but does not normally spill over into the Tibetan Plateau. 2) The deep clouds that form in this layer are typically triggered at the slopes of the Himalaya. The clouds are super-continental microphysically, which means that the cloud drops are very small and prevent any warm rain. However, much ice is formed quickly, probably due to the ice nucleating activity of the aerosols. 3) In the pre-monsoon phase over central and southern India the clouds have similar nature as described for the foothills of the Himalaya, but with lower bases. Still, warm rain is substantially suppressed. During the monsoon, the clouds in the Bangalore-Hyderabad rain shadow area lose quickly their ability to produce warm rain with the increasing levels of CCN eastward away from the west coast. 4) A major finding was the dominance of thick haze in the Arabian Sea during the SW monsoon. It appears to be mostly of Arabian and

  13. On the anomalous precipitation enhancement over the Himalayan foothills during monsoon breaks

    NASA Astrophysics Data System (ADS)

    Vellore, Ramesh K.; Krishnan, R.; Pendharkar, Jayant; Choudhury, Ayantika Dey; Sabin, T. P.

    2014-10-01

    An intriguing feature associated with `breaks' in the Indian summer monsoon is the occurrence of intense/flood-producing precipitation confined to central-eastern parts of the Himalayan (CEH) foothills and north-eastern parts of India. Past studies have documented various large-scale circulation aspects associated with monsoon-breaks, however the dynamical mechanisms responsible for anomalous precipitation enhancement over CEH foothills remain unclear. This problem is investigated using diagnostic analyses of observed and reanalysis products and high-resolution model simulations. The present findings show that the anomalous precipitation enhancement over the CEH foothills during monsoon-breaks emerges as a consequence of interactions between southward intruding mid-latitude westerly troughs and the South Asian monsoon circulation in its weak phase. These interactions facilitate intensification of mid-tropospheric cyclonic vorticity and strong ascending motion over the CEH foothills, so as to promote deep convection and concentrated rainfall activity over the region during monsoon-breaks. Mesoscale orographic effects additionally tend to amplify the vertical motions and precipitation over the CEH foothills as evidenced from the high-resolution model simulations. It is further noted from the model simulations that the coupling between precipitation and circulation during monsoon-breaks can produce nearly a threefold increase of total precipitation over the CEH foothills and neighborhood as opposed to active-monsoon conditions.

  14. Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems.

    PubMed

    Barat, R; Montoya, T; Seco, A; Ferrer, J

    2011-06-01

    The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Reactor (SBR) operated for EBPR and finally validated with two experiments. The precipitation model proposed was able to reproduce the dynamics of amorphous calcium phosphate (ACP) formation and later crystallization to hydroxyapatite (HAP) under different scenarios. The model successfully characterised the EBPR performance of the SBR, including the biological, physical and chemical processes.

  15. Enhanced diffusion and precipitation in Cu: In alloys due to low energy ion bombardment

    NASA Astrophysics Data System (ADS)

    Rivaud, L.; Ward, I. D.; Eltoukhy, A. H.; Greene, J. E.

    1981-01-01

    The effects of low energy Ar + ion bombardment on supersaturated Cu: 10at%-In alloys at room temperature were investigated using scanning transmission electron microscopy and Auger electron spectroscopy. Both 1 and 3 keV Ar + bombardment resulted in the preferential sputter removal of In. The surface and altered layer remained supersaturated however, and ion bombardment enhanced diffusion was sufficient to allow the precipitation of In-rich δ-phase (~30 at% In) particles in the near-surface region. The average precipitate size and number density in samples bombarded with 3 keV Ar + ions were ~200 Å and 10 10 cm -2 as compared to 150 A and 10 9 cm -2 in samples bombarded at 1 keV. The ion bombardment induced precipitates nucleated within the grains rather than, as was observed for thermally induced precipitates, at grain boundaries.

  16. On the Evolution of Precipitation Associated with a Wintertime East Coast Cyclone: A GALE Preliminary Study.

    DTIC Science & Technology

    1985-01-01

    rate versus vertical velocity value. Estoque (1957) used the 500mb height tendency forecast to derive a parabolic vertical motion profile to forecast the...precipitation. He established large-scale vertical motion similar to Estoque by indirectly obtaining vertical motion through 500mb height changes...balance in frontal zones. J AppI Meteor, 4, 196-211. Estoque , M.A., 1957: An approach to quantitative precipitation forecasting. ./ Meteor, 14, 50-54

  17. Antiscalant removal in accelerated desupersaturation of RO concentrate via chemically-enhanced seeded precipitation (CESP).

    PubMed

    McCool, Brian C; Rahardianto, Anditya; Cohen, Yoram

    2012-09-01

    An experimental study was carried out to demonstrate and quantify the feasibility of antiscalant (AS) removal from brackish water RO concentrate of high gypsum scaling propensity via lime treatment prior to seeded gypsum precipitation. Based on studies with model solutions, it was shown that sufficient AS removal (up to ∼90%) from RO concentrate is feasible via a lime treatment step (at a dose significantly lower than that required for conventional lime softening) to enable effective subsequent seeded gypsum precipitation. This two-step chemically-enhanced seeded precipitation (CESP) treatment of primary RO concentrate is suitable as an intermediate concentrate demineralization (ICD) stage for high recovery desalting employing secondary RO desalination. Analysis of gypsum precipitation and lime treatment kinetic data suggests that, after adequate CaCO(3) precipitation has been induced for effective AS scavenging, CaSO(4) desupersaturation can be achieved via seeded gypsum precipitation without retardation due to seed poisoning by AS. Also, the lime dose required to prevent seed poisoning during subsequent gypsum desupersaturation via seeded gypsum precipitation can be adequately assessed with a precipitation kinetics model that considers AS seed poisoning based on a Langmuir adsorption isotherm. The degree of AS removal after lime treatment increased linearly with the logarithm of the single lime dose additions. Staged lime dosing (i.e., multiple lime additions), however, removed a higher degree of AS relative to an equivalent single lime dose addition since a higher driving force for CaCO(3) precipitation could be maintained over the course of the lime treatment period.

  18. Impacts of an integrated crop-livestock system on soil properties to enhance precipitation capture

    USDA-ARS?s Scientific Manuscript database

    Cropping/Livestock systems alter soil properties that are important in enhancing capture of precipitation by developing and maintaining water infiltration and storage. In this paper we will relate soil hydraulic conductivity and other physical properties on managed Old World Bluestem grassland, whea...

  19. A preliminary study on removal of AMD precipitate coatings on pebbles

    NASA Astrophysics Data System (ADS)

    Lee, W.; Min, K.; Lee, H.

    2011-12-01

    AMD(acid mine drainage) having a low pH and elevated concentrations of heavy metals affects environments as a major pollutant. In addition to AMD's water contamination, reddish brown precipitates from AMD spoil the watercourse scenery without suitable removal treatments. To examine the removal potentiality of ultrasonic cleaner, the pebble samples coated by reddish brown precipitates were collected at abandoned mine stream and scraped precipitate coatings were analyzed for their chemical compositions and mineralogy. Their average contents of Fe2O3, SO3, and Al2O3 were 84.3%, 6.13%, and 3.69%, respectively and goethite was the major constituent mineral. Laboratorial tests to remove precipitate coatings were performed in an ultrasonic cleaner with the frequency of 40kHz at 20 to 70oC for 10 to 60 minutes. Water and hydrochloric acid of 0.1M to 1M were used as a cleaning solvent and the ratio of solvent to precipitate coated pebbles was 5 in weight. In result, an ultrasonic cleaning treatment is expected to be applied successively in field and removal efficiency was increased as reaction time, temperature, and concentration of solvent rises.

  20. Enhanced Accident Tolerant Fuels for LWRS - A Preliminary Systems Analysis

    SciTech Connect

    Gilles Youinou; R. Sonat Sen

    2013-09-01

    The severe accident at Fukushima Daiichi nuclear plants illustrates the need for continuous improvements through developing and implementing technologies that contribute to safe, reliable and cost-effective operation of the nuclear fleet. Development of enhanced accident tolerant fuel contributes to this effort. These fuels, in comparison with the standard zircaloy – UO2 system currently used by the LWR industry, should be designed such that they tolerate loss of active cooling in the core for a longer time period (depending on the LWR system and accident scenario) while maintaining or improving the fuel performance during normal operations, operational transients, and design-basis events. This report presents a preliminary systems analysis related to most of these concepts. The potential impacts of these innovative LWR fuels on the front-end of the fuel cycle, on the reactor operation and on the back-end of the fuel cycle are succinctly described without having the pretension of being exhaustive. Since the design of these various concepts is still a work in progress, this analysis can only be preliminary and could be updated as the designs converge on their respective final version.

  1. Principal Modes of Precipitation Variability from Preliminary Series of IMERG Data

    NASA Technical Reports Server (NTRS)

    Savtchenko, A.; Huffman, G.; Vollmer, B.

    2017-01-01

    The Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission, IMERG, is the unified U.S. algorithm that provides merged Microwave Infrared (IR) satellite precipitation product for the U.S. GPM team. Even though IMERG record is still very short, 2014-2016, it is tempting to test if it captures ENSO and NAO signals as compared to the popular, still on-going, TRMM Multi-satellite Precipitation Analysis, TMPA. El Nino Southern Oscillation (ENSO) is the most significant mode of interannual variability of tropical ocean atmosphere. North Atlantic Oscillation (NAO) impact is on monthly scales and is mostly an atmospheric mode in the North Atlantic. There exist well-defined, multivariate, indexes that represent ENSO and NAO conditions and phase.

  2. Environmental controls on stable isotopes of precipitation in Lanzhou, China: An enhanced network at city scale.

    PubMed

    Chen, Fenli; Zhang, Mingjun; Wang, Shengjie; Qiu, Xue; Du, Mingxia

    2017-12-31

    Stable hydrogen and oxygen isotopes in precipitation are very sensitive to environmental changes, and can record evolution of water cycle. The Lanzhou city in northwestern China is jointly influenced by the monsoon and westerlies, which is considered as a vital platform to investigate the moisture regime for this region. Since 2011, an observation network of stable isotopes in precipitation was established across the city, and four stations were included in the network. In 2013, six more sampling stations were added, and the enhanced network might provide more meaningful information on spatial incoherence and synoptic process. This study focused on the variations of stable isotopes (δ(18)O and δD) in precipitation and the environmental controls based on the 1432 samples in this enhanced network from April 2011 to October 2014. The results showed that the precipitation isotopes had great spatial diversity, and the neighboring stations may present large difference in δD and δ(18)O. Based on the observation at ten sampling sites, an isoscape in precipitation was calculated, and the method is useful to produce isoscape for small domains. The temperature effect and amount effect was reconsidered based on the dataset. Taking meteorological parameters (temperature, precipitation amount, relative humidity, water vapor pressure and dew point temperature) as variables in a multi-linear regression, the result of coefficients for these meteorological parameters were calculated. Some cases were also involved in this study, and the isotopic characteristics during one event or continuous days were used to understand the environmental controls on precipitation isotopes. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Enhanced radionuclide immobilization and flow path modifications by dissolution and secondary precipitates.

    PubMed

    Um, Wooyong; Serne, R Jeffrey; Yabusaki, Steven B; Owen, Antoinette T

    2005-01-01

    Caustic radioactive wastes that have leaked at Hanford Site (Richland, WA) induce mineral dissolution and subsequent secondary precipitation that influence the fate and transport of contaminants present in the waste solutions. The effects of secondary mineral precipitates, formed after contacting solids with simulated caustic wastes, on the flow path changes and radionuclide immobilization were investigated by reacting quartz, a mixture of quartz and biotite, and a Hanford sediment (Warden soil: coarse-silty, mixed, superactive, mesic Xeric Haplocambids) with simulated caustic tank waste solution. Continuous Si dissolution and concomitant secondary mineral precipitation were the principal reactions observed in both batch and flow-through tests. Nitrate-cancrinite was the dominant secondary precipitate on mineral surfaces after 3- to 10-d reaction times in batch experiments. X-ray microtomography images of a reacted quartz column revealed that secondary precipitates cemented quartz grains together and modified pore geometry in the center of the column. Along the circumference of the packed column, however, quartz dissolution continuously occurred, suggesting that wastes that leaked from buried tanks in the past likely did not migrate vertically as modeled in risk assessments but rather the pathways likely changed to be dominantly horizontal on precipitation of secondary precipitate phases in the Hanford vadose zone. Based on batch equilibrium sorption results on the reacted sediments, the dominant secondary precipitates (cancrinites) on the mineral surfaces enhanced the sorption capacity of typical Hanford sediment for radionuclides 129I(-I), 79Se(VI), 99Tc(VII), and 90Sr(II), all of which are of major concern at the Hanford Site.

  4. Enhanced radionuclide immobilization and flow path modifications by dissolution and secondary precipitates

    SciTech Connect

    Um, Wooyong; Serne, R JEFFREY.; Yabusaki, Steven B.; Owen, Antionette T.

    2005-07-05

    Caustic radioactive wastes that have leaked at Hanford Site (Richland, WA) induce mineral dissolution and subsequent secondary precipitation that influence the fate and transport of contaminants present in the waste solutions. The effects of secondary mineral precipitates, formed after contacting solids with simulated caustic wastes, on the flow path changes and radionuclide immobilization were investigated by reacting quartz, a mixture of quartz and biotite, and a Hanford sediment (Warden soil) with simulated caustic tank waste solution. Continuous Si dissolution and concomitant secondary mineral precipitation were the principal reactions observed in both batch and flow-through tests. Nitrate-cancrinite was the dominant secondary precipitate on mineral surfaces after 3 to 10 d reaction times in batch experiments. X-ray microtomography images of a reacted quartz column revealed that secondary precipitates cemented quartz grains together and modified pore geometry in the center of the column. Along the circumference of the packed column, however, quartz dissolution continuously occurred, suggesting that wastes that leaked from buried tanks in the past likely did not migrate vertically as modeled in risk assessments but rather the pathways likely changed to be dominantly horizontal upon precipitation of secondary precipitate phases in the Hanford vadose zone. Based on batch equilibrium sorption results on the reacted sediments, the dominant secondary precipitates (cancrinites) on the mineral surfaces enhanced the sorption capacity of typical Hanford sediment for radionuclides 129I(-I), 79Se(VI), 99Tc(VII), and 90Sr(II), all of which are of major concern at the Hanford Site.

  5. Preliminary Results from a Mesocosm Marsh Experiment with Treatments Simulating Three Tidal Flooding and Precipitation Conditions

    EPA Science Inventory

    Our goal was to observe and quantify the effects of low, medium and high tidal flooding regimes and various precipitation conditions on both Spartina alterniflora and Typha angustifolia in greenhouse mesocosms. The experiment was maintained for 4 months. Each of 3 tanks (600L) ha...

  6. Preliminary Results from a Mesocosm Marsh Experiment with Treatments Simulating Three Tidal Flooding and Precipitation Conditions

    EPA Science Inventory

    Our goal was to observe and quantify the effects of low, medium and high tidal flooding regimes and various precipitation conditions on both Spartina alterniflora and Typha angustifolia in greenhouse mesocosms. The experiment was maintained for 4 months. Each of 3 tanks (600L) ha...

  7. Variational merged of hourly gauge-satellite precipitation in China: Preliminary results

    NASA Astrophysics Data System (ADS)

    Li, Huan; Hong, Yang; Xie, Pingping; Gao, Jidong; Niu, Zheng; Kirstetter, Pierre; Yong, Bin

    2015-10-01

    The article describes a variational scheme for the analysis of high-resolution hourly precipitation from China Meteorological Administration gauges and NOAA CMORPH satellite products in China and tests their impact on data-sparse regions and the heavy rainfall occurrences during the summer season (June-August 2009). In the variational scheme, a cost function is defined to measure the distance between analyzed precipitation field and observed rainfall quantity. A recursive filter is incorporated into the cost function which helps spread the observations to nearby grid points. Then a quasi-Newton method is used to solve the optimal estimation problem by minimizing the cost function. The adjoint technique is used to derive the gradient of cost function with respect to analysis precipitation. A series of experiments are performed to intercompare the variational analysis with the original CMORPH satellite products (CMP) and the bias-adjusted satellite products (Adj-CMP) against the observations. The best overall performance is from the variational analysis especially rainfall intensity by more than 10 mm h-1 with a prevailing mean relative spatial bias nearly reduction zero, and the correlation coefficient is almost around 0.5 in convection active areas. Ground cross-validation experiments in which each affected station is withdrawn at once indicated that the variational analysis can particularly be beneficial and subsequent investigation of heavy rainfall events. It also reveals that the precipitation analysis field has the ability to improve the accuracy of rainfall estimation and capture the spatial precipitation pattern agreements in relatively data-sparse regions.

  8. Enhancement of Convective Precipitation by Mesoscale Variations in Vegetative Covering in Semiarid Regions.

    NASA Astrophysics Data System (ADS)

    Anthes, Richard A.

    1984-04-01

    It is hypothesized that planting bands of vegetation with widths of the order of 50-100 km in semiarid regions could, under favorable large-scale atmospheric conditions, result in increases of convective precipitation. These increases, which could be greater than those associated with the uniform vegetating of large areas, would occur through three major mechanisms. The first would be the modification of the environment to a state more conducive to the formation of moist convection through an increase of low-level moist static energy. This increase would be associated with a decrease in albedo, an increase in net radiation, and an increase in evapotranspiration. The second important mechanism would be the generation of mesoscale (horizontal scale of 20-200 km) circulations associated with the surface inhomogeneities created on this scale by the vegetation. The third mechanism would be the increase of atmospheric water vapor through decreased runoff and increased evaporation.A number of observational and theoretical studies which have a bearing on the above hypothesis are reviewed. Although individual studies may contain large uncertainties, taken together they provide considerable support for the hypothesis. In these studies, convective rainfall appears to be associated with increases in vegetation and with variations in surface characteristics in many parts of the world on scales ranging from 10 km to large fractions of continents.A review of recent agricultural research indicates that a variety of plants that thrive in semiarid regions (some under irrigation with saline water) could be suitable for cultivation. Many of these have potential economic value, which could defray or even exceed the cost of the cultivation.Finally, a preliminary estimate of the preferred horizontal scale of the vegetation bands is made using a linear model. For bands of width less than about 20 km, horizontal mixing limits the vertical penetration of the surface heating perturbation to

  9. Probability of afternoon precipitation in eastern United States and Mexico enhanced by high evaporation

    NASA Astrophysics Data System (ADS)

    Findell, Kirsten L.; Gentine, Pierre; Lintner, Benjamin R.; Kerr, Christopher

    2011-07-01

    Moisture and heat fluxes from the land surface to the atmosphere form a critical nexus between surface hydrology and atmospheric processes, particularly those relevant to precipitation. Although current theory suggests that soil moisture generally has a positive impact on subsequent precipitation, individual studies have shown support both for and against this positive feedback. Broad assessment of the coupling between soil moisture and evapotranspiration, and evapotranspiration and precipitation, has been limited by a lack of large-scale observations. Quantification of the influence of evapotranspiration on precipitation remains particularly uncertain. Here, we develop and apply physically based, objective metrics for quantifying the impacts of surface evaporative and sensible heat fluxes on the frequency and intensity of convective rainfall during summer, using North American reanalysis data. We show that high evaporation enhances the probability of afternoon rainfall east of the Mississippi and in Mexico. Indeed, variations in surface fluxes lead to changes in afternoon rainfall probability of between 10 and 25% in these regions. The intensity of rainfall, by contrast, is largely insensitive to surface fluxes. We suggest that local surface fluxes represent an important trigger for convective rainfall in the eastern United States and Mexico during the summer, leading to a positive evaporation-precipitation feedback.

  10. An on-board processor for a spaceborne Doppler precipitation radar : requirements and preliminary design

    NASA Technical Reports Server (NTRS)

    Durden, Stephen L.; Fischman, M. A.; Tanelli, S.; Johnson, R. A.; Chu, A.

    2004-01-01

    Use of Doppler velocity measurement in spaceborne precipitation radar is highly desirable, since it can allow more accurate retrieval of atmospheric latent heating, which depends on both cloud and rain microphysical processes and on dynamical processes, namely, vertical updrafts and downdrafts. However, if the rain within the antenna beam is very non-uniform, biases can result with conventional pulse-pair processing, and more sophisticated processing is required. The solution is a time-frequency approach, which uses the full Doppler spectrum at each point in time. Since precipitation radars normally operate continuously and collect large amounts of data, real-time, on-board processing of data is needed to reduce the data rate. The objective of this work is to develop an on-board data processor for spaceborne Doppler precipitation radar, using field-programmable gate array (FPGA) technology. This paper describes the simulations and analysis that have been completed during the first year of the project. This includes both analytical calculations and bit-true simulations that allow the effects of finite word length to be explored. Tradeoffs have also been considered between speed and space within the chosen FPGA part. The results of these analyses have been used to develop a complete set of requirements for the processor. Initial design work has begun, based on these requirements. The design is being implemented in Verilog, and a description of this early design effort is also be given.

  11. Dual-task practice enhances motor learning: a preliminary investigation.

    PubMed

    Goh, Hui-Ting; Sullivan, Katherine J; Gordon, James; Wulf, Gabriele; Winstein, Carolee J

    2012-10-01

    Practicing a motor task under dual-task conditions can be beneficial to motor learning when the secondary task is difficult (Roche et al. in Percept Psychophys 69(4):513-522, 2007) or when it engages similar processes as the primary motor task (Hemond et al. in J Neurosci 30(2):650-654, 2010). The purpose of this pilot study was to determine which factor, difficulty level or engaged processes, of a secondary task is more critical in determining dual-task benefit. Participants practiced a discrete arm task in conjunction with an audio-vocal reaction time (RT) task. We presented two different RT tasks that differed in difficulty, simple versus choice (i.e., more difficult), at two different arm task phases that differed in engaged processes, preparation versus execution, resulting in four dual-task conditions. A simple RT task is thought to predominantly engage motor execution processes, therefore would engage similar processes as the arm movement task when it is presented during the execution phase, while a choice RT task is thought to engage planning processes and therefore would engage similar processes too when it is presented during the preparation phase. Enhanced motor learning was found in those who engaged similar process as the primary task during dual-tasking (i.e., choice RT presented during preparation and simple RT presented during execution). Moreover, those who showed enhanced learning also demonstrated high dual-task cost (poor RT task performance) during practice, indicating that both tasks were taxing the same resource pool possibly due to engaging similar cognitive processes. To further test the relation between dual-task cost and enhanced learning, we delayed the presentation timing of the choice RT task during the preparation phase and the simple RT task during the execution phase in two control experiments. Dual-task cost was reduced in these delayed timing conditions, and the enhanced learning effect was attenuated. Together, our preliminary

  12. Satellite-Enhanced Regional Downscaling for Applied Studies: Extreme Precipitation Events in Southeastern South America

    NASA Astrophysics Data System (ADS)

    Nunes, A.; Gomes, G.; Ivanov, V. Y.

    2016-12-01

    Frequently found in southeastern South America during the warm season from October through May, strong and localized precipitation maxima are usually associated with the presence of mesoscale convective complexes (MCCs) travelling across the region. Flashfloods and landslides can be caused by these extremes in precipitation, with damages to the local communities. Heavily populated, southeastern South America hosts many agricultural activities and hydroelectric production. It encompasses one of the most important river basins in South America, the La Plata River Basin. Therefore, insufficient precipitation is equally prejudicial to the region socio-economic activities. MCCs are originated in the warm season of many regions of the world, however South American MCCs are related to the most severe thunderstorms, and have significantly contributed to the precipitation regime. We used the hourly outputs of Satellite-enhanced Regional Downscaling for Applied Studies (SRDAS), developed at the Federal University of Rio de Janeiro in Brazil, in the analysis of the dynamics and physical characteristics of MCCs in South America. SRDAS is the 25-km resolution downscaling of a global reanalysis available from January 1998 through December 2010. The Regional Spectral Model is the SRDAS atmospheric component and assimilates satellite-based precipitation estimates from the NOAA/Climate Prediction Center MORPHing technique global precipitation analyses. In this study, the SRDAS atmospheric and land-surface variables, global reanalysis products, infrared satellite imagery, and the physical retrievals from the Atmospheric Infrared Sounder (AIRS), on board of the NASA's Aqua satellite, were used in the evaluation of the MCCs developed in southeastern South America from 2008 and 2010. Low-level circulations and vertical profiles were analyzed together to establish the relevance of the moisture transport in connection with the upper-troposphere dynamics to the development of those MCCs.

  13. Enhancement of perfluoropolyether boundary lubrication performance: I. Preliminary results

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Ajayi, O. O.; Goodell, A. J.; Wedeven, L. D.; Devine, E.; Premore, R. E.

    1995-01-01

    A ball bearing simulator operating under starved conditions was used to evaluate the boundary lubrication performance of a perfluoropolyether (PFPE) Krytox 143 AB. Several approaches to enhance boundary lubrication were studied. These included: (1) soluble boundary additives, (2) bearing surface modifications, (3) 'run-in' surface films, and (4) ceramic bearing components. In addition, results were compared with two non-perfluorinated liquid lubricant formulations. Based on these preliminary tests, the following tentative conclusions can be made: (1) substantial improvements in boundary lubrication performance were observed with a beta-diketone boundary additive and a tricresyl phosphate (TCP) liquid surface pretreatment; (2) the use of rough Si3N4 balls (Ra = 40 micro-in) also provided substantial improvement but with concomitant abrasive wear; (3) marginal improvements were seen with two boundary additives (a phosphine and a phosphatriazine) and a neat (100%) fluid (a carboxylic acid terminated PFPE); and surface pretreatments with a synthetic hydrocarbon, a PTFE coating, and TiC coated 440C and smooth Si3N4 balls (R(sub a) less than 1 micro-in); and (4) two non-PFPE lubricant formulations (a PAO and a synthetic hydrocarbon) yielded substantial improvements.

  14. IN-SITU CHEMICAL STABILIZATION OF METALS AND RADIONUCLIDES THROUGH ENHANCED ANAEROBIC REDUCTIVE PRECIPITATION

    SciTech Connect

    Christopher C. Lutes; Angela Frizzell, PG; Todd A. Thornton; James M. Harrington

    2003-08-01

    The objective of this NETL sponsored bench-scale study was to demonstrate the efficacy of enhanced anaerobic reductive precipitation (EARP) technology for precipitating uranium using samples from contaminated groundwater at the Fernald Closure Project (FCP) in Cincinnati, Ohio. EARP enhances the natural biological reactions in the groundwater through addition of food grade substrates (typically molasses) to drive the oxidative-reductive potential of the groundwater to a lower, more reduced state, thereby precipitating uranium from solution. In order for this in-situ technology to be successful in the long term, the precipitated uranium must not be re-dissolved at an unacceptable rate once groundwater geochemical conditions return to their pretreatment, aerobic state. The approach for this study is based on the premise that redissolution of precipitated uranium will be slowed by several mechanisms including the presence of iron sulfide precipitates and coatings, and sorption onto fresh iron oxides. A bench-scale study of the technology was performed using columns packed with site soil and subjected to a continuous flow of uranium-contaminated site groundwater (476 {micro}g/L). The ''treated'' column received a steady stream of dilute food grade molasses injected into the contaminated influent. Upon attainment of a consistently reducing environment and demonstrated removal of uranium, an iron sulfate amendment was added along with the molasses in the influent solution. After a month long period of iron addition, the treatments were halted, and uncontaminated, aerobic, unamended water was introduced to the treated column to assess rebound of uranium concentrations. In the first two months of treatment, the uranium concentration in the treated column decreased to the clean-up level (30 {micro}g/L) or below, and remained there for the remainder of the treatment period. A brief period of resolubilization of uranium was observed as the treated column returned to aerobic

  15. Alloy development for the enhanced stability of Omega precipitates in aluminum-copper-magnesium-(silver) alloys

    NASA Astrophysics Data System (ADS)

    Gable, Brian M.

    This research involved a combined analytical and experimental approach to the design of an age-hardenable Al-Cu-Mg-Ag alloy for moderate temperature application. The applied methodology involved the complimentary techniques of thermal analysis, calculated phase diagrams, analytical microscopy and quantitative microstructural characterization. The objective of this research was to exploit several avenues for enhancing the coarsening resistance and thermal stability of the O phase through careful control of the alloy chemistry and processing. Differential thermal analysis (DTA) coupled with conventional and analytical transmission electron microscopy (TEM) techniques were implemented to refine the calculation of the Al-rich corner of the quaternary Al-Cu-Mg-Ag phase diagram for subsequent alloy development. Quantitative energy dispersive spectroscopy (EDS) demonstrated that Ag preferentially partitioned to S-phase for all conditions investigated, which ultimately led to a concomitant loss of O precipitates. The elimination of S-phase precipitation and limiting the alloy Si content proved to enhance the nucleation and thermal stability of the O phase. Several O-dominated microstructures were manipulated through various thermo-mechanical processing techniques in order to evaluate the O nucleation density, particle size and thermal stability as a function of alloy composition and processing conditions. The long-term stability of O plates was found to coincide with high levels of Ag and moderate Mg additions, with the latter limiting the competition with S-phase precipitation. Several alloys were found to be dominated by O precipitation, which remained stable through long-term isothermal and double-aging heat treatments. This enhanced thermal stability of O plates is a significant improvement over the previous generation of Al-Cu-Mg-Ag alloys in which O plates dissolved sacrificially at long aging times for moderate aging temperatures. The competitive microstructural

  16. Preliminary experience with precipitating hydrophobic injectable liquid in brain arteriovenous malformations

    PubMed Central

    Koçer, Naci; Hanımoğlu, Hakan; Batur, Şebnem; Kandemirli, Sedat Giray; Kızılkılıç, Osman; Sanus, Zihni; Öz, Büge; Işlak, Civan; Kaynar, Mehmet Yaşar

    2016-01-01

    Advancement in microcatheter design and emergence of new embolic agents offer better results in endovascular treatment of brain arteriovenous malformations (AVMs). Precipitating hydrophobic injectable liquid (PHIL) (Microvention) is a newly introduced dimethyl sulfoxide-based embolic agent for endovascular use. Herein, we present three patients who underwent endovascular treatment of brain AVMs with PHIL, followed by surgical resection. Endovascular features and same-day surgical handling of the new embolic agent PHIL are presented along with histopathologic changes in the acute stage in brain AVMs are presented, and its major differences from Onyx. In our series, PHIL had moderate inflammatory reaction in the acute stage without any associated angionecrosis that is different than Onyx which cause mild inflammatory reaction with angionecrosis. Smallest vessel containing PHIL was 2.9 μm compared to 5 μm with Onyx, which suggests better penetration. PMID:26782157

  17. Signal enhancement strategy for a micro-arrayed polydiacetylene (PDA) immunosensor using enzyme-catalyzed precipitation.

    PubMed

    Lee, Jong Uk; Jeong, Ji Hoon; Lee, Doo Sung; Sim, Sang Jun

    2014-11-15

    This paper describes a signal enhancement strategy to improve the sensitivity of an antibody-based immunosensor that uses polydiacetylene (PDA) liposomes to detect a target protein (human immunoglobulin E [hIgE]). To achieve ultrasensitive detection, multiple stimuli applied to PDA immunosensor chips offer a signal enhancement method that combines the primary immune reaction between antigen and antibody with the sandwich method of polyclonal antibody (pAb)-conjugated horseradish peroxidase (HRP). In the second step, fluorescence is enhanced by the mechanical pressure from the precipitate formed by enzyme catalysis. In order to detect hIgE, the surface of immobilized PDA liposomes was conjugated with monoclonal antibodies against hIgE, and fluorescence signals were detected after the antigen-antibody reaction. In this step, hIgE concentrations as low as 10 ng/mL were detected. Fluorescence signals slightly increased when anti-hIgE pAb-HRP was used as an amplifying agent after primary immunoresponse. After secondary immunoresponse, HRP-catalyzed oxidation of 3,3'-diaminobenzidine produced an insoluble precipitate that strongly stimulated PDA liposomes by their weight and pressure, thereby dramatically increasing the fluorescence signal. Thus, PDA liposome immunosensor could detect hIgE concentrations as low as 0.01 ng/mL, representing a 1000-fold increase in sensitivity over the signal generated by the primary immunoresponse. This study indicates that increasing the external mechanical force applied to PDA liposomes by enzyme-catalyzed precipitate formation enhanced the sensitivity of the PDA liposome immunosensor chip. This strategy can be applied to the detection of other biomolecules in experimental or clinical settings where ultrasensitive and highly specific biosensing is required. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Nucleation mediated interfacial precipitation for architectural perovskite films with enhanced photovoltaic performance.

    PubMed

    Yu, Yu; Yang, Songwang; Lei, Lei; Liu, Yan

    2017-02-16

    Perovskite films are a promising candidate for future highly efficient and low-cost solar cells. The long diffusion length of charge carriers in the perovskite film makes its architecture fabrication seem unnecessary, while the rapid crystallization process increases the difficulty in its architecture fabrication. Here we show the fabrication of perovskite architectures through a nucleation mediated interfacial precipitation method with the proper immiscible anti-solvent. Consecutively evolved architectures from tri-layer porous films to bilayer dense films are obtained. The interfacial precipitation provides the possibility of controlling the crystallization process of perovskite films, while the secondary nucleation is the origin of the porous architecture. The nucleation mediation can be a novel bottom-up approach to fabricate architectural perovskite films. The tri-layer architectural perovskite film exhibits excellent light absorption in the range of 500-800 nm and good photovoltaic performance with 8.2% enhancement in efficiency compared with the bilayer film for the corresponding solar cells.

  19. A novel catalyst of warm-cloud seeding to enhance precipitation

    NASA Astrophysics Data System (ADS)

    Zhu, H. X.; Li, X. D.; Yang, R. J.

    2016-07-01

    Water is necessary for sustaining human life. In many regions of the world, traditional water sources cannot meet increasing water demands. Warm-cloud seeding is an efficient way to augment water supplies. In this paper, we explore two new hygroscopicity catalysts: Poly acrylamide (PAM) and Sodium polyacrylate (PAAS). We designed a series of experiments to investigate the effects of these catalysts together with common catalyst salt powder (NaCl). The experiment was held in a cloud chamber built in our laboratory. The results show that: 1) Catalysed by NaCl, a dose of 0.91g/m3 can obtain the best precipitation efficiency and enhancement rate at 70.8% and 142%, respectively; 2) A 1.36g/m3 dose catalysed by PAM and PAAS exhibits optimal performance at 76.7% and 70.4% precipitation efficiency, respectively; 3) Under the same conditions, PAM shows better catalytic effects than NaCl does.

  20. Surface Display of Small Peptides on Escherichia coli for Enhanced Calcite Precipitation Rates.

    PubMed

    Patel, Tushar N; Park, Ah-Hyung Alissa; Banta, Scott

    2014-03-01

    Mineralization has emerged as a promising strategy for long-term carbon sequestration. These processes involve carbon dioxide hydration followed by mineral precipitation. We have explored the production of whole-cell biocatalysts engineered with carbonic anhydrase (CA) activity to accelerate the CO₂ hydration reaction. In this study, short polypeptides were displayed on the surface of E. coli cells and whole-cell biocatalysts containing periplasmically expressed CAs in an attempt to enhance calcite mineral formation. It was found that cells coexpressing recombinant periplasmic CA and surface-displayed GPA peptide (PEVPEGAFDTAI) outperformed other peptide-expressing biocatalysts evaluated in terms of the amount of precipitate formed, as well as the overall formation rate of solids. Cells expressing the Cab CA isoform (BLR-pCab) and Cam isoform (BLR-pCam) with the surface-displayed GPA peptide exhibited 36 and 59% improvements in precipitation amounts, as well as 18 and 60% improvements in overall formation rates, respectively, over similar biocatalysts without GPA expression. The biocatalyst with the best performance was BLR-pCam/GPA, which generated 0.15 g of CaCO₃, while BLR cells generated only 0.08 g of CaCO₃ under the same small batch reaction conditions. The BLR-pCam/GPA cells also exhibited the fastest formation rates, achieving the maximum change in solution turbidity after only 2.2 min, as opposed to 6.3 min for BLR cells. These results demonstrate that synthetic biology approaches can be used to create novel biocatalysts with the ability to enhance both catalysis and precipitation activities.

  1. Mass Divergence, Temperature and RH Anomalies in Regions of Enhanced Precipitation: Observations vs. GCMs

    NASA Astrophysics Data System (ADS)

    Mitovski, T.; Folkins, I.

    2008-12-01

    The purpose of our research is to compare diagnostics of modeled and observed vertical mass transport. The diagnostics are: dynamical (mass) divergence, temperature anomalies and RH anomaly regression in the regions of enhanced precipitation. The mass divergence provides an insight into the vertical mass transport. Here we are comparing the mass divergence estimated for 7 rings of stations for the rainy season to the same estimated from the third generation coupled global climate model (CGCM3-T63) and from the Geophysical Fluid Dynamics Laboratory Climate Model Version 2.1 (GFDL CM2.1) outputs. The second diagnostic comes from comparing observed to GCMs low level temperature anomalies. It is believed that the temperature anomalies are a result of mesoscale activity in the regions of enhanced precipitation [Folkins et al., 2007]. The low level cooling, a result of the stratiform heating mode [Mapes and Houze, 1995], is important for the excitation of small-scale gravity waves. The small-scale gravity waves contribute to the 'gregariousness' of deep convection by increasing the buoyancy of the neighbouring shallow cumuli [Mapes and Houze, 1993] and, consequently, the small-scale gravity waves create a positive feedback between existing deep convection and newborn shallow convective clouds. The last diagnostic is expressed through RH anomaly regression. The RH anomaly regressions are estimated for two days before and two days after maximum precipitation events from radiosondes and results are compared to regressions estimated from CGCM3 3-hourly output. Two distinct features are seen on the RH regression plot: growing cumuli clouds before the main event and a stratiform anvil after. In addition, there is also a 'pool' of dry mid-tropospheric air just after the maximum precipitation event which might be associated to mesoscale downdrafts.

  2. Forecasting Lake-Effect Precipitation in the Great Lakes Region Using NASA Enhanced-Satellite Data

    NASA Technical Reports Server (NTRS)

    Cipullo, Michelle; Molthan, Andrew; Shafer, Jackie; Case, Jonathan; Jedlovec, Gary

    2011-01-01

    Lake-effect precipitation is common in the Great Lakes region, particularly during the late fall and winter. The synoptic processes of lake-effect precipitation are well understood by operational forecasters, but individual forecast events still present a challenge. Locally run, high resolution models can assist the forecaster in identifying the onset and duration of precipitation, but model results are sensitive to initial conditions, particularly the assumed surface temperature of the Great Lakes. The NASA Short-term Prediction Research and Transition (SPoRT) Center has created a Great Lakes Surface Temperature (GLST) composite, which uses infrared estimates of water temperatures obtained from the MODIS instrument aboard the Aqua and Terra satellites, other coarser resolution infrared data when MODIS is not available, and ice cover maps produced by the NOAA Great Lakes Environmental Research Lab (GLERL). This product has been implemented into the Weather Research and Forecast (WRF) model Environmental Modeling System (WRF-EMS), used within forecast offices to run local, high resolution forecasts. The sensitivity of the model forecast to the GLST product was analyzed with a case study of the Lake Effect Storm Echinacea, which produced 10 to 12 inches of snowfall downwind of Lake Erie, and 8 to 18 inches downwind of Lake Ontario from 27-29 January 2010. This research compares a forecast using the default Great Lakes surface temperatures from the Real Time Global sea surface temperature (RTG SST), in the WRF-EMS model to the enhanced NASA SPoRT GLST product to study forecast impacts. Results from this case study show that the SPoRT GLST contained less ice cover over Lake Erie and generally cooler water temperatures over Lakes Erie and Ontario. Latent and sensible heat fluxes over Lake Ontario were decreased in the GLST product. The GLST product decreased the quantitative precipitation forecast (QPF), which can be correlated to the decrease in temperatures and heat

  3. Development and characterization of a scalable controlled precipitation process to enhance the dissolution of poorly water-soluble drugs.

    PubMed

    Rogers, True L; Gillespie, Ian B; Hitt, James E; Fransen, Kevin L; Crowl, Cindy A; Tucker, Christopher J; Kupperblatt, Gary B; Becker, Joe N; Wilson, Deb L; Todd, Clifford; Broomall, Charles F; Evans, Jonathan C; Elder, Edmund J

    2004-11-01

    Poorly water-soluble compounds are being found with increasing frequency among pharmacologically active new chemical entities, which is a major concern to the pharmaceutical industry. Some particle engineering technologies have been shown to enhance the dissolution of many promising new compounds that perform poorly in formulation and clinical studies (Rogers et. al., Drug Dev Ind Pharm 27:1003-1015). One novel technology, controlled precipitation, shows significant potential for enhancing the dissolution of poorly soluble compounds. In this study, controlled precipitation is introduced; and process variables, such as mixing zone temperature, are investigated. Finally, scale-up of controlled precipitation from milligram or gram to kilogram quantities is demonstrated. Dissolution enhancement capabilities were established using two poorly water-soluble model drugs, danazol and naproxen. Stabilized drug particles from controlled precipitation were compared to milled, physical blend, and bulk drug controls using particle size analysis (Coulter), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), dissolution testing (USP Apparatus 2), and residual solvent analysis. Stabilized nano- and microparticles were produced from controlled precipitation. XRD and SEM analyses confirmed that the drug particles were crystalline. Furthermore, the stabilized particles from controlled precipitation exhibited significantly enhanced dissolution properties. Residual solvent levels were below FDA limits. Controlled precipitation is a viable and scalable technology that can be used to enhance the dissolution of poorly water-soluble pharmaceutical compounds.

  4. Forecasting precipitation and temperatures at the island of Cyprus to enhance wetland management

    NASA Astrophysics Data System (ADS)

    Spanou, Georgios; Ioannou, Konstantinos K.; Iakovoglou, Valasia; Zaimes, George N.

    2014-08-01

    Droughts on the island of Cyprus are more frequently occurring during the last decades. This has and will have major impacts on natural resources, particularly on semi-aquatic and aquatic ecosystems. Wetlands are very important aquatic ecosystems with many functions and values, especially in semi-arid regions. The study area is the Wetland of the Larnanca Salt Lake that belongs to the Natura 2000 Network and the Ramsar Convention. It hosts thousands of migratory birds every year. Forecasting accurately the future climatic conditions of an area can greatly enhance the ability to provide the best possible managerial practices regarding a natural resource (e.g. wetland). These climate forecasts can provide significant information on future conditions of the Wetland of Larnaca Salt Lake, particularly when forecasting when and how long the drying conditions could last. In this study, an Artificial Neural Networks (ANN) was used as a tool for short term prediction of the precipitation in the study area. The methodology used two time series (temperature and precipitation) in order to train the ANN. Temperatures were used as the input variable to the ANN while precipitation was used as the output variables. The forecast was based on data from the period between 1993 and 2013. In order to estimate the accuracy of the produced results the correlation coefficient, the Root Mean Square Error (RMSE) and the Mean Absolute Percentage Error (MAPE) was correlated. Overall, this tool can help the responsible authorities of the wetland to manage it more efficiently.

  5. Preliminary Comparisons of the GPM Dual-Frequency Precipitation Radar to Ground Validation Radars of the GPM Validation Network

    NASA Astrophysics Data System (ADS)

    Morris, K. R.; Schwaller, M.

    2014-12-01

    The Global Precipitation Measurement (GPM) core satellite successfully launched in February, 2014, and is now providing precipitation observations from the Dual-Frequency Precipitation Radar (DPR) and GPM Microwave Imager (GMI). The GPM Validation Network (VN) provides unique, detailed information on the performance of the new DPR on GPM. The GPM VN collects GPM orbit subset data products and coincident ground radar observations, performs a unique spatial matching of the space and ground radar observations, and provides a set of software tools to analyze and visualize the matched data sets. For GPM, a DPR/GR comparison algorithmhas been developed that defines the common volumes in terms of the geometric intersection of DPR and GR rays, where smoothing of the DPR and GR data are minimized and no interpolation is performed. The primary GR data source for the VN is a collection of National Weather Service WSR-88D S-band, dual-polarization radars located primarily in the eastern and central United States. This paper will concentrate on the results of the space- and ground-radar comparisons, and present preliminary evaluations of the performance of the DPR Ku-band radar relative to the legacy TRMM Ku-band PR over the same times and locations. Both the direct measurements of radar reflectivity as well as derived measurements of rain rate from the space and ground radars will be compared, down to the scale of individual instrument measurements. Vertical profiles, site-specific time series, Probability Density Function, scatter plots, and other analyses of the comparison data will be shown. Results for both the Ku-band and Ka-band DPR radars will be presented. Visualizations of the volume-matched and original GPM and ground radar data that assist in the understanding of the DPR-GR volume matching and comparison methods and data coverage will be included. GPM DPR data are still in evaluation and algorithm refinement at the time of this writing and have not been released to

  6. Verification of Precipitation Enhancement due to Winter Orographic Cloud Seeding in the Payette River Basin of Western Idaho

    NASA Astrophysics Data System (ADS)

    Holbrook, V. P.; Kunkel, M. L.; Blestrud, D.

    2013-12-01

    The Idaho Power Company (IPCo) is a hydroelectric based utility serving eastern Oregon and most of southern Idaho. Snowpack is critical to IPCo operations and the company has invested in a winter orographic cloud seeding program for the Payette, Boise, and Upper Snake River basins to augment the snowpack. IPCo and the National Center for Atmospheric Research (NCAR) are in the middle of a two-year study to determine precipitation enhancement due to winter orographic cloud seeding in the Payette River basin. NCAR developed a cloud seeding module, as an enhancement to the Weather Research and Forecast (WRF) model, that inputs silver iodide released from both ground based and/or aircraft generators. The cloud seeding module then increases the precipitation as a function of the cloud seeding. The WRF model used for this program is run at the University of Arizona with a resolution of 1.8 kilometers using Thompson microphysics and Mellor-Yamada-Janic boundary layer scheme. Two different types of verification schemes to determine precipitation enhancement is being used for this program; model versus model and model versus precipitation gauges. In the model versus model method, a control model run uses NCAR developed criteria to identify the best times to operate cloud or airborne seeding generators and also establishes the baseline precipitation. The model is then rerun with the cloud seeding module turned on for the time periods determined by the control run. The precipitation enhancement due to cloud seeding is then the difference in precipitation between the control and seeding model runs. The second verification method is to use the model forecast precipitation in the seeded and non-seeded areas, compare against observed precipitation (from mainly SNOTEL gauges), and determine the precipitation enhancement due to cloud seeding. Up to 15 SNOTEL gauges in or near the Payette River basin along with 14 IPCo high resolution rain gauges will be used with this target

  7. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity

    USDA-ARS?s Scientific Manuscript database

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional dive...

  8. Enhanced interannual precipitation variability increases plant functional diversity that in turn ameliorates negative impact on productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-12-01

    Although precipitation interannual variability is projected to increase due to climate change, effects of changes in precipitation variance have received considerable less attention than effects of changes in the mean state of climate. Interannual precipitation variability effects on functional diversity and its consequences for ecosystem functioning are assessed here using a 6-year rainfall manipulation experiment. Five precipitation treatments were switched annually resulting in increased levels of precipitation variability while maintaining average precipitation constant. Functional diversity showed a positive response to increased variability due to increased evenness. Dominant grasses decreased and rare plant functional types increased in abundance because grasses showed a hump-shaped response to precipitation with a maximum around modal precipitation, whereas rare species peaked at high precipitation values. Increased functional diversity ameliorated negative effects of precipitation variability on primary production. Rare species buffered the effect of precipitation variability on the variability in total productivity because their variance decreases with increasing precipitation variance.

  9. Enhanced dissolution of megestrol acetate microcrystals prepared by antisolvent precipitation process using hydrophilic additives.

    PubMed

    Cho, Eunbi; Cho, Wonkyung; Cha, Kwang-Ho; Park, Junsung; Kim, Min-Soo; Kim, Jeong-Soo; Park, Hee Jun; Hwang, Sung-Joo

    2010-08-30

    Microcrystals of megestrol acetate (MA), a poorly water-soluble drug, were successfully prepared using an antisolvent precipitation technique for improving the dissolution rate. The effective hydrophilic polymers and surfactants used were screened for their abilities to produce smaller particle sizes. Raw micronized MA and processed MA microcrystals were ranked by the Student-Newman-Keuls test in order of increasing particle size and SPAN values as follows: processed MA microcrystals in the presence of polymer and surfactant (mean diameter 1048nm)enhanced as compared to that of the raw micronized MA. This effect is mainly due to a reduction in particle size resulting in an increased surface area. Therefore, it was concluded that the antisolvent precipitation technique in mild conditions could be a simple and useful technique to prepare poorly water-soluble drug particles with reduction in particle size, a narrow particle size distribution and enhanced dissolution properties. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Enhanced precipitation promotes decomposition and soil C stabilization in semiarid ecosystems, but seasonal timing of wetting matters

    USGS Publications Warehouse

    Campos, Xochi; Germino, Matthew; de Graaff, Marie-Anne

    2017-01-01

    AimsChanging precipitation regimes in semiarid ecosystems will affect the balance of soil carbon (C) input and release, but the net effect on soil C storage is unclear. We asked how changes in the amount and timing of precipitation affect litter decomposition, and soil C stabilization in semiarid ecosystems.MethodsThe study took place at a long-term (18 years) ecohydrology experiment located in Idaho. Precipitation treatments consisted of a doubling of annual precipitation (+200 mm) added either in the cold-dormant season or in the growing season. Experimental plots were planted with big sagebrush (Artemisia tridentata), or with crested wheatgrass (Agropyron cristatum). We quantified decomposition of sagebrush leaf litter, and we assessed organic soil C (SOC) in aggregates, and silt and clay fractions.ResultsWe found that: (1) increased precipitation applied in the growing season consistently enhanced decomposition rates relative to the ambient treatment, and (2) precipitation applied in the dormant season enhanced soil C stabilization.ConclusionsThese data indicate that prolonged increases in precipitation can promote soil C storage in semiarid ecosystems, but only if these increases happen at times of the year when conditions allow for precipitation to promote plant C inputs rates to soil.

  11. Effects of turbulence-induced collision enhancement on heavy precipitation: The 21 September 2010 case over the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Lee, Hyunho; Baik, Jong-Jin

    2016-10-01

    The effects of turbulence-induced collision enhancement (TICE) on a heavy precipitation event that occurred on 21 September 2010 over the middle Korean Peninsula are examined. For this purpose, an updated bin microphysics scheme incorporating TICE for drop-drop and drop-graupel collisions is implemented into the Weather Research and Forecasting (WRF) model. The numerical simulation shows some differences in the strong precipitation system compared to the observations but generally captures well the important features of observed synoptic conditions, surface precipitation, and radar reflectivity. While the change in domain-averaged surface precipitation amount due to TICE is small and similar to that due to small initial perturbations, the spatial distribution of surface precipitation amount is somewhat altered due to TICE. The surface precipitation amount is increased due to TICE in the area where the largest surface precipitation occurred, but the effects of different flow realizations also contribute to the changes. TICE accelerates the coalescence between small cloud droplets, which induces a decrease in condensation and an increase in excess water vapor transported upward. This causes an increase in relative humidity with respect to ice at high altitudes, hence increasing the depositional growth of ice particles. Therefore, the ice mass increases due to TICE, and this increase induces the increases in riming and melting of ice particles. A series of these microphysical changes due to TICE are regarded as partially contributing to the increase in surface precipitation amount in some areas, hence inducing alterations in the spatial distribution of surface precipitation amount.

  12. Enhancements to the Precipitation-Runoff Modeling System for simulating in-stream water temperature

    NASA Astrophysics Data System (ADS)

    Markstrom, S. L.; Hay, L.

    2010-12-01

    A stream temperature module has been developed for the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) for simulating maximum- and mean-daily stream temperature. This module provides additional simulation capabilities by coupling PRMS with the U.S. Geological Survey Stream Network Temperature (SNTEMP) model. PRMS is a modular, deterministic, distributed-parameter, physical-process watershed model that simulates watershed response to various combinations of climate and land use. Normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water-balance relations, streamflow regimes, soil-water relations, and ground-water recharge. SNTEMP was developed to help aquatic biologists and engineers predict the effects of flow regime changes on water temperatures. This coupling of PRMS with SNTEMP will allow scientists and watershed managers to evaluate the effects of historical climate and projected climate change, landscape evolution, and resource management scenarios on watershed hydrology and in-stream water temperature. The prototype of this coupled model was developed for the U.S. Geological Survey Southeast Regional Assessment Project (SERAP) and tested in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States. Preliminary results from the prototype are presented.

  13. Complex electrical monitoring of biopolymer and iron mineral precipitation for microbial enhanced hydrocarbon recovery

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Hubbard, C. G.; Dong, W.; Hubbard, S. S.

    2011-12-01

    Microbially enhanced hydrocarbon recovery (MEHR) mechanisms are expected to be impacted by processes and properties that occur over a wide range of scales, ranging from surface interactions and microbial metabolism at the submicron scale to changes in wettability and pore geometry at the pore scale to geological heterogeneities at the petroleum reservoir scale. To eventually ensure successful, production-scale implementation of laboratory-developed MEHR procedures under field conditions, it is necessary to develop approaches that can remotely monitor and accurately predict the complex microbially-facilitated transformations that are expected to occur during MEHR treatments in reservoirs (such as the evolution of redox profiles, oil viscosity or matrix porosity/permeability modifications). Our initial studies are focused on laboratory experiments to assess the geophysical signatures of MEHR-induced biogeochemical transformations, with an ultimate goal of using these approaches to monitor field treatments. Here, we explore the electrical signatures of two MEHR processes that are designed to produce end-products that will plug high permeability zones in reservoirs and thus enhance sweep efficiency. The MEHR experiments to induce biopolymers (in this case dextran) and iron mineral precipitates were conducted using flow-through columns. Leuconostoc mesenteroides, a facultative anaerobe, known to produce dextran from sucrose was used in the biopolymer experiments. Paused injection of sucrose, following inoculation and initial microbial attachment, was carried out on daily basis, allowing enough time for dextran production to occur based on batch experiment observations. Electrical data were collected on daily basis and fluid samples were extracted from the column for characterization. Changes in electrical signal were not observed during initial microbial inoculation. Increase of electrical resistivity and decrease of electrical phase response were observed during the

  14. Formulation and optimization of efavirenz nanosuspensions using the precipitation-ultrasonication technique for solubility enhancement.

    PubMed

    Taneja, Sakshi; Shilpi, Satish; Khatri, Kapil

    2016-05-01

    Efavirenz is a non-nucleoside reverse transcriptase inhibitor, and is classified as BCS Class II API. Its erratic oral absorption and poor bioavailability make it a potential candidate for being formulated as a nanosuspension. The objective of this study was to formulate efavirenz nanosuspensions employing the antisolvent precipitation-ultrasonication method, and to enhance its solubility by reducing particle size to the nanometer range. The effects of different process parameters were studied and optimized with respect to particle size and poly dispersity index (PDI). The optimized formulation was also subjected to lyophilization, to further increase the solubility and stability, and the technology is potentially suited to a range of poorly water-soluble compounds.

  15. Enhancing Local Climate Projections of Precipitation: Assets and Limitations of Quantile Mapping Techniques for Statistical Downscaling

    NASA Astrophysics Data System (ADS)

    Ivanov, Martin; Kotlarski, Sven; Schär, Christoph

    2015-04-01

    The Swiss CH2011 scenarios provide a portfolio of climate change scenarios for the region of Switzerland, specifically tailored for use in climate impact research. Although widely applied by a variety of end-users, these scenarios are subject to several limitations related to the underlying delta change methodology. Examples are difficulties to appropriately account for changes in the spatio-temporal variability of meteorological fields and for changes in extreme events. The recently launched ELAPSE project (Enhancing local and regional climate change projections for Switzerland) is connected to the EU COST Action VALUE (www.value-cost.eu) and aims at complementing CH2011 by further scenario products, including a bias-corrected version of daily scenarios at the site scale. For this purpose the well-established empirical quantile mapping (QM) methodology is employed. Here, daily temperature and precipitation output of 15 GCM-RCM model chains of the ENSEMBLES project is downscaled and bias-corrected to match observations at weather stations in Switzerland. We consider established QM techniques based on all empirical quantiles or linear interpolation between the empirical percentiles. In an attempt to improve the downscaling of extreme precipitation events, we also apply a parametric approximation of the daily precipitation distribution by a dynamically weighted mixture of a Gamma distribution for the bulk and a Pareto distribution for the right tail for the first time in the context of QM. All techniques are evaluated and intercompared in a cross-validation framework. The statistical downscaling substantially improves virtually all considered distributional and temporal characteristics as well as their spatial distribution. The empirical methods have in general very similar performances. The parametric method does not show an improvement over the empirical ones. Critical sites and seasons are highlighted and discussed. Special emphasis is placed on investigating the

  16. Enhancing the Effectiveness of Carbon Dioxide Flooding by Managing Asphaltene Precipitation

    SciTech Connect

    Deo, Milind D.

    2002-02-21

    Objectives of this project was to understand asphaltene precipitation in General and carbon dioxide induced precipitation in particular. To this effect, thermodynamic and kinetic experiments with the Rangely crude oil were conducted and thermodynamic and reservoir models were developed.

  17. Magnetic storm associated enhanced particle precipitation in the South Atlantic anomaly: Evidence from VLF phase measurements

    SciTech Connect

    Abdu, M.A.; Batista, I.S.; Piazza, L.R.; Massambani, O.

    1981-09-01

    Phase recordings at Atibaia, Brazil (23 /sup 0/S, 46 /sup 0/W), of 13.6 -kHz signal transmitted from Golfo Nuevo, Argentian (43 /sup 0/S, 65 /sup 0/W), a trajectory confined almost completely within the South Atlantic anomaly region, show significant perturbations, indicative of the lowering of the VLF reflection level, following the onset of magnetic disturbances. Simultaneous measurements of the E/sub s/ layer parameters f/sub t/E/sub s/ and f/sub b/E/sub s/ over Cachoeira Paulista (22 /sup 0/S, 45 /sup 0/W) also show enhancements, with some delay with respect to the magnetic disturbance onset, as was found in our earlier work (Batista and Abdu, 1977). These results show magnetic storm associated ionization enhancements taking place in a height region from approximately 110 km down to 70 km, which we interpret as having been produced by precipitation of high-energy charged particles in the South Atlantic magnetic anomaly. The results also suggest some degree of day to day variability in the abundance of metallic species and/or in the dynamics of the E region over this region.

  18. The enhancement of cosmic radio noise absorption due to hiss-driven energetic electron precipitation during substorms

    NASA Astrophysics Data System (ADS)

    Li, Haimeng; Yuan, Zhigang; Yu, Xiongdong; Huang, Shiyong; Wang, Dedong; Wang, Zhenzhen; Qiao, Zheng; Wygant, John R.

    2015-07-01

    The Van Allen probes, low-altitude NOAA satellite, MetOp satellite, and riometer are used to analyze variations of precipitating energetic electron fluxes and cosmic radio noise absorption (CNA) driven by plasmaspheric hiss with respect to geomagnetic activities. The hiss-driven energetic electron precipitations (at L ~ 4.7-5.3, magnetic local time (MLT) ~ 8-9) are observed during geomagnetic quiet condition and substorms, respectively. We find that the CNA detected by riometers increased very little in the hiss-driven event during quiet condition on 6 September 2012. The hiss-driven enhancement of riometer was still little during the first substorm on 30 September 2012. However, the absorption detected by the riometer largely increased, while the energies of the injected electrons became higher during the second substorm on 30 September 2012. The enhancement of CNA (ΔCNA) observed by the riometer and calculated with precipitating energetic electrons is in agreement during the second substorm, implying that the precipitating energetic electrons increase CNA to an obviously detectable level of the riometer during the second substorm on 30 September 2012. The conclusion is consistent with Rodger et al. (2012), which suggest that the higher level of ΔCNA prefers to occur in the substorms, because substorms may produce more intense energetic electron precipitation associated with electron injection. Furthermore, the combination of the observations and theory calculations also suggests that higher-energy electron (>55 keV) precipitation contributes more to the ΔCNA than the lower energy electron precipitation. In this paper, the higher-energy electron precipitation is related to lower frequency hiss.

  19. A nanoscale co-precipitation approach for property enhancement of Fe-base alloys.

    PubMed

    Zhang, Zhongwu; Liu, Chain Tsuan; Miller, Michael K; Wang, Xun-Li; Wen, Yuren; Fujita, Takeshi; Hirata, Akihiko; Chen, Mingwei; Chen, Guang; Chin, Bryan A

    2013-01-01

    Precipitate size and number density are two key factors for tailoring the mechanical behavior of nanoscale precipitate-hardened alloys. However, during thermal aging, the precipitate size and number density change, leading to either poor strength or high strength but significantly reduced ductility. Here we demonstrate, by producing nanoscale co-precipitates in composition-optimized multicomponent precipitation-hardened alloys, a unique approach to improve the stability of the alloy against thermal aging and hence the mechanical properties. Our study provides compelling experimental evidence that these nanoscale co-precipitates consist of a Cu-enriched bcc core partially encased by a B2-ordered Ni(Mn, Al) phase. This co-precipitate provides a more complex obstacle for dislocation movement due to atomic ordering together with interphases, resulting in a high yield strength alloy without sacrificing alloy ductility.

  20. A nanoscale co-precipitation approach for property enhancement of Fe-base alloys

    PubMed Central

    Zhang, Zhongwu; Liu, Chain Tsuan; Miller, Michael K.; Wang, Xun-Li; Wen, Yuren; Fujita, Takeshi; Hirata, Akihiko; Chen, Mingwei; Chen, Guang; Chin, Bryan A.

    2013-01-01

    Precipitate size and number density are two key factors for tailoring the mechanical behavior of nanoscale precipitate-hardened alloys. However, during thermal aging, the precipitate size and number density change, leading to either poor strength or high strength but significantly reduced ductility. Here we demonstrate, by producing nanoscale co-precipitates in composition-optimized multicomponent precipitation-hardened alloys, a unique approach to improve the stability of the alloy against thermal aging and hence the mechanical properties. Our study provides compelling experimental evidence that these nanoscale co-precipitates consist of a Cu-enriched bcc core partially encased by a B2-ordered Ni(Mn, Al) phase. This co-precipitate provides a more complex obstacle for dislocation movement due to atomic ordering together with interphases, resulting in a high yield strength alloy without sacrificing alloy ductility. PMID:23429646

  1. Impact of Enhanced Low-level Stratus on Simulated SSTs, Precipitation and the Circulation in the Tropical Atlantic Sector

    NASA Astrophysics Data System (ADS)

    Bader, J.; Eichhorn, A.

    2015-12-01

    Most coupled atmosphere-ocean general circulation models (AOGCMs) show a substantial warm bias in sea-surface temperatures (SSTs) in the eastern tropical Atlantic. The impact of enhanced low-level clouds on SST, precipitation and the circulation in the tropical Atlantic sector is tested. Therefore, we have conducted sensitivity experiments with the atmospheric model ECHAM6 and the coupled version of it (MPI-ESM1) in which we enhance the formation of low-level stratus at the inversion layer in the low troposphere. The impact of enhanced low-level clouds is compared to the standard version of the models. There is a direct cloud impact by reducing the incoming solar radiation at the surface. The reduced incoming solar radiation leads to a cooling of SSTs in the eastern tropical Atlantic in the coupled atmosphere-ocean model. This in turn causes not only locally rainfall reductions in oceanic precipitation but also a remote precipitation enhancement over north east Brazil. These precipitation changes are associated with changes in the equatorial wind-stress forcing. The impact of the wind stress changes on the equatorial zonal SST-gradient and the seasonal cycle is also analysed.

  2. Preliminary Evaluation of an Aviation Safety Thesaurus' Utility for Enhancing Automated Processing of Incident Reports

    NASA Technical Reports Server (NTRS)

    Barrientos, Francesca; Castle, Joseph; McIntosh, Dawn; Srivastava, Ashok

    2007-01-01

    This document presents a preliminary evaluation the utility of the FAA Safety Analytics Thesaurus (SAT) utility in enhancing automated document processing applications under development at NASA Ames Research Center (ARC). Current development efforts at ARC are described, including overviews of the statistical machine learning techniques that have been investigated. An analysis of opportunities for applying thesaurus knowledge to improving algorithm performance is then presented.

  3. The Disposition of Silver Released from Soviet Oblako Rockets in Precipitation during the Hall Suppression Experiment Grossversuch IV. Part I: Measurements of Background and a Preliminary Seeding Test.

    NASA Astrophysics Data System (ADS)

    Lacaux, J.-P.; Warburton, J. A.

    1980-07-01

    In association with Grossversuch IV, a program designed to test the Soviet hail suppression method by seeding clouds with AgI from Oblako rockets, a complementary program was conducted by l'Observatoire du Puy-de-Dôme and the Desert Research Institute to study the diffusion of the seeding material (AgI) in the clouds, based on the analysis of silver in precipitation. This program covered the summers of 1977 and 1978, and this paper describes the results of measurements of natural background silver concentrations in unseeded precipitation. It also describes a new automatic precipitation collector, five of which were first tested in the field in 1977. A more extensive network of 15 collectors was deployed during two months of the 1978 summer.Based on the analysis of 118 unseeded precipitation samples collected in 1977, the natural background concentration of silver was estimated as 0.9 × 1011 g mL1( = 0.6 × 1011 g mL1). Although the standard deviations overlap, the 1978 season results appear to indicate a lower background of 0.5 × 1011 g mL1 ( = 0.3 × 1011 g mL1), based on the analysis of 414 rain samples. The average value for the two seasons was 0.6 × 1011 g mL1 with a standard deviation of 0.5 × 1011 g mL1. These background concentrations were found to be independent of both the length of sampling period and the precipitation intensity, averaged over the sampling periods of the collectors.The background is sufficiently low to permit the detection of the presence of silver iodide emitted from the Soviet rockets in the precipitation. The preliminary results from one case study are presented to support this conclusion.

  4. Enhancing the Effectiveness of Carbon Dioxide Flooding by Managing Asphaltene Precipitation

    SciTech Connect

    Deo, M.D.

    2001-01-12

    The objective of this project was to identify conditions at which carbon dioxide induced precipitation occurred in crude oils. Establishing compositions of the relevant liquid and solid phases was planned. Other goals of the project were to determine if precipitation occurred in cores and to implement thermodynamic and compositional models to examine the phenomenon. Exploring kinetics of precipitation was also one of the project goals. Crude oil from the Rangely Field (eastern Colorado) was used as a prototype.

  5. Application of steel slag coated with sodium hydroxide to enhance precipitation-coagulation for phosphorus removal.

    PubMed

    Park, Taejun; Ampunan, Vanvimol; Maeng, Sungkyu; Chung, Eunhyea

    2017-01-01

    Phosphorus removal has been studied for decades to reduce the environmental impact of phosphorus in natural waterbodies. Slag has been applied for the phosphorus removal by several mechanisms. In this study, sodium hydroxide coating was applied on the slag surface to enhance the efficiency of precipitation-coagulation process. In the batch test, it was found that the capacity of the slag to maintain high pH decreases with increasing its exposure time to the aqueous solution. In the column test, the coarse-grained coated slag showed higher phosphorus removal efficiency than the fine-grained uncoated slag. The coated slag maintained pH higher than uncoated slag and, accordingly, the removal efficiency of phosphorus was higher. Especially, when pH was less than 8, the removal efficiency decreased significantly. However, coated slag provided an excess amount of aluminum and sodium. Thus, a return process to reuse aluminum and sodium as a coagulant was introduced. The return process yields longer lifespan of slag with higher phosphorus removal and lower concentration of cations in the effluent. With the return process, the phosphorus removal efficiency was kept higher than 60% until 150 bed volumes; meanwhile, the efficiency without return process became lower than 60% at 25 bed volumes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Fabrication of doxorubicin nanoparticles by controlled antisolvent precipitation for enhanced intracellular delivery.

    PubMed

    Tam, Yu Tong; To, Kenneth Kin Wah; Chow, Albert Hee Lum

    2016-03-01

    Over-expression of ATP-binding cassette transporters is one of the most important mechanisms responsible for multidrug resistance. Here, we aimed to develop a stable polymeric nanoparticle system by flash nanoprecipitation (FNP) for enhanced anticancer drug delivery into drug resistant cancer cells. As an antisolvent precipitation process, FNP works best for highly lipophilic solutes (logP>6). Thus we also aimed to evaluate the applicability of FNP to drugs with relatively low lipophilicity (logP=1-2). To this end, doxorubicin (DOX), an anthracycline anticancer agent and a P-gp substrate with a logP of 1.3, was selected as a model drug for the assessment. DOX was successfully incorporated into the amphiphilic diblock copolymer, polyethylene glycol-b-polylactic acid (PEG-b-PLA), by FNP using a four-stream multi-inlet vortex mixer. Optimization of key processing parameters and co-formulation with the co-stabilizer, polyvinylpyrrolidone, yielded highly stable, roughly spherical DOX-loaded PEG-b-PLA nanoparticles (DOX.NP) with mean particle size below 100nm, drug loading up to 14%, and drug encapsulation efficiency up to 49%. DOX.NP exhibited a pH-dependent drug release profile with higher cumulative release rate at acidic pHs. Surface analysis of DOX.NP by XPS revealed an absence of DOX on the particle surface, indicative of complete drug encapsulation. While there were no significant differences in cytotoxic effect on P-gp over-expressing LCC6/MDR cell line between DOX.NP and free DOX in buffered aqueous media, DOX.NP exhibited a considerably higher cellular uptake and intracellular retention after efflux. The apparent lack of cytotoxicity enhancement with DOX.NP may be attributable to its slow DOX release inside the cells.

  7. Enhancement of regional wet deposition estimates based on modeled precipitation inputs

    Treesearch

    James A. Lynch; Jeffery W. Grimm; Edward S. Corbett

    1996-01-01

    Application of a variety of two-dimensional interpolation algorithms to precipitation chemistry data gathered at scattered monitoring sites for the purpose of estimating precipitation- born ionic inputs for specific points or regions have failed to produce accurate estimates. The accuracy of these estimates is particularly poor in areas of high topographic relief....

  8. The HyMeX Special Observation Period in Central Italy: Precipitation Measurements, Retrieval Techniques and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Gatlin, Patrick; Wingo, Matt; Petersen, Walt; Marzano, Frank Silvio; Baldini, Luca; Picciotti, Errico; Colantonio, Matteo; Barbieri, Stefano; Di Fabio, Saverio; Montopoli, Mario; Roberto, Nicoletta; Adirosi, Elisa; Gorgucci, Eugenio; Anagnostou, Emmanoil N..; Ferretti, Rossella

    2013-01-01

    The Mediterranean area concentrates the major natural risks related to the water cycle, including heavy precipitation and flash-flooding during the fall season. The capability to predict such high-impact events remains weak because of the contribution of very fine-scale processes and their non-linear interactions with the larger scale processes. These societal and science issues motivate the HyMeX (Hydrological cycle in the Mediterranean Experiment, http://www.hymex.orgl) experimental programme. HyMeX aims at a better quantification and understanding of the water cycle in the Mediterranean with emphasis on intense events. The observation strategy of HyMEX is organized in a long-term (4 years) Enhanced Observation Periods (EOP) and short-term (2 months) Special Observation Periods (SOP). HyMEX has identified 3 main Mediterranean target areas: North-West (NW), Adriatic (A) and South-East (SE). Within each target area several hydrometeorological sites for heavy rainfall and flash flooding have been set up. The hydrometeorological sire in Central Italy (CI) is interested by both western and eastern fronts coming from the Atlantic Ocean and Siberia, respectively. Orographic precipitations play an important role due to the central Apennine range, which reaches nearly 3000 m (Gran Sasso peak). Moreover, convective systems commonly develop in CI during late summer and beginning of autumn, often causing localized hailstorms with cluster organized cells. Western fronts may heavily hit the Tiber basin crossing large urban areas (Rome), whereas eastern fronts can cause flash floods along the Adriatic coastline. Two major basins are involved within Cl region: Tiber basin (1000 km long) and its tributary Aniene and the Aterno-Pescara basin (300 km long). The first HyMeX SOP1.1 was carried out from Sept. till Nov. 2012 in the NW target area The Italian SOP1.1 was coordinated by the Centre of Excellence CETEMPS, University of L'Aquila, a city located in the CI heart. The CI area

  9. Exogenous N addition enhances the responses of gross primary productivity to individual precipitation events in a temperate grassland

    PubMed Central

    Guo, Qun; Hu, Zhong-min; Li, Sheng-gong; Yu, Gui-rui; Sun, Xiao-min; Li, Ling-hao; Liang, Nai-shen; Bai, Wen-ming

    2016-01-01

    Predicted future shifts in the magnitude and frequency (larger but fewer) of precipitation events and enhanced nitrogen (N) deposition may interact to affect grassland productivity, but the effects of N enrichment on the productivity response to individual precipitation events remain unclear. In this study, we quantified the effects of N addition on the response patterns of gross primary productivity (GPP) to individual precipitation events of different sizes (Psize) in a temperate grassland in China. The results showed that N enrichment significantly increased the time-integrated amount of GPP in response to an individual precipitation event (GPPtotal), and the N-induced stimulation of GPP increased with increasing Psize. N enrichment rarely affected the duration of the GPP response, but it significantly stimulated the maximum absolute GPP response. Higher foliar N content might play an important role in the N-induced stimulation of GPP. GPPtotal in both the N-addition and control treatments increased linearly with Psize with similar Psize intercepts (approximately 5 mm, indicating a similar lower Psize threshold to stimulate the GPP response) but had a steeper slope under N addition. Our work indicates that the projected larger precipitation events will stimulate grassland productivity, and this stimulation might be amplified by increasing N deposition. PMID:27264386

  10. Enhancing the ag precipitation by surface mechanical attrition treatment on Cu-Ag alloys

    NASA Astrophysics Data System (ADS)

    Liu, Jiabin; Zhang, Lehao; Liu, Jingjing; Huang, Liuyi; Gu, Hao; Fang, Youtong; Meng, Liang; Zhang, Jian

    2016-09-01

    The influence of surface mechanical attrition treatment (SMAT) on Ag precipitation in Cu-Ag alloys was investigated. Cu-6 wt% Ag was melt, cold rolled and solution treated to be Cu-Ag solid solution, which was either aged at 250 and 350 °C for 24 h directly or SMAT-ed before aging. Ag precipitates were hard be found in the directly aged Cu-Ag sample while they were observed clearly in the SMAT-ed counterpart at 250 °C. The Ag precipitates formed in the surface layer by SMAT are much coarser than those in the un-SMAT-ed sample. It is obvious that the precipitating behavior of Ag was promoted significantly by SMAT approach. A large number of defects were generated by SMAT and they were acting as fast atomic diffusion channels that facilitated the atomic diffusion of Ag.

  11. Wintertime Precipitation Enhancement Opportunities in the Great Dividing Range of Southeastern Australia.

    NASA Astrophysics Data System (ADS)

    Carter, Elizabeth Jean

    The field of weather modification began in 1946 when Dr. Irving Langmuir along with his assistant, Vincent Schefer, experimented with Dry Ice in a refrigerated chamber and created ice crystals. Today, weather modification is seen as a possible mechanism for increasing water supplies. Such modification projects pertain either directly to seeding or studying supercooled clouds in mountainous regions where water supply augmentation might be attempted. The Australian Winter Storms Experiment AWSE II was conducted during the winter of 1990 in the mountains of southeastern Australia and is the focus of this dissertation. This dissertation determines and explains the water budget and precipitation efficiency of winter mountain storms in southeastern Australia. Precipitation efficiency is a measure of how much precipitation a storm puts on the ground relative to how much condensed-phase water substance passes overhead. This dissertation took a unique approach to precipitation efficiency and studied it in a time-resolved manner. It was determined that during prefrontal ( overline{rm PE} = 0 to 65% in the upwind budget volume, overline{ rm PE} = 0.043 to 44% in the downwind budget volume) and postfrontal (overline {rm PE} = 5 to 50% in the upwind budget volume, overline{rm PE } = 9 to 70% in the downwind budget volume) periods the supercooled liquid water in the clouds is produced at a greater rate than it is removed by diffusion or accretion, suggesting that the natural precipitation process is not efficient and the clouds are then "seedable" (i.e., precipitation efficiency for these periods is low). Precipitation efficiency is a tool which enables one to compare its changes among and throughout storm stages but it is ultimately the amount, location and extent of the supercooled liquid water that determines whether or not a storm is seedable.

  12. New Products for Near Real-Time Enhanced Landslide Identification and Precipitation Monitoring

    NASA Astrophysics Data System (ADS)

    Roberts-Pierel, J.; Ahamed, A.; Fayne, J.; Rumsey, A.

    2015-12-01

    Nepal and the Himalayan region are hotspots for landslide activity due to mountainous topography, complex terrain, and monsoon rains. Current research in landslide modeling and detection generally requires high resolution imagery with software aided classification or manual digitization by analysts. These methods are plagued by low spatial and temporal accuracy. Addressing issues in conventional measurement, this study combined optical data from Landsat 8, a Digital Elevation Model (DEM) generated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and precipitation data from the Global Precipitation Measurement Mission (GPM) to create two products. The Sudden Landslide Identification Product (SLIP) uses Landsat 8 and the ASTER DEM to identify landslides in near real-time, and provides damage assessments by mapping landslides triggered by precipitation. Detecting Real-time Increased Precipitation (DRIP) monitors precipitation levels extracted from the GPM-IMERG 30-minute product to create alerts in near real-time when current rainfall levels exceed regional threshold values. After a landslide detection is made by SLIP, historical rainfall data from DRIP is analyzed to estimate a date for the detected landslide. Together, DRIP and SLIP will be used by local and regional organizations in Nepal such as the International Centre for Integrated Mountain Development (ICIMOD), as well as the international scientific community to protect lives, preserve infrastructure, and manage local ecosystems.

  13. Irradiation-enhanced α' precipitation in model FeCrAl alloys

    SciTech Connect

    Edmondson, Philip D.; Briggs, Samuel A.; Yamamoto, Yukinori; Howard, Richard H.; Sridharan, Kumar; Terrani, Kurt A.; Field, Kevin G.

    2016-02-17

    We have irradiated the model FeCrAl alloys with varying compositions (Fe(10–18)Cr(10–6)Al at.%) with a neutron at ~ 320 to damage levels of ~ 7 displacements per atom (dpa) to investigate the compositional influence on the formation of irradiation-induced Cr-rich α' precipitates using atom probe tomography. In all alloys, significant number densities of these precipitates were observed. Cluster compositions were investigated and it was found that the average cluster Cr content ranged between 51.1 and 62.5 at.% dependent on initial compositions. Furthermore, this is significantly lower than the Cr-content of α' in binary FeCr alloys. As a result, significant partitioning of the Al from the α' precipitates was also observed.

  14. Irradiation-enhanced α' precipitation in model FeCrAl alloys

    DOE PAGES

    Edmondson, Philip D.; Briggs, Samuel A.; Yamamoto, Yukinori; ...

    2016-02-17

    We have irradiated the model FeCrAl alloys with varying compositions (Fe(10–18)Cr(10–6)Al at.%) with a neutron at ~ 320 to damage levels of ~ 7 displacements per atom (dpa) to investigate the compositional influence on the formation of irradiation-induced Cr-rich α' precipitates using atom probe tomography. In all alloys, significant number densities of these precipitates were observed. Cluster compositions were investigated and it was found that the average cluster Cr content ranged between 51.1 and 62.5 at.% dependent on initial compositions. Furthermore, this is significantly lower than the Cr-content of α' in binary FeCr alloys. As a result, significant partitioning ofmore » the Al from the α' precipitates was also observed.« less

  15. Incorporation of adenovirus in calcium phosphate precipitates enhances gene transfer to airway epithelia in vitro and in vivo.

    PubMed Central

    Fasbender, A; Lee, J H; Walters, R W; Moninger, T O; Zabner, J; Welsh, M J

    1998-01-01

    Adenovirus (Ad)-mediated gene transfer to airway epithelia is inefficient because the apical membrane lacks the receptor activity to bind adenovirus fiber protein. Calcium phosphate (CaPi) precipitates have been used to deliver plasmid DNA to cultured cell lines. However, such precipitates are not effective in many primary cultures or in vivo. Here we show that incorporating recombinant adenovirus into a CaPi coprecipitate markedly enhances transgene expression in cells that are resistant to adenovirus infection. Enhancement requires that the virus be contained in the precipitate and viral proteins are required to increase expression. Ad: CaPi coprecipitates increase gene transfer by increasing fiber-independent binding of virus to cells. With differentiated cystic fibrosis (CF) airway epithelia in vitro, a 20-min application of Ad:CaPi coprecipitates that encode CF transmembrane conductance regulator produced as much CF transmembrane conductance regulator Cl- current as a 24-h application of adenovirus alone. We found that Ad:CaPi coprecipitates also increased transgene expression in mouse lung in vivo; importantly, expression was particularly prominent in airway epithelia. These results suggest a new mechanism for gene transfer that may be applicable to a number of different gene transfer applications and could be of value in gene transfer to CF airway epithelia in vivo. PMID:9649572

  16. Enhancing the Effectiveness of Carbon Dioxide Flooding by Managing Asphaltene Precipitation

    SciTech Connect

    Deo, Milind D.

    2002-02-21

    This project was undertaken to understand fundamental aspects of carbon dioxide (CO2) induced asphaltene precipitation. Oil and asphaltene samples from the Rangely field in Colorado were used for most of the project. The project consisted of pure component and high-pressure, thermodynamic experiments, thermodynamic modeling, kinetic experiments and modeling, targeted corefloods and compositional modeling.

  17. Plan and Some Results of "Advanced Study on Precipitation Enhancement in Arid and Semi-Arid Regions"

    NASA Astrophysics Data System (ADS)

    Murakami, M.

    2016-12-01

    There are several technologies to secure water resources, including the desalination of seawater, recycling of industrial water and reuse of wastewater. However precipitation enhancement is the only way we can create a large amount of water for industrial use, for example, water for irrigation, provided we find clouds suitable for cloud seeding and apply appropriate and effective methods to increase precipitation. Therefore, rain enhancement research is critical in the quest for new water security options and innovative solutions in the UAE and other arid and semi-arid regions. The main objective of our project is to better evaluate, and ultimately improve, the effectiveness of rain enhancement in the UAE and other arid and semi-arid regions using hygroscopic and glaciogenic seeding techniques. One of the major questions regarding rain enhancement today is the effectiveness of hygroscopic seeding for warm and supercooled convective clouds. Our research will investigate the microphysical processes in seeded and unseeded clouds using a combination of laboratory experiments, numerical simulations and in-situ aircraft measurements in order to decipher the mechanism responsible for precipitation augmentation due to hygroscopic seeding. In our research, major elements of cloud seeding, e.g., assessment of seedability, development of optimal seeding methods and evaluation of seeding effects, will be investigated in the most efficient and realistic way, within three years, using mainly the numerical models with the sophisticated seeding scheme, which is developed on a basis of laboratory experiments and then validated against in-situ and remote sensing observations. In addition to the research plan, the outcomes of the research projects, which will be made available to the public at the end of the project and benefit the broader society, is discussed.

  18. Column tests to enhance sulphide precipitation with liquid organic electron donators to remediate AMD-influenced groundwater

    NASA Astrophysics Data System (ADS)

    Bilek, Felix

    2006-03-01

    Dump groundwaters in the former East-German lignite-mining district are characterized by high amounts of ferrous iron and sulphate. Both the pyrite weathering products endanger the surface water quality when discharged into lakes. Only the precipitation of both contaminants in the subsurface can prevent the further contamination of surface waters. The two-step process of microbial catalyzed sulphate reduction and iron sulphide precipitation is limited by the low availability of natural organic substances as electron donators. Therefore, a new remediation technique is developed based on the injection of a liquid organic electron donator (methanol) into the contaminated aquifer. The saturated aquifer is used as a bioreactor, where iron monosulphides are precipitated in the groundwater-filled pore space. Column experiments were performed under natural pressure and temperature conditions with natural anoxic groundwater and original sediments to test the remediation technology. The test showed that a complete iron removal (4 mmol/l), even under rather acid conditions (pH 3.8), is possible after having established an active sulphate reducer population. The turnover of the added organic substance with sulphate is complete and the amount of the resulting sulphide controls the effluent pH. In addition, intensified microbial activity triggers the turnover of natural organic substances. Also, natural Fe(III) hydroxides react with the sulphide produced. Considering the long natural retention times (decades), artificially enhanced FeS precipitation is spontaneous, although it shows kinetic behaviour in the range of days. In light of the promising results, the development of a field scale application of this technique is considered to be necessary. It will have to focus on the improved precipitation control of the FeS in the subsurface.

  19. On the fall 2010 Enhancements of the Global Precipitation Climatology Centre's Data Sets

    NASA Astrophysics Data System (ADS)

    Becker, A. W.; Schneider, U.; Meyer-Christoffer, A.; Ziese, M.; Finger, P.; Rudolf, B.

    2010-12-01

    Precipitation is meanwhile a top listed parameter on the WMO GCOS list of 44 essential climate variables (ECV). This is easily justified by its crucial role to sustain any form of life on earth as major source of fresh water, its major impact on weather, climate, climate change and related issues of society’s adaption to the latter. Finally its occurrence is highly variable in space and time thus bearing the potential to trigger major flood and draught related disasters. Since its start in 1989 the Global precipitation Climatology Centre (GPCC) performs global analyses of monthly precipitation for the earth’s land-surface on the basis of in-situ measurements. The effort was inaugurated as part of the Global Precipitation Climatology Project of the WMO World Climate Research Program (WCRP). Meanwhile, the data set has continuously grown both in temporal coverage (original start of the evaluation period was 1986), as well as extent and quality of the underlying data base. The number of stations involved in the related data base has approximately doubled in the past 8 years by trespassing the 40, 60 and 80k thresholds in 2002, 2006 and 2010. Core data source of the GPCC analyses are the data from station networks operated by the National Meteorological Services worldwide; data deliveries have been received from ca. 190 countries. The GPCC integrates also other global precipitation data collections (i.e. FAO, CRU and GHCN), as well as regional data sets. Currently the Africa data set from S. Nicholson (Univ. Tallahassee) is integrated. As a result of these efforts the GPCC holds the worldwide largest and most comprehensive collection of precipitation data, which is continuously updated and extended. Due to the high spatial-temporal variability of precipitation, even its global analysis requires this high number of stations to provide for a sufficient density of measurement data on almost any place on the globe. The acquired data sets are pre-checked, reformatted

  20. Simulations of The Extreme Precipitation Event Enhanced by Sea Surface Temperature Anomaly over the Black Sea

    NASA Astrophysics Data System (ADS)

    Hakan Doǧan, Onur; Önol, Barış

    2016-04-01

    Istanbul Technical University, Aeronautics and Astronautics Faculty, Meteorological Engineering, Istanbul, Turkey In this study, we examined the extreme precipitation case over the Eastern Black Sea region of Turkey by using regional climate model, RegCM4. The flood caused by excessive rain in August 26, 2010 killed 12 people and the landslides in Rize province have damaged many buildings. The station based two days total precipitation exceeds 200 mm. One of the usual suspects for this extreme event is positive anomaly of sea surface temperature (SST) over the Black Sea where the significant warming trend is clear in the last three decades. In August 2010, the monthly mean SST is higher than 3 °C with respect to the period of 1981-2010. We designed three sensitivity simulations with RegCM4 to define the effects of the Black Sea as a moisture source. The simulation domain with 10-km horizontal resolution covers all the countries bordering the Black Sea and simulation period is defined for entire August 2010. It is also noted that the spatial variability of the precipitation produced by the reference simulation (Sim-0) is consistent with the TRMM data. In terms of analysis of the sensitivity to SST, we forced the simulations by subtracting 1 °C (Sim-1), 2 °C (Sim-2) and 3 °C (Sim-3) from the ERA-Interim 6-hourly SST data (considering only the Black Sea). The sensitivity simulations indicate that daily total precipitation for all these simulations gradually decreased based on the reference simulation (Sim-0). 3-hourly maximum precipitation rates for Sim-0, Sim-1, Sim-2 and Sim-3 are 32, 25, 13 and 10.5 mm respectively over the hotspot region. Despite the fact that the simulations signal points out the same direction, degradation of the precipitation intensity does not indicate the same magnitude for all simulations. It is revealed that 2 °C (Sim-2) threshold is critical for SST sensitivity. We also calculated the humidity differences from the simulation and these

  1. Cognitive enhancement therapy improves emotional intelligence in early course schizophrenia: preliminary effects.

    PubMed

    Eack, Shaun M; Hogarty, Gerard E; Greenwald, Deborah P; Hogarty, Susan S; Keshavan, Matcheri S

    2007-01-01

    This research examined the preliminary effects of Cognitive Enhancement Therapy (CET) on social cognition in early course schizophrenia, using an objective, performance-based measure of emotional intelligence. Individuals in the early course of schizophrenia were randomly assigned to either CET (n=18) or Enriched Supportive Therapy (n=20), and assessed at baseline and after 1 year of treatment with the Mayer-Salovey-Caruso Emotional Intelligence Test. A series of analyses of covariance showed highly significant (p=.005) and large (Cohen's d=.96) effects favoring CET for improving emotional intelligence, with the most pronounced improvements occurring in patients' ability to understand and manage their own and others' emotions. These findings lend preliminary support to the previously documented benefits of CET on social cognition in schizophrenia, and suggest that such benefits can be extended to patients in the early course of the illness.

  2. Cognitive Enhancement Therapy Improves Emotional Intelligence in Early Course Schizophrenia: Preliminary Effects

    PubMed Central

    Eack, Shaun M.; Hogarty, Gerard E.; Greenwald, Deborah P.; Hogarty, Susan S.; Keshavan, Matcheri S.

    2007-01-01

    This research examined the preliminary effects of Cognitive Enhancement Therapy (CET) on social cognition in early course schizophrenia, using an objective, performance-based measure of emotional intelligence. Individuals in the early course of schizophrenia were randomly assigned to either CET (n = 18) or Enriched Supportive Therapy (n = 20), and assessed at baseline and after one year of treatment with the Mayer-Salovey-Caruso Emotional Intelligence Test. A series of analyses of covariance showed highly significant (p = .005) and large (Cohen's d = .96) effects favoring CET for improving emotional intelligence, with the most pronounced improvements occurring in patients' ability to understand and manage their own and others' emotions. These findings lend preliminary support to the previously documented benefits of CET on social cognition in schizophrenia, and suggest that such benefits can be extended to patients in the early course of the illness (141 words). PMID:17055227

  3. Preliminary Laboratory Results on the Coalescence of Small Precipitation-Size Drops Falling Freely in a Refrigerated Environment.

    NASA Astrophysics Data System (ADS)

    Czys, Robert R.

    1994-11-01

    Results from laboratory observations of isolated collisions between small precipitation-size drops falling freely at terminal velocity in a refrigerated collision chamber are presented. The average radii of the size pair studied were 353 and 306 m. Air temperatures ranged from 20° to 15°C. Drop temperatures ranged from 20° to approximately 2°C. Experimentation revealed that the coalescence efficiency increased from approximately 42% for mean drop temperatures between 20° and 10°C to about 81% for mean drop temperatures between 10° and 2°C. A particularly interesting finding was an abrupt, rather than gradual, increase in coalescence efficiency at a mean drop temperature of about 10°C. A reduction in drop deformation during impact due to a substantial increase in viscosity with decreasing temperature is considered as a mechanism that can act to promote coalescence. The apparent abrupt increase in coalescence efficiency requires further investigation. The extent to which these results may be extended to collection processes in clouds remains uncertain because of the effect that reduced pressure can have on deformation through drop fall speed and interaction time and because the drops were not at thermal equilibrium. The results of this experiment point to the need for further investigation in which free-fall drop collisions are produced at thermal equilibrium and at lower pressures and suggest that precipitation processes involving drizzle and raindrops may be considerably more complicated than previously suggested by experiment.

  4. [Preliminary Investigation of the Amount, the Molecular Weight and the Activity of Polysaccharides from Chaenomeles Speciosa Fruits in Ethanol Fractional Precipitation].

    PubMed

    Tian, Bing-mei; Xie, Xiao-mei; Shen, Pan-pan; Yang, Mo; Zhang, Sheng-long; Tang, Qing-jiu

    2015-05-01

    Chaenomeles speciosa fruits were extracted using water. The extracts were precipitated with 20%~95% (φ) ethanol, respectively. The amount of total polysaccharide was measured with phenol-sulfuric acid method. A method using high-performance size-exclusion chromatography (HPSEC) equipped with multiangle laser-light-scattering photometry (MALLS) and differential refractometry (RI) was presented for determining the molecular weight and molecular weigh distribution. RAW264.7 macrophage were cultured and stimulated with the polysaccharides in vitro and the production of nitric oxide in the cells was determined by the Griess assay. The aim of the study is to determine the amount and the molecular weight of the polysaccharides from Chaenomeles speciosa fruits, and preliminary investigate the immunomodulatory activity, The study provided the basis datas for the further research of Chaenomeles speciosa fruits. , and provided a simple and system method for the research of natural polysaccharide. The ethanol fractional precipitation showed that the order of total polysaccharide content was 95%>80%>40% ≥60%>20%. The results indicated that most polysaccharide from Chaenomeles speciosa fruits might be precipitated when ethanol concentration was up to 95% (T) and the crude polysaccharide purity had risen from 35. 1% to 45. 0% when the concentration of ethanol increased from 20% to 95%. HPSEC-MALLS-RI system showed that all the polysaccharide samples had the similar compositions. They appeared three chromatographic peaks and the retention time were not apparently different. The Mw were 6. 570 X 10(4) g . mol-1 and 1. 393 X 10(4) g . mol-1 respectively, and one less than 10 000 which was failure to obtain accurate values. The molecular weight of the first two polysaccharide distribution index(Mw/Mn)were 1. 336 and 1. 639 respectively. The polysaccharide samples had not exhibited immunomodulatory activity assessed on the basis of nitric oxide production by RAW264. 7 macrophage

  5. Enhanced biomolecular detection based on localized surface plasmon resonance (LSPR) using enzyme-precipitation reaction.

    PubMed

    Lee, Seung-Woo; Ahn, Junhyoung; Kim, Min-Gon; Shin, Yong-Beom; Lee, Jae Jong; Lim, Ki-Pil; Kim, Ki-Bum

    2010-05-01

    An enzyme-catalyzed precipitation reaction was employed as a means to increase the change in the LSPR signal after intermolecular bindings between antigens and antibodies occurred on gold nanodot surfaces. The gold nanodot array with an diameter of 175 nm and a thickness of 20 nm was fabricated on a glass wafer using thermal nanoimprint lithography. The human interleukin (hIL) 5 antibody was immobilized on the gold nanodot, followed by binding of hIL 5 to the anti-hIL 5. Subsequently, a biotinylated anti-hIL 5 and a alkaline phosphatase conjugated with streptavidin were simultaneously introduced. A mixture of 5-bromo-4-chloro-3-indolyl phosphate p-toluidine (BCIP) and nitro blue tetrazolium (NBT) was then used for precipitation, which resulted from the biocatalytic reaction of the alkaline phosphatase on gold nanodot. The LSPR spectra were obtained after each binding process. Using this analysis, the enzyme-catalyzed precipitation reaction on gold nanodots was found to be effective in amplifying the change in the peak wavelength of LSPR after molecular bindings.

  6. Role of nanoscale precipitates on the enhanced magnetostriction of heat-treated galfenol (Fe1-xGax) alloys.

    PubMed

    Cao, H; Gehring, P M; Devreugd, C P; Rodriguez-Rivera, J A; Li, J; Viehland, D

    2009-03-27

    We report neutron diffuse scattering measurements on highly magnetostrictive Fe1-xGax alloys (0.14precipitates embedded in a long-range ordered, body-centered cubic matrix. A large peak splitting is observed at (300) for x=0.19, which indicates that the nanoprecipitates are not cubic and have a large elastic strain. This implies a structural origin for the enhanced magnetostriction.

  7. A preliminary study of filariasis related acute adenolymphangitis with special reference to precipitating factors and treatment modalities.

    PubMed

    Shenoy, R K; Sandhya, K; Suma, T K; Kumaraswami, V

    1995-06-01

    Episodic adenolymphangitis (ADL) is one of the important clinical manifestations of lymphatic filariasis. Recurrent ADLs contribute to the progress of the disease and also have important socioeconomic implications since they cause significant loss of man days. The present study was conducted in order to identify the precipitating factors responsible for ADL attacks and also to examine the different modalities of treatment. Sixty-five individuals with filariasis related ADL attacks, who are residents of Alleppey district (endemic for Brugia malayi) were studied. All efforts were taken to identify the precipitating factors for ADLs in these individuals. They were hospitalized for a period of five days or more. All of them received symptomatic antipyretic/antiinflammatory therapy and topical antibiotic/antifungal treatment of the affected limbs. They were then randomly allocated to one of the following four regimens: group I - symptomatic alone; group II - symptomatic plus antibiotics; group III - symptomatic followed by diethylcarbamazine citrate (DEC) and group IV - symptomatic plus antibiotic followed by DEC. Patients in groups III and IV received DEC every three months up to one year. There was a significant relationship between the number of ADL attacks and the grade of edema. Presence of focus of infection in the affected limb could be identified in 28 of the 65 patients. In the majority of patients (48) response to treatment was rapid (resolution in less than five days). Neither antibiotics nor DEC (given at intervals of three months) appeared to alter the frequency of ADL attacks. On the otherhand simple hygienic measures combined with good foot care and local antibiotic/antifungal cream application (where required), were effective in reducing the number of ADL attacks.

  8. Enhanced Preliminary Assessment Report: Fort Wingate Depot Activity Gallup, New Mexico

    DTIC Science & Technology

    1990-03-01

    Fort Wingate Depot Activity * Gallup, New Mexico I fMarch 1990 DTIC I il E-LEcTrEII JUN 12 1990U Is eQ prepared for U Commander U.S. Army Toxic and...Activity Gallup, New Mexico March 1990 prepared for Commander, U.S. Army Toxic and Hazardous Materials Agency, Aberdeen Proving Ground, Maryland 21010...Claslification) Enhanced Preliminary Assessment Report: Fort Wingate Depot Activity, Gallup, New Mexico 12. PERSONAL AUTHOR(S) 3a. TYPE OF REPORT 13b

  9. Precipitation regime shift enhanced the rain pulse effect on soil respiration in a semi-arid steppe.

    PubMed

    Yan, Liming; Chen, Shiping; Xia, Jianyang; Luo, Yiqi

    2014-01-01

    The effect of resource pulses, such as rainfall events, on soil respiration plays an important role in controlling grassland carbon balance, but how shifts in long-term precipitation regime regulate rain pulse effect on soil respiration is still unclear. We first quantified the influence of rainfall event on soil respiration based on a two-year (2006 and 2009) continuously measured soil respiration data set in a temperate steppe in northern China. In 2006 and 2009, soil carbon release induced by rainfall events contributed about 44.5% (83.3 g C m(-2)) and 39.6% (61.7 g C m(-2)) to the growing-season total soil respiration, respectively. The pulse effect of rainfall event on soil respiration can be accurately predicted by a water status index (WSI), which is the product of rainfall event size and the ratio between antecedent soil temperature to moisture at the depth of 10 cm (r2 = 0.92, P<0.001) through the growing season. It indicates the pulse effect can be enhanced by not only larger individual rainfall event, but also higher soil temperature/moisture ratio which is usually associated with longer dry spells. We then analyzed a long-term (1953-2009) precipitation record in the experimental area. We found both the extreme heavy rainfall events (>40 mm per event) and the long dry-spells (>5 days) during the growing seasons increased from 1953-2009. It suggests the shift in precipitation regime has increased the contribution of rain pulse effect to growing-season total soil respiration in this region. These findings highlight the importance of incorporating precipitation regime shift and its impacts on the rain pulse effect into the future predictions of grassland carbon cycle under climate change.

  10. Precipitation Regime Shift Enhanced the Rain Pulse Effect on Soil Respiration in a Semi-Arid Steppe

    PubMed Central

    Yan, Liming; Chen, Shiping; Xia, Jianyang; Luo, Yiqi

    2014-01-01

    The effect of resource pulses, such as rainfall events, on soil respiration plays an important role in controlling grassland carbon balance, but how shifts in long-term precipitation regime regulate rain pulse effect on soil respiration is still unclear. We first quantified the influence of rainfall event on soil respiration based on a two-year (2006 and 2009) continuously measured soil respiration data set in a temperate steppe in northern China. In 2006 and 2009, soil carbon release induced by rainfall events contributed about 44.5% (83.3 g C m−2) and 39.6% (61.7 g C m−2) to the growing-season total soil respiration, respectively. The pulse effect of rainfall event on soil respiration can be accurately predicted by a water status index (WSI), which is the product of rainfall event size and the ratio between antecedent soil temperature to moisture at the depth of 10 cm (r2 = 0.92, P<0.001) through the growing season. It indicates the pulse effect can be enhanced by not only larger individual rainfall event, but also higher soil temperature/moisture ratio which is usually associated with longer dry spells. We then analyzed a long-term (1953–2009) precipitation record in the experimental area. We found both the extreme heavy rainfall events (>40 mm per event) and the long dry-spells (>5 days) during the growing seasons increased from 1953–2009. It suggests the shift in precipitation regime has increased the contribution of rain pulse effect to growing-season total soil respiration in this region. These findings highlight the importance of incorporating precipitation regime shift and its impacts on the rain pulse effect into the future predictions of grassland carbon cycle under climate change. PMID:25093573

  11. STIMULATION OF MICROBIAL UREA HYDROLYSIS IN GROUNDWATER TO ENHANCE CALCITE PRECIPITATION

    SciTech Connect

    Yoshiko Fujita; Joanna L. Taylor; Tina L. Gresham; Mark E. Delwiche; Frederick S. Colwell; Travis McLing; Lynn Petzke; Robert W. Smith

    2008-04-01

    Sequential addition of molasses and urea was tested as a means of stimulating microbial urea hydrolysis in the Eastern Snake River Plain Aquifer in Idaho. Ureolysis is an integral component of a novel remediation approach for divalent trace metal and radionuclide contaminants in groundwater and associated geomedia, where the contaminants are immobilized by coprecipitation in calcite. The generation of carbonate alkalinity from ureolysis promotes calcite precipitation. In calcite-saturated aquifers, this represents a potential long-term contaminant sequestration mechanism. In a single well experiment, dilute molasses was injected three times over two weeks to promote overall microbial growth, followed by one urea injection. With molasses addition, total cell numbers in the groundwater increased one to two orders of magnitude. Estimated ureolysis rates in recovered groundwater samples increased from <0.1 nmol L-1 hr-1 to >25 nmol L-1 hr-1. A quantitative PCR assay for the bacterial ureC gene indicated that urease gene numbers increased up to 170 times above pre-injection levels. Following urea injection, calcite precipitates were recovered. Estimated values for an in situ first order ureolysis rate constant ranged from 0.016 to 0.057 day-1. The results are promising with respect to the potential to manipulate in situ biogeochemical processes to promote contaminant sequestration.

  12. Stimulation of microbial urea hydrolysis in groundwater to enhance calcite precipitation.

    PubMed

    Fujita, Yoshiko; Taylor, Joanna L; Gresham, Tina L T; Delwiche, Mark E; Colwell, Frederick S; Mcling, Travis L; Petzke, Lynn M; Smith, Robert W

    2008-04-15

    Addition of molasses and urea was tested as a means of stimulating microbial urea hydrolysis in the Eastern Snake River Plain Aquifer in Idaho. Ureolysis is an integral component of a novel remediation approach for divalent trace metal and radionuclide contaminants in groundwater and associated geomedia, where the contaminants are immobilized by coprecipitation in calcite. Generation of carbonate alkalinity from ureolysis promotes calcite precipitation. In calcite-saturated aquifers, this represents a potential long-term contaminant sequestration mechanism. In a single-well experiment, dilute molasses was injected three times over two weeks to promote overall microbial growth, followed by one urea injection. With molasses addition, total cell numbers in the groundwater increased 1-2 orders of magnitude. Estimated ureolysis rates in recovered groundwater samples increased from < 0.1 to > 25 nmol L(-1) hr(-1). A quantitative PCR assay for the bacterial ureC gene indicated that urease gene numbers increased up to 170 times above pre-injection levels. Following urea injection, calcite precipitates were recovered. Estimated values for an in situ first order ureolysis rate constant ranged from 0.016 to 0.057 d(-1). Although collateral impacts such as reduced permeability were observed, overall results indicated the viability of manipulating biogeochemical processes to promote contaminant sequestration.

  13. Harnessing a radiation inducible promoter of Deinococcus radiodurans for enhanced precipitation of uranium.

    PubMed

    Misra, Chitra Seetharam; Mukhopadhyaya, Rita; Apte, Shree Kumar

    2014-11-10

    Bioremediation is an attractive option for the treatment of radioactive waste. We provide a proof of principle for augmentation of uranium bioprecipitation using the radiation inducible promoter, Pssb from Deinococcus radiodurans. Recombinant cells of D. radiodurans carrying acid phosphatase gene, phoN under the regulation of Pssb when exposed to 7 kGy gamma radiation at two different dose rates of 56.8 Gy/min and 4 Gy/min, showed 8-9 fold increase in acid phosphatase activity. Highest whole cell PhoN activity was obtained after 2h in post irradiation recovery following 8 kGy of high dose rate radiation. Such cells showed faster removal of high concentrations of uranium than recombinant cells expressing PhoN under a radiation non-inducible deinococcal promoter, PgroESL and could precipitate uranium even after continuous exposure to 0.6 Gy/min gamma radiation for 10 days. Radiation induced recombinant D. radiodurans cells when lyophilized retained high levels of PhoN activity and precipitated uranium efficiently. These results highlight the importance of using a suitable promoter for removal of radionuclides from solution.

  14. Amplified electrochemical detection of a cancer biomarker by enhanced precipitation using horseradish peroxidase attached on carbon nanotubes.

    PubMed

    Akter, Rashida; Rahman, Md Aminur; Rhee, Choong Kyun

    2012-08-07

    An electrochemical nanoimmunosensor based on multiwall carbon nanotubes (MWCNTs)/gold nanoparticles (AuNPs) was developed for the amplified detection of prostate specific antigen (PSA). The amplified detection was achieved by the enhanced precipitation of 4-chloro-1-naphthol (CN) using a higher number of horseradish peroxidase (HRP) molecules attached on MWCNTs. The PSA nanoimmunosensor was fabricated by immobilizing a monoclonal anti-PSA antibody (anti-PSA) on the AuNP-attached thiolated MWCNT on a gold electrode. The sensor surface was characterized using scanning electron microscope, transmission electron microscope, quartz crystal microbalance, and electrochemical techniques. Cyclic and square wave voltammetric techniques were used to monitor the enhanced precipitation of CN that accumulated on the electrode surface and subsequent decrement in the electrode surface area by monitoring the reduction process of the Fe(CN)(6)(3-)/Fe(CN)(6)(4-) redox couple. Under the optimized experimental condition, the linear range and the detection limit of PSA immunosensor were determined to be 1.0 pg/mL to 10.0 ng/mL and 0.40 ± 0.03 pg/mL, respectively. The validity of the proposed method was compared with an enzyme-linked immunosorbent assay method in various PSA spiked human serum samples.

  15. Enhancement of solubility, antioxidant ability and bioavailability of taxifolin nanoparticles by liquid antisolvent precipitation technique.

    PubMed

    Zu, Yuangang; Wu, Weiwei; Zhao, Xiuhua; Li, Yong; Wang, Weiguo; Zhong, Chen; Zhang, Yin; Zhao, Xue

    2014-08-25

    Taxifolin is a kind of flavanonol, whose antioxidant ability is superior to that of ordinary flavonoids compounds owing to its special structure. However, its low bioavailability is a major obstacle for biomedical applications, so the experiment is designed to prepare taxifolin nanoparticles by liquid antisolvent precipitation (LAP) to improve its bioavailability. We selected ethanol as solvent, deionized water as antisolvent, and investigated primarily the type of surfactant and adding amount, drug concentration, volume ratio of antisolvent to solvent, precipitation temperature, dropping speed, stirring speed, stirring time factors affecting drug particles size. Results showed that the poloxamer 188 was selected as the surfactant and the particle size of taxifolin obviously reduced with the increase of the poloxamer 188 concentration, the drug concentration and the dropping speed from 0.08% to 0.45%, from 0.04 g/ml to 0.12 g/ml, from 1 ml/min to 5 ml/min, respectively, when the volume ratio of antisolvent to solvent increased from 2.5 to 20, the particle size of taxifolin first increased and then decreased, the influence of precipitation temperature, stirring speed, stirring time on particle size were not obvious, but along with the increase of mixing time, the drug solution would separate out crystallization. The optimum conditions were: the poloxamer 188 concentration was 0.25%, the drug concentration was 0.08 g/ml, the volume ratio of antisolvent to solvent was 10, the precipitation temperature was 25 °C, the dropping speed was 4 ml/min, the stirring speed was 800 r/min, the stirring time was 5 min. Taxifolin nanosuspension with a MPS of 24.6 nm was obtained under the optimum conditions. For getting taxifolin nanoparticles, the lyophilization method was chosen and correspondingly γ-cyclodextrin was selected as cryoprotectant from γ-cyclodextrin, mannitol, lactose, glucose. Then the properties of raw taxifolin and taxifolin nanoparticles were characterized by

  16. Enhancing elevated temperature strength of copper containing aluminium alloys by forming L12 Al3Zr precipitates and nucleating θ″ precipitates on them.

    PubMed

    Kumar Makineni, Surendra; Sugathan, Sandeep; Meher, Subhashish; Banerjee, Rajarshi; Bhattacharya, Saswata; Kumar, Subodh; Chattopadhyay, Kamanio

    2017-09-11

    Strengthening by precipitation of second phase is the guiding principle for the development of a host of high strength structural alloys, in particular, aluminium alloys for transportation sector. Higher efficiency and lower emission demands use of alloys at higher operating temperatures (200 °C-250 °C) and stresses, especially in applications for engine parts. Unfortunately, most of the precipitation hardened aluminium alloys that are currently available can withstand maximum temperatures ranging from 150-200 °C. This limit is set by the onset of the rapid coarsening of the precipitates and consequent loss of mechanical properties. In this communication, we present a new approach in designing an Al-based alloy through solid state precipitation route that provides a synergistic coupling of two different types of precipitates that has enabled us to develop coarsening resistant high-temperature alloys that are stable in the temperature range of 250-300 °C with strength in excess of 260 MPa at 250 °C.

  17. Soft-X-ray-enhanced electrostatic precipitation for protection against inhalable allergens, ultrafine particles, and microbial infections.

    PubMed

    Kettleson, Eric M; Schriewer, Jill M; Buller, R Mark L; Biswas, Pratim

    2013-02-01

    Protection of the human lung from infectious agents, allergens, and ultrafine particles is difficult with current technologies. High-efficiency particulate air (HEPA) filters remove airborne particles of >0.3 μm with 99.97% efficiency, but they are expensive to maintain. Electrostatic precipitation has been used as an inexpensive approach to remove large particles from airflows, but it has a collection efficiency minimum in the submicrometer size range, allowing for a penetration window for some allergens and ultrafine particles. Incorporating soft X-ray irradiation as an in situ component of the electrostatic precipitation process greatly improves capture efficiency of ultrafine particles. Here we demonstrate the removal and inactivation capabilities of soft-X-ray-enhanced electrostatic precipitation technology targeting infectious agents (Bacillus anthracis, Mycobacterium bovis BCG, and poxviruses), allergens, and ultrafine particles. Incorporation of in situ soft X-ray irradiation at low-intensity corona conditions resulted in (i) 2-fold to 9-fold increase in capture efficiency of 200- to 600-nm particles and (ii) a considerable delay in the mean day of death as well as lower overall mortality rates in ectromelia virus (ECTV) cohorts. At the high-intensity corona conditions, nearly complete protection from viral and bacterial respiratory infection was afforded to the murine models for all biological agents tested. When optimized for combined efficient particle removal with limited ozone production, this technology could be incorporated into stand-alone indoor air cleaners or scaled for installation in aircraft cabin, office, and residential heating, ventilating, and air-conditioning (HVAC) systems.

  18. Soft-X-Ray-Enhanced Electrostatic Precipitation for Protection against Inhalable Allergens, Ultrafine Particles, and Microbial Infections

    PubMed Central

    Kettleson, Eric M.; Schriewer, Jill M.; Buller, R. Mark L.

    2013-01-01

    Protection of the human lung from infectious agents, allergens, and ultrafine particles is difficult with current technologies. High-efficiency particulate air (HEPA) filters remove airborne particles of >0.3 μm with 99.97% efficiency, but they are expensive to maintain. Electrostatic precipitation has been used as an inexpensive approach to remove large particles from airflows, but it has a collection efficiency minimum in the submicrometer size range, allowing for a penetration window for some allergens and ultrafine particles. Incorporating soft X-ray irradiation as an in situ component of the electrostatic precipitation process greatly improves capture efficiency of ultrafine particles. Here we demonstrate the removal and inactivation capabilities of soft-X-ray-enhanced electrostatic precipitation technology targeting infectious agents (Bacillus anthracis, Mycobacterium bovis BCG, and poxviruses), allergens, and ultrafine particles. Incorporation of in situ soft X-ray irradiation at low-intensity corona conditions resulted in (i) 2-fold to 9-fold increase in capture efficiency of 200- to 600-nm particles and (ii) a considerable delay in the mean day of death as well as lower overall mortality rates in ectromelia virus (ECTV) cohorts. At the high-intensity corona conditions, nearly complete protection from viral and bacterial respiratory infection was afforded to the murine models for all biological agents tested. When optimized for combined efficient particle removal with limited ozone production, this technology could be incorporated into stand-alone indoor air cleaners or scaled for installation in aircraft cabin, office, and residential heating, ventilating, and air-conditioning (HVAC) systems. PMID:23263945

  19. Predictability of horizontal water vapor transport relative to precipitation: Enhancing situational awareness for forecasting western U.S. extreme precipitation and flooding

    USGS Publications Warehouse

    Lavers, David A.; Waliser, Duane E.; Ralph, F. Martin; Dettinger, Michael

    2016-01-01

    The western United States is vulnerable to socioeconomic disruption due to extreme winter precipitation and floods. Traditionally, forecasts of precipitation and river discharge provide the basis for preparations. Herein we show that earlier event awareness may be possible through use of horizontal water vapor transport (integrated vapor transport (IVT)) forecasts. Applying the potential predictability concept to the National Centers for Environmental Prediction global ensemble reforecasts, across 31 winters, IVT is found to be more predictable than precipitation. IVT ensemble forecasts with the smallest spreads (least forecast uncertainty) are associated with initiation states with anomalously high geopotential heights south of Alaska, a setup conducive for anticyclonic conditions and weak IVT into the western United States. IVT ensemble forecasts with the greatest spreads (most forecast uncertainty) have initiation states with anomalously low geopotential heights south of Alaska and correspond to atmospheric rivers. The greater IVT predictability could provide warnings of impending storminess with additional lead times for hydrometeorological applications.

  20. In Situ Analysis of a Silver Nanoparticle-Precipitating Shewanella Biofilm by Surface Enhanced Confocal Raman Microscopy

    PubMed Central

    Schkolnik, Gal; Schmidt, Matthias; Mazza, Marco G.; Harnisch, Falk; Musat, Niculina

    2015-01-01

    Shewanella oneidensis MR-1 is an electroactive bacterium, capable of reducing extracellular insoluble electron acceptors, making it important for both nutrient cycling in nature and microbial electrochemical technologies, such as microbial fuel cells and microbial electrosynthesis. When allowed to anaerobically colonize an Ag/AgCl solid interface, S. oneidensis has precipitated silver nanoparticles (AgNp), thus providing the means for a surface enhanced confocal Raman microscopy (SECRaM) investigation of its biofilm. The result is the in-situ chemical mapping of the biofilm as it developed over time, where the distribution of cytochromes, reduced and oxidized flavins, polysaccharides and phosphate in the undisturbed biofilm is monitored. Utilizing AgNp bio-produced by the bacteria colonizing the Ag/AgCl interface, we could perform SECRaM while avoiding the use of a patterned or roughened support or the introduction of noble metal salts and reducing agents. This new method will allow a spatially and temporally resolved chemical investigation not only of Shewanella biofilms at an insoluble electron acceptor, but also of other noble metal nanoparticle-precipitating bacteria in laboratory cultures or in complex microbial communities in their natural habitats. PMID:26709923

  1. Two- and Three-Dimensional Cloud-Resolving Model Simulations of the Mesoscale Enhancement of Surface Heat Fluxes by Precipitating Deep Convection.

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoqing; Guimond, Stephen

    2006-01-01

    Two-dimensional (2D) and three-dimensional (3D) cloud-resolving model (CRM) simulations are conducted to quantify the enhancement of surface sensible and latent heat fluxes by tropical precipitating cloud systems for 20 days (10 30 December 1992) during the Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE). The mesoscale enhancement appears to be analogous across both 2D and 3D CRMs, with the enhancement for the sensible heat flux accounting for 17% of the total flux for each model and the enhancement for the latent heat flux representing 18% and 16% of the total flux for 2D and 3D CRMs, respectively. The convection-induced gustiness is mainly responsible for the enhancement observed in each model simulation. The parameterization schemes of the mesoscale enhancement by the gustiness in terms of convective updraft, downdraft, and precipitation, respectively, are examined using each version of the CRM. The scheme utilizing the precipitation was found to yield the most desirable estimations of the mean fluxes with the smallest rms error. The results together with previous findings from other studies suggest that the mesoscale enhancement of surface heat fluxes by the precipitating deep convection is a subgrid process apparent across various CRMs and is imperative to incorporate into general circulation models (GCMs) for improved climate simulation.

  2. Documentation of a daily mean stream temperature module—An enhancement to the Precipitation-Runoff Modeling System

    USGS Publications Warehouse

    Sanders, Michael J.; Markstrom, Steven L.; Regan, R. Steven; Atkinson, R. Dwight

    2017-09-15

    A module for simulation of daily mean water temperature in a network of stream segments has been developed as an enhancement to the U.S. Geological Survey Precipitation Runoff Modeling System (PRMS). This new module is based on the U.S. Fish and Wildlife Service Stream Network Temperature model, a mechanistic, one-dimensional heat transport model. The new module is integrated in PRMS. Stream-water temperature simulation is activated by selection of the appropriate input flags in the PRMS Control File and by providing the necessary additional inputs in standard PRMS input files.This report includes a comprehensive discussion of the methods relevant to the stream temperature calculations and detailed instructions for model input preparation.

  3. Does GPM-based multi-satellite precipitation enhance rainfall estimates over Pakistan and Bolivia arid regions?

    NASA Astrophysics Data System (ADS)

    Hussain, Y.; Satgé, F.; Bonnet, M. P.; Pillco, R.; Molina, J.; Timouk, F.; Roig, H.; Martinez-Carvajal, H., Sr.; Gulraiz, A.

    2016-12-01

    Arid regions are sensitive to rainfall variations which are expressed in the form of flooding and droughts. Unfortunately, those regions are poorly monitored and high quality rainfall estimates are still needed. The Global Precipitation Measurement (GPM) mission released two new satellite rainfall products named Integrated Multisatellite Retrievals GPM (IMERG) and Global Satellite Mapping of Precipitation version 6 (GSMaP-v6) bringing the possibility of accurate rainfall monitoring over these countries. This study assessed both products at monthly scale over Pakistan considering dry and wet season over the 4 main climatic zones from 2014 to 2016. With similar climatic conditions, the Altiplano region of Bolivia is considered to quantify the influence of big lakes (Titicaca and Poopó) in rainfall estimates. For comparison, the widely used TRMM-Multisatellite Precipitation Analysis 3B43 (TMPA-3B43) version 7 is also involved in the analysis to observe the potential enhancement in rainfall estimate brought by GPM products. Rainfall estimates derived from 110 rain-gauges are used as reference to compare IMERG, GSMaP-v6 and TMPA-3B43 at the 0.1° and 0.25° spatial resolution. Over both regions, IMERG and GSMaP-v6 capture the spatial pattern of precipitation as well as TMPA-3B43. All products tend to over estimates rainfall over very arid regions. This feature is even more marked during dry season. However, during this season, both reference and estimated rainfall remain very low and do not impact seasonal water budget computation. On a general way, IMERG slightly outperforms TMPA-3B43 and GSMaP-v6 which provides the less accurate rainfall estimate. The TMPA-3B43 rainfall underestimation previously found over Lake Titicaca is still observed in IMERG estimates. However, GSMaP-v6 considerably decreases the underestimation providing the most accurate rainfall estimate over the lake. MOD11C3 Land Surface Temperature (LST) and ASTER Global Emissivity Dataset reveal strong

  4. Enhanced performance of electrostatic precipitators through chemical modification of particle resistivity and cohesion

    SciTech Connect

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J.

    1995-11-01

    Control of fine particles, including particulate air toxics, from utility boilers is required near-term by state and federal air regulations. Electrostatic precipitators (ESP) serve as the primary air pollution control device for the majority of coal-fired utility boilers in the Eastern and Midwestern united States. Cost-effective retrofit technologies for fine particle control, including flue gas conditioning, are needed for the large base of existing ESPs. Flue has conditioning is an attractive option because it requires minimal structural changes and lower capital costs. For flue gas conditioning to be effective for fine particle control, cohesive and particle agglomerating agents are needed to reduce reentrainment losses, since a large percentage of particulate emissions from well-performing ESPs are due to erosion, rapping, and non-rapping reentrainment. A related and somewhat ironic development is that emissions reductions of SO{sub 2} from utility boilers, as required by the Title IV acid rain program of the 1990 Clean Air Act amendments, has the potential to substantially increase particulate air toxics from existing ESPs. The switch to low-sulfur coals as an SO{sub 2} control strategy by many utilities has exacerbated ESP performance problems associated with high resistivity flyash. The use of flue gas conditioning has increased in the past several years to maintain adequate performance in ESPs which were not designed for high resistivity ash. However, commercially available flue gas conditioning systems, including NH{sub 3}/SO{sub 3} dual gas conditioning systems, have problems and inherent drawbacks which create a need for alternative conditioning agents. in particular, NH{sub 3}/SO{sub 3} systems can create odor and ash disposal problems due to ammonia outgassing. In addition, there are concerns over chemical handling safety and the potential for accidental releases.

  5. Delivery Order 9 enhanced preliminary assessment, Woodbridge Research Facility, Virginia. Final report, Dec 91-Mar 92

    SciTech Connect

    Shimko, R.G.; Turner, R.E.

    1992-03-01

    An enhanced preliminary assessment was conducted at Woodbridge Research Facility (WRF) in Woodbridge, Virginia. WRF is a 579-acre facility located 22 miles southeast of Washington, D.C. It is operated by Harry Diamond Laboratory (HDL) at Adelphi, Maryland for the U.S. Army Laboratory Command. Its mission is to support HDL in a variety of programs involving nuclear weapons effects and Army systems survivability. Based on information obtained during and subsequent to a site visit (18 through 20 September 1991), 27 areas requiring environmental evaluation (AREE) were identified, including landfills, a pistol range, oil-contaminated areas, waste handling areas, storage areas, test areas, underground storage tanks, transformers, oil/water separators, asbestos, drainage ditches and spill areas. This report presents a summary of findings for each AREE and recommendations for further action.

  6. Detect signals of interdecadal climate variations from an enhanced suite of reconstructed precipitation products since 1850 using the historical station data from Global Historical Climatology Network and the dynamical patterns derived from Global Precipitation Climatology Project

    NASA Astrophysics Data System (ADS)

    Shen, S. S.

    2015-12-01

    This presentation describes the detection of interdecadal climate signals in a newly reconstructed precipitation data from 1850-present. Examples are on precipitation signatures of East Asian Monsoon (EAM), Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillations (AMO). The new reconstruction dataset is an enhanced edition of a suite of global precipitation products reconstructed by Spectral Optimal Gridding of Precipitation Version 1.0 (SOGP 1.0). The maximum temporal coverage is 1850-present and the spatial coverage is quasi-global (75S, 75N). This enhanced version has three different temporal resolutions (5-day, monthly, and annual) and two different spatial resolutions (2.5 deg and 5.0 deg). It also has a friendly Graphical User Interface (GUI). SOGP uses a multivariate regression method using an empirical orthogonal function (EOF) expansion. The Global Precipitation Climatology Project (GPCP) precipitation data from 1981-20010 are used to calculate the EOFs. The Global Historical Climatology Network (GHCN) gridded data are used to calculate the regression coefficients for reconstructions. The sampling errors of the reconstruction are analyzed according to the number of EOF modes used in the reconstruction. Our reconstructed 1900-2011 time series of the global average annual precipitation shows a 0.024 (mm/day)/100a trend, which is very close to the trend derived from the mean of 25 models of the CMIP5 (Coupled Model Intercomparison Project Phase 5). Our reconstruction has been validated by GPCP data after 1979. Our reconstruction successfully displays the 1877 El Nino (see the attached figure), which is considered a validation before 1900. Our precipitation products are publically available online, including digital data, precipitation animations, computer codes, readme files, and the user manual. This work is a joint effort of San Diego State University (Sam Shen, Gregori Clarke, Christian Junjinger, Nancy Tafolla, Barbara Sperberg, and

  7. Plasmonically enhanced Faraday effect in metal and ferrite nanoparticles composite precipitated inside glass.

    PubMed

    Nakashima, Seisuke; Sugioka, Koji; Tanaka, Katsuhisa; Shimizu, Masahiro; Shimotsuma, Yasuhiko; Miura, Kiyotaka; Midorikawa, Katsumi; Mukai, Kohki

    2012-12-17

    Using femtosecond laser irradiation and subsequent annealing, nanocomposite structures composed of spinel-type ferrimagnetic nanoparticles (NPs) and plasmonic metallic NPs have been formed space-selectively within glass doped with both α-Fe(2)O(3) and Al. The Faraday rotation spectra exhibit a distinct negative peak at around 400 nm, suggesting that the ferrimagnetic Faraday response is enhanced by the localized surface plasmon resonance (LSPR) due to metallic Al NPs. At the interfaces in the nanocomposites, the ferrimagnetism of magnetite NPs is directly coupled with the plasmon in the Al NPs. The control of the resonance wavelength of the magneto-optical peaks, namely, the size of plasmonic NPs has been demonstrated by changing the irradiation or annealing conditions.

  8. Competitive removal of Cu-EDTA and Ni-EDTA via microwave-enhanced Fenton oxidation with hydroxide precipitation.

    PubMed

    Lin, Qintie; Pan, Hanping; Yao, Kun; Pan, Yonggang; Long, Wei

    2015-01-01

    Ethylenediaminetetraacetic acid (EDTA) can form very stable complexes with heavy metal ions, greatly inhibiting conventional metal-removal technologies used in water treatment. Both the oxidation of EDTA and the reduction of metal ions in metal-EDTA systems via the microwave-enhanced Fenton reaction followed by hydroxide precipitation were investigated. The Cu(II)-Ni(II)-EDTA, Cu(II)-EDTA and Ni(II)-EDTA exhibited widely different decomplexation efficiencies under equivalent conditions. When the reaction reached equilibrium, the chemical oxygen demand was reduced by a microwave-enhanced Fenton reaction in different systems and the reduction order from high to low was Cu(II)-Ni(II)-EDTA ≈ Cu(II)-EDTA > Ni(II)-EDTA. The removal efficiencies of both Cu(2+) and Ni(2+) in Cu-Ni-EDTA wastewaters were much higher than those in a single heavy metal system. The degradation efficiency of EDTA in Cu-Ni-EDTA was lower than that in a single metal system. In the Cu-Ni-EDTA system, the microwave thermal degradation and the Fenton-like reaction created by Cu catalyzed H2O2 altered the EDTA degradation pathway and increased the pH of the wastewater system, conversely inhibiting residual EDTA degradation.

  9. Seeding Experiment of Liquid Carbon Dioxide for Enhancing Winter-time Precipitation in Saga Prefecture,Northern Kyushu,Japan

    NASA Astrophysics Data System (ADS)

    Wakimizu, K.; Nishiyama, K.; Tomine, K.; Maki, T.; Suzuki, Y.; Morita, O.

    2012-12-01

    ice perticles formed by LC seeding grew to the precipitable size and resultant snowfall was detected by radar in approximately 120 min. after seeding operation. In this study, based on these observed facts, optimum design for enhancing winter-time water resources by LC seeding method was suggested. Successive low-level horizontal penetrations of operational aircraft with seeding LC into many moving super-cooled cumuli towards the Japan Islands will lead to the spreading of cloud volume and subsequent coversion of large amount of iv active cloud volume into newly exploited artificial precipitation. As a result, these experiments succeeded, and the total amount of estimated radar precipitation of the be able to secure a large amount of water resource from these experiment results.

  10. Preliminary studies of enhanced contrast radiography in anatomy and embryology of insects with Elettra synchrotron light

    NASA Astrophysics Data System (ADS)

    Hönnicke, M. G.; Foerster, L. A.; Navarro-Silva, M. A.; Menk, R.-H.; Rigon, L.; Cusatis, C.

    2005-08-01

    Enhanced contrast X-ray imaging is achieved by exploiting the real part of the refraction index, which is responsible for the phase shifts, in addition to the imaginary part, which is responsible for the absorption. Such techniques are called X-ray phase contrast imaging. An analyzer-based X-ray phase contrast imaging set-up with Diffraction Enhanced Imaging processing (DEI) were used for preliminary studies in anatomy and embryology of insects. Parasitized stinkbug and moth eggs used as control agents of pests in vegetables and adult stinkbugs and mosquitoes ( Aedes aegypti) were used as samples. The experimental setup was mounted in the SYRMEP beamline at ELETTRA. Images were obtained using a high spatial resolution CCD detector (pixel size 14×14 μm 2) coupled with magnifying optics. Analyzer-based X-ray phase contrast images (PCI) and edge detection images show contrast and details not observed with conventional synchrotron radiography and open the possibility for future study in the embryonic development of insects.

  11. Levodopa enhances explicit new-word learning in healthy adults: a preliminary study.

    PubMed

    Shellshear, Leanne; MacDonald, Anna D; Mahoney, Jeffrey; Finch, Emma; McMahon, Katie; Silburn, Peter; Nathan, Pradeep J; Copland, David A

    2015-09-01

    While the role of dopamine in modulating executive function, working memory and associative learning has been established; its role in word learning and language processing more generally is not clear. This preliminary study investigated the impact of increased synaptic dopamine levels on new-word learning ability in healthy young adults using an explicit learning paradigm. A double-blind, placebo-controlled, between-groups design was used. Participants completed five learning sessions over 1 week with levodopa or placebo administered at each session (five doses, 100 mg). Each session involved a study phase followed by a test phase. Test phases involved recall and recognition tests of the new (non-word) names previously paired with unfamiliar objects (half with semantic descriptions) during the study phase. The levodopa group showed superior recall accuracy for new words over five learning sessions compared with the placebo group and better recognition accuracy at a 1-month follow-up for words learnt with a semantic description. These findings suggest that dopamine boosts initial lexical acquisition and enhances longer-term consolidation of words learnt with semantic information, consistent with dopaminergic enhancement of semantic salience. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Implementation of an enhanced probation program: evaluating process and preliminary outcomes.

    PubMed

    Shannon, Lisa M; Hulbig, Shelia K; Birdwhistell, Shira; Newell, Jennifer; Neal, Connie

    2015-04-01

    Supervision, Monitoring, Accountability, Responsibility, and Treatment (SMART) is Kentucky's enhanced probation pilot program modeled after Hawaii's Opportunity Probation with Enforcement (HOPE). SMART is proposed to decrease substance use, new violations, and incarceration-related costs for high-risk probationers by increasing and randomizing drug testing, intensifying supervision, and creating linkages with needed resources (i.e., mental health and substance use). SMART adopts a holistic approach to rehabilitation by addressing mental health and substance abuse needs as well as life skills for fostering deterrence of criminal behavior vs. punitive action only. A mixed methods evaluation was implemented to assess program implementation and effectiveness. Qualitative interviews with key stakeholders (i.e., administration, judges, attorneys, and law enforcement/corrections) suggested successful implementation and collaboration to facilitate the pilot program. Quantitative analyses of secondary Kentucky Offender Management System (KOMS) data (grant Year 1: 07/01/2012-06/30/2013) also suggested program effectiveness. Specifically, SMART probationers showed significantly fewer: violations of probation (1.2 vs. 2.3), positive drug screens (8.6% vs. 29.4%), and days incarcerated (32.5 vs. 118.1) than comparison probationers. Kentucky's SMART enhanced probation shows preliminary success in reducing violations, substance use, and incarceration. Implications for practice and policy will be discussed.

  13. SolarOil Project, Phase I preliminary design report. [Solar Thermal Enhanced Oil Recovery project

    SciTech Connect

    Baccaglini, G.; Bass, J.; Neill, J.; Nicolayeff, V.; Openshaw, F.

    1980-03-01

    The preliminary design of the Solar Thermal Enhanced Oil Recovery (SolarOil) Plant is described in this document. This plant is designed to demonstrate that using solar thermal energy is technically feasible and economically viable in enhanced oil recovery (EOR). The SolarOil Plant uses the fixed mirror solar concentrator (FMSC) to heat high thermal capacity oil (MCS-2046) to 322/sup 0/C (611/sup 0/F). The hot fluid is pumped from a hot oil storage tank (20 min capacity) through a once-through steam generator which produces 4.8 MPa (700 psi) steam at 80% quality. The plant net output, averaged over 24 hr/day for 365 days/yr, is equivalent to that of a 2.4 MW (8.33 x 10/sup 6/ Btu/hr) oil-fired steam generator having an 86% availability. The net plant efficiency is 57.3% at equinox noon, a 30%/yr average. The plant will be demonstrated at an oilfield site near Oildale, California.

  14. Drivers and mechanisms for enhanced summer monsoon precipitation over East Asia during the mid-Pliocene in the IPSL-CM5A

    NASA Astrophysics Data System (ADS)

    Sun, Yong; Zhou, Tianjun; Ramstein, Gilles; Contoux, Camille; Zhang, Zhongshi

    2016-03-01

    A comparative analysis of East Asian summer monsoon (EASM) precipitation is performed to reveal the drivers and mechanisms controlling the similarities of the mid-Pliocene EASM precipitation changes compared to the corresponding pre-industrial (PI) experiments derived from atmosphere-only (i.e. AGCM) and fully coupled (i.e. CGCM) simulations, as well as the large simulated differences in the mid-Pliocene EASM precipitation between the two simulations. The area-averaged precipitation over the EASM domain is enhanced in the mid-Pliocene compared to the corresponding PI experiments performed by both the AGCM (LMDZ5A) and the CGCM (IPSL-CM5A). Moisture budget analysis reveals that it is the surface warming over East Asia that drives the area-averaged EASM precipitation increase in the mid-Pliocene in both simulations. The surface warming increases the atmospheric moisture content, as revealed by an increase in the thermodynamic component of vertical moisture advection, resulting in enhanced mid-Pliocene EASM precipitation compared to PI in both simulations. Moist static energy diagnosis identifies the combined effect of enhanced zonal thermal contrast and column-integrated meridional stationary eddy velocity overline{{v^{*} }} and its convergence {overline{{partial v^{*} }} }/partial y as the physical mechanisms that sustain the enhancement of mid-Pliocene EASM precipitation in both simulations compared to the PI experiments. This takes place through a strengthening of the EASM circulation and moisture transport into the EASM domain associated with an increase in local moisture convergence in the mid-Pliocene in both simulations. Moisture budget analysis also reveals that the larger area-averaged mid-Pliocene EASM precipitation increase in the CGCM compared to its AGCM component is mainly caused by the dynamical component contributing more to the vertical moisture advection in the CGCM (i.e. IPSL-CM5A) compared to its AGCM (LMDZ5). The large simulated differences in

  15. Effects of experimentally-enhanced precipitation and nitrogen on resistance, recovery and resilience of a semi-arid grassland after drought.

    PubMed

    Xu, Zhuwen; Ren, Haiyan; Cai, Jiangping; Wang, Ruzhen; Li, Mai-He; Wan, Shiqiang; Han, Xingguo; Lewis, Bernard J; Jiang, Yong

    2014-12-01

    Resistance, recovery and resilience are three important properties of ecological stability, but they have rarely been studied in semi-arid grasslands under global change. We analyzed data from a field experiment conducted in a native grassland in northern China to explore the effects of experimentally enhanced precipitation and N deposition on both absolute and relative measures of community resistance, recovery and resilience--calculated in terms of community cover--after a natural drought. For both absolute and relative measures, communities with precipitation enhancement showed higher resistance and lower recovery, but no change in resilience compared to communities with ambient precipitation in the semi-arid grassland. The manipulated increase in N deposition had little effect on these community stability metrics except for decreased community resistance. The response patterns of these stability metrics to alterations in precipitation and N are generally consistent at community, functional group and species levels. Contrary to our expectations, structural equation modeling revealed that water-driven community resistance and recovery result mainly from changes in community species asynchrony rather than species diversity in the semi-arid grassland. These findings suggest that changes in precipitation regimes may have significant impacts on the response of water-limited ecosystems to drought stress under global change scenarios.

  16. Response of aboveground carbon balance to long-term, experimental enhancements in precipitation seasonality is contingent on plant community type in cold-desert rangelands.

    PubMed

    McAbee, Kathryn; Reinhardt, Keith; Germino, Matthew J; Bosworth, Andrew

    2017-03-01

    Semi-arid rangelands are important carbon (C) pools at global scales. However, the degree of net C storage or release in water-limited systems is a function of precipitation amount and timing, as well as plant community composition. In northern latitudes of western North America, C storage in cold-desert ecosystems could increase with boosts in wintertime precipitation, in which climate models predict, due to increases in wintertime soil water storage that enhance summertime productivity. However, there are few long-term, manipulative field-based studies investigating how rangelands will respond to altered precipitation amount or timing. We measured aboveground C pools and fluxes at leaf, soil, and ecosystem scales over a single growing season in plots that had 200 mm of supplemental precipitation added in either winter or summer for the past 21 years, in shrub- and exotic-bunchgrass-dominated garden plots. At our cold-desert site (298 mm precipitation during the study year), we hypothesized that increased winter precipitation would stimulate the aboveground C uptake and storage relative to ambient conditions, especially in plots containing shrubs. Our hypotheses were generally supported: ecosystem C uptake and long-term biomass accumulation were greater in winter- and summer-irrigated plots compared to control plots in both vegetation communities. However, substantial increases in the aboveground biomass occurred only in winter-irrigated plots that contained shrubs. Our findings suggest that increases in winter precipitation will enhance C storage of this widespread ecosystem, and moreso in shrub- compared to grass-dominated communities.

  17. Response of aboveground carbon balance to long-term, experimental enhancements in precipitation seasonality is contingent on plant community type in cold-desert rangelands

    USGS Publications Warehouse

    McAbee, Kathryn; Reinhardt, Keith; Germino, Matthew; Bosworth, Andrew

    2017-01-01

    Semi-arid rangelands are important carbon (C) pools at global scales. However, the degree of net C storage or release in water-limited systems is a function of precipitation amount and timing, as well as plant community composition. In northern latitudes of western North America, C storage in cold-desert ecosystems could increase with boosts in wintertime precipitation, in which climate models predict, due to increases in wintertime soil water storage that enhance summertime productivity. However, there are few long-term, manipulative field-based studies investigating how rangelands will respond to altered precipitation amount or timing. We measured aboveground C pools and fluxes at leaf, soil, and ecosystem scales over a single growing season in plots that had 200 mm of supplemental precipitation added in either winter or summer for the past 21 years, in shrub- and exotic-bunchgrass-dominated garden plots. At our cold-desert site (298 mm precipitation during the study year), we hypothesized that increased winter precipitation would stimulate the aboveground C uptake and storage relative to ambient conditions, especially in plots containing shrubs. Our hypotheses were generally supported: ecosystem C uptake and long-term biomass accumulation were greater in winter- and summer-irrigated plots compared to control plots in both vegetation communities. However, substantial increases in the aboveground biomass occurred only in winter-irrigated plots that contained shrubs. Our findings suggest that increases in winter precipitation will enhance C storage of this widespread ecosystem, and moreso in shrub- compared to grass-dominated communities.

  18. State of the tropical Pacific Ocean and its enhanced impact on precipitation over East Asia during marine isotopic stage 13

    NASA Astrophysics Data System (ADS)

    Karami, M. P.; Herold, N.; Berger, A.; Yin, Q. Z.; Muri, H.

    2015-02-01

    Multiple terrestrial records suggest that marine isotopic stage 13 (MIS-13), an interglacial period approximately 0.5 million years ago, had the strongest East Asian summer monsoon (EASM) of the last one million years. This is unexpected given that, compared to other interglacials, MIS-13 was globally cooler with a lower CO2 concentration. We use two coupled atmosphere-ocean general circulation models, the Hadley Centre Coupled Model, version 3 (HadCM3) and Community Climate System Model, version 3.0 (CCSM3), to simulate the climate of MIS-13 forced with different insolation and greenhouse gas concentrations relative to the pre-industrial (PrI) situation. Both models confirm a stronger EASM during MIS-13 compared to PrI. Here we specially focus on analyzing the impact of the tropical Pacific Ocean on the EASM. Our simulations suggest that the mean climatic state in the tropical Pacific during MIS-13 was La Niña-like and that associated teleconnections with the extra-tropics favored increased precipitation over the EASM. As compared to PrI, it is found that the summer (June-July-August) sea surface temperature (SST) is warmer in the eastern tropical Pacific Ocean and colder to the west. In concert with previous studies, we show that colder summer SSTs in the central tropical Pacific during MIS-13 promotes an upper-level teleconnection between the tropical Pacific Ocean and EASM. It also contributes to the strengthening of the northern Pacific subtropical high and, therefore, the transport of more moisture into the EASM. We suggest that the reduced east-west SST difference in the tropical Pacific in summer helps to maintain the teleconnection between the tropical Pacific and EASM. The correlation between tropical Pacific SSTs and the EASM was higher in our MIS-13 simulations, further supporting the enhancement of their relationship. It is found that the pure impact of El Niño Southern Oscillation on EASM precipitation increases by up to 30 % in MIS-13 for HadCM3

  19. Vacancy enhanced formation and phase transition of Cu-rich precipitates in α - iron under neutron irradiation

    NASA Astrophysics Data System (ADS)

    Lv, G. C.; Zhang, H.; He, X. F.; Yang, W.; Su, Y. J.

    2016-04-01

    In this paper, we employed both molecular statics and molecular dynamics simulation methods to investigate the role of vacancies in the formation and phase transition of Cu-rich precipitates in α-iron. The results indicated that vacancies promoted the diffusion of Cu atoms to form Cu-rich precipitates. After Cu-rich precipitates formed, they further trapped vacancies. The supersaturated vacancy concentration in the Cu-rich precipitate induced a shear strain, which triggered the phase transition from bcc to fcc structure by transforming the initial bcc (110) plane into fcc (111) plane. In addition, the formation of the fcc-twin structure and the stacking fault structure in the Cu-rich precipitates was observed in dynamics simulations.

  20. Vacancy enhanced formation and phase transition of Cu-rich precipitates in α - iron under neutron irradiation

    SciTech Connect

    Lv, G. C.; Zhang, H.; He, X. F.; Yang, W.; Su, Y. J.

    2016-04-15

    In this paper, we employed both molecular statics and molecular dynamics simulation methods to investigate the role of vacancies in the formation and phase transition of Cu-rich precipitates in α-iron. The results indicated that vacancies promoted the diffusion of Cu atoms to form Cu-rich precipitates. After Cu-rich precipitates formed, they further trapped vacancies. The supersaturated vacancy concentration in the Cu-rich precipitate induced a shear strain, which triggered the phase transition from bcc to fcc structure by transforming the initial bcc (110) plane into fcc (111) plane. In addition, the formation of the fcc-twin structure and the stacking fault structure in the Cu-rich precipitates was observed in dynamics simulations.

  1. Preliminary Study for Technology Enhanced Learning: Comparative Study of England and Northern Cyprus

    ERIC Educational Resources Information Center

    Tenekeci, Ebru Heyberi

    2011-01-01

    The purpose of this paper is to present the preliminary study findings from an ongoing PhD study. In this paper, the researcher presents the preliminary study that was carried out with a number of schools in England and Northern Cyprus in order to identify the background or big pictures of each country in terms of available ICT tools that are…

  2. Analysis of Multiple Precipitation Products and Preliminary Assessment of Their Impact on Global Land Data Assimilation System (GLDAS) Land Surface States

    NASA Technical Reports Server (NTRS)

    Gottschalck, Jon; Meng, Jesse; Rodel, Matt; Houser, paul

    2005-01-01

    Land surface models (LSMs) are computer programs, similar to weather and climate prediction models, which simulate the stocks and fluxes of water (including soil moisture, snow, evaporation, and runoff) and energy (including the temperature of and sensible heat released from the soil) after they arrive on the land surface as precipitation and sunlight. It is not currently possible to measure all of the variables of interest everywhere on Earth with sufficient accuracy and space-time resolution. Hence LSMs have been developed to integrate the available observations with our understanding of the physical processes involved, using powerful computers, in order to map these stocks and fluxes as they change in time. The maps are used to improve weather forecasts, support water resources and agricultural applications, and study the Earth's water cycle and climate variability. NASA's Global Land Data Assimilation System (GLDAS) project facilitates testing of several different LSMs with a variety of input datasets (e.g., precipitation, plant type). Precipitation is arguably the most important input to LSMs. Many precipitation datasets have been produced using satellite and rain gauge observations and weather forecast models. In this study, seven different global precipitation datasets were evaluated over the United States, where dense rain gauge networks contribute to reliable precipitation maps. We then used the seven datasets as inputs to GLDAS simulations, so that we could diagnose their impacts on output stocks and fluxes of water. In terms of totals, the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) had the closest agreement with the US rain gauge dataset for all seasons except winter. The CMAP precipitation was also the most closely correlated in time with the rain gauge data during spring, fall, and winter, while the satellitebased estimates performed best in summer. The GLDAS simulations revealed that modeled soil moisture is highly

  3. Analysis of Multiple Precipitation Products and Preliminary Assessment of Their Impact on Global Land Data Assimilation System (GLDAS) Land Surface States

    NASA Technical Reports Server (NTRS)

    Gottschalck, Jon; Meng, Jesse; Rodel, Matt; Houser, paul

    2005-01-01

    Land surface models (LSMs) are computer programs, similar to weather and climate prediction models, which simulate the stocks and fluxes of water (including soil moisture, snow, evaporation, and runoff) and energy (including the temperature of and sensible heat released from the soil) after they arrive on the land surface as precipitation and sunlight. It is not currently possible to measure all of the variables of interest everywhere on Earth with sufficient accuracy and space-time resolution. Hence LSMs have been developed to integrate the available observations with our understanding of the physical processes involved, using powerful computers, in order to map these stocks and fluxes as they change in time. The maps are used to improve weather forecasts, support water resources and agricultural applications, and study the Earth's water cycle and climate variability. NASA's Global Land Data Assimilation System (GLDAS) project facilitates testing of several different LSMs with a variety of input datasets (e.g., precipitation, plant type). Precipitation is arguably the most important input to LSMs. Many precipitation datasets have been produced using satellite and rain gauge observations and weather forecast models. In this study, seven different global precipitation datasets were evaluated over the United States, where dense rain gauge networks contribute to reliable precipitation maps. We then used the seven datasets as inputs to GLDAS simulations, so that we could diagnose their impacts on output stocks and fluxes of water. In terms of totals, the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) had the closest agreement with the US rain gauge dataset for all seasons except winter. The CMAP precipitation was also the most closely correlated in time with the rain gauge data during spring, fall, and winter, while the satellitebased estimates performed best in summer. The GLDAS simulations revealed that modeled soil moisture is highly

  4. Enhanced bioavailability of a poorly water-soluble weakly basic compound using a combination approach of solubilization agents and precipitation inhibitors: a case study.

    PubMed

    Li, Shu; Pollock-Dove, Crystal; Dong, Liang C; Chen, Jing; Creasey, Abla A; Dai, Wei-Guo

    2012-05-07

    Poorly water-soluble weakly basic compounds which are solubilized in gastric fluid are likely to precipitate after the solution empties from the stomach into the small intestine, leading to a low oral bioavailability. In this study, we reported an approach of combining solubilization agents and precipitation inhibitors to produce a supersaturated drug concentration and to prolong such a drug concentration for an extended period of time for an optimal absorption, thereby improving oral bioavailability of poorly water-soluble drugs. A weakly basic compound from Johnson and Johnson Pharmaceutical Research and Development was used as a model compound. A parallel microscreening precipitation method using 96-well plates and a TECAN robot was used to assess the precipitation of the tested compound in the simulated gastric fluid (SGF) and the simulated intestinal fluid (SIF), respectively, for lead solubilizing agents and precipitation inhibitors. The precipitation screening results showed vitamin E TPGS was an effective solubilizing agent and Pluronic F127 was a potent precipitation inhibitor for the tested compound. Interestingly, the combination of Pluronic F127 with vitamin E TPGS resulted in a synergistic effect in prolonging compound concentration upon dilution in SIF. In addition, HPMC E5 and Eudragit L100-55 were found to be effective precipitation inhibitors for the tested compounds in SGF. Furthermore, optimization DOE study results suggested a formulation sweet spot comprising HPMC, Eudragit L 100-55, vitamin E TPGS, and Pluronic F127. The lead formulation maintained the tested compound concentration at 300 μg/mL upon dilution in SIF, and more than 70% of the compound remained solubilized compared with the compound alone at <1 μg/mL of its concentration. Dosing of the solid dosage form predissolved in SGF in dogs resulted in 52% of oral bioavailability compared to 26% for the suspension control, a statistically significant increase (p = 0.002). The enhanced

  5. Precipitation-enhanced diffusion of nickel in dislocation-free silicon studied by in-diffusion and annealing processes

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuji; Kitagawa, Hajime; Ikari, Tetsuo

    2001-12-01

    To examine the site-exchange mechanism of nickel atoms in dislocation-free silicon, the effect of nickel precipitates on the in-diffusion and annealing rates has been investigated. The variation of the concentration of substitutional nickel atoms with time in these processes follow well the theoretical prediction for the dissociative mechanism. It is suggested that nickel atoms in dislocation-free silicon exchange their sites via the dissociative mechanism, or the dominant point defects mediating the site exchange are vacancies. In-diffusion and annealing processes of nickel atoms are accelerated by the presence of the nickel precipitation, indicating that nickel precipitates, or precipitation-induced lattice defects play a role of sinks and sources of vacancies in the bulk.

  6. Atom probe study of irradiation-enhanced α' precipitation in neutron-irradiated Fe–Cr model alloys

    SciTech Connect

    Chen, Wei -Ying; Miao, Yinbin; Wu, Yaqiao; Tomchik, Carolyn A.; Mo, Kun; Gan, Jian; Okuniewski, Maria A.; Maloy, Stuart A.; Stubbins, James F.

    2015-07-01

    Atom probe tomography (APT) was performed to study the effects of Cr concentrations, irradiation doses and irradiation temperatures on a' phase formation in Fe-Cr model alloys (10-16 at.%) irradiated at 300 and 450°C to 0.01, 0.1 and 1 dpa. For 1 dpa specimens, α' precipitates with an average radius of 1.0-1.3 nm were observed. The precipitate density varied significantly from 1.1x10²³ to 2.7x10²⁴ 1/m³, depending on Cr concentrations and irradiation temperatures. The volume fraction of α' phase in 1 dpa specimens qualitatively agreed with the phase diagram prediction. For 0.01 dpa and 0.1 dpa, frequency distribution analysis detected slight Cr segregation in high-Cr specimens, but not in Fe-10Cr specimens. Proximity histogram analysis showed that the radial Cr concentration was highest at the center of a' precipitates. For most precipitates, the Cr contents were significantly lower than that predicted by the phase diagram. The Cr concentration at precipitate center increased with increasing precipitate size.

  7. [A preliminary study on the chemical properties of precipitation, throughfall, stemflow and surface run-off in major forest types at Dinghushan under acid deposition].

    PubMed

    Liu, Juxiu; Zhang, Deqiang; Zhou, Guoyi; Wen, Dazhi; Zhang, Qianmei

    2003-08-01

    Studies on the chemical properties of precipitation, throughfall, stemflow and surface run-off in major forest types at Dinghushan under acid deposition showed that the pH value of precipitation was about 4.90, and the frequency of acid rain was over 62%. In broad-leaved forest, the pH value of precipitation was lower than that of throughfall, but higher than that of stemflow and especially the surface run-off, indicating that the soil was naturally acidified. In mixed forest, both throughfall and surface run-off had a higher pH value, but stemflow had a lower pH value than precipitation. The throughfall and stemflow were more acidified than precipitation in coniferous pine forest, but the surface run-off had a higher pH value than precipitation. These results suggested that among the three major forest types at Dinghushan, the canopy of broad-leaved forest had the highest buffering ability, whereas for the soil, the coniferous forest had the highest soil buffering capacity. The concentrations of nutrient elements, such as P, K, Ca, Na and Mg in the throughfall, stemflow and surface run-off were higher than those in bulk precipitation in all forests at Dinghushan, some even 10 times higher, indicating that a large amount of nutrients were leached from the canopy. The concentrations of nutrient elements in stemflow were higher than those in throughfall in all forests, and the concentration of nutrient elements in surface water was higher than those in atmospheric rainfall. Coniferous forest had a higher concentration of nutrients in the throughfall and stemflow and a lower nutrient concentration in the surface run-off than other forest types, which implied that nutrient loss was more serious in broad-leaved and mixed forests than in coniferous forests.

  8. Fusing enhanced radar precipitation, in-situ hydrometeorological measurements and airborne LIDAR snowpack estimates in a hyper-resolution hydrologic model to improve seasonal water supply forecasts

    NASA Astrophysics Data System (ADS)

    Gochis, D. J.; Busto, J.; Howard, K.; Mickey, J.; Deems, J. S.; Painter, T. H.; Richardson, M.; Dugger, A. L.; Karsten, L. R.; Tang, L.

    2015-12-01

    Scarcity of spatially- and temporally-continuous observations of precipitation and snowpack conditions in remote mountain watersheds results in fundamental limitations in water supply forecasting. These limitationsin observational capabilities can result in strong biases in total snowmelt-driven runoff amount, the elevational distribution of runoff, river basin tributary contributions to total basin runoff and, equally important for water management, the timing of runoff. The Upper Rio Grande River basin in Colorado and New Mexico is one basin where observational deficiencies are hypothesized to have significant adverse impacts on estimates of snowpack melt-out rates and on water supply forecasts. We present findings from a coordinated observational-modeling study within Upper Rio Grande River basin whose aim was to quanitfy the impact enhanced precipitation, meteorological and snowpack measurements on the simulation and prediction of snowmelt driven streamflow. The Rio Grande SNOwpack and streamFLOW (RIO-SNO-FLOW) Prediction Project conducted enhanced observing activities during the 2014-2015 water year. Measurements from a gap-filling, polarimetric radar (NOXP) and in-situ meteorological and snowpack measurement stations were assimilated into the WRF-Hydro modeling framework to provide continuous analyses of snowpack and streamflow conditions. Airborne lidar estimates of snowpack conditions from the NASA Airborne Snow Observatory during mid-April and mid-May were used as additional independent validations against the various model simulations and forecasts of snowpack conditions during the melt-out season. Uncalibrated WRF-Hydro model performance from simulations and forecasts driven by enhanced observational analyses were compared against results driven by currently operational data inputs. Precipitation estimates from the NOXP research radar validate significantly better against independent in situ observations of precipitation and snow-pack increases

  9. Enhanced precipitation-variability effects on water losses and ecosystem functioning: Differential response of arid and mesic regions

    USDA-ARS?s Scientific Manuscript database

    Climate change will result in increased precipitation variability with more extreme events across a range of temporal scales. We used a process-based ecosystem model to simulate water losses and soil water availability to plants at 35 grassland locations in the central U.S. under four level of prec...

  10. The Enhancement of Resilience via a Wilderness Therapy Program. A Preliminary Investigation

    ERIC Educational Resources Information Center

    Gillespie, E.; Allen-Craig, Sandy

    2009-01-01

    This paper presents the findings of a recent preliminary study into the effects of a wilderness therapy program on the resilience of male youth at-risk. The study focused on participants who completed a wilderness therapy program at Typo Station. The residential program involved a five-week stay at the Typo Station property in north east Victoria,…

  11. One-pot glyco-affinity precipitation purification for enhanced proteomics: the flexible alignment of solution-phase capture/release and solid-phase separation.

    PubMed

    Sun, Xue-Long; Haller, Carolyn A; Wu, XiaoYi; Conticello, Vincent P; Chaikof, Elliot L

    2005-01-01

    A one-pot affinity precipitation purification of carbohydrate-binding protein was demonstrated by designing thermally responsive glyco-polypeptide polymers, which were synthesized by selective coupling of pendant carbohydrate groups to a recombinant elastin-like triblock protein copolymer (ELP). The thermally driven inverse transition temperature of the ELP-based triblock polymer is maintained upon incorporation of carbohydrate ligands, which was confirmed by differential scanning calorimetry and (1)H NMR spectroscopy experiments. As a test system, lactose derivatized ELP was used to selectively purify a galactose-specific binding lectin through simple temperature-triggered precipitation in a high level of efficiency. Potential opportunities might be provided for enhanced proteomic, cell isolation as well as pathogen detection applications.

  12. Electrostatic Precipitator

    NASA Image and Video Library

    2017-06-09

    New Electrostatic Precipitator in a flow-through system. The precipitator system is being developed to remove dust from the atmospheric intakes of the MARS ISRU chambers. It uses electrostatic forces for the dust removal.

  13. Effect of Cr content on the thermal stability of tempered lath structures and precipitates in strength enhanced ferritic steels

    NASA Astrophysics Data System (ADS)

    Ghassemi Armaki, H.; Chen, R. P.; Kano, S.; Maruyama, K.; Igarashi, M.

    2010-07-01

    The effect of Cr content on the thermal stability of tempered laths (or elongated subgrains) and precipitates has been studied during long-term aging at 650 °C in three P122 grade steels with increasing Cr content from 9 to 10.5 and 12%. Addition of Cr accelerates the coarsening of subgrains during long-term aging. The number fraction of MX precipitates does change up to 104 h aging in 9% and 10.5% Cr steels, whereas it decreases significantly in 12% Cr steel due to the formation of Z phase. The coarsening rate of M23C6 precipitates, mostly located on the subgrain boundaries, increases from 9 to 12% Cr and steel containing 9% Cr has the highest number density of M23C6 after 104 h aging. The addition of Cr from 9 to 12% accelerates the coarsening rate of Laves phase particles during aging. As a result, 9% Cr steel shows the most stable tempered lath martesitic structure during long-term aging.

  14. Preliminary study on enhancing waste management best practice model in Malaysia construction industry

    NASA Astrophysics Data System (ADS)

    Jamaludin, Amril Hadri; Karim, Nurulzatushima Abdul; Noor, Raja Nor Husna Raja Mohd; Othman, Nurulhidayah; Malik, Sulaiman Abdul

    2017-08-01

    Construction waste management (CWM) is the practice of minimizing and diverting construction waste, demolition debris, and land-clearing debris from disposal and redirecting recyclable resources back into the construction process. Best practice model means best choice from the collection of other practices that was built for purpose of construction waste management. The practice model can help the contractors in minimizing waste before the construction activities will be started. The importance of minimizing wastage will have direct impact on time, cost and quality of a construction project. This paper is focusing on the preliminary study to determine the factors of waste generation in the construction sites and identify the effectiveness of existing construction waste management practice conducted in Malaysia. The paper will also include the preliminary works of planned research location, data collection method, and analysis to be done by using the Analytical Hierarchy Process (AHP) to help in developing suitable waste management best practice model that can be used in the country.

  15. Cognitive Enhancement Therapy Improves Frontolimbic Regulation of Emotion in Alcohol and/or Cannabis Misusing Schizophrenia: A Preliminary Study

    PubMed Central

    Wojtalik, Jessica A.; Hogarty, Susan S.; Cornelius, Jack R.; Phillips, Mary L.; Keshavan, Matcheri S.; Newhill, Christina E.; Eack, Shaun M.

    2016-01-01

    Individuals with schizophrenia who misuse substances are burdened with impairments in emotion regulation. Cognitive enhancement therapy (CET) may address these problems by enhancing prefrontal brain function. A small sample of outpatients with schizophrenia and alcohol and/or cannabis substance use problems participating in an 18-month randomized trial of CET (n = 10) or usual care (n = 4) completed posttreatment functional neuroimaging using an emotion regulation task. General linear models explored CET effects on brain activity in emotional neurocircuitry. Individuals treated with CET had significantly greater activation in broad regions of the prefrontal cortex, limbic, and striatal systems implicated in emotion regulation compared to usual care. Differential activation favoring CET in prefrontal regions and the insula mediated behavioral improvements in emotional processing. Our data lend preliminary support of CET effects on neuroplasticity in frontolimbic and striatal circuitries, which mediate emotion regulation in people with schizophrenia and comorbid substance misuse problems. PMID:26793128

  16. Enhanced intestinal absorption activity and hepatoprotective effect of herpetrione via preparation of nanosuspensions using pH-dependent dissolving-precipitating/homogenization process.

    PubMed

    Shen, Baode; Jin, Shiying; Lv, Qingyuan; Jin, Shixiao; Yu, Chao; Yue, Pengfei; Han, Jin; Yuan, Hailong

    2013-09-01

    The main purpose of this study was to enhance the intestinal absorption activity and hepatoprotective effect of herpetrione by drug nanosuspensions. Herpetrione nanosuspensions (HNS) were prepared using pH-dependent dissolving-precipitating/homogenization process and then systematically characterized. The intestinal absorption activity of HNS were studied using the recirculating perfusion technique in comparison with herpetrione coarse suspensions (HCS) and pure herpetrione using the recirculating perfusion technique. The protective effect of HNS against acute liver injury induced by carbon tetrachloride (CCl4 ) in mice was also investigated and compared with that of HCS. The mean particle size of HNS was 269 ± 7 nm with a polydispersity index of 0.187 ± 0.021. The result of X-ray powder diffraction indicated that herpetrione was in amorphous state in both coarse powder and nanosuspensions. The intestinal absorption activity of HNS were superior to the HCS and pure herpetrione. As evidenced by the lowering of serum aminotransferase levels and the improvement of the degree of liver lesion, pretreatment with HNS markedly enhanced the hepatoprotective effect of herpetrione against acute liver injury induced by CCl4 in mice. HNS prepared using pH-dependent dissolving-precipitating/homogenization technique are able to significantly enhance the intestinal absorption activity and the hepatoprotective effect of herpetrione due to the particle size reduction. © 2013 Royal Pharmaceutical Society.

  17. A monitor for continuous measurement of temperature, pH, and conductance of wet precipitation: Preliminary results from the Adirondack Mountains, New York

    USGS Publications Warehouse

    Johnsson, P.A.; Reddy, M.M.

    1990-01-01

    This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.This report describes a continuous wet-only precipitation monitor designed by the U.S. Geological Survey to record variations in rainfall temperature, pH, and specific conductance at 1-min intervals over the course of storms. Initial sampling in the Adirondack Mountains showed that rainfall acidity varied over the course of summer storms, with low initial pH values increasing as storm intensity increased.

  18. A new single source molecular precursor for synthesis of ZrO2/Pb3O4 nanocomposite by co-precipitation enhanced sol—gel method

    NASA Astrophysics Data System (ADS)

    Ullah, Hameed; Sultan, Nabeela; Akhtar, Zareen

    2015-04-01

    A new heterometal-pseudo-alkoxide, [(bpy)Cl2Pb(μ-OtBu)2ZrCl2(THF)2], compound was developed, and applied as single source molecular precursor (SSP) for the synthesis of ZrO2/Pb3O4 nanocomposite employing co-precipitation enhanced sol-gel method. The SSP has been obtained in the form of monomer in which the metallic centers are bridged through the oxygen atom of the tert-butoxy group. The bipyridyl (bpy) and tetrahydroduran (THF), respectively, coordinated to the lead (Pb) and zirconium (Zr) centers contain the degree of polymerization of the bimetallic molecule. The chlorides present as terminal groups are balancing the overall charge of the molecule. The thermal decomposition pattern of the SSP was established by TGA analysis (equation (1)). The molecular SSP was hydrolyzed by adding an equimolar amount of water and the powder was precipitated at pH = 10 adding NH4OH solution as co-precipitating agent. The analytical techniques, i.e. XRD, SEM, EDX and IR spectroscopy, were used to find the composition, phase, and morphology of the resulting powder. The post sintering (400 °C) sample was confirmed as ZrO2/Pb3O4 nanocomposite. However, the pre-sintering material was amorphous. The pre- and post-sintering samples have rod-shaped nanoparticles. The latter have thinner nanorods than the former.

  19. The Global Precipitation Climatology Project (GPCP) Combined Precipitation Dataset

    NASA Technical Reports Server (NTRS)

    Huffman, George J.; Adler, Robert F.; Arkin, Philip; Chang, Alfred; Ferraro, Ralph; Gruber, Arnold; Janowiak, John; McNab, Alan; Rudolf, Bruno; Schneider, Udo

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit -satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5 deg x 2.5 deg latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  20. The Global Precipitation Climatology Project (GPCP) combined precipitation dataset

    SciTech Connect

    Huffman, G.J.

    1997-01-01

    The Global Precipitation Climatology Project (GPCP) has released the GPCP Version 1 Combined Precipitation Data Set, a global, monthly precipitation dataset covering the period July 1987 through December 1995. The primary product in the dataset is a merged analysis incorporating precipitation estimates from low-orbit-satellite microwave data, geosynchronous-orbit-satellite microwave data, geosynchronous-orbit-satellite infrared data, and rain gauge observations. The dataset also contains the individual input fields, a combination of the microwave and infrared satellite estimates, and error estimates for each field. The data are provided on 2.5{degrees} x 2.5{degrees} latitude-longitude global grids. Preliminary analyses show general agreement with prior studies of global precipitation and extends prior studies of El Nino-Southern Oscillation precipitation patterns. At the regional scale there are systematic differences with standard climatologies.

  1. Characterization of a Marine Microbial Community Used for Enhanced Sulfate Reduction and Copper Precipitation in a Two-Step Process.

    PubMed

    García-Depraect, Octavio; Guerrero-Barajas, Claudia; Jan-Roblero, Janet; Ordaz, Alberto

    2016-11-23

    Marine microorganisms that are obtained from hydrothermal vent sediments present a great metabolic potential for applications in environmental biotechnology. However, the work done regarding their applications in engineered systems is still scarce. Hence, in this work, the sulfate reduction process carried out by a marine microbial community in an upflow anaerobic sludge blanket (UASB) reactor was investigated for 190 days under sequential batch mode. The effects of 1000 to 5500 mg L(-1) of SO4(-2) and the chemical oxygen demand (COD)/SO4(-2) ratio were studied along with a kinetic characterization with lactate as the electron donor. Also, the feasibility of using the sulfide produced in the UASB for copper precipitation in a second column was studied under continuous mode. The system presented here is an alternative to sulfidogenesis, particularly when it is necessary to avoid toxicity to sulfide and competition with methanogens. The bioreactor performed better with relatively low concentrations of sulfate (up to 1100 mg L(-1)) and COD/SO4(-2) ratios between 1.4 and 3.6. Under the continuous regime, the biogenic sulfide was sufficient to precipitate copper at a removal rate of 234 mg L(-1) day(-1). Finally, the identification of the microorganisms in the sludge was carried out; some genera of microorganisms identified were Desulfitobacterium and Clostridium.

  2. Electrostatic precipitation

    SciTech Connect

    Albanese, V.

    1980-07-22

    A method is described of improving the conductivity of particles entrained in a stream of particle-laden gas formed by the burning of coal. The particles are collected by an electrostatic precipitator which comprises treating said gas containing particles prior to contact with the electrostatic precipitator at a temperature not greater than about 800/sup 0/F with a resistivitydecreasing amount of hexamethylene tetramine or its water-soluble salts and thereafter passing the gas to the electrostatic precipitator.

  3. Defect- and Strain-enhanced Cavity Formation and Au Precipitation at nano-crystalline ZrO2/SiO2/Si Interfaces

    SciTech Connect

    Edmondson, Philip D.; Zhang, Yanwen; Namavar, Fereydoon; Wang, Chong M.; Zhu, Zihua; Weber, William J.

    2011-01-15

    Defect- and strain-enhanced cavity formation and Au precipitation at the interfaces of a nanocrystalline ZrO2/SiO2/Si multilayer structure resulting from 2 MeV Au+ irradiation at temperatures of 160 and 400 K have been studied. Under irradiation, loss of oxygen is observed, and the nanocrystalline grains in the ZrO2 layer increase in size. In addition, small cavities are observed at the ZrO2/SiO2 interface with the morphology of the cavities being dependent on the damage state of the underlying Si lattice. Elongated cavities are formed when crystallinity is still retained in the heavily-damaged Si substrate; however, the morphology of the cavities becomes spherical when the substrate is amorphized. With further irradiation, the cavities appear to become stabilized and begin to act as gettering sites for the Au. As the cavities become fully saturated with Au, the ZrO2/SiO2 interface then acts as a gettering site for the Au. Analysis of the results suggests that oxygen diffusion along the grain boundaries contributes to the growth of cavities and that oxygen within the cavities may affect the gettering of Au. Mechanisms of defect- and strain-enhanced cavity formation and Au precipitation at the interfaces will be discussed with focus on oxygen diffusion and vacancy accumulation, the role of the lattice strain on the morphology of the cavities, and the effect of the binding free energy of the cavities on the Au precipitation.

  4. Blooming gelatin: an individual additive for enhancing nanoapatite precipitation, physical properties, and osteoblastic responses of nanostructured macroporous calcium phosphate bone cements.

    PubMed

    Orshesh, Ziba; Hesaraki, Saeed; Khanlarkhani, Ali

    2017-01-01

    In recent years, there has been a great interest in using natural polymers in the composition of calcium phosphate bone cements to enhance their physical, mechanical, and biological performance. Gelatin is a partially hydrolyzed form of collagen, a natural component of bone matrix. In this study, the effect of blooming gelatin on the nanohydroxyapatite precipitation, physical and mechanical properties, and cellular responses of a calcium phosphate bone cement (CPC) was investigated. Various concentrations of blooming gelatin (2, 5, and 8 wt.%) were used as the cement liquid and an equimolar mixture of tetracalcium phosphate and dicalcium phosphate was used as solid phase. The CPC without any gelatin additive was also evaluated as a control group. The results showed that gelatin accelerated hydraulic reactions of the cement paste, in which the reactants were immediately converted into nanostructured apatite precipitates after hardening. Gelatin molecules induced 4%-10% macropores (10-300 μm) into the cement structure, decreased initial setting time by ~190%, and improved mechanical strength of the as-set cement. Variation in the above-mentioned properties was influenced by the gelatin concentration and progressed with increasing the gelatin content. The numbers of the G-292 osteoblastic cells on gelatin-containing CPCs were higher than the control group at entire culture times (1-14 days), meanwhile better alkaline phosphatase (ALP) activity was determined using blooming gelatin additive. The observation of cell morphologies on the cement surfaces revealed an appropriate cell attachment with extended cell membranes on the cements. Overall, adding gelatin to the composition of CPC improved the handling characteristics such as setting time and mechanical properties, enhanced nanoapatite precipitation, and augmented the early cell proliferation rate and ALP activity.

  5. Electroless reduction of silver chloride precipitates for the preparation of highly sensitive substrates for surface-enhanced infrared absorption (SEIRA) measurements.

    PubMed

    Rao, Gadupudi Purna Chandra; Yang, Jyisy

    2015-01-01

    To prepare silver nanoparticles (AgNPs) on infrared-transmitting crystal for surface-enhanced infrared absorption (SEIRA) measurements, a new strategy is proposed and demonstrated using electroless reduction of preformed silver chloride (AgCl) particles. Silver chloride precipitates were formed using an additive of polyvinyl pyrrolidone (PVP) to vary the size and shape of the precipitates. After settling on germanium substrates, the preformed particles of AgCl were reduced electrolessly and spontaneously coagulated to AgNPs. The resulting AgNPs showed a multilayer structure, but the AgNPs were isolated, as shown by the lack of absorption-band distortion in the SEIRA measurements. Hence, the sensitivity and analyte-loading capacity for SEIRA measurements are improved significantly. To optimize the chemical deposition and electroless reduction method, we examined several parameters, including the concentrations of reagents during AgCl precipitation and the reaction time required in the deposition-reduction steps. We used para-nitrobenzoic acid (pNBA) to probe the intensity of the SEIRA effect for the prepared substrates. To better correlate the SEIRA performances with each variable, we examined the prepared substrates using a scanning electron microscope and SEIRA. The results indicate that two major morphologies of AgNPs are observed: nanoparticles and nanorods. The distributions of nanorods we observed were related to the procedures used to prepare the substrates. Based on SEIRA signals, we observed enhancement factors approaching three orders of magnitude compared to conventional transmission measurement. Also, based on the morphologies, the large signals were mainly caused by the formation of multilayers of non-percolated AgNPs.

  6. Blooming gelatin: an individual additive for enhancing nanoapatite precipitation, physical properties, and osteoblastic responses of nanostructured macroporous calcium phosphate bone cements

    PubMed Central

    Orshesh, Ziba; Hesaraki, Saeed; Khanlarkhani, Ali

    2017-01-01

    In recent years, there has been a great interest in using natural polymers in the composition of calcium phosphate bone cements to enhance their physical, mechanical, and biological performance. Gelatin is a partially hydrolyzed form of collagen, a natural component of bone matrix. In this study, the effect of blooming gelatin on the nanohydroxyapatite precipitation, physical and mechanical properties, and cellular responses of a calcium phosphate bone cement (CPC) was investigated. Various concentrations of blooming gelatin (2, 5, and 8 wt.%) were used as the cement liquid and an equimolar mixture of tetracalcium phosphate and dicalcium phosphate was used as solid phase. The CPC without any gelatin additive was also evaluated as a control group. The results showed that gelatin accelerated hydraulic reactions of the cement paste, in which the reactants were immediately converted into nanostructured apatite precipitates after hardening. Gelatin molecules induced 4%–10% macropores (10–300 μm) into the cement structure, decreased initial setting time by ~190%, and improved mechanical strength of the as-set cement. Variation in the above-mentioned properties was influenced by the gelatin concentration and progressed with increasing the gelatin content. The numbers of the G-292 osteoblastic cells on gelatin-containing CPCs were higher than the control group at entire culture times (1–14 days), meanwhile better alkaline phosphatase (ALP) activity was determined using blooming gelatin additive. The observation of cell morphologies on the cement surfaces revealed an appropriate cell attachment with extended cell membranes on the cements. Overall, adding gelatin to the composition of CPC improved the handling characteristics such as setting time and mechanical properties, enhanced nanoapatite precipitation, and augmented the early cell proliferation rate and ALP activity. PMID:28176961

  7. Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy).

    PubMed

    Seiler, Ruedi; Kirchner, James W; Krusic, Paul J; Tognetti, Roberto; Houlié, Nicolas; Andronico, Daniele; Cullotta, Sebastiano; Egli, Markus; D'Arrigo, Rosanne; Cherubini, Paolo

    2017-01-01

    On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We consequently aimed at determining whether an increase in ambient temperature or additional water availability owing to the rise of magma and degassing of water vapour prior to the eruption could have increased photosynthesis of Mt. Etna's trees. Using dendro-climatic analyses we quantified the sensitivity of tree ring widths to temperature and precipitation at high elevation stands on Mt. Etna. Our findings suggest that tree growth at high elevation on Mt. Etna is weakly influenced by climate, and that neither an increase in water availability nor an increase in temperature induced by pre-eruptive activity is a plausible mechanism for enhanced photosynthesis before the 2002/2003 flank eruption. Our findings thus imply that other, yet unknown, factors must be sought as causes of the pre-eruption enhancement of NDVI on Mt. Etna.

  8. Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy)

    PubMed Central

    Krusic, Paul J.; Tognetti, Roberto; Houlié, Nicolas; Andronico, Daniele; Egli, Markus; D'Arrigo, Rosanne

    2017-01-01

    On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We consequently aimed at determining whether an increase in ambient temperature or additional water availability owing to the rise of magma and degassing of water vapour prior to the eruption could have increased photosynthesis of Mt. Etna's trees. Using dendro-climatic analyses we quantified the sensitivity of tree ring widths to temperature and precipitation at high elevation stands on Mt. Etna. Our findings suggest that tree growth at high elevation on Mt. Etna is weakly influenced by climate, and that neither an increase in water availability nor an increase in temperature induced by pre-eruptive activity is a plausible mechanism for enhanced photosynthesis before the 2002/2003 flank eruption. Our findings thus imply that other, yet unknown, factors must be sought as causes of the pre-eruption enhancement of NDVI on Mt. Etna. PMID:28099435

  9. Antidepressant response to aripiprazole augmentation associated with enhanced FDOPA utilization in striatum: a preliminary PET study

    PubMed Central

    Conway, Charles R.; Chibnall, John T.; Cumming, Paul; Mintun, Mark A.; Gebara, Marie Anne I.; Perantie, Dana C.; Price, Joseph L.; Cornell, Martha E.; McConathy, Jonathan E.; Gangwani, Sunil; Sheline, Yvette I.

    2014-01-01

    Several double blind, prospective trials have demonstrated an antidepressant augmentation efficacy of aripiprazole in depressed patients unresponsive to standard antidepressant therapy. Although aripiprazole is now widely used for this indication, and much is known about its receptor-binding properties, the mechanism of its antidepressant augmentation remains ill-defined. In vivo animal studies and in vitro human studies using cloned dopamine dopamine D2 receptors suggest aripiprazole is a partial dopamine agonist; in this preliminary neuroimaging trial, we hypothesized that aripiprazole’s antidepressant augmentation efficacy arises from dopamine partial agonist activity. To test this, we assessed the effects of aripiprazole augmentation on the cerebral utilization of 6-[18F]-fluoro-3,4-dihydroxy-L-phenylalanine (FDOPA) using positron emission tomography (PET). Fourteen depressed patients, who had failed 8 weeks of antidepressant therapy with selective serotonin reuptake inhibitors, underwent FDOPA PET scans before and after aripiprazole augmentation; eleven responded to augmentation. Whole brain, voxel-wise comparisons of pre- and post-aripiprazole scans revealed increased FDOPA trapping in the right medial caudate of augmentation responders. An exploratory analysis of depressive symptoms revealed that responders experienced large improvements only in putatively dopaminergic symptoms of lassitude and inability to feel. These preliminary findings suggest that augmentation of antidepressant response by aripiprazole may be associated with potentiation of dopaminergic activity. PMID:24468015

  10. Antidepressant response to aripiprazole augmentation associated with enhanced FDOPA utilization in striatum: a preliminary PET study.

    PubMed

    Conway, Charles R; Chibnall, John T; Cumming, Paul; Mintun, Mark A; Gebara, Marie Anne I; Perantie, Dana C; Price, Joseph L; Cornell, Martha E; McConathy, Jonathan E; Gangwani, Sunil; Sheline, Yvette I

    2014-03-30

    Several double blind, prospective trials have demonstrated an antidepressant augmentation efficacy of aripiprazole in depressed patients unresponsive to standard antidepressant therapy. Although aripiprazole is now widely used for this indication, and much is known about its receptor-binding properties, the mechanism of its antidepressant augmentation remains ill-defined. In vivo animal studies and in vitro human studies using cloned dopamine dopamine D2 receptors suggest aripiprazole is a partial dopamine agonist; in this preliminary neuroimaging trial, we hypothesized that aripiprazole's antidepressant augmentation efficacy arises from dopamine partial agonist activity. To test this, we assessed the effects of aripiprazole augmentation on the cerebral utilization of 6-[(18)F]-fluoro-3,4-dihydroxy-l-phenylalanine (FDOPA) using positron emission tomography (PET). Fourteen depressed patients, who had failed 8 weeks of antidepressant therapy with selective serotonin reuptake inhibitors, underwent FDOPA PET scans before and after aripiprazole augmentation; 11 responded to augmentation. Whole brain, voxel-wise comparisons of pre- and post-aripiprazole scans revealed increased FDOPA trapping in the right medial caudate of augmentation responders. An exploratory analysis of depressive symptoms revealed that responders experienced large improvements only in putatively dopaminergic symptoms of lassitude and inability to feel. These preliminary findings suggest that augmentation of antidepressant response by aripiprazole may be associated with potentiation of dopaminergic activity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Insights from preliminary modeling and observational evaluation of a precipitating continental cumulus event observed during the MC3E field campaign

    NASA Astrophysics Data System (ADS)

    Mechem, D. B.; Fish, C. S.; Giangrande, S. E.; Borque, P.; Kollias, P.

    2013-12-01

    A case of extensive precipitating cumulus congestus sampled during the MC3E field campaign is analyzed using a multi-sensor observational approach and numerical simulation. The ARM SGP (Atmospheric Radiation Measurement Program Southern Great Plains) radar suite characterizes the evolving statistical behavior of the precipitating cloud system through distributions of reflectivity, horizontal divergence, and different measures of cloud geometry. Large-eddy simulation (LES) with size-resolved (bin) microphysics is employed to determine the forcings most important in producing the salient aspects of the cloud system captured in the radar observations. Specifically, we address how the characteristic spatial scale of the forcing imposed on the simulation influences the evolution of cloud system properties. Additionally, the importance of time-varying vs. steady-state large-scale forcing is evaluated in assessing the model's ability to capture the transient behavior of the cloud system sampled by the radar suite. The long-term goal of this effort is to promote cross-pollination between high-resolution cloud radar observations and LES.

  12. Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

    PubMed

    Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

    2007-12-01

    Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

  13. Breast contrast-enhanced ultrasound: is a scoring system feasible? A preliminary study in China.

    PubMed

    Xiao, Xiaoyun; Ou, Bing; Yang, Haiyun; Wu, Huan; Luo, Baoming

    2014-01-01

    Although many studies about breast contrast-enhanced ultrasound had been conducted, clear diagnostic criteria for evaluating enhancement patterns are still lacking. This study aims to identify significant indicators for breast contrast-enhanced ultrasound and to establish an initial scoring system. Totally 839 patients were included in the study. This study was divided into two parts. 364 patients were included in part 1 while 475 in part 2. Conventional ultrasound and contrast-enhanced ultrasound were used to examine each lesion. Only the cases in part 2 were also examined by elastography. In part 1, Logistic regression analysis was performed to predict significant variables. A 5-point scoring system was developed based on the results. In part 2, the scoring system was used to evaluate all the breast lesions. To evaluate the diagnostic efficacy of the new scoring system, it was compared with the system established for elastography and conventional ultrasound (BI-RADS). Three independent variables, namely, lesion scope, margin, and shape were selected in the final step of the logistic regression analysis in part 1. In part 2, the area under the ROC (receiver operating characteristic) curve for the contrast-enhanced scoring system was 0.912. The difference in the diagnostic capabilities of the contrast-enhanced scoring system and elastography was not statistically significant (P = 0.17). The difference in the diagnostic capabilities of the contrast-enhanced scoring system and BI-RADS was statistically significant (P<0.001). The contrast-enhanced patterns of benign and malignant breast tumors are different. The application of a 5-point scoring system for contrast-enhanced ultrasound is clinically promising.

  14. Breast Contrast-Enhanced Ultrasound: Is a Scoring System Feasible? ----A Preliminary Study in China

    PubMed Central

    Xiao, Xiaoyun; Ou, Bing; Yang, Haiyun; Wu, Huan; Luo, Baoming

    2014-01-01

    Objectives Although many studies about breast contrast-enhanced ultrasound had been conducted, clear diagnostic criteria for evaluating enhancement patterns are still lacking. This study aims to identify significant indicators for breast contrast-enhanced ultrasound and to establish an initial scoring system. Materials and Methods Totally 839 patients were included in the study. This study was divided into two parts. 364 patients were included in part 1 while 475 in part 2. Conventional ultrasound and contrast-enhanced ultrasound were used to examine each lesion. Only the cases in part 2 were also examined by elastography. In part 1, Logistic regression analysis was performed to predict significant variables. A 5-point scoring system was developed based on the results. In part 2, the scoring system was used to evaluate all the breast lesions. To evaluate the diagnostic efficacy of the new scoring system, it was compared with the system established for elastography and conventional ultrasound (BI-RADS). Results Three independent variables, namely, lesion scope, margin, and shape were selected in the final step of the logistic regression analysis in part 1. In part 2, the area under the ROC (receiver operating characteristic) curve for the contrast-enhanced scoring system was 0.912. The difference in the diagnostic capabilities of the contrast-enhanced scoring system and elastography was not statistically significant (P = 0.17). The difference in the diagnostic capabilities of the contrast-enhanced scoring system and BI-RADS was statistically significant (P<0.001). Conclusions The contrast-enhanced patterns of benign and malignant breast tumors are different. The application of a 5-point scoring system for contrast-enhanced ultrasound is clinically promising. PMID:25133534

  15. Evidence that bio-metallic mineral precipitation enhances the complex conductivity response at a hydrocarbon contaminated site

    NASA Astrophysics Data System (ADS)

    Mewafy, Farag M.; Werkema, D. Dale; Atekwana, Estella A.; Slater, Lee D.; Abdel Aal, Gamal; Revil, André; Ntarlagiannis, Dimitrios

    2013-11-01

    The complex conductivity signatures of a hydrocarbon contaminated site, undergoing biodegradation, near Bemidji, Minnesota were investigated. This site is characterized by a biogeochemical process where iron reduction is coupled with the oxidation of hydrocarbon contaminants. The biogeochemical transformations have resulted in precipitation of different bio-metallic iron mineral precipitates such as magnetite, ferroan calcite, and siderite. Our main objective was to elucidate the major factors controlling the complex conductivity response at the site. We acquired laboratory complex conductivity measurements along four cores retrieved from the site in the frequency range between 0.001 and 1000 Hz. Our results show the following: (1) in general higher imaginary conductivity was observed for samples from contaminated locations compared to samples from the uncontaminated location, (2) the imaginary conductivity for samples contaminated with residual and free phase hydrocarbon (smear zone) was higher compared to samples with dissolved phase hydrocarbon, (3) vadose zone samples located above locations with free phase hydrocarbon show higher imaginary conductivity magnitude compared to vadose zone samples from the dissolved phase and uncontaminated locations, (4) the real conductivity was generally elevated for samples from the contaminated locations, but not as diagnostic to the presence of contamination as the imaginary conductivity; (5) for most of the contaminated samples the imaginary conductivity data show a well-defined peak between 0.001 and 0.01 Hz, and (6) sample locations exhibiting higher imaginary conductivity are concomitant with locations having higher magnetic susceptibility. Controlled experiments indicate that variations in electrolytic conductivity and water content across the site are unlikely to fully account for the higher imaginary conductivity observed within the smear zone of contaminated locations. Instead, using magnetite as an example of the

  16. Enhanced red emission from YVO4:Eu3+ nano phosphors prepared by simple Co-Precipitation Method

    NASA Astrophysics Data System (ADS)

    Grandhe, Bhaskar Kumar; Bandi, Vengala Rao; Jang, Kiwan; Ramaprabhu, Sundara; Yi, Soung-Soo; Jeong, Jung-Hyun

    2011-06-01

    Eu3+ doped YVO4 nano phosphors were synthesized by adopting a simple Co-Precipitation Method (CPM). In order to compare and evaluate this method's potentiality, we prepared the same phosphor by using a conventional Solid State Reaction method (SSR). X-Ray Diffraction (XRD) profile confirms the tetragonal nature of Eu3+ doped YVO4 nano phosphors. The efficiency of the prepared phosphors was analyzed by means of its emission spectral profiles. We also observed a rich red emission from the prepared phosphors under a Ultra-Violet (UV) source. Such luminescent powders are expected to be applied as red phosphors in display device applications. In addition, Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier-Transform IR spectroscopy (FTIR), and Raman Spectrum were also used to characterize the synthesized phosphor.

  17. Alanine with the Precipitate of Tomato Juice Administered to Rats Enhances the Reduction in Blood Ethanol Levels.

    PubMed

    Oshima, Shunji; Shiiya, Sachie; Tokumaru, Yoshimi; Kanda, Tomomasa

    2015-01-01

    Delay in gastric emptying (GE) lowers the blood ethanol concentration (BEC) after alcohol administration. We previously demonstrated that water-insoluble fractions, mainly comprising dietary fiber derived from many types of botanical foods, possessed the ability to absorb ethanol-containing aqueous solutions. Furthermore, there was a significant correlation between the absorption of ethanol and lowering of BEC because of delay in GE. Here we identified dietary nutrients that synergize with the water-insoluble fraction of tomatoes to lower BEC in rats. Consequently, unlike tomato juice without alanine, tomato juice with 5.0% alanine decreased BEC depending on the delay in GE and mediated the ethanol-induced decrease in the spontaneous motor activity (an indicator of drunkenness). Our findings indicate that the synergism between tomato juice and alanine to reduce the absorption of ethanol was attributable to the effect of alanine on precipitates such as the water-insoluble fraction of tomatoes.

  18. Alanine with the Precipitate of Tomato Juice Administered to Rats Enhances the Reduction in Blood Ethanol Levels

    PubMed Central

    Oshima, Shunji; Shiiya, Sachie; Tokumaru, Yoshimi; Kanda, Tomomasa

    2015-01-01

    Delay in gastric emptying (GE) lowers the blood ethanol concentration (BEC) after alcohol administration. We previously demonstrated that water-insoluble fractions, mainly comprising dietary fiber derived from many types of botanical foods, possessed the ability to absorb ethanol-containing aqueous solutions. Furthermore, there was a significant correlation between the absorption of ethanol and lowering of BEC because of delay in GE. Here we identified dietary nutrients that synergize with the water-insoluble fraction of tomatoes to lower BEC in rats. Consequently, unlike tomato juice without alanine, tomato juice with 5.0% alanine decreased BEC depending on the delay in GE and mediated the ethanol-induced decrease in the spontaneous motor activity (an indicator of drunkenness). Our findings indicate that the synergism between tomato juice and alanine to reduce the absorption of ethanol was attributable to the effect of alanine on precipitates such as the water-insoluble fraction of tomatoes. PMID:26713162

  19. CT urography of urinary diversions with enhanced CT digital radiography: preliminary experience.

    PubMed

    Sudakoff, Gary S; Guralnick, Michael; Langenstroer, Peter; Foley, W Dennis; Cihlar, Krista L; Shakespear, Jonathan S; See, William A

    2005-01-01

    The purpose of this study was to determine if 3D-rendered CT urography (CTU) depicts both normal and abnormal findings in patients with urinary diversions and if the addition of contrast-enhanced CT digital radiography (CTDR) improves opacification of the urinary collecting system. Thirty CTU and contrast-enhanced CTDR examinations were performed in 24 patients who underwent cystectomy for bladder cancer. Indications for evaluation included hematuria, tumor surveillance, or suspected diversion malfunction. All examinations were evaluated without knowledge of the stage or grade of a patient's tumor and were compared with the clinical records. Opacification of the urinary collecting system was evaluated with 3D CTU alone, contrast-enhanced CTDR alone, and combined CTU and CTDR. Nine abnormalities were identified including distal ureteral strictures (n = 4), vascular compression of the mid left ureter (n = 1), scarring of the mid right pole infundibulum (n = 1), bilateral hydronephrosis and hydroureter (n = 1), urinary reservoir calculus (n = 1), and tumor recurrence invading the afferent limb of the neobladder (n = 1). Eight of the nine detected abnormalities were surgically or pathologically confirmed. All abnormalities were identified on all three imaging techniques but were best seen on 3D CTU and enhanced CTDR images. Incomplete opacification of the urinary collecting system occurred in 17 patients with CTU alone, 12 patients with contrast-enhanced CTDR alone, and nine patients with combined CTU and contrast-enhanced CTDR. Compared with CTU alone, the combined technique of 3D CTU and contrast-enhanced CTDR improved opacification by a statistically significant difference (p = 0.037). CTU with 3D rendering can accurately depict both normal and abnormal postoperative findings in patients with urinary diversions. Adding enhanced CTDR can improve visualization of the urinary collecting system.

  20. Preliminary geologic investigations in the Colorado Plateau using enhanced ERTS images

    NASA Technical Reports Server (NTRS)

    Goetz, A. F. H.; Billingsley, F. C.; Elston, D. P.; Lucchitta, I.; Shoemaker, E. M.

    1973-01-01

    Bulk and computer enhanced frames of the Verde Valley region of Central Arizona, have been analyzed for structural information and rock unit identification. Most major rock units in areas of sparse ground cover are identifiable on enhanced false-color composites. Regional structural patterns are strikingly visible on the ERTS images. New features have been identified which will aid in the search for ground water near Flagstaff, Sedona and Stewart Ranch.

  1. Enhancing Global Land Surface Hydrology Estimates from the NASA MERRA Reanalysis Using Precipitation Observations and Model Parameter Adjustments

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf; Koster, Randal; DeLannoy, Gabrielle; Forman, Barton; Liu, Qing; Mahanama, Sarith; Toure, Ally

    2011-01-01

    The Modern-Era Retrospective analysis for Research and Applications (MERRA) is a state-of-the-art reanalysis that provides. in addition to atmospheric fields. global estimates of soil moisture, latent heat flux. snow. and runoff for J 979-present. This study introduces a supplemental and improved set of land surface hydrological fields ('MERRA-Land') generated by replaying a revised version of the land component of the MERRA system. Specifically. the MERRA-Land estimates benefit from corrections to the precipitation forcing with the Global Precipitation Climatology Project pentad product (version 2.1) and from revised parameters in the rainfall interception model, changes that effectively correct for known limitations in the MERRA land surface meteorological forcings. The skill (defined as the correlation coefficient of the anomaly time series) in land surface hydrological fields from MERRA and MERRA-Land is assessed here against observations and compared to the skill of the state-of-the-art ERA-Interim reanalysis. MERRA-Land and ERA-Interim root zone soil moisture skills (against in situ observations at 85 US stations) are comparable and significantly greater than that of MERRA. Throughout the northern hemisphere, MERRA and MERRA-Land agree reasonably well with in situ snow depth measurements (from 583 stations) and with snow water equivalent from an independent analysis. Runoff skill (against naturalized stream flow observations from 15 basins in the western US) of MERRA and MERRA-Land is typically higher than that of ERA-Interim. With a few exceptions. the MERRA-Land data appear more accurate than the original MERRA estimates and are thus recommended for those interested in using '\\-tERRA output for land surface hydrological studies.

  2. Enhancing Global Land Surface Hydrology Estimates from the NASA MERRA Reanalysis Using Precipitation Observations and Model Parameter Adjustments

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf; Koster, Randal; DeLannoy, Gabrielle; Forman, Barton; Liu, Qing; Mahanama, Sarith; Toure, Ally

    2011-01-01

    The Modern-Era Retrospective analysis for Research and Applications (MERRA) is a state-of-the-art reanalysis that provides. in addition to atmospheric fields. global estimates of soil moisture, latent heat flux. snow. and runoff for J 979-present. This study introduces a supplemental and improved set of land surface hydrological fields ('MERRA-Land') generated by replaying a revised version of the land component of the MERRA system. Specifically. the MERRA-Land estimates benefit from corrections to the precipitation forcing with the Global Precipitation Climatology Project pentad product (version 2.1) and from revised parameters in the rainfall interception model, changes that effectively correct for known limitations in the MERRA land surface meteorological forcings. The skill (defined as the correlation coefficient of the anomaly time series) in land surface hydrological fields from MERRA and MERRA-Land is assessed here against observations and compared to the skill of the state-of-the-art ERA-Interim reanalysis. MERRA-Land and ERA-Interim root zone soil moisture skills (against in situ observations at 85 US stations) are comparable and significantly greater than that of MERRA. Throughout the northern hemisphere, MERRA and MERRA-Land agree reasonably well with in situ snow depth measurements (from 583 stations) and with snow water equivalent from an independent analysis. Runoff skill (against naturalized stream flow observations from 15 basins in the western US) of MERRA and MERRA-Land is typically higher than that of ERA-Interim. With a few exceptions. the MERRA-Land data appear more accurate than the original MERRA estimates and are thus recommended for those interested in using '\\-tERRA output for land surface hydrological studies.

  3. Preliminary Results on Simulations of Ground Level Enhancements (GLEs) detected by The High Altitude Water Cherenkov Observatory (HAWC)

    NASA Astrophysics Data System (ADS)

    Enriquez Rivera, O.; Lara, A.

    2014-12-01

    The High Altitude Water Cherenkov Observatory (HAWC) is currently under construction at the Sierra Negra Volcano, Puebla in Mexico. Located 4100 m above sea level, this large array is mainly designed to observe high energy gamma rays (TeV). However, by recording scaler data that correspond to the rates of individual photomultiplier tubes, the detection and study of solar energetic particles (known as Ground Level Enhancements) as well as the decrease of the cosmic ray flux due to solar transients (known as Forbush decreases) will also be possible. In order to determine the response of the array to solar transients, we have performed simulations of the scaler output using different sub-array configurations. We present here our preliminary results of such simulations and their comparison with observed Forbush decreases.

  4. Crystallization and preliminary X-ray analysis of the Pax6 paired domain bound to the Pax6 gene enhancer

    SciTech Connect

    Ito, Makoto Oyama, Takuji; Okazaki, Kenji; Morikawa, Kosuke

    2005-11-01

    The mammalian Pax6 paired domain has been cocrystallizaed with a 25 bp DNA fragment of the Pax6 gene enhancer. Pax6 is a member of the Pax family of transcription factors and is essential for eye development. Pax6 has two DNA-binding domains: the paired domain and the homeodomain. The Pax6 paired domain is involved in Pax6 gene autoregulation by binding to its enhancer. In this study, crystallization and preliminary X-ray diffraction analysis of the mammalian Pax6 paired domain in complex with the Pax6 gene enhancer was attempted. The Pax6 paired domain complexed with an optimized 25 bp DNA fragment was crystallized by the hanging-drop vapour-diffusion method. The crystal diffracted synchrotron radiation to 3.0/3.7 Å resolution and belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 62.21, b = 70.69, c = 176.03 Å, β = 90.54°. Diffraction data were collected to 3.7 Å resolution.

  5. Combined Observational and Modeling Efforts to Better Understand Aerosol-Cloud-Precipitation Interactions Over Land: Preliminary Results from 7-SEAS/BASELInE 2013

    NASA Technical Reports Server (NTRS)

    Loftus, Adrian M.; Tsay, Si-Chee

    2015-01-01

    This talk presents some of the detailed observations of low-level stratocumulus over northern Vietnam during 7-SEASBASELInE 2013 by SMARTLabs' ACHIEVE W-band cloud radar and other remote sensing instruments. These observations are the first of their kind for this region and will aid in ongoing studies of biomass-burning aerosol impacts on local and regional weather and climate. Preliminary results from simulations using the Goddard Cumulus Ensemble (GCE) with recently implemented triple-moment bulk microphysics to examine the sensitivity of low-level stratocumulus over land to aerosols are also presented. Recommendations for future observational activities in the 7-SEAS northern region in collaboration with international partners will also be discussed.

  6. A preliminary evaluation of self-made nanobubble in contrast-enhanced ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Li, Chunfang; Wu, Kaizhi; Li, Jing; Liu, Haijuan; Zhou, Qibing; Ding, Mingyue

    2014-03-01

    Nanoscale bubbles (nanobubbles) have been reported to improve contrast in tumor-targeted ultrasound imaging due to the enhanced permeation and retention effects at tumor vascular leaks. In this work, a self-made nanobubble ultrasound contrast agent was preliminarily characterized and evaluated in-vitro and in-vivo. Fundamental properties such as morphology appearance, size distribution, zeta potential, bubble concentration (bubble numbers per milliliter contrast agent suspension) and the stability of nanobubbles were assessed by light microscope and particle sizing analysis. Then the concentration intensity curve and time intensity curves (TICs) were acquired by ultrasound imaging experiment in-vitro. Finally, the contrast-enhanced ultrasonography was performed on rat to investigate the procedure of liver perfusion. The results showed that the nanobubbles had good shape and uniform distribution with the average diameter of 507.9 nm, polydispersity index (PDI) of 0.527, and zeta potential of -19.17 mV. Significant contrast enhancement was observed in in-vitro ultrasound imaging, demonstrating that the self-made nanobubbles can enhance the contrast effect of ultrasound imaging efficiently in-vitro. Slightly contrast enhancement was observed in in-vivo ultrasound imaging, indicating that the nanobubbles are not stable enough in-vivo. Future work will be focused on improving the ultrasonic imaging performance, stability, and antibody binding of the nanoscale ultrasound contrast agent.

  7. Monitoring radiation belt particle precipitation - automatic detection of enhanced transient ionisation in the lower plasmasphere using subionospheric narrow band VLF signals

    NASA Astrophysics Data System (ADS)

    Steinbach, P.; Lichtenberger, J.; Ferencz, Cs.

    2009-04-01

    Signals of naval VLF transmitters, propagating long distances along the Earth-ionosphere waveguide (EIWG) have been widely applied as effective tools for monitoring transient ionization at mesospheric altitudes. Perturbations in recorded amplitude and/or phase data series of stable frequency signals may refer to the effect of transient enhanced ionization in the EIWG, due to e.g. loss-cone precipitation of trapped energetic electrons (Carpenter et al., 1984, Dowden and Adams, 1990), burst of solar plasma particles (Clilverd et al., 2001). The contribution of precipitating particles are thought to be substantial in certain Sun-to-Earth energy flow processes in the upper atmosphere (Rodger et al., 2005). Narrow band VLF measuring network has been set up, developed and operated in Hungary, running in the last decade almost continuously, dedicated to monitor ionization enhancement regions along numerous transmitter-receiver paths. This setup is based on Omnipal and Ultra-MSK equipment, logging amplitude and phase data of received signals, sampled at frequencies of selected VLF transmitters. Signal trajectories, selected for recording represent proper configuration to survey transient ionization caused by energetic particles in the sub-polar region, such as effect of scattered particles of the inner radiation belt. Reprocessing of the mass archived recordings has been started using a newly developed signal processing code, detecting and classifying different sort of perturbations automatically on narrow band VLF series. Occurrence rates, daily and seasonal variation, statistics of transient ionization enhancements, their geographic distribution within the surveyed range and time period, and correlation with intense geomagnetic and/or Solar event is yielded by this analysis. References: Carpenter, D.L., Inan, U.S., Trimpi, M.L., Helliwell, R.A., and Katsufrakis, J.P.: Perturbations of subionospheric LF and MF signals due to whistler-induced electron precipitation burst

  8. Enhanced methane combustion over Co3O4 catalysts prepared by a facile precipitation method: Effect of aging time

    NASA Astrophysics Data System (ADS)

    Pu, Zhiying; Zhou, Huan; Zheng, Yifan; Huang, Wanzhen; Li, Xiaonian

    2017-07-01

    A series of Co3O4 catalysts were prepared by a facile precipitation method just changing the aging time and tested for methane combustion. It was found that the activity for the reaction increased firstly and then decreased with increasing aging time in the form of a volcano curve. The Co3O4 aged for 8 h (Co3O4-8) exhibited the best catalytic performance with the specific reaction rate (Rs) of 25.91 nmol s-1 m-2 at 340 °C, which was 29.5 times than Co3O4-96 sample, although the Co3O4-8 catalyst showed the minimum BET surface area and the largest particle size. The XPS and Raman results indicated that the Co3O4-8 catalyst possessed the highest ratio of ATetrahedral/AOctahedral at the surface of the catalyst. H2-TPR and in situ XRD results also confirmed the Co3O4-8 catalyst behaved with excellent high-temperature reduction ability. In combination with the activity performance, the Co3O4-8 catalyst had the best performance of methane combustion due to abundant active tetrahedral Co2+ cationic species. The long-term stability tests demonstrated that the step of aging in the process of preparation can improve water tolerance of Co3O4 catalyst for methane combustion.

  9. Synthesis of novel phytosphingosine derivatives and their preliminary biological evaluation for enhancing radiation therapy.

    PubMed

    Moon, Byung Seok; Park, Moon-Taek; Park, Jeong Hoon; Kim, Sang Wook; Lee, Kyo Chul; An, Gwang Il; Yang, Seung Dae; Chi, Dae Yoon; Cheon, Gi Jeong; Lee, Su-Jae

    2007-12-01

    Eight d-ribo-phytosphingosine derivatives were synthesized from d-ribo-phytosphingosine and diverse acyl chlorides with N,N-diisopropylethylamine in tetrahydrofuran for 1h at room temperature. Effect of these compounds on IR-induced cell death was evaluated on blood cancer cells (Jurkat). Among these, 3d showed the highest enhancement of radiosensitizing effect.

  10. Motivational Enhancement Therapy for Adolescent Marijuana Users: A Preliminary Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Walker, Denise D.; Roffman, Roger A.; Stephens, Robert S.; Wakana, Kim; Berghuis, James

    2006-01-01

    This study's aims were (a) to investigate the feasibility of a school-based motivational enhancement therapy (MET) intervention in voluntarily attracting adolescents who smoke marijuana regularly but who are not seeking formal treatment and (b) to evaluate the efficacy of the intervention in reducing marijuana use. Ninety-seven adolescents who had…

  11. Motivational Enhancement Therapy for Adolescent Marijuana Users: A Preliminary Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Walker, Denise D.; Roffman, Roger A.; Stephens, Robert S.; Wakana, Kim; Berghuis, James

    2006-01-01

    This study's aims were (a) to investigate the feasibility of a school-based motivational enhancement therapy (MET) intervention in voluntarily attracting adolescents who smoke marijuana regularly but who are not seeking formal treatment and (b) to evaluate the efficacy of the intervention in reducing marijuana use. Ninety-seven adolescents who had…

  12. Preliminary Evidence for the Enhancement of Self-Conducted Exposures for OCD using Cognitive Bias Modification

    PubMed Central

    Amir, Nader; Kuckertz, Jennie M.; Najmi, Sadia; Conley, Sara L.

    2015-01-01

    Exposure and Response Prevention (ERP) is the most effective treatment for OCD but it is not accessible to most patients. Attempts to increase the accessibility of ERP via self-directed ERP (sERP) programs such as computerized delivery and bibliotherapy have met with noncompliance, presumably because patients find the exposure exercises unacceptable. Previous research suggests that Cognitive Bias Modification (CBM) interventions may help individuals approach feared situations. The goal of the current study was to test the efficacy of a treatment program for OCD that integrates sERP with CBM. Twenty-two individuals meeting diagnostic criteria for OCD enrolled in our 7-week treatment program. Results suggest that sERP with CBM led to significant reduction of OCD symptoms and functional impairment. Indeed, the magnitude of the effect of this novel treatment, that requires only an initial session with a clinician trained in ERP for OCD, was comparable to that of the gold standard clinician-administered ERP. Moreover, preliminary evidence suggests that CBM interventions targeting interpretation bias may be most effective, whereas those targeting attention and working memory bias may not be so. PMID:26366021

  13. Preliminary Evidence for the Enhancement of Self-Conducted Exposures for OCD using Cognitive Bias Modification.

    PubMed

    Amir, Nader; Kuckertz, Jennie M; Najmi, Sadia; Conley, Sara L

    2015-08-01

    Exposure and Response Prevention (ERP) is the most effective treatment for OCD but it is not accessible to most patients. Attempts to increase the accessibility of ERP via self-directed ERP (sERP) programs such as computerized delivery and bibliotherapy have met with noncompliance, presumably because patients find the exposure exercises unacceptable. Previous research suggests that Cognitive Bias Modification (CBM) interventions may help individuals approach feared situations. The goal of the current study was to test the efficacy of a treatment program for OCD that integrates sERP with CBM. Twenty-two individuals meeting diagnostic criteria for OCD enrolled in our 7-week treatment program. Results suggest that sERP with CBM led to significant reduction of OCD symptoms and functional impairment. Indeed, the magnitude of the effect of this novel treatment, that requires only an initial session with a clinician trained in ERP for OCD, was comparable to that of the gold standard clinician-administered ERP. Moreover, preliminary evidence suggests that CBM interventions targeting interpretation bias may be most effective, whereas those targeting attention and working memory bias may not be so.

  14. Enhanced electrochemical sensitivity of enzyme precipitate coating (EPC)-based glucose oxidase biosensors with increased free CNT loadings.

    PubMed

    Kim, Jae Hyun; Jun, Sun-Ae; Kwon, Yongchai; Ha, Su; Sang, Byong-In; Kim, Jungbae

    2015-02-01

    Enzymatic electrodes were fabricated by using three different immobilizations of glucose oxidase (GOx): covalent enzyme attachment (CA), enzyme coating (EC), and enzyme precipitate coating (EPC), here referred to as CA-E, EC-E, and EPC-E, respectively. When additional carbon nanotubes (CNTs) were introduced from 0 to 75wt% for the EPC-E design, its initial biosensor sensitivity was improved from 2.40×10(-3) to 16.26×10(-3) A∙M(-1)∙cm(-2), while its electron charge transfer rate constant was increased from 0.33 to 1.47s(-1). When a fixed ratio of CNTs was added for three different electrode systems, EPC-E showed the best glucose sensitivity and long-term thermal stability. For example, when 75wt% of additional CNTs was added, the initial sensitivity of EPC-E was 16.26×10(-3) A∙M(-1)∙cm(-2), while those of EC-E and CA-E were only 6.42×10(-3) and 1.18×10(-3) A∙M(-1)∙cm(-2), respectively. Furthermore, EPC-E retained 63% of its initial sensitivity after thermal treatment at 40°C over 41days, while EC-E and CA-E showed only 12% and 1% of initial sensitivities, respectively. Consequently, the EPC approach with additional CNTs achieved both high sensitivity and long-term stability, which are required for continuous and accurate glucose monitoring.

  15. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  16. Precipitation Recycling

    NASA Technical Reports Server (NTRS)

    Eltahir, Elfatih A. B.; Bras, Rafael L.

    1996-01-01

    The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

  17. Polarity-enhanced gas-sensing performance of Au-loaded ZnO nanospindles synthesized via precipitation and microwave irradiation

    NASA Astrophysics Data System (ADS)

    Li, Yan; Lv, Tan; Zhao, Fang-Xian; Lian, Xiao-Xue; Zou, Yun-Ling; Wang, Qiong

    2016-05-01

    Loading noble metal and exploring suitable morphology to achieve excellent gas-sensing performance is very crucial for the fabrication of gas sensors. We have successfully synthesized Au-loaded ZnO (Au/ZnO) nanospindles (NSs) through a really facile procedure involving a precipitation and subsequent microwave irradiation. The as-prepared products have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The formation and gas-sensing mechanism of Au/ZnO NSs were discussed. The SEM micrographs revealed an interesting morphological evolution of the Au/ZnO NSs with Au-loading content ranging from 0 at. % to 7 at. %. The nanostructures were employed for gas-sensing measurement toward various gases. It indicated that the Au/ZnO NSs based sensor showed a highly enhanced response (226.81) to 400 ppm acetone gas at a relatively low working temperature (270°C), and exhibited a fast response (1 s) and recovery speed (10 s). The highly enhanced acetone gas sensitivity of Au/ZnO NSs based sensor could be attributed to its enhanced polarity owing to the peculiar morphology, Schottcky barriers, as well as catalytic effect of Au NPs. [Figure not available: see fulltext.

  18. Evaluation of the thrombus of abdominal aortic aneurysms using contrast enhanced ultrasound - preliminary results

    NASA Astrophysics Data System (ADS)

    Łukasiewicz, Adam; Garkowski, Adam; Rutka, Katarzyna; Janica, Jacek; Łebkowska, Urszula

    2016-09-01

    It is hypothesized that the degree of vascularization of the thrombus may have a significant impact on the rupture of aortic aneurysms. The presence of neovascularization of the vessel wall and mural thrombus has been confirmed only in histopathological studies. However, no non-invasive imaging technique of qualitative assessment of thrombus and neovascularization has been implemented so far. Contrast-enhanced ultrasound (CEUS) has been proposed as a feasible and minimally invasive technique for in vivo visualization of neovascularization in the evaluation of tumors and atherosclerotic plaques. The aim of this study was the evaluation of mural thrombus and AAAs wall with CEUS. CEUS was performed in a group of seventeen patients with AAAs. The mural thrombus enhancement was recognized in 12 cases, yet no significant correlation between the degree of contrast enhancement and AAAs diameter, thrombus width, and thrombus echogenicity was found. We observed a rise in AAAs thrombus heterogeneity with the increase in the aneurysm diameter (r = 0.62, p = 0.017). In conclusion CEUS can visualize small channels within AAAs thrombus, which could be a result of an ongoing angiogenesis. There is a need for further research to find out whether the degree of vascularization of the thrombus may have a significant impact on the rupture of aneurysms.

  19. A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

    PubMed Central

    Rodriguez, Isaac A.; Sell, Scott A.; McCool, Jennifer M.; Saxena, Gunjan; Spence, Andrew J.; Bowlin, Gary L.

    2013-01-01

    The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma), hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone. PMID:24709699

  20. STRONTIUM PRECIPITATION

    DOEpatents

    McKenzie, T.R.

    1960-09-13

    A process is given for improving the precipitation of strontium from an aqueous phosphoric-acid-containing solution with nickel or cobalt ferrocyanide by simultaneously precipitating strontium or calcium phosphate. This is accomplished by adding to the ferrocyanide-containing solution calcium or strontium nitrate in a quantity to yield a concentration of from 0.004 to 0.03 and adjusting the pH of the solution to a value of above 8.

  1. Technical Report on Preliminary Methodology for Enhancing Risk Monitors with Integrated Equipment Condition Assessment

    SciTech Connect

    Ramuhalli, Pradeep; Coles, Garill A.; Coble, Jamie B.; Hirt, Evelyn H.

    2013-09-17

    Small modular reactors (SMRs) generally include reactors with electric output of ~350 MWe or less (this cutoff varies somewhat but is substantially less than full-size plant output of 700 MWe or more). Advanced SMRs (AdvSMRs) refer to a specific class of SMRs and are based on modularization of advanced reactor concepts. AdvSMRs may provide a longer-term alternative to traditional light-water reactors (LWRs) and SMRs based on integral pressurized water reactor concepts currently being considered. Enhancing affordability of AdvSMRs will be critical to ensuring wider deployment. AdvSMRs suffer from loss of economies of scale inherent in small reactors when compared to large (~greater than 600 MWe output) reactors. Some of this loss can be recovered through reduced capital costs through smaller size, fewer components, modular fabrication processes, and the opportunity for modular construction. However, the controllable day-to-day costs of AdvSMRs will be dominated by operation and maintenance (O&M) costs. Technologies that help characterize real-time risk are important for controlling O&M costs. Risk monitors are used in current nuclear power plants to provide a point-in-time estimate of the system risk given the current plant configuration (e.g., equipment availability, operational regime, and environmental conditions). However, current risk monitors are unable to support the capability requirements listed above as they do not take into account plant-specific normal, abnormal, and deteriorating states of active components and systems. This report documents technology developments that are a step towards enhancing risk monitors that, if integrated with supervisory plant control systems, can provide the capability requirements listed and meet the goals of controlling O&M costs. The report describes research results from an initial methodology for enhanced risk monitors by integrating real-time information about equipment condition and POF into risk monitors.

  2. Cyclic Dipeptide Shuttles as a Novel Skin Penetration Enhancement Approach: Preliminary Evaluation with Diclofenac

    PubMed Central

    Namjoshi, Sarika; Giralt, Ernest; Benson, Heather

    2016-01-01

    This study demonstrates the effectiveness of a peptide shuttle in delivering diclofenac into and through human epidermis. Diclofenac was conjugated to a novel phenylalanyl-N-methyl-naphthalenylalanine-derived diketopiperazine (DKP) shuttle and to TAT (a classical cell penetrating peptide), and topically applied to human epidermis in vitro. DKP and TAT effectively permeated into and through human epidermis. When conjugated to diclofenac, both DKP and TAT enhanced delivery into and through human epidermis, though DKP was significantly more effective. Penetration of diclofenac through human epidermis (to receptor) was increased by conjugation to the peptide shuttle and cell penetrating peptide with enhancement of 6x by DKP-diclofenac and 3x by TAT-diclofenac. In addition, the amount of diclofenac retained within the epidermis was significantly increased by peptide conjugation. COX-2 inhibition activity of diclofenac was retained when conjugated to DKP. Our study suggests that the peptide shuttle approach may offer a new strategy for targeted delivery of small therapeutic and diagnostic molecules to the skin. PMID:27548780

  3. Investigations into pulsed-high intensity focused ultrasound enhanced delivery: Preliminary evidence for a novel mechanism

    PubMed Central

    Hancock, Hilary A.; Smith, Lauren H.; Cuesta, Julian; Durrani, Amir K.; Angstadt, Mary; Palmeri, Mark L.; Kimmel, Eitan; Frenkel, Victor

    2009-01-01

    Pulsed-high intensity focused ultrasound (HIFU) exposures without ultrasound contrast agents have been used for non-invasively enhancing the delivery of various agents to improve their therapeutic efficacy in a variety of tissue models in a non-destructive manner. Despite the versatility of these exposures, little is known about the mechanisms by which their effects are produced. In this study pulsed-HIFU exposures were given in the flank muscle of mice, followed by the administration a variety of fluorophores, both soluble and particulate, by local or systemic injection. In vivo imaging (whole animal and microscopic) was used to quantify observations of increased extravasation and interstitial transport of the fluorophores as a result of the exposures. Histological analysis indicated that the exposures caused some structural alterations such as enlarged gaps between muscle fibers. These effects were consistent with increasing the permeability of the tissues; however they were found to be transient and reversed themselves gradually within 72 hrs. Simulations of radiation force induced displacements and the resulting local shear strain they produced were carried out to potentially explain the manner by which these effects occurred. A better understanding of the mechanisms involved with pulsed-HIFU exposures for non-invasively enhancing delivery will facilitate the process for optimizing their use. PMID:19616368

  4. Electrophysiological alterations during hypnosis for ego-enhancement: a preliminary investigation.

    PubMed

    Stevens, Larry; Brady, Brian; Goon, Angela; Adams, Deanna; Rebarchik, Jennifer; Gacula, Lisa; Johnson, Jeff; Wright, Chris; Hank, Nicole; McManus, Patrick; Arsuffi, Lara; Morris, Lisa; Verdugo, Sherri

    2004-04-01

    EEG activity at the midfrontal (Fz) region was recorded during pre- and postbaselines, live hypnotic induction, arm levitation and progressive relaxation (PNR) deepening, and therapeutic ego-enhancing suggestions among 60 college student volunteers, previously screened with the Stanford Hypnotic Susceptibility Scale, Form C. Comparisons across conditions for delta, theta, alpha, and beta activity were made between low, moderate, high, and very high hypnotizable groups. Results indicated (a) significant increases in theta EEGs across the hypnosis process with a peak at PNR and a drop in theta thereafter to termination, with highs showing significantly more dramatic effects than moderates; (b) a similar inverted U-shaped pattern for beta EEGs across hypnosis conditions, with very highs significantly higher in beta power than moderates and lows, and with highs significantly higher than moderates; (c) general profile differences between the highs for theta and the highs and very highs for beta in comparison to the moderates and lows, with peak theta and beta power occurring during ego-enhancing suggestions for more highly hypnotizable participants; (d) a drop in alpha EEGs across the trance process with a return to baseline after hypnosis, with moderates showing significantly lower alpha power; and (e) an increase in delta power across conditions to PNR and then a decrease to post-hypnosis baseline, with moderates significantly lower than highs.

  5. Selective enhancement of attentional networks in college table tennis athletes: a preliminary investigation.

    PubMed

    Wang, Biye; Guo, Wei; Zhou, Chenglin

    2016-01-01

    The purpose of the study was to investigate the characteristics of the attentional network in college table tennis athletes. A total of 65 college students categorized as table tennis athlete group or non-athlete group participated in the study. All participants completed the attentional network test (ANT) which measured the alerting, orienting and executive control networks. The results showed a significant difference between the athlete and non-athlete group for executive control network (p < 0.01), while no differences were observed for alerting (p > 0.05) or orienting (p > 0.05) networks. These results combined suggest that college table tennis athletes exhibited selectively enhanced executive control of attentional networks.

  6. Preliminary results with sutured colonic anastomoses reinforced with dye-enhanced fibrinogen and a diode laser

    NASA Astrophysics Data System (ADS)

    Libutti, Steven K.; Williams, Matthew R.; Oz, Mehmet C.; Forde, Kenneth A.; Bass, Lawrence S.; Weinstein, Samuel; Auteri, Joseph S.; Treat, Michael R.; Nowygrod, Roman

    1991-07-01

    A common cause of morbidity in patients recovering from bowel surgery is leakage from colonic anastomoses. A technique utilizing a laser activated protein solder to strengthen colonic anastomoses in a canine model was evaluated. Following creation of six single-layer interrupted suture anastomoses in four dogs, a protein solder consisting of indocyanine green dye and fibrinogen was topically appied to the serosal surface and exposed to 808 nm continuous wave diode laser energy. Immediately following anastomosis, the mean leakage pressure of sutures alone was 129 +/- 14 mm hg (n equals 6), while the mean leakage pressure of sutures reinforced with the laser welded solder was 312 +/- 32 mm hg (n equals 6) (p <0.001). Histologic examination of sections take through the anastomosis demonstrated a layer of fibrinogen across the anastomotic gap without evidence of thermal injury. Laser activated protein solder significantly enhances the immediate strength of sutured colonic anastomoses without causing appreciable thermal injury to surrounding tissues.

  7. Enhanced Contaminated Human Remains Pouch: initial development and preliminary performance assessments

    SciTech Connect

    Iseli, A.M.; Kwen, H.D.; Ul-Alam, M.; Balasubramanian, M.; Rajagopalan, S.

    2011-11-07

    The objective is to produce a proof of concept prototype Enhanced Contaminated Human Remains Pouch (ECHRP) with self-decontamination capability to provide increased protection to emergency response personnel. The key objective was to decrease the concentration of toxic chemicals through the use of an absorbent and reactive nanocellulose liner. Additionally, nanomaterials with biocidal properties were developed and tested as a 'stand-alone' treatment. The setting was a private company research laboratory. The main outcome measures were production of a functional prototype. A functional prototype capable of mitigating the threats due to sulfur mustard, Soman, and a large variety of liquid and vapor toxic industrial chemicals was produced. Stand-alone biocidal treatment efficacy was validated. The ECHRP provides superior protection from both chemical and biological hazards to various emergency response personnel and human remains handlers.

  8. Selective enhancement of attentional networks in college table tennis athletes: a preliminary investigation

    PubMed Central

    Wang, Biye; Guo, Wei

    2016-01-01

    The purpose of the study was to investigate the characteristics of the attentional network in college table tennis athletes. A total of 65 college students categorized as table tennis athlete group or non-athlete group participated in the study. All participants completed the attentional network test (ANT) which measured the alerting, orienting and executive control networks. The results showed a significant difference between the athlete and non-athlete group for executive control network (p < 0.01), while no differences were observed for alerting (p > 0.05) or orienting (p > 0.05) networks. These results combined suggest that college table tennis athletes exhibited selectively enhanced executive control of attentional networks. PMID:27957396

  9. MO-FG-BRA-08: A Preliminary Study of Gold Nanoparticles Enhanced Diffuse Optical Tomography

    SciTech Connect

    Xu, K; Dogan, N; Yang, Y

    2015-06-15

    Purpose: To develop an imaging method by using gold nanoparticles (GNP) to enhance diffuse optical tomography (DOT) for better tumor detection. Methods: Experiments were performed on a tissue-simulating cylindrical optical phantom (30mm diameter, 60mm length). The GNP used are gold nanorods (10nm diameter, 44nm length) with peak light absorption at 840nm. 0.085ml GNP colloid of 96nM concentration was loaded into a 6mm diameter cylindrical hole in the phantom. An 856nm laser beam (14mW) was used as light source to irradiate the phantom at multiple locations through rotating and elevating the phantom. A CCD camera captured the light transmission through the phantom for each irradiation with total 40 projections (8 rotation angles in 45degree steps and 5 elevations with 3mm apart). Cone beam CT of the phantom was used to generate the three-dimensional mesh for DOT reconstruction and to identify the true location of the GNP volume. A forward simulation was performed with known phantom optical properties to establish a relationship between the absorption coefficient and concentration of the GNP by matching the simulated and measured transmission. DOT image reconstruction was performed to restore the GNP within the phantom. In addition, a region-constrained reconstruction was performed by confining the solutions within the GNP volume detected from CT. Results: The position of the GNP volume was reconstructed with <2mm error. The reconstructed average GNP concentration within an identical volume was 104nM, 8% difference from the truth. When the CT was used as “a priori”, the reconstructed average GNP concentration was 239nM, about 2.5 times of the true concentration. Conclusion: This study is the first to demonstrate GNP enhanced DOT with phantom imaging. The GNP can be differentiated from their surrounding background. However, the reconstruction methods needs to be improved for better spatial and quantification accuracy.

  10. Quantitative dynamic contrast-enhanced MR imaging analysis of complex adnexal masses: a preliminary study.

    PubMed

    Thomassin-Naggara, Isabelle; Balvay, Daniel; Aubert, Emilie; Daraï, Emile; Rouzier, Roman; Cuenod, Charles A; Bazot, Marc

    2012-04-01

    To evaluate the ability of quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate malignant from benign adnexal tumours. Fifty-six women with 38 malignant and 18 benign tumours underwent MR imaging before surgery for complex adnexal masses. Microvascular parameters were extracted from high temporal resolution DCE-MRI series, using a pharmacokinetic model in the solid tissue of adnexal tumours. These parameters were tissue blood flow (F(T)), blood volume fraction (Vb), permeability-surface area product (PS), interstitial volume fraction (Ve), lag time (Dt) and area under the enhancing curve (rAUC). Area under the receiver operating curve (AUROC) was calculated as a descriptive tool to assess the overall discrimination of parameters. Malignant tumours displayed higher F(T), Vb, rAUC and lower Ve than benign tumours (P < 0.0001, P = 0.0006, P = 0.04 and P = 0.0002, respectively). F(T) was the most relevant factor for discriminating malignant from benign tumours (AUROC = 0.86). Primary ovarian invasive tumours displayed higher F(T) and shorter Dt than borderline tumours. Malignant adnexal tumours with associated peritoneal carcinomatosis at surgery displayed a shorter Dt than those without peritoneal carcinomatosis at surgery (P = 0.01). Quantitative DCE-MRI is a feasible and accurate technique to differentiate malignant from benign adnexal tumours and could potentially help oncologists with management decisions. Quantitative DCE MR imaging allows accurate differentiation between malignant and benign tumours. Quantitative DCE MRI may help predict peritoneal carcinomatosis associated with ovarian tumors. Quantitative DCE MRI helps distinguish between invasive and borderline primary ovarian tumours.

  11. SU-E-T-63: A Preliminary Study of Gold Nanoparticles Enhanced Cone Beam Computed Tomography

    SciTech Connect

    Chen, K; Sha, H; Yang, Y

    2015-06-15

    Purpose: Gold nanoparticles (GNPs) have potential of being used as a new-generation contrast agent to enhance CT imaging of cancer. This feasibility study is to determine the GNP concentration required to provide sufficient image contrast in small animal cone beam CT (CBCT) imaging. Methods: The GNPs used are nanorods with 10nm diameter and 44nm length. A 50µl GNP colloid with an original GNP concentration of 3.6mg/ml was diluted to five different concentrations at 2.4, 2.1, 2.0, 1.9 and 1.8mg/ml, respectively. The GNP colloid was enclosed in a 150µl vial, and the GNP colloid vial was submerged in a water bottle for CBCT. CBCTs were acquired with x-ray energy of 65kVp and tube current of 1.5mA. In addition, to evaluate the optimal x-ray energy for GNP detection in CBCT, the GNP colloid of 1.8mg/ml was also imaged at x-ray energy of 45kVp and 85kVp. Regions of interest were placed in axial CBCT slices contouring the GNP colloid volume and a same volume in the surrounding water to calculate the signal and contrast. Results: For the GNP colloid at concentrations of 3.6, 2.4, 2.1, 2.0, 1.9 and 1.8mg/ml, the image contrasts between GNP colloid and water were 68±4, 33±4, 23±3, 20±3, 13±4, and 10±3 HU, respectively. At 1.8mg/ml concentration level, the image contrasts were 16±3 and 7±4 HU, respectively, when the x-ray energy was set at 45kVp and 85kVp. Conclusion: The minimal GNP concentration required on our small animal CBCT was estimated to be around 1.8mg/ml due to the fact that the minimum image contrast for adequate differentiation in CT is about 8 HU. CBCT at lower x-ray energy, i.e. 45kVp, can provide better image contrast than at higher energies, i.e., 65kVp and 85kVp. A study of GNP enhanced CBCT for in vivo small animal imaging is ongoing efforts in our group.

  12. Novel spinal instrumentation to enhance osteogenesis and fusion: a preliminary study.

    PubMed

    MacEwan, Matthew R; Talcott, Michael R; Moran, Daniel W; Leuthardt, Eric C

    2016-09-01

    OBJECTIVE Instrumented spinal fusion continues to exhibit high failure rates in patients undergoing multilevel lumbar fusion or pseudarthrosis revision; with Grade II or higher spondylolisthesis; or in those possessing risk factors such as obesity, tobacco use, or metabolic disorders. Direct current (DC) electrical stimulation of bone growth represents a unique surgical adjunct in vertebral fusion procedures, yet existing spinal fusion stimulators are not optimized to enhance interbody fusion. To develop an advanced method of applying DC electrical stimulation to promote interbody fusion, a novel osteogenic spinal system capable of routing DC through rigid instrumentation and into the vertebral bodies was fabricated. A pilot study was designed to assess the feasibility of osteogenic instrumentation and compare the ability of osteogenic instrumentation to promote successful interbody fusion in vivo to standard spinal instrumentation with autograft. METHODS Instrumented, single-level, posterior lumbar interbody fusion (PLIF) with autologous graft was performed at L4-5 in adult Toggenburg/Alpine goats, using both osteogenic spinal instrumentation (plus electrical stimulation) and standard spinal instrumentation (no electrical stimulation). At terminal time points (3 months, 6 months), animals were killed and lumbar spines were explanted for radiographic analysis using a SOMATOM Dual Source Definition CT Scanner and high-resolution Microcat II CT Scanner. Trabecular continuity, radiodensity within the fusion mass, and regional bone formation were examined to determine successful spinal fusion. RESULTS Quantitative analysis of average bone density in pedicle screw beds confirmed that electroactive pedicle screws used in the osteogenic spinal system focally enhanced bone density in instrumented vertebral bodies. Qualitative and quantitative analysis of high-resolution CT scans of explanted lumbar spines further demonstrated that the osteogenic spinal system induced solid

  13. Relaxation enhanced compressed sensing three-dimensional black-blood vessel wall MR imaging: Preliminary studies.

    PubMed

    Li, Bo; Li, Hao; Li, Jun; Zhang, Yuchen; Wang, Xiaoying; Zhang, Jue; Dong, Li; Fang, Jing

    2015-09-01

    In this study, we sought to investigate the feasibility of a new technique termed relaxation enhanced compressed sensing three-dimensional motion-sensitizing driven equilibrium prepared 3D rapid gradient echo sequence (RECS-3D MERGE). The RECS-3D MERGE sequence consisted of a 3D MERGE sequence for imaging, a period of delay time (TD) for relaxation enhancement, and a pseudo-centric phase encoding order used for under-sampling acquisition to maintain scan efficiency. Seven healthy volunteers and six patients with 40% to 75% carotid artery stenosis were recruited in this study. Healthy subjects underwent 3D MERGE, RECS-3D MERGE and two-dimensional (2D) T1-weighted double inversion recovery fast spin echo (T1W DIR-FSE) scans. The signal ratio (SR) values of 21 RECS-3D MERGE scans were compared in order to determine the optimal scan parameter set of acceleration factor (AF) and delay time (TD) for RECS-3D MERGE sequence. Patients then underwent 3D MERGE, RECS-3D MERGE using the aforementioned optimal scan parameter set and 2D T1W DIR-FSE scans. Two radiologists, blinded to the imaging technique, qualitatively graded each image on a six-point ordinal scale. The highest value of SR occurred with the scan parameter set of 3-fold AF and 800ms TD. Compared to 3D MERGE, RECS-3D MERGE with the parameter set significantly improved the image quality for both healthy subjects and patients experiments, while the scan efficiency was not sacrificed. And no significant differences were observed in the subjective scores of RECS-3D MERGE and 2D T1W DIR-FSE image qualities. RECS-3D MERGE technique achieved significant improvement in black-blood image quality compared with 3D MERGE. And the image quality of this 3D rapid carotid black-blood imaging technique is comparable to 2D T1W DIR-FSE while it has much higher scan efficiency. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Enhanced Colloidal Stability of CeO2 Nanoparticles by Ferrous Ions: Adsorption, Redox Reaction, and Surface Precipitation.

    PubMed

    Liu, Xuyang; Ray, Jessica R; Neil, Chelsea W; Li, Qingyun; Jun, Young-Shin

    2015-05-05

    Due to the toxicity of cerium oxide (CeO2) nanoparticles (NPs), a better understanding of the redox reaction-induced surface property changes of CeO2 NPs and their transport in natural and engineered aqueous systems is needed. This study investigates the impact of redox reactions with ferrous ions (Fe2+) on the colloidal stability of CeO2 NPs. We demonstrated that under anaerobic conditions, suspended CeO2 NPs in a 3 mM FeCl2 solution at pH 4.8 were much more stable against sedimentation than those in the absence of Fe2+. Redox reactions between CeO2 NPs and Fe2+ lead to the formation of 6-line ferrihydrite on the CeO2 surfaces, which enhanced the colloidal stability by increasing the zeta potential and hydrophilicity of CeO2 NPs. These redox reactions can affect the toxicity of CeO2 NPs by increasing cerium dissolution, and by creating new Fe(III) (hydr)oxide reactive surface layers. Thus, these findings have significant implications for elucidating the phase transformation and transport of redox reactive NPs in the environment.

  15. Electrostatic Precipitator

    NASA Image and Video Library

    2017-06-09

    In their Swamp Works laboratory at NASA's Kennedy Space Center, Dr. Carlos Calle and Jay Phillips are testing an electrostatic precipitator using dust that closely approximates the make-up of that on Mars. They upgraded their electrostatic precipitator to fully simulate Martian atmosphere by designing and constructing a dust aerosolization pre-chamber. The agency's Journey to Mars requires cutting-edge technologies to solve the problems explorers will face on the Red Planet. Scientists are developing some of the needed solutions by adapting a device to remove the ever-present dust from valuable elements in the Martian atmosphere. Those commodities include oxygen, water and methane.

  16. Biodistribution of inhaled metal oxide nanoparticles mimicking occupational exposure: a preliminary investigation using enhanced darkfield microscopy.

    PubMed

    Guttenberg, Marissa; Bezerra, Leonardo; Neu-Baker, Nicole M; Del Pilar Sosa Idelchik, María; Elder, Alison; Oberdörster, Günter; Brenner, Sara A

    2016-10-01

    Inhalation exposure to engineered nanomaterials (ENMs) may result in adverse pulmonary and/or systemic health effects. In this study, enhanced darkfield microscopy (EDFM) was used as a novel approach to visualizing industrial metal oxide nanoparticles (NPs) (silica, ceria, or alumina) in multiple tissue types following inhalation in rats mimicking occupational exposures. Advantages of EDFM over electron microscopy (EM) include reduced cost, time, and ease of sample preparation and operation. Following 4-6 hour inhalation exposures at three concentrations (3.5-34.0 mg/m(3) ), lungs and secondary organs were harvested at 24 hours or 7 days post-exposure and prepared for brightfield (BF) microscopy and EDFM. NPs were visualized within the lung and associated lymphatic tissues and in major organs of excretion (liver, spleen, kidney). EDFM also revealed NPs within pulmonary blood vessels and localization within specific regions of toxicological relevance in liver and kidney, indicating pathways of excretion. Results demonstrate the utility of EDFM for rapid direct visualization of NPs in various tissue types and suggest the potential for metal oxide NPs to distribute to secondary tissues following inhalation exposure. Confirmation of the composition, distribution, and relative abundance of inhaled NPs will be pursued by combining EDFM with hyperspectral imaging (HSI) and mapping.

  17. Memory enhancement training for older adults with mild cognitive impairment: a preliminary study.

    PubMed

    Rapp, S; Brenes, G; Marsh, A P

    2002-02-01

    'Mild cognitive impairment' (MCI) in older adults refers to a significant decline in memory function but not other cognitive functions. Pharmacological and non-pharmacological treatments for MCI are needed. The present randomized clinical trial tests the efficacy of a cognitive and behavioral treatment to improve memory performance and participants' attitudes about their memory. A multi-faceted intervention that included education about memory loss, relaxation training, memory skills training, and cognitive restructuring for memory-related beliefs was compared to a no-treatment control condition. Outcomes included memory performance and appraisals of memory function and control. Results indicate that the treated group had significantly better memory appraisals than controls at the end of treatment and at a six-month follow-up. There were no differences between groups on memory performance at post-test but at follow-up the trained individuals showed a trend toward better word list recall than controls. Findings suggest that individuals with MCI can benefit from multi-component memory enhancement training. Further development of such training programs and tests of their efficacy alone and in combination with medications are needed.

  18. Antisolvent precipitation technique: A very promising approach to crystallize curcumin in presence of polyvinyl pyrrolidon for solubility and dissolution enhancement.

    PubMed

    Sadeghi, Fatemeh; Ashofteh, Mohammad; Homayouni, Alireza; Abbaspour, Mohammadreza; Nokhodchi, Ali; Garekani, Hadi Afrasiabi

    2016-11-01

    Curcumin with a vast number of pharmacological activities is a poorly water soluble drug which its oral bioavailability is profoundly limited by its dissolution or solubility in GI tract. Curcumin could be a good anticancer drug if its solubility could be increased. Therefore, the aim of the present study was to increase the dissolution rate of curcumin by employing antisolvent crystallization technique and to investigate the effect of polyvinyl pyrrolidone K30 (PVP) as colloidal particles in crystallization medium on resultant particles. Curcumin was crystalized in the presence of different amounts of PVP by antisolvent crystallization method and their physical mixtures were prepared for comparison purposes. The samples were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FT-IR). The solubility and dissolution of the treated and untreated curcumin were also determined. Antisolvent crystallization of curcumin led to the formation of particles with no definite geometric shape. It was interesting to note that the DSC and XRPD studies indicated the formation of a new polymorph and less crystallinity for particles crystallized in the absence of PVP. However, the crystallized curcumin in the presence of PVP was completely amorphous. All crystalized curcumin samples showed much higher dissolution rate compared to untreated curcumin. The amount of curcumin dissolved within 10 for treated curcumin in the presence of PVP (1:1 curcumin:PVP) was 7 times higher than untreated curcumin and this enhancement in the dissolution for curcumin samples crystallized in the absence of PVP was around 5 times. Overall' the results of this study showed that antisolvent crystallization method in the absence or presence of small amounts of PVP is very efficient in increasing the dissolution rate of curcumin to achieve better efficiency for curcumin.

  19. Preliminary results of BRAVO project: brain computer interfaces for Robotic enhanced Action in Visuo-motOr tasks.

    PubMed

    Bergamasco, Massimo; Frisoli, Antonio; Fontana, Marco; Loconsole, Claudio; Leonardis, Daniele; Troncossi, Marco; Foumashi, Mohammad Mozaffari; Parenti-Castelli, Vincenzo

    2011-01-01

    This paper presents the preliminary results of the project BRAVO (Brain computer interfaces for Robotic enhanced Action in Visuo-motOr tasks). The objective of this project is to define a new approach to the development of assistive and rehabilitative robots for motor impaired users to perform complex visuomotor tasks that require a sequence of reaches, grasps and manipulations of objects. BRAVO aims at developing new robotic interfaces and HW/SW architectures for rehabilitation and regain/restoration of motor function in patients with upper limb sensorimotor impairment through extensive rehabilitation therapy and active assistance in the execution of Activities of Daily Living. The final system developed within this project will include a robotic arm exoskeleton and a hand orthosis that will be integrated together for providing force assistance. The main novelty that BRAVO introduces is the control of the robotic assistive device through the active prediction of intention/action. The system will actually integrate the information about the movement carried out by the user with a prediction of the performed action through an interpretation of current gaze of the user (measured through eye-tracking), brain activation (measured through BCI) and force sensor measurements.

  20. A Preliminary Engineering Design of Intravascular Dual-Frequency Transducers for Contrast-Enhanced Acoustic Angiography and Molecular Imaging

    PubMed Central

    Ma, Jianguo; Martin, K. Heath; Dayton, Paul A.; Jiang, Xiaoning

    2014-01-01

    Current intravascular ultrasound (IVUS) probes are not optimized for contrast detection because of their design for high-frequency fundamental-mode imaging. However, data from transcutaneous contrast imaging suggests the possibility of utilizing contrast ultrasound for molecular imaging or vasa vasorum assessment to further elucidate atherosclerotic plaque deposition. This paper presents the design, fabrication, and characterization of a small-aperture (0.6 × 3 mm) IVUS probe optimized for high-frequency contrast imaging. The design utilizes a dual-frequency (6.5 MHz/30 MHz) transducer arrangement for exciting microbubbles at low frequencies (near their resonance) and detecting their broadband harmonics at high frequencies, minimizing detected tissue backscatter. The prototype probe is able to generate nonlinear microbubble response with more than 1.2 MPa of rarefractional pressure (mechanical index: 0.48) at 6.5 MHz, and is also able to detect microbubble response with a broadband receiving element (center frequency: 30 MHz, −6-dB fractional bandwidth: 58.6%). Nonlinear super-harmonics from microbubbles flowing through a 200-μm-diameter micro-tube were clearly detected with a signal-to-noise ratio higher than 12 dB. Preliminary phantom imaging at the fundamental frequency (30 MHz) and dual-frequency super-harmonic imaging results suggest the promise of small aperture, dual-frequency IVUS transducers for contrast-enhanced IVUS imaging. PMID:24801226

  1. Preliminary Analysis of Clinical Situations Involved in Quantification of Contrast-Enhanced Ultrasound in Crohn's Disease.

    PubMed

    Cheng, Wenjie; Gao, Xiang; Wang, Weili; Zhi, Min; Tang, Jian; Wen, Yan-Ling; Yu, Junli; Chen, Yao; Liu, Xiaoyin; Yang, Chuan; Hu, Pinjin; Liu, Guangjian

    2016-08-01

    To assess influencing factors for quantitative analysis of contrast-enhanced ultrasound (CEUS) in Crohn's disease (CD), dynamic CEUS examinations from 77 consecutive CD patients were recorded. Peak intensity (PI) values were calculated using the pre-installed quantification software of the ultrasound scanner. The influence of depth, pressure from the ultrasound probe and intraluminal gas was analyzed. The PI value of the anterior wall was lower than that of the posterior wall when the depth was ≤3.4 cm (17.9 dB vs. 21.3 dB; p < 0.05) or evident pressure was exerted (19.1 dB vs. 22.5 dB; p < 0.01). In the presence of intraluminal gas, the PI of the anterior wall was higher than that of the posterior wall (20.7 dB vs. 18.8 dB; p < 0.05). Nevertheless, no significant difference was found between the PI value of anterior and posterior walls when the depth was >3.4 cm (19.8 dB vs. 20.3 dB), moderate pressure was exerted (20.5 dB vs. 21.1 dB) or luminal gas was excluded between the two bowel walls (18.9 dB vs. 21.2 dB; p ≥ 0.05). The factors of depth, pressure from the ultrasound probe and intraluminal gas can affect the quantification results of CEUS. It is preferable to place the region of interest in the posterior wall when luminal gas is absent and in the anterior wall when luminal gas is present. In the latter case, more attention should be paid to reducing pressure by the ultrasound probe.

  2. Assessment of renal perfusion with contrast-enhanced ultrasound: Preliminary results in early diabetic nephropathies.

    PubMed

    Dong, Yi; Wang, Wen-Ping; Lin, Pan; Fan, Peili; Mao, Feng

    2016-01-01

    We performed a prospective study to evaluate the value of contrast-enhanced ultrasound (CEUS) in quantitative evaluation of renal cortex perfusion in patients suspected of early diabetic nephropathies (DN), with the estimated GFR (MDRD equation) as the gold standard. The study protocol was approved by the hospital review board; each patient gave written informed consent. Our study included 46 cases (21 males and 25 females, mean age 55.6 ± 4.14 years) of clinical confirmed early DN patients. After intravenous bolus injection of 1 ml sulfur hexafluoride microbubbles of ultrasound contrast agent, real time CEUS of renal cortex was performed successively using a 2-5 MHz convex probe. Time-intensity curves (TICs) and quantitative indexes were created with Qlab software. Receiver operating characteristic (ROC) curves were used to predict the diagnostic criteria of CEUS quantitative indexes, and their diagnostic efficiencies were compared with resistance index (RI) and peak systolic velocity (PSV) of renal segmental arteries by chi square test. Our control group included forty-five healthy volunteers. Difference was considered statistically significant with P <  0.05. Changes of area under curve (AUC), derived peak intensity (DPI) were statistically significant (P <  0.05). DPI less than 12 and AUC greater than 1400 had high utility in DN, with 71.7% and 67.3% sensitivity, 77.8% and 80.0% specificity. These results were significantly better than those obtained with RI and PSV which had no significant difference in early stage of DN (P > 0.05). CEUS might be helpful to improve early diagnosis of DN by quantitative analyses. AUC and DPI might be valuable quantitative indexes.

  3. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia.

    PubMed

    Iuculano, Teresa; Cohen Kadosh, Roi

    2014-01-01

    Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small-yet constant-current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education.

  4. Preliminary evidence for performance enhancement following parietal lobe stimulation in Developmental Dyscalculia

    PubMed Central

    Iuculano, Teresa; Cohen Kadosh, Roi

    2014-01-01

    Nearly 7% of the population exhibit difficulties in dealing with numbers and performing arithmetic, a condition named Developmental Dyscalculia (DD), which significantly affects the educational and professional outcomes of these individuals, as it often persists into adulthood. Research has mainly focused on behavioral rehabilitation, while little is known about performance changes and neuroplasticity induced by the concurrent application of brain-behavioral approaches. It has been shown that numerical proficiency can be enhanced by applying a small—yet constant—current through the brain, a non-invasive technique named transcranial electrical stimulation (tES). Here we combined a numerical learning paradigm with transcranial direct current stimulation (tDCS) in two adults with DD to assess the potential benefits of this methodology to remediate their numerical difficulties. Subjects learned to associate artificial symbols to numerical quantities within the context of a trial and error paradigm, while tDCS was applied to the posterior parietal cortex (PPC). The first subject (DD1) received anodal stimulation to the right PPC and cathodal stimulation to the left PPC, which has been associated with numerical performance's improvements in healthy subjects. The second subject (DD2) received anodal stimulation to the left PPC and cathodal stimulation to the right PPC, which has been shown to impair numerical performance in healthy subjects. We examined two indices of numerical proficiency: (i) automaticity of number processing; and (ii) mapping of numbers onto space. Our results are opposite to previous findings with non-dyscalculic subjects. Only anodal stimulation to the left PPC improved both indices of numerical proficiency. These initial results represent an important step to inform the rehabilitation of developmental learning disabilities, and have relevant applications for basic and applied research in cognitive neuroscience, rehabilitation, and education

  5. Electron irradiation of aluminium-zinc alloys. 3. Radiation-enhanced precipitation in an aluminium-4.5 at% zinc alloy

    NASA Astrophysics Data System (ADS)

    Zhang, Y. G.

    1989-06-01

    An aluminium-4.5 at% zinc alloy was irradiated at temperatures between 25 and 170°C to doses of 7 dpa to 14 dpa at a dose rate of ~3.88 × 10 -3dpa/s. Irradiation produced a very high density of coherent G.P. zones in the temperature range ~80-~130°C, coherent plate shaped precipitates in the temperature range ~130-~160°C and, under some irradiation conditions, large Zn precipitates on the foil surfaces. No precipitates occurred along the grain boundaries in the irradiated area. The matrix precipitation was interpreted in terms of the theory of Cauvin and Martin. The surface precipitation is ascribed to surface segregation of Zn and the non-appearance of precipitates along the grain boundaries in the irradiated area is thought to be due to the high metastability of the precipitates on the boundaries under irradiation.

  6. Precipitation Matters

    ERIC Educational Resources Information Center

    McDuffie, Thomas

    2007-01-01

    Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

  7. Precipitation Matters

    ERIC Educational Resources Information Center

    McDuffie, Thomas

    2007-01-01

    Although weather, including its role in the water cycle, is included in most elementary science programs, any further examination of raindrops and snowflakes is rare. Together rain and snow make up most of the precipitation that replenishes Earth's life-sustaining fresh water supply. When viewed individually, raindrops and snowflakes are quite…

  8. Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.

    PubMed

    Kamesh Iyer, Srikant; Tasdizen, Tolga; Burgon, Nathan; Kholmovski, Eugene; Marrouche, Nassir; Adluru, Ganesh; DiBella, Edward

    2016-09-01

    Current late gadolinium enhancement (LGE) imaging of left atrial (LA) scar or fibrosis is relatively slow and requires 5-15min to acquire an undersampled (R=1.7) 3D navigated dataset. The GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) based parallel imaging method is the current clinical standard for accelerating 3D LGE imaging of the LA and permits an acceleration factor ~R=1.7. Two compressed sensing (CS) methods have been developed to achieve higher acceleration factors: a patch based collaborative filtering technique tested with acceleration factor R~3, and a technique that uses a 3D radial stack-of-stars acquisition pattern (R~1.8) with a 3D total variation constraint. The long reconstruction time of these CS methods makes them unwieldy to use, especially the patch based collaborative filtering technique. In addition, the effect of CS techniques on the quantification of percentage of scar/fibrosis is not known. We sought to develop a practical compressed sensing method for imaging the LA at high acceleration factors. In order to develop a clinically viable method with short reconstruction time, a Split Bregman (SB) reconstruction method with 3D total variation (TV) constraints was developed and implemented. The method was tested on 8 atrial fibrillation patients (4 pre-ablation and 4 post-ablation datasets). Blur metric, normalized mean squared error and peak signal to noise ratio were used as metrics to analyze the quality of the reconstructed images, Quantification of the extent of LGE was performed on the undersampled images and compared with the fully sampled images. Quantification of scar from post-ablation datasets and quantification of fibrosis from pre-ablation datasets showed that acceleration factors up to R~3.5 gave good 3D LGE images of the LA wall, using a 3D TV constraint and constrained SB methods. This corresponds to reducing the scan time by half, compared to currently used GRAPPA methods. Reconstruction of 3D LGE images

  9. Controllable synthesis of spinel lithium nickel manganese oxide cathode material with enhanced electrochemical performances through a modified oxalate co-precipitation method

    NASA Astrophysics Data System (ADS)

    Liu, Hongmei; Zhu, Guobin; Zhang, Li; Qu, Qunting; Shen, Ming; Zheng, Honghe

    2015-01-01

    A spinel lithium nickel manganese oxide (LiNi0.5Mn1.5O4) cathode material is synthesized with a modified oxalate co-precipitation method by controlling pH value of the precursor solution and introducing excessive Li source in the precursor. All the samples synthesized through this method are of Fd3m phase with a small amount of P4332 phase. It is found that pH value of the precursor solution considerably affects the morphology, stoichiometry and crystallographic structure of the target material, thereby resulting in different amounts of Mn3+ (i.e., different degree of disorder). 5% excessive Li source in the precursor may compensate for the lithium loss during the high-temperature sintering process and eliminate the LixNi1-xO impurity phase. Under the optimized synthesis conditions, the obtained high-purity LiNi0.5Mn1.5O4 spinel exhibits enhanced electrochemical performances. A reversible capacity of ca. 140 mAh g-1 can be delivered at 0.1C and the electrode retains 106 mAh g-1 at 10C rate. When cycled at 0.2C, a capacity retention of more than 98% is obtained in the initial 50 electrochemical cycles.

  10. The effect of polymer-surfactant interaction on the rheological properties of surfactant enhanced alkaline flooding formulations. [Phase separation, precipitation and viscosity loss

    SciTech Connect

    French, T.R.; Josephson, C.B.

    1993-02-01

    Surfactant-enhanced, lower pH (weak) alkaline chemicals are effective for mobilizing residual oil. Polymer is used for mobility control because if mobility control is lost, then oil recovery is reduced. The ability to maintain mobility control during surfactant-alkaline flooding can be adversely affected by chemical interaction. In this work, interaction between polymers and surfactants was shown to be affected by pH, ionic strength, crude oil, and the properties of the polymers and surfactants. Polymer-surfactant interaction (phase separation, precipitation, and viscosity loss) occurred between most of the polymers and surfactants that were tested. Polymer-surfactant interaction is difficult to eliminate, and no method was found for completely eliminating interaction. Polymer-surfactant interaction occurred at optimal salinity and below optimal salinity. Polymer-surfactant interaction had an adverse effect on polymer rheology; however, the adverse effect of interaction on polymer rheology was lessened when oil was present. Increasing the pH of chemical systems further reduced the adverse effects of interaction on polymer rheology.

  11. Highly sensitive photoelectrochemical immunoassay with enhanced amplification using horseradish peroxidase induced biocatalytic precipitation on a CdS quantum dots multilayer electrode.

    PubMed

    Zhao, Wei-Wei; Ma, Zheng-Yuan; Yu, Pei-Pei; Dong, Xiao-Ya; Xu, Jing-Juan; Chen, Hong-Yuan

    2012-01-17

    Herein we demonstrate the protocol of a biocatalytic precipitation (BCP)-based sandwich photoelectrochemical (PEC) horseradish peroxidase (HRP)-linked immunoassay on the basis of their synergy effect for the ultrasensitive detection of mouse IgG (antigen, Ag) as a model protein. The hybrid film consisting of oppositely charged polyelectrolytes and CdS quantum dots (QDs) is developed by the classic layer by layer (LbL) method and then employed as the photoactive antibody (Ab) immobilization matrix for the subsequent sandwich-type Ab-Ag affinity interactions. Improved sensitivity is achieved through using the bioconjugates of HRP-secondary antibodies (Ab(2)). In addition to the much enhanced steric hindrance compared with the original one, the presence of HRP would further stimulate the BCP onto the electrode surface for signal amplification, concomitant to a competitive nonproductive absorption that lowers the photocurrent intensity. As a result of the multisignal amplification in this HRP catalyzed BCP-based PEC immunoassay, it possesses excellent analytical performance. The antigen could be detected from 0.5 pg/mL to 5.0 ng/mL with a detection limit of 0.5 pg/mL.

  12. Enhanced UVB emission and analysis of chemical states of Ca5(PO4)3OH:Gd3+,Pr3+ phosphor prepared by co-precipitation

    NASA Astrophysics Data System (ADS)

    Mokoena, P. P.; Nagpure, I. M.; Kumar, Vinay; Kroon, R. E.; Olivier, E. J.; Neethling, J. H.; Swart, H. C.; Ntwaeaborwa, O. M.

    2014-08-01

    Hydroxyapatite (Ca5(PO4)3OH) is a well-known bioceramic material used in medical applications because of its ability to form direct chemical bonds with living tissues. This mineral is currently used as a host for rare-earth ions (e.g. Gd3+, Pr3+, Tb3+, etc.) to prepare phosphors that can be used in light emitting devices of different types. In this study Ca5(PO4)3OH:Gd3+,Pr3+ phosphors were prepared by the co-precipitation method and were characterised by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, energy dispersive x-ray spectroscopy and photoluminescence spectroscopy. The x-ray diffraction pattern was consistent with the hexagonal phase of Ca5(PO4)3OH referenced in JCPDS card number 73-0293. The x-ray photoelectron spectroscopy data indicated that Ca2+ occupied two different lattice sites, referred to as Ca1 and Ca2. The photoluminescence data exhibited a narrowband emission located at 313 nm, which is associated with the 6P7/2→8S7/2 transition of the Gd3+ ion. This emission is classified as ultraviolet B and it is suitable for use in phototherapy lamps to treat various skin diseases. The photoluminescence intensity of the 313 nm emission was enhanced considerably by Pr3+ co-doping.

  13. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  14. Enhanced Preliminary Assessment

    DTIC Science & Technology

    1992-02-01

    TRADOC). Based on infor- mation obtained during and subsequent to a site visit ( 15 through 18 October 1991), 36 types of Areas Requiring...County, Indiana between 15 October and 18 October 1991. Past site conditions and management practices were evaluated based on readily available records and...Maintenance Shops (AREE 7) 3-13 3.2.2 Former Maintenance Shops (AREE 8) 3- 15 3.2.3 Wash Racks, Grease Racks, and Oil/Water Separators (AREE 9) 3-18

  15. Precipitation hardening austenitic superalloys

    DOEpatents

    Korenko, Michael K.

    1985-01-01

    Precipitation hardening, austenitic type superalloys are described. These alloys contain 0.5 to 1.5 weight percent silicon in combination with about 0.05 to 0.5 weight percent of a post irradiation ductility enhancing agent selected from the group of hafnium, yttrium, lanthanum and scandium, alone or in combination with each other. In addition, when hafnium or yttrium are selected, reductions in irradiation induced swelling have been noted.

  16. Electrostatic Precipitator

    NASA Image and Video Library

    2017-06-09

    Dr. Carlos Calle, lead scientist in the Kennedy Space Center's Electrostatics and Surface Physics Laboratory, left, and Jay Phillips, a research physicist, are modifying an electrostatic precipitator to help remove dust from simulated Martian atmosphere. NASA's Journey to Mars requires cutting-edge technologies to solve the problems explorers will face on the Red Planet. Scientists are developing some of the needed solutions by adapting a device to remove the ever-present dust from valuable elements in the Martian atmosphere. Those commodities include oxygen, water and methane.

  17. Electrostatic Precipitator

    NASA Image and Video Library

    2017-06-09

    Dr. Carlos Calle, lead scientist in the Kennedy Space Center's Electrostatics and Surface Physics Laboratory, left, and Jay Phillips, a research physicist, are modifying an electrostatic precipitator to help remove dust from a simulated Martian atmosphere. NASA's Journey to Mars requires cutting-edge technologies to solve the problems explorers will face on the Red Planet. Scientists are developing some of the needed solutions by adapting a device to remove the ever-present dust from valuable elements in the Martian atmosphere. Those commodities include oxygen, water and methane.

  18. Electrostatic Precipitator

    NASA Image and Video Library

    2017-06-09

    Jay Phillips, a research physicist in the Kennedy Space Center's Electrostatics and Surface Physics Laboratory, left, and Dr. Carlos Calle, lead scientist in the lab, are modifying an electrostatic precipitator to help remove dust from simulated Martian atmosphere. NASA's Journey to Mars requires cutting-edge technologies to solve the problems explorers will face on the Red Planet. Scientists are developing some of the needed solutions by adapting a device to remove the ever-present dust from valuable elements in the Martian atmosphere. Those commodities include oxygen, water and methane.

  19. The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Braun, Scott; Kummerow, Christian

    2000-01-01

    The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.

  20. The Global Precipitation Mission

    NASA Technical Reports Server (NTRS)

    Braun, Scott; Kummerow, Christian

    2000-01-01

    The Global Precipitation Mission (GPM), expected to begin around 2006, is a follow-up to the Tropical Rainfall Measuring Mission (TRMM). Unlike TRMM, which primarily samples the tropics, GPM will sample both the tropics and mid-latitudes. The primary, or core, satellite will be a single, enhanced TRMM satellite that can quantify the 3-D spatial distributions of precipitation and its associated latent heat release. The core satellite will be complemented by a constellation of very small and inexpensive drones with passive microwave instruments that will sample the rainfall with sufficient frequency to be not only of climate interest, but also have local, short-term impacts by providing global rainfall coverage at approx. 3 h intervals. The data is expected to have substantial impact upon quantitative precipitation estimation/forecasting and data assimilation into global and mesoscale numerical models. Based upon previous studies of rainfall data assimilation, GPM is expected to lead to significant improvements in forecasts of extratropical and tropical cyclones. For example, GPM rainfall data can provide improved initialization of frontal systems over the Pacific and Atlantic Oceans. The purpose of this talk is to provide information about GPM to the USWRP (U.S. Weather Research Program) community and to discuss impacts on quantitative precipitation estimation/forecasting and data assimilation.

  1. Creep Behavior and Degradation of Subgrain Structures Pinned by Nanoscale Precipitates in Strength-Enhanced 5 to 12 Pct Cr Ferritic Steels

    NASA Astrophysics Data System (ADS)

    Ghassemi Armaki, Hassan; Chen, Ruiping; Maruyama, Kouichi; Igarashi, Masaaki

    2011-10-01

    Creep behavior and degradation of subgrain structures and precipitates of Gr. 122 type xCr-2W-0.4Mo-1Cu-VNb ( x = 5, 7, 9, 10.5, and 12 pct) steels were evaluated during short-term and long-term static aging and creep with regard to the Cr content of steel. Creep rupture life increased from 5 to 12 pct Cr in the short-term creep region, whereas in the long-term creep region, it increased up to 9 pct Cr and then decreased with the addition of Cr from 9 to 12 pct. Behavior of creep rupture life was attributed to the size of elongated subgrains. In the short-term creep region, subgrain size decreased from 5 to 12 pct Cr, corresponding to the longer creep strength. However, in the long-term creep region after 104 hours, subgrain size increased up to 9 pct Cr and then decreased from 9 to 12 pct, corresponding to the behavior of creep rupture life. M23C6 and MX precipitates had the highest number fraction among all of the precipitates present in the studied steels. Cr concentration dependence of spacing of M23C6 and MX precipitates exhibited a V-like shape during short-term as well as long-term aging at 923 K (650 °C), and the minimum spacing of precipitates belonged to 9 pct Cr steel, corresponding to the lowest recovery speed of subgrain structures. In the short-term creep region, subgrain coarsening during creep was controlled by strain and proceeded slower with the addition of Cr, whereas in long-term creep region, subgrain coarsening was controlled by the stability of precipitates rather than due to the creep plastic deformation and took place faster from 9 to 12 pct and 9 to 5 pct Cr. However, M23C6 precipitates played a more important role than MX precipitates in the control of subgrain coarsening, and there was a closer correlation between spacing of M23C6 precipitates and subgrain size during static aging and long-term creep region.

  2. Precipitation zones of west-central Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Medina, Rose L.

    2007-01-01

    Whether Nevada can sustain its fast rate of growth depends in part on accurately quantifying the amount of water that is available, including precipitation. The Precipitation-Zone Method (PZM) is a way of estimating mean annual precipitation at any point. The PZM was developed using data from west-central Nevada and northeastern California, but preliminary analysis indicates it can be applied to the entire state. Patterns in the spatial distribution of precipitation were identified by mapping station locations and plotting 1971-2000 precipitation normals versus station elevation. Precipitation zones are large areas where precipitation is linearly related to elevation. Four precipitation zones with different linear relations were delineated; these zones cover much of west-central Nevada. Regression equations with adjusted R2 values of 0.89 to 0.95 were developed for each zone. All regression equations estimate similar precipitation rates at 4,000 feet, but the slopes of the regression equations become progressively shallower to the south. A geographic information system, 30-meter digital elevation model, and the regression equations were used to estimate the distribution and volumes of precipitation in each zone and in hydrographic areas of the Walker River Basin. Comparison between the PZM and Parameter-elevation Regressions on Independent Slopes Model (PRISM) indicate PRISM estimates are linearly related to elevation at low elevations in each zone, but PRISM estimates become non-linear at high elevations and are up to 2.5 times greater than the normals. However, PRISM under-estimates more than it over-estimates precipitation compared to the PZM. The PZM estimated the same or larger volumes of precipitation compared to PRISM in three of the zones, and the larger volumes mostly were from areas that receive greater than 15 inches/year of precipitation. Additional work is needed to accurately estimate mean annual precipitation throughout Nevada.

  3. Online Activities for Enhancing Sex Education Curricula: Preliminary Evidence on the Effectiveness of the Abstinence and Contraception Education Storehouse

    PubMed Central

    Raghupathy, Shobana; Klein, Charles; Card, Josefina

    2013-01-01

    The purpose of this research was to conduct a preliminary evaluation of the Abstinence and Contraception Education Storehouse (ACES), a digital, classroom-based resource designed to supplement existing sex education curricula with highly interactive materials such as video clips, multimedia polls and quizzes, and audiovisual demonstrations. 335 students ages 14–19 were randomly assigned to an ACES–based (treatment) or a standard (control) sex education curriculum. Data were collected at the onset of the intervention and 3-months after the completion of the intervention. Preliminary results were highly encouraging, with ACES participants who were sexually initiated at baseline reporting at the 3-month follow-up significant reductions in the number of times they had sex in the past four weeks. Both sexually initiated and non-sexually initiated youth who experienced the ACES curriculum also demonstrated greater intent to abstain from the sex during the follow-up period than those in the control group. PMID:24078799

  4. High-Throughput Screening of Potential Skin Penetration-Enhancers Using Stratum Corneum Lipid Liposomes: Preliminary Evaluation for Different Concentrations of Ethanol

    PubMed Central

    Kitao, Yuki

    2017-01-01

    In this study, we developed a technique for high-throughput screening (HTS) of skin penetration-enhancers using stratum corneum lipid liposomes (SCLLs). A fluorescent marker, sodium fluorescein (FL), entrapped in SCLLs was prepared to provide a preliminary evaluation of the effect of different concentrations of ethanol on the disruption effect of SCLLs, which is an alternative for skin penetration-enhancing effects. In addition, SCLLs containing a fluorescent probe (DPH, TMA-DPH, or ANS) were also prepared and utilized to investigate SCLL fluidity. The results using SCLL-based techniques were compared with conventional skin permeation and skin impedance test using hairless rat skin. The obtained correlations were validated between FL leakage, SCLL fluidity with various probes, or skin impedance and increases in the skin permeation enhancement ratio (ER) of caffeine as a model penetrant. As a result, FL leakage and SCLL fluidity using ANS were considered to be good indices for the skin penetration-enhancing effect, suggesting that the action of ethanol on the SC lipid and penetration-enhancing is mainly on the polar head group of intercellular lipids. In addition, this screening method using SCLL could be utilized as an alternative HTS technique for conventional animal tests. Simultaneously, the method was found to be time-saving and sensitive compared with a direct assay using human and animal skins. PMID:28321359

  5. Precipitation control and activation enhancement in boron-doped p{sup +}-BaSi{sub 2} films grown by molecular beam epitaxy

    SciTech Connect

    Khan, M. Ajmal; Nakamura, K.; Du, W.; Toko, K.; Usami, N.; Suemasu, T.

    2014-06-23

    Precipitation free boron (B)-doped as-grown p{sup +}-BaSi{sub 2} layer is essential for the BaSi{sub 2} p-n junction solar cells. In this article, B-doped p-BaSi{sub 2} layers were grown by molecular beam epitaxy on Si(111) substrates, and the influence of substrate growth temperature (T{sub S}) and B temperature (T{sub B}) in the Knudsen cell crucible were investigated on the formation of B precipitates and the activation efficiency. The hole concentration, p, reached 1.0 × 10{sup 19 }cm{sup −3} at room temperature for T{sub S} = 600 and T{sub B} = 1550 °C. However, the activation rate of B was only 0.1%. Furthermore, the B precipitates were observed by transmission electron microscopy (TEM). When the T{sub S} was raised to 650 °C and the T{sub B} was decreased to 1350 °C, the p reached 6.8 × 10{sup 19 }cm{sup −3}, and the activation rate increased to more than 20%. No precipitation of B was also confirmed by TEM.

  6. Ecohydro-geomorphic implications of orographic precipitation on landform evolution using a landscape evolution model

    NASA Astrophysics Data System (ADS)

    Yetemen, O.; Saco, P. M.

    2016-12-01

    Orography induced precipitation and its implications on vegetation dynamics and landscape morphology have long been documented in the literature. However a numerical framework that integrates a range of ecohydrologic and geomorphic processes to explore the coupled ecohydro-geomorphic landscape response of catchments where pronounced orographic precipitation prevails has been missing. In this study, our aim is to realistically represent orographic-precipitation-driven ecohydrologic dynamics in a landscape evolution model (LEM). The model is used to investigate how ecohydro-geomorphic differences caused by differential precipitation patterns on the leeward and windward sides of low-relief landscapes lead to differences in the organization of modelled topography, soil moisture and plant biomass. We use the CHILD LEM equipped with a vegetation dynamics component that explicitly tracks above- and below-ground biomass, and a precipitation forcing component that simulates rainfall as a function of elevation and orientation. The preliminary results of the model show how the competition between an increased shear stress through runoff production and an enhanced resistance force due to denser canopy cover shape the landscape. Moreover, orographic precipitation leads to not only the migration of the divide between leeward and windward slopes but also a change in the concavity of streams. These results clearly demonstrate the strong coupling between landform evolution and climate processes.

  7. Using hydrological modelling for a preliminary assessment of under-catch of precipitation in some Alpine Catchments of Sierra Nevada (Spain). Sensitivity to different conceptual approaches and spatio-temporal scale

    NASA Astrophysics Data System (ADS)

    Jimeno-Saez, Patricia; Pulido-Velazquez, David; Pegalajar-Cuellar, Manuel; Collados-Lara, Antonio-Juan; Pardo-Iguzquiza, Eulogio

    2017-04-01

    Precipitation (P) measurements show important biases due to under-catch, especially in windy conditions. Gauges modify the wind fields, producing important under-catch in solid P. In this work we intent to perform a global assessment of the under-catch phenomenon in some alpine catchments of Sierra Nevada Mountain Range (Spain) by using different conceptual hydrological models. They are based on the available information about daily natural streamflow and daily fields of P and temperature (T) in each catchment. We want to analyse long time periods (more than 20 years at daily scale) in order to obtain conclusions taking into account the stochastic behaviour of the natural streamflow and P and T variables. The natural streamflowin each basin has been obtained from the streamflow measurements in the gauges by making some simple mathematical operations to eliminate the anthropic influences. The daily climatic fieldswere estimated with spatial resolution of 1kmx1km by applying geostatistic techniques using data coming from 119climatic gauges existing in the area.We have considered to model options: Monthly and yearly variogram to characterize the spatial data correlation. The Elevation has been considered as secondary variable for the estimation. The analysis of the experimental data showed a linear relationhip between mean T and elevation. Therefore, we decided to apply a kriging with linear external drift to estimate the P and T fields. The mean daily P data show a quadratic relationship with the elevation. Different hypothesis have been considered to approach these P fields by applying kriging with linear drift, with quadratic drift, and regression kriging. A cross-validation analysis showed that the best approximation to the data is obtained with the kriging with linear drift. The P and T fields obtained with this technique were employed to feed different hydrological models in which different conceptual approaches of the hydrological processes related with the

  8. Tackling U.S. energy challenges and opportunities: preliminary policy recommendations for enhancing energy innovation in the United States

    SciTech Connect

    Anadon, Laura Diaz; Gallagher, Kelly Sims; Bunn, Matthew; Jones, Charles

    2009-02-18

    The report offers preliminary recommendations for near-term actions to strengthen the U.S. effort to develop and deploy advanced energy technologies. The report comes as the Obama Administration and the 111th U.S. Congress face enormous challenges and opportunities in tackling the pressing security, economic, and environmental problems posed by the energy sector. Improving the technologies of energy supply and end-use is a prerequisite for surmounting these challenges in a timely and cost-effective way, and this report elaborates on how policy can support develop of these important energy technologies.

  9. Ensemble Cannonical Correlation Prediction of Seasonal Precipitation Over the US

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong; Shen, Samuel; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This paper presents preliminary results of an ensemble cannonical correlation (ECC) prediction scheme developed at the Climate and Radiation Branch, NASA/Goddard Space Flight Center for determining the potential predictability of regional precipitation, and for climate downscaling studies. The scheme is tested on seasonal hindcasts of anomalous precipitation over the continental United States using global sea surface temperature (SST) for 1951-2000. To maximize the forecast skill derived from SST, the world ocean is divided into nonoverlapping sectors. The cannonical SST modes for each sector are used as the predictor for the ensemble hindcasts. Results show that the ECC yields a substantial (10-25%) increase in prediction skills for all regions of the US and for all seasonal compared to traditional CCA prediction schemes. For the boreal winter, the tropical Pacific contributes the largest potential predictability to precipitation in the southwestern and southeastern regions, while the North Pacific and the North Atlantic are responsible for enhanced forecast skills in the Pacific Northwest, the northern Great Plains and Ohio Valley. Most importantly, the ECC increases skill for summertime precipitation prediction and substantially reduced the spring predictability barrier over all regions of the US continent. Besides SST, the ECC is designed with the flexibility to include any number of predictor fields, such as soil moisture, snow cover and regional regional data. Moreover, the ECC forecasts can be applied to other climate subsystems and, in conjunction with further diagnostic or model studies will enables a better understanding of the dynamic links between climate variations and precipitation, not only for the US, but also for other regions of the world.

  10. Stable isotopes in alpine precipitation as tracers of atmospheric deposition

    NASA Astrophysics Data System (ADS)

    Wasiuta, V. L.; Lafreniere, M. J.; Kyser, T. K.; Norman, A. L.; Mayer, B.; Wieser, M.

    2010-12-01

    Alpine ecosystems, which are generally nutrient poor and exist under extreme climatic conditions, are particularly sensitive to environmental and climatic stressors. Studies in the USA Rocky Mountains and European Alps have shown that alpine terrestrial and aquatic ecosystems are particularly sensitive to enhanced deposition of reactive nitrogen and can show ecologically destructive responses at relatively low levels of nitrogen deposition. However, there is no base line for atmospheric deposition of natural and anthropogenic contaminants in the Canadian alpine. Preliminary results of isotopic and chemical analyses of precipitation from an elevational transect on a glaciated alpine site in the Canadian Rockies are presented. Precipitation accumulating from early autumn through to spring (2008/2009 and 2009/2010) was sampled by means of seasonal snow cover on alpine glaciers. Summer precipitation was sampled through July and August 2010 using bulk collectors installed at the sites of winter sampling. The isotope ratios of dissolved sulphate (δ34S, δ18O), nitrogen (δ15N, δ18O), as well as precipitation (δ2H, δ18O) are utilized in addition to major ion concentrations and trace metal concentrations. Results from 2008/2009 snowpack samples indicate a strong seasonal trend in sulphate (SO42-) and nitrogen (NO3-) deposition which is consistent across the altitudinal transect. Snow horizons representing early autumn and spring precipitation show higher SO42- and NO3- concentrations in contrast to lower concentrations in winter horizons. The aforementioned suite of isotopic and chemical analyses are used to investigate the variability in dominant geographic source regions for atmospheric SO42- and NO3- (local, regional, or long range transported contaminants), as well as to identify contributions from the major biogeochemical source types (e.g. hydrocarbon combustion, lithogenic dust, agricultural emissions).

  11. Grassland responses to precipitation extremes

    USDA-ARS?s Scientific Manuscript database

    Grassland ecosystems are naturally subjected to periods of prolonged drought and sequences of wet years. Climate change is expected to enhance the magnitude and frequency of extreme events at the intraannual and multiyear scales. Are grassland responses to extreme precipitation simply a response to ...

  12. Precipitation Indices Low Countries

    NASA Astrophysics Data System (ADS)

    van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

    2009-09-01

    Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period

  13. PRECIPITATION OF PLUTONOUS PEROXIDE

    DOEpatents

    Barrick, J.G.; Manion, J.P.

    1961-08-15

    A precipitation process for recovering plutonium values contained in an aqueous solution is described. In the process for precipitating plutonium as plutonous peroxide, hydroxylamine or hydrazine is added to the plutoniumcontaining solution prior to the addition of peroxide to precipitate plutonium. The addition of hydroxylamine or hydrazine increases the amount of plutonium precipitated as plutonous peroxide. (AEC)

  14. The efficiency of Gd-EOB-DTPA-enhanced magnetic resonance cholangiography in living donor liver transplantation: a preliminary study.

    PubMed

    Ogul, Hayri; Kantarci, Mecit; Pirimoglu, Berhan; Karaca, Leyla; Aydinli, Bulent; Okur, Aylin; Ozturk, Gurkan; Kizrak, Yesim

    2014-03-01

    The aim of this study was to evaluate utility of gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance cholangiography (MRC) for the detection of biliary complications after living donor liver transplantation (LDLT). A total of 18 patients with suspected biliary complications underwent MRC. T2-weighted MRC and contrast-enhanced MRC (CE-MRC) were used to identify the biliary complications. MRC included routine breath-hold T2-weighted MRC using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences and Gd-EOB-DTPA-enhanced MRC T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences. Before confirming the biliary complications, one observer reviewed the MRC images and the CE-MRC images separately. The verification procedures and MRC findings were compared, and the sensitivity, specificity, and accuracy of both techniques were calculated for the identification of biliary complications. The observer found six of seven biliary complications using CE-MRC. The sensitivity was 85.7% and the accuracy was 94.4%. Using MRC alone, sensitivity was 57.1% and accuracy was 55.5%. The accuracy of Gd-EOB-DTPA-enhanced MRC was superior to MRC in locating biliary leaks (p < 0.05). The usage of Gd-EOB-DTPA-enhanced MRC yields information that complements the MRC findings that improve the identification of biliary complications. We recommend the use of MRC in addition to Gd-EOB-DTPA-enhanced MRC to increase the preoperative accuracy when assessing the biliary complications after LDLT.

  15. Enhancement of activity of cross-linked enzyme aggregates by a sugar-assisted precipitation strategy: technical development and molecular mechanism.

    PubMed

    Wang, Mengfan; Qi, Wei; Jia, Chenxi; Ren, Yufei; Su, Rongxin; He, Zhimin

    2011-10-20

    The precipitation of enzyme causes the major activity loss in the conventional protocol for CLEAs preparation. Herein, a sugar-assisted strategy was developed to minimize the activity loss in the step of enzyme precipitation by adding sugar as the stabilizer, which contributed to improve the activity yield of resulting CLEAs. Penicillin G acylase (PGA) was employed as a model enzyme. The effects of glucose, sucrose and trehalose on the activity yields of CLEAs were investigated. The highest activity was obtained in the case of adding trehalose. Confocal laser scanning microscopy and Fourier transform infrared spectroscopy showed that the polar microenvironment and the secondary structure of native enzyme were preserved to some extent when PGA was prepared as sugar-assisted CLEAs, resulting in PGA's higher activity than sugar-free CLEAs. Scanning electron microscope revealed the different inner morphologies, and the kinetic studies showed the higher affinity and resist-inhibition capacity of sugar-assisted CLEAs. Furthermore, stability experiments demonstrated that CLEAs prepared in sugar-assisted strategy remained higher thermal stability when it was incubated at high temperature. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Experimental investigation of Mars meandering rivers: Chemical precipitation process

    NASA Astrophysics Data System (ADS)

    Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.

    2014-12-01

    On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.

  17. Studies on medicinal herbs for cognitive enhancement based on the text mining of Dongeuibogam and preliminary evaluation of its effects.

    PubMed

    Pak, Malk Eun; Kim, Yu Ri; Kim, Ha Neui; Ahn, Sung Min; Shin, Hwa Kyoung; Baek, Jin Ung; Choi, Byung Tae

    2016-02-17

    In literature on Korean medicine, Dongeuibogam (Treasured Mirror of Eastern Medicine), published in 1613, represents the overall results of the traditional medicines of North-East Asia based on prior medicinal literature of this region. We utilized this medicinal literature by text mining to establish a list of candidate herbs for cognitive enhancement in the elderly and then performed an evaluation of their effects. Text mining was performed for selection of candidate herbs. Cell viability was determined in HT22 hippocampal cells and immunohistochemistry and behavioral analysis was performed in a kainic acid (KA) mice model in order to observe alterations of hippocampal cells and cognition. Twenty four herbs for cognitive enhancement in the elderly were selected by text mining of Dongeuibogam. In HT22 cells, pretreatment with 3 candidate herbs resulted in significantly reduced glutamate-induced cell death. Panax ginseng was the most neuroprotective herb against glutamate-induced cell death. In the hippocampus of a KA mice model, pretreatment with 11 candidate herbs resulted in suppression of caspase-3 expression. Treatment with 7 candidate herbs resulted in significantly enhanced expression levels of phosphorylated cAMP response element binding protein. Number of proliferated cells indicated by BrdU labeling was increased by treatment with 10 candidate herbs. Schisandra chinensis was the most effective herb against cell death and proliferation of progenitor cells and Rehmannia glutinosa in neuroprotection in the hippocampus of a KA mice model. In a KA mice model, we confirmed improved spatial and short memory by treatment with the 3 most effective candidate herbs and these recovered functions were involved in a higher number of newly formed neurons from progenitor cells in the hippocampus. These established herbs and their combinations identified by text-mining technique and evaluation for effectiveness may have value in further experimental and clinical

  18. Preliminary MIPCC Enhanced F-4 and F-15 Preformance Characteristics for a First Stage Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Kloesel, Kurt J.; Clark, Casie M.

    2013-01-01

    Performance increases in turbojet engines can theoretically be achieved through Mass Injection Pre-Compressor Cooling (MIPCC), a process involving injecting water or oxidizer or both into an afterburning turbojet engine. The injection of water results in pre-compressor cooling, allowing the propulsion system to operate at high altitudes and Mach numbers. In this way, a MIPCC-enhanced turbojet engine could be used to power the first stage of a reusable launch vehicle or be integrated into an existing aircraft that could launch a 100-lbm payload to a reference 100-nm altitude orbit at 28 deg inclination. The two possible candidates for MIPCC flight demonstration that are evaluated in this study are the F-4 Phantom II airplane and the F-15 Eagle airplane (both of McDonnell Douglas, now The Boeing Company, Chicago, Illinois), powered by two General Electric Company (Fairfield, Connecticut) J79 engines and two Pratt & Whitney (East Hartford, Connecticut) F100-PW-100 engines, respectively. This paper presents a conceptual discussion of the theoretical performance of each of these aircraft using MIPCC propulsion techniques. Trajectory studies were completed with the Optimal Trajectories by Implicit Simulation (OTIS) software (NASA Glenn Research Center, Cleveland, Ohio) for a standard F-4 airplane and a standard F-15 airplane. Standard aircraft simulation models were constructed, and the thrust in each was altered in accordance with estimated MIPCC performance characteristics. The MIPCC and production aircraft model results were then reviewed to assess the feasibility of a MIPCC-enhanced propulsion system for use as a first-stage reusable launch vehicle; it was determined that the MIPCC-enhanced F-15 model showed a significant performance advantage over the MIPCC-enhanced F-4 model.

  19. Six month outcomes of a peer-enhanced community reinforcement approach for emerging adults with substance misuse: A Preliminary Study

    PubMed Central

    Smith, Douglas C.; Davis, Jordan P.; Ureche, Daniel J.; Dumas, Tara M.

    2015-01-01

    Little substance use disorder (SUD) treatment research with emerging adults ages 18–25 has been done in community settings, and it is well-known that peers influence emerging adult substance use. The purpose of this study was to develop and test the feasibility of a peer-enhanced behavioral treatment for emerging adults with substance use problems. Emerging adults (n = 35) received a peer-enhanced version of the Community Reinforcement Approach (Peer-CRA), in which their peers (n = 34) were trained to provide alcohol-specific social support. Both identified clients and peers were interviewed at treatment intake, and again three and six months later. Six month outcomes included days of abstinence adjusted for controlled environment days, social costs due to substance use, and binge drinking days in the past 90 days. Treatments were delivered with high fidelity, and a high proportion of participants were retained in treatment and follow-up assessments. Growth curve analyses revealed that emerging adults and their peers significantly increased their days of abstinence and reduced their binge drinking over time. Larger randomized trials should a) test whether peer-enhanced treatments are efficacious relative to treatment as usual, b) investigate whether secondary benefits exist for non-treatment seeking peers supporting another’s treatment, and c) examine whether proposed mechanisms of change (i.e., peer support and peer reductions in substance use) account for any differences in outcomes. PMID:26482135

  20. A preliminary test of the application of the Lightning Detection and Ranging System (LDAR) as a thunderstorm warning and location device for the FHA including a correlation with updrafts, turbulence, and radar precipitation echoes

    NASA Technical Reports Server (NTRS)

    Poehler, H. A.

    1978-01-01

    Results of a test of the use of a Lightning Detection and Ranging (LDAR) remote display in the Patrick AFB RAPCON facility are presented. Agreement between LDAR and radar precipitation echoes of the RAPCON radar was observed, as well as agreement between LDAR and pilot's visual observations of lightning flashes. A more precise comparison between LDAR and KSC based radars is achieved by the superposition of LDAR precipitation echoes. Airborne measurements of updrafts and turbulence by an armored T-28 aircraft flying through the thunderclouds are correlated with LDAR along the flight path. Calibration and measurements of the accuracy of the LDAR System are discussed, and the extended range of the system is illustrated.

  1. Precipitation Climate Data Records

    NASA Astrophysics Data System (ADS)

    Nelson, B. R.; Prat, O.; Vasquez, L.

    2015-12-01

    Five precipitation CDRs are now or soon will be transitioned to NOAA's CDR program. These include the PERSIANN data set, which is a 30-year record of daily adjusted global precipitation based on retrievals from satellite microwave data using artificial neural networks. The AMSU-A/B/Hydrobundle is an 11-year record of precipitable water, cloud water, ice water, and other variables. CMORPH (the NOAA Climate Prediction Center Morphing Technique) is a 17-year record of daily and sub-daily adjusted global precipitation measured from passive microwave and infrared data at high spatial and temporal resolution. GPCP (the Global Precipitation Climatology Project) is an approximately 30-year record of monthly and pentad adjusted global precipitation and a 17-year record of daily adjusted global precipitation. The NEXRAD Reanalysis is a 10-year record of high resolution NEXRAD radar based adjusted CONUS-wide hourly and daily precipitation. This study provides an assessment of the existing and transitioned long term precipitation CDRs and includes the verification of the five precipitation CDRs using various methods including comparison with in-situ data sets and trend analysis. As all of the precipitation related CDRs are transitioned, long term analyses can be performed. Comparisons at varying scales (hourly, daily and longer) of the precipitation CDRs with in-situ data sets are provided as well as a first look at what could be an ensemble long term precipitation data record.

  2. Percutaneous Ultrasound-Guided Laser Ablation with Contrast-Enhanced Ultrasonography for Hyperfunctioning Parathyroid Adenoma: A Preliminary Case Series

    PubMed Central

    Jiang, Tianan; Chen, Fen; Zhou, Xiang; Hu, Ying; Zhao, Qiyu

    2015-01-01

    The study was to evaluate the safety and effectiveness of ultrasound-guided percutaneous laser ablation (pLA) as a nonsurgical treatment for primary parathyroid adenoma. Surgery was contraindicated in, or refused by, the included patients. No lesion enhancement on contrast-enhanced ultrasound immediately after pLA was considered “complete ablation.” Nodule size, serum calcium, and parathyroid hormone level were compared before and after pLA. Complete ablation was achieved in all 21 patients with 1 (n = 20) or 2 (n = 1) sessions. Nodule volume decreased from 0.93 ± 0.58 mL at baseline to 0.53 ± 0.38 and 0.48 ± 0.34 mL at 6 and 12 months after pLA (P < 0.05). At 1 day, 6 months, and 12 months after pLA, serum PTH decreased from 15.23 ± 3.00 pmol/L at baseline to 7.41 ± 2.79, 6.95 ± 1.78, and 6.90 ± 1.46 pmol/L, serum calcium decreased from 3.77 ± 0.77 mmol/L at baseline to 2.50 ± 0.72, 2.41 ± 0.37, and 2.28 ± 0.26 mmol/L, respectively (P < 0.05). At 12 months, treatment success (normalization of PTH and serum calcium) was achieved in 81%. No serious complications were observed. Ultrasound-guided pLA with contrast-enhanced ultrasound is a viable alternative to surgery for primary parathyroid adenoma. PMID:26788059

  3. Preliminary Study of Oxygen-Enhanced Longitudinal Relaxation in MRI: A Potential Novel Biomarker of Oxygenation Changes in Solid Tumors

    SciTech Connect

    O'Connor, James P.B.; Naish, Josephine H.; Parker, Geoff J.M.; Waterton, John C.; Watson, Yvonne; Jayson, Gordon C.; Buonaccorsi, Giovanni A.; Cheung, Sue; Buckley, David L.; McGrath, Deirdre M.; West, Catharine M.L.; Davidson, Susan E.; Roberts, Caleb; Mills, Samantha J.; Mitchell, Claire L.; Hope, Lynn; Ton, N. Chan; Jackson, Alan

    2009-11-15

    Purpose: There is considerable interest in developing non-invasive methods of mapping tumor hypoxia. Changes in tissue oxygen concentration produce proportional changes in the magnetic resonance imaging (MRI) longitudinal relaxation rate (R{sub 1}). This technique has been used previously to evaluate oxygen delivery to healthy tissues and is distinct from blood oxygenation level-dependent (BOLD) imaging. Here we report application of this method to detect alteration in tumor oxygenation status. Methods and materials: Ten patients with advanced cancer of the abdomen and pelvis underwent serial measurement of tumor R{sub 1} while breathing medical air (21% oxygen) followed by 100% oxygen (oxygen-enhanced MRI). Gadolinium-based dynamic contrast-enhanced MRI was then performed to compare the spatial distribution of perfusion with that of oxygen-induced DELTAR{sub 1}. Results: DELTAR{sub 1} showed significant increases of 0.021 to 0.058 s{sup -1} in eight patients with either locally recurrent tumor from cervical and hepatocellular carcinomas or metastases from ovarian and colorectal carcinomas. In general, there was congruency between perfusion and oxygen concentration. However, regional mismatch was observed in some tumor cores. Here, moderate gadolinium uptake (consistent with moderate perfusion) was associated with low area under the DELTAR{sub 1} curve (consistent with minimal increase in oxygen concentration). Conclusions: These results provide evidence that oxygen-enhanced longitudinal relaxation can monitor changes in tumor oxygen concentration. The technique shows promise in identifying hypoxic regions within tumors and may enable spatial mapping of change in tumor oxygen concentration.

  4. PRELIMINARY DATA REPORT: HUMATE INJECTION AS AN ENHANCED ATTENUATION METHOD AT THE F-AREA SEEPAGE BASINS, SAVANNAH RIVER SITE

    SciTech Connect

    Millings, M.

    2013-09-16

    A field test of a humate technology for uranium and I-129 remediation was conducted at the F-Area Field Research Site as part of the Attenuation-Based Remedies for the Subsurface Applied Field Research Initiative (ABRS AFRI) funded by the DOE Office of Soil and Groundwater Remediation. Previous studies have shown that humic acid sorbed to sediments strongly binds uranium at mildly acidic pH and potentially binds iodine-129 (I-129). Use of humate could be applicable for contaminant stabilization at a wide variety of DOE sites however pilot field-scale tests and optimization of this technology are required to move this technical approach from basic science to actual field deployment and regulatory acceptance. The groundwater plume at the F-Area Field Research Site contains a large number of contaminants, the most important from a risk perspective being strontium-90 (Sr-90), uranium isotopes, I-129, tritium, and nitrate. Groundwater remains acidic, with pH as low as 3.2 near the basins and increasing to the background pH of approximately 5at the plume fringes. The field test was conducted in monitoring well FOB 16D, which historically has shown low pH and elevated concentrations of Sr-90, uranium, I-129 and tritium. The field test included three months of baseline monitoring followed by injection of a potassium humate solution and approximately four and half months of post monitoring. Samples were collected and analyzed for numerous constituents but the focus was on attenuation of uranium, Sr-90, and I-129. This report provides background information, methodology, and preliminary field results for a humate field test. Results from the field monitoring show that most of the excess humate (i.e., humate that did not sorb to the sediments) has flushed through the surrounding formation. Furthermore, the data indicate that the test was successful in loading a band of sediment surrounding the injection point to a point where pH could return to near normal during the study

  5. A Lunchtime Walk in Nature Enhances Restoration of Autonomic Control during Night-Time Sleep: Results from a Preliminary Study.

    PubMed

    Gladwell, Valerie F; Kuoppa, Pekka; Tarvainen, Mika P; Rogerson, Mike

    2016-03-03

    Walking within nature (Green Exercise) has been shown to immediately enhance mental well-being but less is known about the impact on physiology and longer lasting effects. Heart rate variability (HRV) gives an indication of autonomic control of the heart, in particular vagal activity, with reduced HRV identified as a risk factor for cardiovascular disease. Night-time HRV allows vagal activity to be assessed whilst minimizing confounding influences of physical and mental activity. The aim of this study was to investigate whether a lunchtime walk in nature increases night-time HRV. Participants (n = 13) attended on two occasions to walk a 1.8 km route through a built or a natural environment. Pace was similar between the two walks. HRV was measured during sleep using a RR interval sensor (eMotion sensor) and was assessed at 1-2 h after participants noted that they had fallen asleep. Markers for vagal activity were significantly greater after the walk in nature compared to the built walk. Lunchtime walks in nature-based environments may provide a greater restorative effect as shown by vagal activity than equivalent built walks. Nature walks may improve essential recovery during night-time sleep, potentially enhancing physiological health.

  6. A Lunchtime Walk in Nature Enhances Restoration of Autonomic Control during Night-Time Sleep: Results from a Preliminary Study

    PubMed Central

    Gladwell, Valerie F.; Kuoppa, Pekka; Tarvainen, Mika P.; Rogerson, Mike

    2016-01-01

    Walking within nature (Green Exercise) has been shown to immediately enhance mental well-being but less is known about the impact on physiology and longer lasting effects. Heart rate variability (HRV) gives an indication of autonomic control of the heart, in particular vagal activity, with reduced HRV identified as a risk factor for cardiovascular disease. Night-time HRV allows vagal activity to be assessed whilst minimizing confounding influences of physical and mental activity. The aim of this study was to investigate whether a lunchtime walk in nature increases night-time HRV. Participants (n = 13) attended on two occasions to walk a 1.8 km route through a built or a natural environment. Pace was similar between the two walks. HRV was measured during sleep using a RR interval sensor (eMotion sensor) and was assessed at 1–2 h after participants noted that they had fallen asleep. Markers for vagal activity were significantly greater after the walk in nature compared to the built walk. Lunchtime walks in nature-based environments may provide a greater restorative effect as shown by vagal activity than equivalent built walks. Nature walks may improve essential recovery during night-time sleep, potentially enhancing physiological health. PMID:26950138

  7. Bilateral Transcranial Direct Current Stimulation Language Treatment Enhances Functional Connectivity in the Left Hemisphere: Preliminary Data from Aphasia.

    PubMed

    Marangolo, Paola; Fiori, Valentina; Sabatini, Umberto; De Pasquale, Giada; Razzano, Carmela; Caltagirone, Carlo; Gili, Tommaso

    2016-05-01

    Several studies have already shown that transcranial direct current stimulation (tDCS) is a useful tool for enhancing recovery in aphasia. However, no reports to date have investigated functional connectivity changes on cortical activity because of tDCS language treatment. Here, nine aphasic persons with articulatory disorders underwent an intensive language therapy in two different conditions: bilateral anodic stimulation over the left Broca's area and cathodic contralesional stimulation over the right homologue of Broca's area and a sham condition. The language treatment lasted 3 weeks (Monday to Friday, 15 sessions). In all patients, language measures were collected before (T0) and at the end of treatment (T15). Before and after each treatment condition (real vs. sham), each participant underwent a resting-state fMRI study. Results showed that, after real stimulation, patients exhibited the greatest recovery not only in terms of better accuracy in articulating the treated stimuli but also for untreated items on different tasks of the language test. Moreover, although after the sham condition connectivity changes were confined to the right brain hemisphere, real stimulation yielded to stronger functional connectivity increase in the left hemisphere. In conclusion, our data provide converging evidence from behavioral and functional imaging data that bilateral tDCS determines functional connectivity changes within the lesioned hemisphere, enhancing the language recovery process in stroke patients.

  8. Co-evolution of landforms and vegetation under the influence of orographic precipitation

    NASA Astrophysics Data System (ADS)

    Yetemen, Omer; Srivastava, Ankur; Saco, Patricia M.

    2017-04-01

    Landforms are controlled by the interaction between tectonics, climate, and vegetation. Orography induced precipitation not only has implications on erosion resistance through vegetation dynamics but also affects erosive forces through modifying runoff production. The implications of elevated precipitation due to orography on landscape morphology requires a numerical framework that integrates a range of ecohydrologic and geomorphic processes to explore the competition between erosive and resisting forces in catchments where pronounced orographic precipitation prevails. In this study, our aim was to realistically represent ecohydrology driven by orographic precipitation and explore its implications on landscape evolution through a numerical model. The model was used to investigate how ecohydro-geomorphic differences caused by differential precipitation patterns as a result of orographic influence and rain-shadow effect lead to differences in the organization of modelled topography, soil moisture, and plant biomass. We use the CHILD landscape evolution model equipped with a vegetation dynamics component that explicitly tracks above- and below-ground biomass, and a precipitation forcing component that simulates rainfall as a function of elevation and orientation. The preliminary results of the model have shown how the competition between an increased shear stress through runoff production and an enhanced resistance force due to denser canopy cover, shape the landscape. Hillslope asymmetry between polar- and equator-facing hillslopes are enhanced (diminished) when they coincide with windward (leeward) side of the mountain series. The mountain divide accommodates itself by migrating toward the windward direction to increase (decrease) hillslope gradients on windward (leeward) slopes. These results clearly demonstrate the strong coupling between landform evolution and climate processes.

  9. Deposition of Sulphate and Nitrogen in Alpine Precipitation of the Southern Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wasiuta, V. L.; Lafreniere, M. J.

    2011-12-01

    Atmospheric nitrogen (N) and sulphur (S) are the main contributors to acid precipitation which causes regionally persistent ecological problems. Enhanced deposition of reactive N, mainly as nitrate (NO3-) and ammonium (NH4+), also contributes to major ecological problems associated with ecosystem N saturation. Alpine ecosystems, which are generally nutrient poor and exist under extreme climatic conditions, are sensitive to environmental and climatic stressors. Studies in the USA Rocky Mountains and European Alps have shown alpine ecosystems have a particularly sensitivity to enhanced deposition of reactive N and can show ecologically destructive responses at relatively low levels of N deposition. However, evaluation of atmospheric sulphur and nitrogen deposition in mid latitude alpine Western Canada has been initiated only very recently and at only a few locations. There is little comprehension of current atmospheric flux to high altitudes or the importance of contributions from major emission sources This work quantifies the atmospheric deposition of SO42- NH4+ and NO3- to a remote alpine site in the Southern Canadian Rocky Mountains by characterizing alpine precipitation. The effect of elevation and aspect on deposition are assessed using sampling sites along elevational transects in the adjacent Haig and Robertson Valleys. Seasonal variations in deposition of SO42- NH4+ and NO3- are evaluated using the autumn, winter, and spring precipitation accumulated in the seasonal snowpack at glacial and fore glacial locations, along with collected bulk summer precipitation. Preliminary results show lower precipitation volumes, which are associated with higher SO42- and NH4+ loads, in the north west facing Robertson Valley than the south east facing Haig Glacier. However trends in deposition of SO42- NH4+ and NO3- with elevation and aspect are inconsistent over the 2008-2009 and 2009-2010 snow accumulation seasons, and 2010 bulk summer precipitation seasons that were

  10. Supercritical fluid precipitation of ketoprofen in novel structured lipid carriers for enhanced mucosal delivery--a comparison with solid lipid particles.

    PubMed

    Gonçalves, V S S; Matias, A A; Rodríguez-Rojo, S; Nogueira, I D; Duarte, C M M

    2015-11-10

    Structured lipid carriers based on mixture of solid lipids with liquid lipids are the second generation of solid lipid particles, offering the advantage of improved drug loading capacity and higher storage stability. In this study, structured lipid carriers were successfully prepared for the first time by precipitation from gas saturated solutions. Glyceryl monooleate (GMO), a liquid glycerolipid, was selected in this work to be incorporated into three solid glycerolipids with hydrophilic-lipophilic balance (HLB) ranging from 1 to 13, namely Gelucire 43/01™, Geleol™ and Gelucire 50/13™. In general, microparticles with a irregular porous morphology and a wide particle size distribution were obtained. The HLB of the individual glycerolipids might be a relevant parameter to take into account during the processing of solid:liquid lipid blends. As expected, the addition of a liquid lipid into a solid lipid matrix led to increased stability of the lipid carriers, with no significant modifications in their melting enthalpy after 6 months of storage. Additionally, Gelucire 43/01™:GMO particles were produced with different mass ratios and loaded with ketoprofen. The drug loading capacity of the structured lipid carriers increased as the GMO content in the particles increased, achieving a maximum encapsulation efficiency of 97% for the 3:1 mass ratio. Moreover, structured lipid carriers presented an immediate release of ketoprofen from its matrix with higher permeation through a mucous-membrane model, while solid lipid particles present a controlled release of the drug with less permeation capacity.

  11. A preliminary study of spatial resolution enhancement of confocal and triangulation displacement meters using contact mode scanning probes.

    PubMed

    Gaitas, Angelo

    2008-02-01

    This paper presents a method for the spatial resolution enhancement of confocal and triangulation meters using cantilever probes. Integration of a cantilever with existing commercially available meters is substantially eased by the absence of feedback control of the cantilever position. Confocal and triangulation meters are used for a number of applications in research and industrial settings including thickness measurements, topography measurements, step height measurements, flatness measurements, and profile measurements. These instruments provide a vertical (out-of-plane) resolution of a few nanometers. However, they are limited in their spatial resolution to the laser beam diameter, which is typically larger than 2 microm and often about 20 microm. Using a cantilever probe to make contact with the sample, the lateral resolution of standard commercial instruments can be improved to less than 1 microm.

  12. PRELIMINARY RESULTS FROM NEOWISE: AN ENHANCEMENT TO THE WIDE-FIELD INFRARED SURVEY EXPLORER FOR SOLAR SYSTEM SCIENCE

    SciTech Connect

    Mainzer, A.; Bauer, J.; Masiero, J.; Eisenhardt, P.; Grav, T.; Cutri, R. M.; Dailey, J.; Alles, R.; Beck, R.; Brandenburg, H.; Conrow, T.; Evans, T.; Fowler, J.; Jarrett, T.; McMillan, R. S.; Wright, E.; Walker, R.; Jedicke, R.; Tholen, D.; Spahr, T.

    2011-04-10

    The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called 'NEOWISE' that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and {approx}120 comets. The NEOWISE data set will enable a panoply of new scientific investigations.

  13. Demonstrating Improvements from a NWP-based Satellite Precipitation Adjustment Technique in Tropical Mountainous Regions

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Anagnostou, E. N.

    2016-12-01

    This research contributes to the improvement of high resolution satellite applications in tropical regions with mountainous topography. Such mountainous regions are usually covered by sparse networks of in-situ observations while quantitative precipitation estimation from satellite sensors exhibits strong underestimation of heavy orographically enhanced storm events. To address this issue, our research applies a satellite error correction technique based solely on high-resolution numerical weather predictions (NWP). Our previous work has demonstrated the accuracy of this method in two mid-latitude mountainous regions (Zhang et al. 2013*1, Zhang et al. 2016*2), while the current research focuses on a comprehensive evaluation in three topical mountainous regions: Colombia, Peru and Taiwan. In addition, two different satellite precipitation products, NOAA Climate Prediction Center morphing technique (CMORPH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS), are considered. The study includes a large number of heavy precipitation events (68 events over the three regions) in the period 2004 to 2012. The NWP-based adjustments of the two satellite products are contrasted to their corresponding gauge-adjusted post-processing products. Preliminary results show that the NWP-based adjusted CMORPH product is consistently improved relative to both original and gauge-adjusted precipitation products for all regions and storms examined. The improvement of PERSIANN-CCS product is less significant and less consistent relative to the CMORPH performance improvements from the NWP-based adjustment. *1Zhang, Xinxuan, Emmanouil N. Anagnostou, Maria Frediani, Stavros Solomos, and George Kallos. "Using NWP simulations in satellite rainfall estimation of heavy precipitation events over mountainous areas." Journal of Hydrometeorology 14, no. 6 (2013): 1844-1858.*2 Zhang, Xinxuan, Emmanouil N. Anagnostou

  14. Slow release chelate enhancement of lead phytoextraction by corn (Zea mays L.) from contaminated soil--a preliminary study.

    PubMed

    Li, Haifeng; Wang, Qingren; Cui, Yanshan; Dong, Yiting; Christie, Peter

    2005-03-01

    Short-term enhancement of lead (Pb) and zinc (Zn) uptake by corn (Zea mays L.) seedlings from a contaminated soil was compared using slow-release coated EDTA granules-a coated chelating agent (CCA), uncoated EDTA granules, and EDTA solution in a greenhouse experiment. Soil Pb and Zn fractions were determined using a sequential extraction scheme. Release of the metals in the soil was examined in a column leaching study. After only 7 days of seedling growth, shoot biomass was decreased by all EDTA treatments compared with the zero-EDTA control. The amount of shoot biomass produced was highest with uncoated EDTA, intermediate with CCA, and lowest with the EDTA solution. Shoot Pb contents were highest with solid EDTA, intermediate with CCA, and lowest with EDTA solution, and they were always higher with EDTA treatments than in controls. In contrast, shoot Zn contents following EDTA treatments were lower than in the control. Levels of soil dissolved organic carbon (DOC) in aqueous soil extracts were much lower after CCA application than following treatments with solid EDTA and EDTA solution. After 17 days of plant growth, when most of the chelating agent had been released from the CCA, soil organic carbon levels remained relatively constant and similar to those in the control, indicating that a relatively low chelating agent concentration can be maintained for the plants to take up the metals. The distribution of Pb in the sequential extraction procedure showed that the Pb level in the exchangeable+carbonate-bound fraction with CCA was significantly lower than that with solid EDTA or EDTA solution, further indicating that slow release of CCA improves the bioavailability of metals in the soil to match plant uptake of those metals. The results suggest that CCA can enhance shoot content of Pb but not of Zn from the contaminated soil in the short term, and may also reduce the risk of metal leaching from the soil.

  15. Recombinant human TAT-OP1 to enhance NGF neurogenic potential: preliminary studies on PC12 cells.

    PubMed

    Di Liddo, R; Grandi, C; Venturini, M; Dalzoppo, D; Negro, A; Conconi, M T; Parnigotto, P P

    2010-11-01

    Osteogenic protein 1 (OP1), also known as bone morphogenic protein-7 (BMP7), is a multifunctional cytokine with demonstrated neurogenic potential. As the recombinant OP1 (rhOP1) was shown to provide axonal guidance cues and to prevent the reduction of dendritic growth in the injury-induced cortical cultures, it was suggested that an in vivo efficient rhOP1 delivery could enhance neurite growth and functional reconnectivity in the damaged brain. In the present work, we engineered a chimeric molecule in which rhBMP7 was fused to a protein transduction domain derived from HIV-1 TAT protein to deliver the denatured recombinant BMP7 into cells and obtain its chaperone-mediated folding, circumventing the expensive and not much efficient in vitro refolding procedures. When tested on rat PC12 cells, a widely used in vitro neurogenic differentiation model, the resulting fusion protein (rhTAT-OP1) demonstrated to enter fastly into the cells, lose HIV-TAT sequence and interact with membrane receptors activating BMP pathway by SMAD 1/5/8 phosphorylation. In comparison with nerve growth factor (NGF) and BMP7, it proved itself effective to induce the formation of more organized H and M neurofilaments. Moreover, if used in combination with NGF, it stimulated a significant (P < 0.05) and more precocious dendritic outgrowth with respect to NGF alone. These results indicate that rhTAT-OP1 fused with TAT transduction domain shows neurogenic activity and may be a promising enhancer factor in NGF-based therapies.

  16. In vitro model test and preliminary clinical application of a new method of ultrasonographic imaging: Vascular enhancement technology.

    PubMed

    Liu, Xi; Duan, Yun You; Wang, Jia; Sun, Si Guo; Li, Juan; Hou, Wei Hua; Cao, Tie Sheng

    2009-09-01

    Vascular enhancement technology (VET) is a new form of ultrasonographic technology that can optimize images by enhancing the B-mode display with information derived from power Doppler. We designed an in vitro model to evaluate the accuracy and application method of VET and to apply this technology preliminarily in vivo in the vascular periphery. An in vitro model was designed with a flow pump system to simulate blood flow in soft tissue and the intracranial vasculature. Modeling vessels were imaged by traditional B mode, color Doppler flow imaging and VET. The diameter of the various silicon tubes was measured to verify the accuracy of VET. For in vivo application, 15 normal subjects and 26 patients suspected of having carotid artery plaques and cerebrovascular disease were examined using these three image modes. The imaging effects were observed and compared. VET imaging could clarify the lumens of the modeling vessels and reduce artifacts. The caliber of three sizes of silicon tubing was also measured accurately by VET. Of 15 normal subjects, sound artifacts in large vessels were inhibited and the intermedia membrane was clearly displayed by VET. The boundaries of carotid plaques were manifested by VET with well-defined edges. Three cases of hypoechoic soft plaque on the anterior wall missed in B-mode imaging were detected by VET. Intracranial scanning with VET identified cerebral vascular disease, including cerebral stenosis, arteriovenous malformations and aneurysms. The size and shape of the focus displayed by VET coincided with that observed using digital subtraction arteriography. VET is helpful in improving detection of the boundary of vessels and visualization of the microvasculature.

  17. Spatial distribution of precipitation extremes in Norway

    NASA Astrophysics Data System (ADS)

    Verpe Dyrrdal, Anita; Skaugen, Thomas; Lenkoski, Alex; Thorarinsdottir, Thordis; Stordal, Frode; Førland, Eirik J.

    2015-04-01

    Estimates of extreme precipitation, in terms of return levels, are crucial in planning and design of important infrastructure. Through two separate studies, we have examined the levels and spatial distribution of daily extreme precipitation over catchments in Norway, and hourly extreme precipitation in a point. The analyses were carried out through the development of two new methods for estimating extreme precipitation in Norway. For daily precipitation we fit the Generalized Extreme Value (GEV) distribution to areal time series from a gridded dataset, consisting of daily precipitation during the period 1957-today with a resolution of 1x1 km². This grid-based method is more objective and less manual and time-consuming compared to the existing method at MET Norway. In addition, estimates in ungauged catchments are easier to obtain, and the GEV approach includes a measure of uncertainty, which is a requirement in climate studies today. Further, we go into depth on the debated GEV shape parameter, which plays an important role for longer return periods. We show that it varies according to dominating precipitation types, having positive values in the southeast and negative values in the southwest. We also find indications that the degree of orographic enhancement might affect the shape parameter. For hourly precipitation, we estimate return levels on a 1x1 km² grid, by linking GEV distributions with latent Gaussian fields in a Bayesian hierarchical model (BHM). Generalized linear models on the GEV parameters, estimated from observations, are able to incorporate location-specific geographic and meteorological information and thereby accommodate these effects on extreme precipitation. Gaussian fields capture additional unexplained spatial heterogeneity and overcome the sparse grid on which observations are collected, while a Bayesian model averaging component directly assesses model uncertainty. We find that mean summer precipitation, mean summer temperature, latitude

  18. Convective and stratiform precipitation trends in the Spanish Mediterranean coast

    NASA Astrophysics Data System (ADS)

    Ruiz Leo, Ana M.; Hernández Martín, Emiliano; Queralt, Sara; Cony, Marco Marco

    2010-05-01

    Eastern Iberian Peninsula is characterized by the large occurrence of convective precipitation events, which entail important economic and social damages. It is necessary to achieve a good knowledge and understanding of the meteorological processes involved. In this regard, an algorithm for classifying convective and stratiform precipitation components has been applied to a decadal precipitation record. Dataset were provided by National Spanish Meteorological Agency (AEMET) for the period 1998-2008. Hourly precipitation records have been analyzed. The goals of this study are: a) classifying total precipitation into its stratiform and convective components in Levante region (located in the Eastern Spanish coast) and b) analyzing annual and seasonal trends of such components. In order to determine both convective and stratiform precipitation components, a suitable exponential function has been used. After iterative computation process critical precipitation intensity (so-called Rc) is obtained for each year and season of the study period. Every precipitation episode in Levante region is classified into prevailing convective or stratiform regime according to the threshold value defined by Rc. First results show an annual and seasonal significant positive trend in total precipitation and stratiform component for 1998-2008 decade. Further analysis reveals that convective precipitation exhibits no significant trend. Therefore, preliminary conclusions state that the total precipitation amounts in Levante Region strongly depends on the stratiform component evolution. Current analyses are focused on evaluating the importance of convective precipitation component and assessing the main triggering factors involved in the severe weather episodes registered.

  19. Crystallization and preliminary X-ray diffraction analysis of the Pax9 paired domain bound to a DC5 enhancer DNA element.

    PubMed

    Narasimhan, Kamesh; Hilbig, Antonia; Udayasuryan, Barath; Jayabal, Sriram; Kolatkar, Prasanna R; Jauch, Ralf

    2014-10-01

    Pax genes belong to a family of metazoan transcription factors that are known to play a critical role in eye, ear, kidney and neural development. The mammalian Pax family of transcription factors is characterized by a ∼128-amino-acid DNA-binding paired domain that makes sequence-specific contacts with DNA. The diversity in Pax gene activities emerges from complex modes of interaction with enhancer regions and heterodimerization with multiple interaction partners. Based on in vitro optimal binding-site selection studies and enhancer identification assays, it has been suggested that Pax proteins may recognize and bind their target DNA elements with different binding modes/topologies, however this hypothesis has not yet been structurally explored. One of the most extensively studied DNA target elements of the Pax6 paired domain is the eye-lens specific DC5 (δ-crystallin) enhancer element. In order to shed light on Pax6-DC5 DNA interactions, the related paired-domain prototype Pax9 was crystallized with the minimal δ-crystallin DC5 enhancer element and preliminary X-ray diffraction analysis was attempted. A 3.0 Å resolution native data set was collected at the National Synchrotron Light Source (NSLS), Brookhaven from crystals grown in a solution consisting of 10%(w/v) PEG 20K, 20%(v/v) PEG 550 MME, 0.03 M NaNO3, 0.03 M Na2HPO4, 0.03 M NH2SO4, 0.1 M MES/imidazole pH 6.5. The data set was indexed and merged in space group C2221, with unit-cell parameters a = 75.74, b = 165.59, c = 70.14 Å, α = β = γ = 90°. The solvent content in the unit cell is consistent with the presence of one Pax9 paired domain bound to duplex DNA in the asymmetric unit.

  20. Dual-energy approach to contrast-enhanced mammography using the balanced filter method: Spectral optimization and preliminary phantom measurement

    SciTech Connect

    Saito, Masatoshi

    2007-11-15

    Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced filter method without switching the tube voltages is described. For the spectral optimization of dual-energy mammography using the balanced filters, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced filter material, and the optimization of the latter's thickness with respect to some critical quantity--in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:Tl scintillator, we predict that the optimal tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced filters. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm{sup 2} iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral optimization, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components - acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues.

  1. Perfusion of subchondral bone marrow in knee osteoarthritis: A dynamic contrast-enhanced magnetic resonance imaging preliminary study.

    PubMed

    Budzik, Jean-François; Ding, Juliette; Norberciak, Laurène; Pascart, Tristan; Toumi, Hechmi; Verclytte, Sébastien; Coursier, Raphaël

    2017-03-01

    The role of inflammation in the pathogenesis of osteoarthritis is being given major interest, and inflammation is closely linked with vascularization. It was recently demonstrated that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could identify the subchondral bone marrow vascularization changes occurring in osteoarthritis in animals. These changes appeared before cartilage lesions were visible and were correlated with osteoarthritis severity. Thus the opportunity to obtain an objective assessment of bone vascularization in non-invasive conditions in humans might help better understanding osteoarthritis pathophysiology and finding new biomarkers. We hypothesized that, as in animals, DCE-MRI has the ability to identify subchondral bone marrow vascularization changes in human osteoarthritis. We performed knee MRI in 19 patients with advanced knee osteoarthritis. We assessed subchondral bone marrow vascularization in medial and lateral femorotibial compartments with DCE-MRI and graded osteoarthritis lesions on MR images. Statistical analysis assessed intra- and inter-observer agreement, compared DCE-MRI values between the different subchondral zones, and sought for an influence of age, sex, body mass index, and osteoarthritis garde on these values. The intra- and inter-observer agreement for DCE-MRI values were excellent. These values were significantly higher in the femorotibial compartment the most affected by osteoarthritis, both in femur and tibia (p<0.0001) and were significantly and positively correlated with cartilage lesions (p=0.02) and bone marrow oedema grade (p<0.0001) after adjustment. We concluded that, as in animals, subchondral bone marrow vascularization changes assessed with DCE-MRI were correlated with osteoarthritis severity in humans.

  2. Contrast-enhanced ultrasonography in the diagnosis of upper urinary tract urothelial cell carcinoma: a preliminary study.

    PubMed

    Drudi, F M; Di Candio, G; Di Leo, N; Malpassini, F; Gnecchi, M; Cantisani, V; Iori, F; Liberatore, M

    2013-02-01

    The main objective was to assess the effectiveness of contrast-enhanced ultrasonography (CEUS) in the diagnosis of upper urinary tract malignancies by comparing with multidetector computed tomographic urography (MDCTU) and magnetic resonance urography (MRU). Secondary objectives were to compare the tumor size measured with CEUS, MDCTU and MRU and to assess the usefulness of CEUS in distinguishing high-grade tumors from low-grade ones. In connection with this prospective study carried out from January 2009 to September 2011, 18 patients underwent MDCTU or MRU, grayscale ultrasonography (US), color Doppler ultrasonography and CEUS followed by surgery and histological examination of the specimen. Quantitative analysis was performed using perfusion software. Time intensity curves were extracted and the following parameters were considered: wash-in time, time-to-peak, maximum signal intensity and wash-out time. Grayscale US identified 15/18 lesions; color Doppler showed no flow signal in 8 lesions, low color signal in 9 lesions and an intense color signal in 1 lesion; CEUS identified 17/18 lesions with the undetected lesion being the smallest one (1.2 cm) located in the upper pelvicalyceal system. Semi-quantitative analysis produced different data for high-grade and low-grade urothelial cell carcinoma (UCC). All detected upper urinary tract masses were UCCs. MRU, MDCTU and grayscale US overestimated the tumor size, while CEUS was the most accurate. CEUS is useful for evaluating upper urinary tract masses as this method permits differentiation between high-grade and low-grade tumors as well as distinction of the tumor from the adjacent structures and accurate mass measurements. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Preliminary Evidence That Anodal Transcranial Direct Current Stimulation Enhances Time to Task Failure of a Sustained Submaximal Contraction

    PubMed Central

    Williams, Petra S.; Hoffman, Richard L.; Clark, Brian C.

    2013-01-01

    The purpose of this study was to determine whether anodal transcranial direct current stimulation (tDCS) delivered while performing a sustained submaximal contraction would increase time to task failure (TTF) compared to sham stimulation. Healthy volunteers (n = 18) performed two fatiguing contractions at 20% of maximum strength with the elbow flexors on separate occasions. During fatigue task performance, either anodal or sham stimulation was delivered to the motor cortex for up to 20 minutes. Transcranial magnetic stimulation (TMS) was used to assess changes in cortical excitability during stimulation. There was no systematic effect of the anodal tDCS stimulation on TTF for the entire subject set (n = 18; p = 0.64). Accordingly, a posteriori subjects were divided into two tDCS-time groups: Full-Time (n = 8), where TTF occurred prior to the termination of tDCS, and Part-Time (n = 10), where TTF extended after tDCS terminated. The TTF for the Full-Time group was 31% longer with anodal tDCS compared to sham (p = 0.04), whereas TTF for the Part-Time group did not differ (p = 0.81). Therefore, the remainder of our analysis addressed the Full-Time group. With anodal tDCS, the amount of muscle fatigue was 6% greater at task failure (p = 0.05) and the amount of time the Full-Time group performed the task at an RPE between 8–10 (“very hard”) increased by 38% (p = 0.04) compared to sham. There was no difference in measures of cortical excitability between stimulation conditions (p = 0.90). That the targeted delivery of anodal tDCS during task performance both increased TTF and the amount of muscle fatigue in a subset of subjects suggests that augmenting cortical excitability with tDCS enhanced descending drive to the spinal motorpool to recruit more motor units. The results also suggest that the application of tDCS during performance of fatiguing activity has the potential to bolster the capacity to exercise under conditions

  4. Measurement of precipitation using lysimeters

    NASA Astrophysics Data System (ADS)

    Fank, Johann; Klammler, Gernot

    2013-04-01

    wind speeds and the measured outliers of lysimeter mass. Moreover, the influence of wind seems to be varying for different lysimeters. At the agricultural test site Wagna, Austria, two precipitation gauges in high temporal resolution (weighing-recording gauge and tipping-bucket gauge; both 200 cm² surface; measuring height 1.5 m) are installed. Furthermore, mass time series of various lysimeters cultivated with different vegetation is also available for the same location. Appropriate methods to compensate the influence of wind on measuring precipitation using lysimeters are investigated and results between the different measuring devices are compared. Results show that precipitation measured with lysimeters is generally higher, especially compared to the weighing-recording gauge. In addition it is detected that also the data interval of lysimeter mass time series used for quantifying precipitation (e.g., 1 day, 1 hour, 30 minutes, 10 minutes) is a crucial factor and influences the result. Summarizing, the potential of using highly precise weighable lysimeters for measuring precipitation at the point scale is rather high. However, methods used to compensate external effects on lysimeter weighing have to be enhanced for a global application of using lysimeters as precipitation gauges. Meissner, R., J. Seeger, H. Rupp, M. Seyfarth & H. Borg, 2007: Measurement of dew, fog, and rime with a high-precision gravitation Lysimeter. J. Plant Nutr. Soil Sci. 2007, 170, p. 335-344. WMO (World Meteorological Organization), 2008. Guide to Meteorological Instruments and Methods of Observation. WMO-No. 8, 140 pp.

  5. Precipitation Recycling in the NASA GEOS Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Bosilovich, Michael G.; Schubert, Siegfried; Molod, Andrea; Takacs, Lawrence L.

    1999-01-01

    Analysis of precipitation recycling can improve the understanding of regional hydrologic anomalies, especially their evolution and maintenance. Diagnostic models of the recycling of precipitation and are applied to 15 years of the NASA Goddard Earth Observing System (GEOS) Data Assimilation System (DAS). Recycled precipitation is defined as the fraction of precipitation within a given region that originated as surface evaporation from the same region. The focus of the present work is on the interannual variability of the central United States hydrologic cycle and precipitation recycling. The extreme years of 1988 (drought) and 1993 (flood) are compared with the 15 year base period mean annual cycle. The results indicate that recycling ratio (the amount of precipitation with a local source relative to the total precipitation) is greater in 1988 than both the base period mean and the 1993 season (with 1993 recycling ratio less than the mean). On the other hand, both the summers of 1988 and 1993 show less total recycled precipitation than the mean. The results also show that precipitation recycling may have been more important in the spring of 1993, when the region was primed for flooding, than the summer, when the sever flooding occurred. The diagnostic approaches to precipitation recycling suffer from some weaknesses. Numerical simulations and assimilation using passive tracers have the potential to provide more accurate calculations of precipitation recycling and the remote sources of water. This ability is being incorporated into the latest GEOS data assimilation system, and some preliminary results will be presented.

  6. Uncertainty Estimation of Global Precipitation Measurement through Objective Validation Strategy

    NASA Astrophysics Data System (ADS)

    KIM, H.; Utsumi, N.; Seto, S.; Oki, T.

    2014-12-01

    Since Tropical Rainfall Measuring Mission (TRMM) has been launched in 1997 as the first satellite mission dedicated to measuring precipitation, the spatiotemporal gaps of precipitation observation have been filled significantly. On February 27th, 2014, Dual-frequency Precipitation Radar (DPR) satellite has been launched as a core observatory of Global Precipitation Measurement (GPM), an international multi-satellite mission aiming to provide the global three hourly map of rainfall and snowfall. In addition to Ku-band, Ka-band radar is newly equipped, and their combination is expected to introduce higher precision than the precipitation measurement of TRMM/PR. In this study, the GPM level-2 orbit products are evaluated comparing to various precipitation observations which include TRMM/PR, in-situ data, and ground radar. In the preliminary validation over intercross orbits of DPR and TRMM, Ku-band measurements in both satellites shows very close spatial pattern and intensity, and the DPR is capable to capture broader range of precipitation intensity than of the TRMM. Furthermore, we suggest a validation strategy based on 'objective classification' of background atmospheric mechanisms. The Japanese 55-year Reanalysis (JRA-55) and auxiliary datasets (e.g., tropical cyclone best track) is used to objectively determine the types of precipitation. Uncertainty of abovementioned precipitation products is quantified as their relative differences and characterized for different precipitation mechanism. Also, it is discussed how the uncertainty affects the synthesis of TRMM and GPM for a long-term satellite precipitation observation records which is internally consistent.

  7. Resonance Emission Enhancement (REE) for Narrow Band Red-Emitting A2GeF6:Mn(4+) (A = Na, K, Rb, Cs) Phosphors Synthesized via a Precipitation-Cation Exchange Route.

    PubMed

    Lian, Hongzhou; Huang, Qingming; Chen, Yeqing; Li, Kai; Liang, Sisi; Shang, Mengmeng; Liu, Manman; Lin, Jun

    2017-10-02

    Narrow band red-emitting A2GeF6:Mn(4+) (A = Na, K, Rb, Cs) phosphors were prepared through a two-step precipitation-cation exchange route using a K2MnF6 precursor as the Mn(4+) source. The phase purity, morphology, and constituent were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectric spectroscopy (XPS), and electron paramagnetic resonance (EPR) examination. Optical properties were investigated by photoluminescence spectra (PL and PLE) and high-resolution PL. A temperature-dependent PL examination was performed to investigate the electron-phonon coupling emission mechanism of Mn(4+) in these alkali fluorogermanates. The PL data show that both ordered distribution and appropriate distance between Mn(4+) ions are propitious for enhancement of the emission intensity. A resonance emission enhancement (REE) mechanism has been proposed to explain the intensity increment among these products. These phosphors present bright red emission under blue light (467 nm) illumination, among which Cs2GeF6:0.03Mn(4+) exhibits the most excellent optical properties with a quantum yield (QY) of 93%. A WLED (white light-emitting diode) fabricated with blend of commercial YAG:Ce(3+) and this phosphor emits intense warm white light with low color temperature (CCT = 3385 K) and high color rendering index (Ra = 90.5), implying its potential application as red phosphor in WLEDs.

  8. Co-precipitation synthesis of nano-composites consists of zinc and tin oxides coatings on glass with enhanced photocatalytic activity on degradation of Reactive Blue 160 KE2B

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-01

    Nano-composite containing zinc oxide-tin oxide was obtained by a facile co-precipitation route using tin chloride tetrahydrate and zinc chloride as precursors and coated on glass by Doctor Blade deposition. The crystalline structure and morphology of composites were evaluated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The XRD results showed peaks relative to zinc oxide with hexagonal wurtzite structure and tin oxide with tetragonal structure. FESEM observations showed that the nano-composite consisted of aggregates of particles with an average particle size of 18 nm. The photocatalytic activity of the pure SnO2, pure ZnO, ZnSnO3-Zn2SnO4 and ZnO-SnO2 nano-structure thin films was examined using the degradation of a textile dye Reactive Blue 160 (KE2B). ZnO-SnO2 nano-composite showed enhanced photo-catalytic activity than the pure zinc oxide and tin oxide. The enhanced photo-catalytic activity of the nano-composite was ascribed to an improved charge separation of the photo-generated electron-hole pairs.

  9. Co-precipitation synthesis of nano-composites consists of zinc and tin oxides coatings on glass with enhanced photocatalytic activity on degradation of Reactive Blue 160 KE2B.

    PubMed

    Habibi, Mohammad Hossein; Mardani, Maryam

    2015-02-25

    Nano-composite containing zinc oxide-tin oxide was obtained by a facile co-precipitation route using tin chloride tetrahydrate and zinc chloride as precursors and coated on glass by Doctor Blade deposition. The crystalline structure and morphology of composites were evaluated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The XRD results showed peaks relative to zinc oxide with hexagonal wurtzite structure and tin oxide with tetragonal structure. FESEM observations showed that the nano-composite consisted of aggregates of particles with an average particle size of 18 nm. The photocatalytic activity of the pure SnO2, pure ZnO, ZnSnO3-Zn2SnO4 and ZnO-SnO2 nano-structure thin films was examined using the degradation of a textile dye Reactive Blue 160 (KE2B). ZnO-SnO2 nano-composite showed enhanced photo-catalytic activity than the pure zinc oxide and tin oxide. The enhanced photo-catalytic activity of the nano-composite was ascribed to an improved charge separation of the photo-generated electron-hole pairs.

  10. Global Precipitation Measurement

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.; Skofronick-Jackson, Gail; Kummerow, Christian D.; Shepherd, James Marshall

    2008-01-01

    This chapter begins with a brief history and background of microwave precipitation sensors, with a discussion of the sensitivity of both passive and active instruments, to trace the evolution of satellite-based rainfall techniques from an era of inference to an era of physical measurement. Next, the highly successful Tropical Rainfall Measuring Mission will be described, followed by the goals and plans for the Global Precipitation Measurement (GPM) Mission and the status of precipitation retrieval algorithm development. The chapter concludes with a summary of the need for space-based precipitation measurement, current technological capabilities, near-term algorithm advancements and anticipated new sciences and societal benefits in the GPM era.

  11. Cerium oxalate precipitation

    SciTech Connect

    Chang, T.P.

    1987-02-01

    Cerium, a nonradioactive, common stand-in for plutonium in development work, has been used to simulate several plutonium precipitation processes at the Savannah River Laboratory. There are similarities between the plutonium trifluoride and the cerium oxalate precipitations in particle size and extent of plating, but not particle morphology. The equilibrium solubility, precipitation kinetics, particle size, extent of plating, and dissolution characteristics of cerium oxalate have been investigated. Interpretations of particle size and plating based on precipitation kinetics (i.e., nucleation and crystal growth) are presented. 16 refs., 7 figs., 6 tabs.

  12. Phase Behavior, Solid Organic Precipitation, and Mobility Characterization Studies in Support of Enhanced Heavy Oil Recovery on the Alaska North Slope

    SciTech Connect

    Shirish Patil; Abhijit Dandekar; Santanu Khataniar

    2008-12-31

    The medium-heavy oil (viscous oil) resources in the Alaska North Slope are estimated at 20 to 25 billion barrels. These oils are viscous, flow sluggishly in the formations, and are difficult to recover. Recovery of this viscous oil requires carefully designed enhanced oil recovery processes. Success of these recovery processes is critically dependent on accurate knowledge of the phase behavior and fluid properties, especially viscosity, of these oils under variety of pressure and temperature conditions. This project focused on predicting phase behavior and viscosity of viscous oils using equations of state and semi-empirical correlations. An experimental study was conducted to quantify the phase behavior and physical properties of viscous oils from the Alaska North Slope oil field. The oil samples were compositionally characterized by the simulated distillation technique. Constant composition expansion and differential liberation tests were conducted on viscous oil samples. Experiment results for phase behavior and reservoir fluid properties were used to tune the Peng-Robinson equation of state and predict the phase behavior accurately. A comprehensive literature search was carried out to compile available compositional viscosity models and their modifications, for application to heavy or viscous oils. With the help of meticulously amassed new medium-heavy oil viscosity data from experiments, a comparative study was conducted to evaluate the potential of various models. The widely used corresponding state viscosity model predictions deteriorate when applied to heavy oil systems. Hence, a semi-empirical approach (the Lindeloff model) was adopted for modeling the viscosity behavior. Based on the analysis, appropriate adjustments have been suggested: the major one is the division of the pressure-viscosity profile into three distinct regions. New modifications have improved the overall fit, including the saturated viscosities at low pressures. However, with the limited

  13. Experience from practice: compound storm surge and high precipitation in a coastal area in the Netherlands

    NASA Astrophysics Data System (ADS)

    van Oldenborgh, Geert Jan; van den Hurk, Bart; van Heeringen, Klaas Jan; Gooijer, Jan

    2013-04-01

    In Januari 2012 a near-flooding occurred in Northern Netherlands by compound occurrence of a high soil moisture saturation degree due to past long term precipitation, a strong 1/10 year precipitation event and a coinciding storm surge that prevented the area to drain water to the Northsea for 5 days. The situation was nearly critical: reserved floodplains were used to reduce the water level in the populated areas, and evacuation plans were standby. After 5 days, the end of the storm surge allowed to discharge large water volumes, restoring the situation to normal conditions. The event has triggered the awareness in both the arenas of water management and science. Are the current standards adequate when these compound events occur more frequently than expected from random correlation? And do weather and climate modellers pay adequate attention to the output of their models that is truly meaningful to society, like combinations of strong winds over sea and high precipitation volumes in land? Preliminary analyses with observed records show that safety standards are sensitive to the assumed correlation between storm surge and local precipitation. Output from high resolution climate model projections for future conditions (with increased winter time precipitation and increased sea level) has been analysed particularly for climate induced chnages in the probability of simultaneous occurrence of these relevant events. Sea level rise is shown to give a pronounced contribution to an increased occurrence of adverse conditions, while increases in precipitation intensity weakly enhance this occurrence. The paper is concluded by a summary of required model experiments and analyses needed to address the influence of current and future compound events on safety standards in the coastal areas in the Netherlands.

  14. Microbially Catalyzed Calcite Precipitation in Porous Media: Potential for Geophysical Mapping of Precipitate Distribution

    NASA Astrophysics Data System (ADS)

    Fujita, Y.; Redden, G. D.; Smith, R. W.; Wu, Y.; Versteeg, R. J.

    2006-05-01

    Coprecipitation of trace metals in calcite offers a mechanism for in situ immobilization of inorganic contaminants in the subsurface. We have been investigating the potential for stimulating microbially mediated urea hydrolysis to promote the precipitation of calcium carbonate and the co-precipitation of trace metals as a method for treating 90Sr -contaminated systems. Urea hydrolysis results in an increase in both pH and carbonate alkalinity, and these factors can promote carbonate mineral precipitation. The ability to hydrolyze urea is widespread among subsurface microorganisms, and therefore remediation schemes based upon this approach could rely on indigenous organisms. In environments that favor calcite stability, which includes many aquifers in the western United States, this approach could result in long-term stabilization of the contaminants. Development of this concept into a practical remediation approach requires that we be able to control where precipitation occurs and at what rate. This requires a better understanding of the controls on the spatial distributions of mineral precipitation and the ureolysis reactions. A particular challenge is to understand how the system permeability and fluid flow changes over time, which is coupled to the precipitation rates and distribution of the precipitate. As part of our efforts to study these coupled processes, we are testing the application of complex resistivity (CR) as a means of mapping the distribution of precipitated calcite in a porous media column. CR measurements are sensitive to and are affected by chemical surface properties, porosity, grain size, and pore space distribution, and therefore we anticipate that mineral precipitation within the column will be detectable by CR. In this presentation we will report on our preliminary efforts to characterize the CR response within a porous media column where calcite precipitation is induced by extracellular ureolysis.

  15. Influence of ENSO and MJO Phases on Extreme Events of Precipitation over Amazon

    NASA Astrophysics Data System (ADS)

    Shimizu, M. H.; Ambrizzi, T.

    2014-12-01

    Several droughts and floods in Amazonia has occurred in the last years - some of them being classified as the most severe in the last 40 years - and future projections from Intergovernmental Panel on Climate Change (IPCC) indicate an increase of these extreme events. El Niño Southern Oscillation (ENSO) is one of the phenomena associated with extreme rainfall events in the Amazon. However, some recent studies have indicated that the basic response of ENSO is dependent on the phase of the Madden-Julian Oscillation (MJO). Hence, this study aims to analyze the influence of the MJO on the extreme events over northern South America, and especially over Amazon, in El Niño and La Niña years. We intend to explore the relative importance of the MJO to precipitation anomalies during ENSO events. Extreme events of precipitation over northern South America for the austral summer (November to March) were obtained through a composite analysis of the combinations of ENSO and MJO phases. The results showed that the MJO convection can enhance or weaken the basic response of ENSO on extreme precipitation events. Moreover, the results show that during positive extreme rainfall events (floods) over Amazon there is also an enhancement of the precipitation over the South Atlantic Convergence Zone (SACZ) when the MJO is active (inactive) in El Niño (La Niña) years. Air circulation at high levels were also analyzed and supports these patterns. Therefore, they suggest that the influence of ENSO may be modulate by the MJO phase. This work contributes to a better understanding of the climate variability and will be helpful for the forecast of ENSO effects on extreme events of temperature and precipitation over South America. Also, this study presents preliminary results of one of the Collaborative Researches in Support of GOAmazon Campaign Science, funding by U.S. Department of Energy (DoE) and São Paulo Research Foundation (FAPESP).

  16. Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography.

    PubMed

    Chu, W C W; Lam, W W M; Chan, K W; Yeung, C K; Lee, K H; Sihoe, J D Y

    2004-04-01

    To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function. Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies. Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23). These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

  17. Non-Precipitating Antithyroglubulin Studied by the Ouchterlony Technique

    PubMed Central

    Goudie, R. B.; Anderson, J. R.; Gray, Kathleen G.

    1959-01-01

    Non-precipitating antibody reacting with human thyroglobulin has been found in the serum of a patient with Hashimoto's disease. On Ouchterlony plates this antibody causes a clear line to develop in the slightly cloudy agar instead of the usual dense white precipitate: it is capable of blocking the action of certain precipitating Hashimoto sera, whereas other `enhancing' Hashimoto sera enable the non-precipitating serum to take part in precipitate formation. A consideration of this phenomenon suggests that the non-precipitating serum reacts at different sites on the same antigen molecule from the enhancing serum. This reaction provides a mechanism whereby two lines of precipitate may be formed in agar with a single pure antigen. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7FIG. 9 PMID:13828562

  18. Enhanced Al and Zn removal from coal-mine drainage during rapid oxidation and precipitation of Fe oxides at near-neutral pH

    USGS Publications Warehouse

    Burrows, Jill E.; Cravotta, Charles A.; Peters, Stephen C.

    2017-01-01

    Net-alkaline, anoxic coal-mine drainage containing ∼20 mg/L FeII and ∼0.05 mg/L Al and Zn was subjected to parallel batch experiments: control, aeration (Aer 1 12.6 mL/s; Aer 2 16.8 mL/s; Aer 3 25.0 mL/s), and hydrogen peroxide (H2O2) to test the hypothesis that aeration increases pH, FeII oxidation, hydrous FeIII oxide (HFO) formation, and trace-metal removal through adsorption and coprecipitation with HFO. During 5.5-hr field experiments, pH increased from 6.4 to 6.7, 7.1, 7.6, and 8.1 for the control, Aer 1, Aer 2, and Aer 3, respectively, but decreased to 6.3 for the H2O2 treatment. Aeration accelerated removal of dissolved CO2, Fe, Al, and Zn. In Aer 3, dissolved Al was completely removed within 1 h, but increased to ∼20% of the initial concentration after 2.5 h when pH exceeded 7.5. H2O2 promoted rapid removal of all dissolved Fe and Al, and 13% of dissolved Zn.Kinetic modeling with PHREEQC simulated effects of aeration on pH, CO2, Fe, Zn, and Al. Aeration enhanced Zn adsorption by increasing pH and HFO formation while decreasing aqueous CO2 available to form ZnCO30 and Zn(CO3)22− at high pH. Al concentrations were inconsistent with solubility control by Al minerals or Al-containing HFO, but could be simulated by adsorption on HFO at pH < 7.5 and desorption at higher pH where Al(OH)4− was predominant. Thus, aeration or chemical oxidation with pH adjustment to ∼7.5 could be effective for treating high-Fe and moderate-Zn concentrations, whereas chemical oxidation without pH adjustment may be effective for treating high-Fe and moderate-Al concentrations.

  19. PRECIPITATION OF PROTACTINIUM

    DOEpatents

    Moore, R.L.

    1958-07-15

    An lmprovement in the separation of protactinium from aqueous nitric acid solutions is described. 1t covers the use of lead dioxide and tin dioxide as carrier precipitates for the protactinium. In carrying out the process, divalent lead or divalent tin is addcd to the solution and oxidized, causing formation of a carrier precipitate of lead dioxide or stannic oxide, respectively.

  20. Ensemble Canonical Correlation Prediction of Seasonal Precipitation Over the United States: Raising the Bar for Dynamical Model Forecasts

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong; Shen, S. P.

    2001-01-01

    This paper presents preliminary results of an ensemble canonical correlation (ECC) prediction scheme developed at the Climate and Radiation Branch, NASA/Goddard Space Flight Center for determining the potential predictability of regional precipitation, and for climate downscaling studies. The scheme is tested on seasonal hindcasts of anomalous precipitation over the continental United States using global sea surface temperature (SST) for 1951-2000. To maximize the forecast skill derived from SST, the world ocean is divided into non-overlapping sectors. The canonical SST modes for each sector are used as the predictor for the ensemble hindcasts. Results show that the ECC yields a substantial (10-25%) increase in prediction skills for all the regions of the US in every season compared to traditional CCA prediction schemes. For the boreal winter, the tropical Pacific contributes the largest potential predictability to precipitation in the southwestern and southeastern regions, while the North Pacific and the North Atlantic are responsible to the enhanced forecast skills in the Pacific Northwest, the northern Great Plains and Ohio Valley. Most importantly, the ECC increases skill for summertime precipitation prediction and substantially reduces the spring predictability barrier over all the regions of the US continent. Besides SST, the ECC is designed with the flexibility to include any number of predictor fields, such as soil moisture, snow cover and additional local observations. The enhanced ECC forecast skill provides a new benchmark for evaluating dynamical model forecasts.

  1. Ensemble Canonical Correlation Prediction of Seasonal Precipitation Over the United States: Raising the Bar for Dynamical Model Forecasts

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong; Shen, S. P.

    2001-01-01

    This paper presents preliminary results of an ensemble canonical correlation (ECC) prediction scheme developed at the Climate and Radiation Branch, NASA/Goddard Space Flight Center for determining the potential predictability of regional precipitation, and for climate downscaling studies. The scheme is tested on seasonal hindcasts of anomalous precipitation over the continental United States using global sea surface temperature (SST) for 1951-2000. To maximize the forecast skill derived from SST, the world ocean is divided into non-overlapping sectors. The canonical SST modes for each sector are used as the predictor for the ensemble hindcasts. Results show that the ECC yields a substantial (10-25%) increase in prediction skills for all the regions of the US in every season compared to traditional CCA prediction schemes. For the boreal winter, the tropical Pacific contributes the largest potential predictability to precipitation in the southwestern and southeastern regions, while the North Pacific and the North Atlantic are responsible to the enhanced forecast skills in the Pacific Northwest, the northern Great Plains and Ohio Valley. Most importantly, the ECC increases skill for summertime precipitation prediction and substantially reduces the spring predictability barrier over all the regions of the US continent. Besides SST, the ECC is designed with the flexibility to include any number of predictor fields, such as soil moisture, snow cover and additional local observations. The enhanced ECC forecast skill provides a new benchmark for evaluating dynamical model forecasts.

  2. Catalyzed precipitation in aluminum

    NASA Astrophysics Data System (ADS)

    Mitlin, David

    The work reported in Chapter 1 concerned the influence of Si on the precipitation of theta' (metastable Al2Cu) during the isothermal aging of Al-2Cu-1Si (wt. %). The binary alloys Al-2Cu and Al-1Si were studied for comparison. Only two precipitate phases were detected: pure Si in Al-Si and Al-Cu-Si, and theta' (metastable Al 2Cu) in Al-Cu and Al-Cu-Si. On aging the ternary, Si precipitates first, and provides heterogeneous sites to nucleate theta'. As a consequence, the density of theta' precipitates in Al-Cu-Si is much higher than in the binary Al-Cu. Also, the theta ' precipitates in the ternary alloy have lower aspect ratio (at given particle size) and lose coherence on their broad faces at a slower rate. The principal focus of Chapter 2 is to explain precipitation in Al-lat.%Si-lat%Ge. The microstructure is characterized using conventional and high resolution transmission electron microscopy, as well as energy dispersive X-ray spectroscopy. The first precipitates to come out of solid solution have a cube-cube orientation relationship with the matrix. High resolution TEM demonstrated that all the precipitates start out, and remain multiply twinned throughout the aging treatment. There is a variation in the stoichiometry of the precipitates, with the mean composition being Si-44.5at%Ge. It is also shown that in Al-Si-Ge it is not possible to achieve satisfactory hardness through a conventional heat treatment. This result is explained in terms of sluggish precipitation of the diamond-cubic Si-Ge phase coupled with particle coarsening. The purpose of Chapters 3 and 4 is to explain these properties in terms of the role that the Si-Ge additions have on modifying the conventional Al-Cu aging sequence. In both AlCu and AlCuSiGe the room temperature microstructure consists of both GP zones and theta″ precipitates. Upon aging at 190°C Al-Cu displays the well known precipitation sequence; the slow dissolution of GP zones and theta″ and the gradual formation of theta

  3. Effect of transition metals on oxygen precipitation in silicon

    NASA Astrophysics Data System (ADS)

    Talvitie, H.; Haarahiltunen, A.; Yli-Koski, M.; Savin, H.; Sinkkonen, J.

    2008-03-01

    Effects of iron and copper impurities on the amount of precipitated oxygen and the oxide precipitate and stacking fault densities in Czochralski-grown silicon have been studied under varying thermal anneals. Silicon wafers were intentionally contaminated with iron or copper and subsequently subjected to different two-step heat treatments to induce oxygen precipitation. The iron contamination level was 2 × 1013 cm-3 and copper contamination level 6 × 1013 cm-3. Experiments did not show that iron contamination would have any effect on the amount of precipitated oxygen or the defect densities. Copper contamination tests showed some indication of enhanced oxygen precipitation.

  4. Precipitation sensitivity to warming estimated from long island records

    NASA Astrophysics Data System (ADS)

    Polson, D.; Hegerl, G. C.; Solomon, S.

    2016-07-01

    Some of the most damaging impacts of climate change are a consequence of changes to the global water cycle. Atmospheric warming causes the water cycle to intensify, increasing both atmospheric water vapor concentrations and global precipitation and enhancing existing patterns of precipitation minus evaporation (P - E). This relationship between temperature and precipitation therefore makes understanding how precipitation has changed with global temperatures in the past crucial for projecting changes with future warming. In situ observations cannot readily estimate global precipitation sensitivity to temperature (dP/dT), as land precipitation changes are affected by water limitation. Satellite observations of precipitation over ocean are only available after 1979, but studies based on them suggest a precipitation sensitivity over wet tropical (30N-30S) oceans that exceeds the Clausius-Clapeyron value. Here, we determine for the first time precipitation sensitivity using longer (1930-2005), island-based in situ observations to estimate dP/dT over islands. The records show a robust pattern of increasing precipitation in the tropics and decreasing precipitation in the subtropics, as predicted from physical arguments, and heavy precipitation shows a stronger sensitivity than mean precipitation over many islands. The pattern and magnitude of island-based dP/dT agree with climate models if masked to island locations, supporting model predictions of future changes.

  5. Potential impact of acid precipitation on arsenic and selenium.

    PubMed Central

    Mushak, P

    1985-01-01

    The potential impact of acidic precipitation on the environmental mobility of the metalloids arsenic (As) and selenium (Se) has not been given much attention and is poorly understood. As with other elements, the interest here is the potential effect of environmental acidification on environmental behavior in ways that are relevant to human exposure to these metalloids. Available information on acid precipitation and the environmental behavior of these metalloids do, however, permit some preliminary conclusions to be drawn. Both As and Se appear to be mobilized from household plumbing into tap water by the corrosive action of soft, mildly acidic water, while surface water catchment systems in areas impacted by acidic deposition may contain elevated soluble As levels. Acidification of aquatic ecosystems that are drinking water sources may pose the prospect of enhanced release of As from sediment to water as well as reduction in water levels of Se. Acidification of ground waters, where As appears to be especially mobile, is of particular concern in this regard. The potential impact of acidic deposition on As and Se in soils cannot readily be assessed with respect to human exposure, but it would appear that the behavior of these metalloids in poorly buffered, poorly immobilizing soils, e.g., sandy soils of low metal hydrous oxide content, would be most affected. The effect is opposite for the two elements; lowered pH would appear to enhance As mobility and to reduce Se availability. Altered acidity of both soil and aquatic systems poses a risk for altered biotransformation processes involving both As and Se, thereby affecting the relative amounts of different chemical forms varying in their toxicity to humans as well as influencing biogeochemical cycling. PMID:4076075

  6. Energetic particle precipitation effects on the Northern Hemisphere stratosphere observed by LIMS

    NASA Astrophysics Data System (ADS)

    Holt, L. A.; Randall, C. E.; Harvey, L.; Funke, B.; Stiller, G. P.

    2009-12-01

    Energetic particle precipitation (EPP) in the upper atmosphere contributes to polar stratospheric enhancements of NOx. The first experimental evidence of this emerged when the Limb Infrared Monitor of the Stratosphere (LIMS) observed stratospheric NOx enhancements during the Arctic winter of 1978/79. Such enhancements have since been observed on numerous occasions, but until recently were much less obvious in the Northern Hemisphere than in the Southern Hemisphere. It is now understood that the magnitude of these stratospheric NOx enhancements depends on both the level of EPP and dynamical conditions. Three out of the last six Arctic winters have seen much larger than average polar stratospheric NOx enhancements due to EPP that have been attributed to extraordinary meteorological events. These are unique events on record and affirm that even with low levels of EPP, the stratosphere can still be influenced to a large degree by EPP. In this study, data from the LIMS instrument is revisited in order to understand the NOx enhancement it observed with respect to meteorological conditions and EPP activity. The temporal evolution of NOx in the polar vortex as measured by LIMS is compared to more recent satellite data, including the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. Preliminary results indicate that the enhancements are caused neither by elevated EPP nor unusual dynamical conditions, but rather are seen because of the ability of LIMS to observe in the polar night.

  7. Precipitation Estimates for Hydroelectricity

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

    2011-01-01

    Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

  8. My NASA Data Precipitation

    NASA Image and Video Library

    This lesson has two activities that help students develop a basic understanding of the relationship between cloud type and the form of precipitation and the relationship between the amount of water...

  9. IMERG Global Precipitation Rates

    NASA Image and Video Library

    NASA's Global Precipitation Measurement mission has produced its first global map of rainfall and snowfall. The GPM Core Observatory launched one year ago on Feb. 27, 2014 as a collaboration betwee...

  10. Chemisorption And Precipitation Reactions

    EPA Science Inventory

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  11. Chemisorption And Precipitation Reactions

    EPA Science Inventory

    The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

  12. Precipitation Estimates for Hydroelectricity

    NASA Technical Reports Server (NTRS)

    Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

    2011-01-01

    Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

  13. Integration of deployable fluid lenses and reflectors with endoluminal therapeutic ultrasound applicators: Preliminary investigations of enhanced penetration depth and focal gain.

    PubMed

    Adams, Matthew S; Salgaonkar, Vasant A; Scott, Serena J; Sommer, Graham; Diederich, Chris J

    2017-07-06

    , with greater achievable performance using perfluorocarbon lens fluid. Simulations of a 50 mm balloon OD, 10 mm transducer outer diameter (OD), 1.5 MHz assembly in water resulted in maximum intensity gain of ~170 (focal dimensions: ~12 mm length × 1.4 mm width) at ~5 cm focal depth and focal gains above 100 between 24 and 84 mm depths. A smaller (10 mm balloon OD, 4 mm transducer OD, 1.5 MHz) configuration produced a maximum gain of 6 at 9 mm depth. Compared to a conventional applicator with a fixed spherically focused transducer of 12 mm diameter, focal gain was enhanced at depths beyond 20 mm for assembly configurations with balloon diameters ≥ 20 mm. Hydrophone characterizations of the experimental assembly (31 mm reflector/lens diameter, 4.75 mm transducer radius, 1.7 MHz) illustrated focusing at variable depths between 10-70 mm with a maximum gain of ~60 and demonstrated agreement with theoretical simulations. Biothermal simulations (30 s sonication, 75 °C maximum) indicate that investigated applicator assembly configurations, at 30 mm and 50 mm balloon diameters, could create localized ellipsoidal thermal lesions increasing in size from 10 to 55 mm length × 3-6 mm width in liver tissue as target depth increased from 2 to 10 cm. Preliminary theoretical and experimental analysis demonstrates that combining endoluminal ultrasound with an expandable acoustic reflector and fluid lens assembly can significantly enhance acoustic focal gain and penetration from inherently smaller diameter catheter-based applicators. © 2017 American Association of Physicists in Medicine.

  14. Mercury Wet Scavenging and Deposition Differences by Precipitation Type.

    PubMed

    Kaulfus, Aaron S; Nair, Udaysankar; Holmes, Christopher D; Landing, William M

    2017-03-07

    We analyze the effect of precipitation type on mercury wet deposition using a new database of individual rain events spanning the contiguous United States. Measurements from the Mercury Deposition Network (MDN) containing single rainfall events were identified and classified into six precipitation types. Mercury concentrations in surface precipitation follow a power law of precipitation depth that is modulated by precipitation system morphology. After controlling for precipitation depth, the highest mercury deposition occurs in supercell thunderstorms, with decreasing deposition in disorganized thunderstorms, quasi-linear convective systems (QLCS), extratropical cyclones, light rain, and land-falling tropical cyclones. Convective morphologies (supercells, disorganized, and QLCS) enhance wet deposition by a factor of at least 1.6 relative to nonconvective morphologies. Mercury wet deposition also varies by geographic region and season. After controlling for other factors, we find that mercury wet deposition is greater over high-elevation sites, seasonally during summer, and in convective precipitation.

  15. Calcium Carbonate Precipitation by Ureolytic Subsurface Bacteria

    SciTech Connect

    Fujita, Y.; Colwell, Frederick Scott; Smith, Robert William; Ferris, F. G.; Lawson, R. L.

    2000-10-01

    Coprecipitation in carbonate minerals offers a means of slowing the transport of divalent radionuclides and contaminant metals (e.g.,90Sr2+, UO2+, Co2+) in the subsurface. It may be possible to accelerate this process by stimulating the native microbial community to generate chemical conditions favoring carbonate precipitation. In a preliminary evaluation of this approach, we investigated the ability of ureolytic subsurface bacteria to produce alkaline conditions conducive to calcium carbonate precipitation. Groundwater samples from the Eastern Snake River Plain (ESRP) aquifer in Idaho were screened for urea-hydrolyzing microorganisms; three isolates were selected for further evaluation. Analysis of 16S rRNA gene sequences indicated that two of the ESRP isolates were of the genus Pseudomonas , and the other was a Variovorax sp. The specific urease activities of the ESRP isolates appeared to be similar to each other but less than that of Bacillus pasteurii , a known urease-positive organism. However, calcium carbonate was rapidly precipitated in all cultures that were supplied with urea and calcium, and X-ray diffraction analyses indicated that calcite was always the predominant carbonate polymorph produced. The correspondence between measured calcium concentrations and equilibrium predictions suggested that the rate of calcite precipitation was directly linked to the rate of urea hydrolysis. These results are promising with respect to the potential utility of this approach for in situ remediation and indicate that further evaluation of this approach under conditions more closely simulating environmental conditions is warranted.

  16. Centrifugal precipitation chromatography.

    PubMed

    Ito, Yoichiro; Qi, Lin

    2010-01-15

    Centrifugal precipitation chromatography separates analytes according their solubility in ammonium sulfate (AS) solution and other precipitants. The separation column is made from a pair of long spiral channels partitioned with a semipermeable membrane. In a typical separation, concentrated ammonium sulfate is eluted through one channel while water is eluted through the other channel in the opposite direction. This countercurrent process forms an exponential AS concentration gradient through the water channel. Consequently, protein samples injected into the water channel is subjected to a steadily increasing AS concentration and at the critical AS concentration they are precipitated and deposited in the channel bed by the centrifugal force. Then the chromatographic separation is started by gradually reducing the AS concentration in the AS channel which lowers the AS gradient concentration in the water channel. This results in dissolution of deposited proteins which are again precipitated at an advanced critical point as they move through the channel. Consequently, proteins repeat precipitation and dissolution through a long channel and finally eluted out from the column in the order of their solubility in the AS solution. The present method has been successfully applied to a number of analytes including human serum proteins, recombinant ketosteroid isomerase, carotenoid cleavage enzymes, plasmid DNA, polysaccharide, polymerized pigments, PEG-protein conjugates, etc. The method is capable to single out the target species of proteins by affinity ligand or immunoaffinity separation.

  17. as the Strengthening Precipitates

    NASA Astrophysics Data System (ADS)

    Lu, Qi; Xu, Wei; van der Zwaag, Sybrand

    2014-12-01

    Generally, Laves phase and M23C6 are regarded as undesirable phases in creep-resistant steels due to their very high-coarsening rates and the resulting depletion of beneficial alloying elements from the matrix. In this study, a computational alloy design approach is presented to develop martensitic steels strengthened by Laves phase and/or M23C6, for which the coarsening rates are tailored such that they are at least one order of magnitude lower than those in existing alloys. Their volume fractions are optimized by tuning the chemical composition in parallel. The composition domain covering 10 alloying elements at realistic levels is searched by a genetic algorithm to explore the full potential of simultaneous maximization of the volume fraction and minimization of the precipitates coarsening rate. The calculations show that Co and W can drastically reduce the coarsening rate of Laves and M23C6 and yield high-volume fractions of precipitates. Mo on the other hand was shown to have a minimal effect on coarsening. The strengthening effects of Laves phase and M23C6 in the newly designed alloys are compared to existing counterparts, showing substantially higher precipitation-strengthening contributions especially after a long service time. New alloys were designed in which both Laves phase and M23C6 precipitates act as strengthening precipitates. Successfully combining MX and M23C6 was found to be impossible.

  18. Sono-precipitation of Ag2CrO4-C composite enhanced by carbon-based materials (AC, GO, CNT and C3N4) and its activity in photocatalytic degradation of acid orange 7 in water.

    PubMed

    Azami, Mina; Haghighi, Mohammad; Allahyari, Somaiyeh

    2018-01-01

    Enhancing the photocatalytic activity of Ag2CrO4 with coupled carbon-based materials like activated carbon, graphene oxide, carbon nanotubes and carbon nitride has been investigated in removal of Acid Orange 7 from wastewater. Sono precipitated Ag2CrO4-C composite based photocatalysts were characterized by XRD, BET, FESEM, FTIR and UV-vis DRS and the photocatalytic activity of theses samples was evaluated in terms of degradation amount of acid orange 7 under visible light irradiations. BET analysis showed that with addition of carbon based materials, the specific surface area of the Ag2CrO4-C composite increased. XRD analysis indicated that the crystallinity of Ag2CrO4 peaks decreased after addition of all studied carbon-based materials and C3N4 has lowered the crystallinity of Ag2CrO4 less than others. Higher crystallinity has the positive effect of higher photocatalytic activity because among above mentioned composites, Ag2CrO4-C3N4 photocatalyst exhibited higher photocatalytic activity and stability under visible light irradiations. DRS analysis confirmed good match of electronic structures of Ag2CrO4 and C3N4. On the other hand Ag2CrO4 and C3N4 formed heterojunction which separates photo-generated electron-hole pairs effectively. Also evaluation of photocatalytic reaction in various operating parameters showed Ag2CrO4-C3N4 had the highest photocatalytic activity in neutral pH and 1g/L of catalyst loading. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Changes in the annual range of precipitation under global warming

    NASA Astrophysics Data System (ADS)

    Chou, C.; Lan, C.

    2011-12-01

    The annual range of precipitation, which is the difference between maximum and minimum precipitation within a year, is examined in climate model simulations under global warming. For global averages, the annual range of precipitation tends to increase as the globe warms. On a regional basis, this enhancement is found over most areas of the world, except for the bands along 30°S and 30N°, respectively. The enhancement in the annual range of precipitation is mainly associated with larger upward trends of maximum precipitation and smaller upward trends or downward trends of minimum precipitation. Based on the moisture budget analysis, the dominant mechanism is vertical moisture advection, both on a global average and on a regional scale. The vertical moisture advection, moisture convergence induced by vertical motion, includes the thermodynamic component, which is associated with increased water vapor, and the dynamic component, which is associated with changes in circulation. Generally, the thermodynamic component enhances the annual range of precipitation, while the dynamic component tends to reduce it. Evaporation has a positive contribution to both maximum and minimum precipitation, but very little to the annual range of precipitation. Even though evaporation and horizontal moisture advection are small for a global average, they could be important on a regional basis.

  20. FORMATION OF URANIUM PRECIPITATES

    DOEpatents

    Googin, J.M. Jr.

    1959-03-17

    A method is described for precipitation of uranium peroxide from uranium- containing solutions so as to obtain larger aggregates which facilitates washings decantations filtrations centrifugations and the like. The desired larger aggregate form is obtained by maintaining the pH of the solution in the approximate range of 1 to 3 and the temperature at about 25 deg C or below while carrytng out the precipitation. Then prior to removal of the precipitate a surface active sulfonated bicarboxyacids such as di-octyl sodium sulfo-succinates is incorporated in an anount of the order of 0.01 to 0.05 percent by weights and the slurry is allowed to ripen for about one-half hour at a temperatare below 10 deg C.

  1. URANIUM PRECIPITATION PROCESS

    DOEpatents

    Thunaes, A.; Brown, E.A.; Smith, H.W.; Simard, R.

    1957-12-01

    A method for the recovery of uranium from sulfuric acid solutions is described. In the present process, sulfuric acid is added to the uranium bearing solution to bring the pH to between 1 and 1.8, preferably to about 1.4, and aluminum metal is then used as a reducing agent to convert hexavalent uranium to the tetravalent state. As the reaction proceeds, the pH rises amd a selective precipitation of uranium occurs resulting in a high grade precipitate. This process is an improvement over the process using metallic iron, in that metallic aluminum reacts less readily than metallic iron with sulfuric acid, thus avoiding consumption of the reducing agent and a raising of the pH without accomplishing the desired reduction of the hexavalent uranium in the solution. Another disadvantage to the use of iron is that positive ferric ions will precipitate with negative phosphate and arsenate ions at the pH range employed.

  2. Estimation of tropical precipitation using 19.35 GHz SSM/I data

    NASA Technical Reports Server (NTRS)

    Shih, Chi-Fan; Weng, Fuzhong; Vonder Haar, Thomas H.

    1992-01-01

    Special Sensor Microwave Imager (SSM/I) data are analyzed using a new direct method to estimate mean monthly precipitation between 50 deg S and 50 deg N. A brief description of the algorithm used is presented along with preliminary results for January and July 1990. The amounts of the precipitation estimates are in good agreement with the mean monthly climatological values.

  3. Application of the precipitation-runoff model in the Warrior Coal Field

    SciTech Connect

    Kidd, R.E.; Bossong, C.R.

    1987-01-01

    This report describes the application of the Precipitation-Runoff Modeling System to two small basins located in the Warrior Coal Field in Alabama. Preliminary daily and storm calibrations were developed for Bear Creek basin (undisturbed) and Turkey Creek basin (surface coal mine). Preliminary parameter values of geology and land use were included in the model calibrations.

  4. Precipitation-Regulated Feedback

    NASA Astrophysics Data System (ADS)

    Voit, Mark

    2016-07-01

    Star formation in the central galaxies of galaxy clusters appears to be fueled by precipitation of cold clouds out of hot circumgalactic gas via thermal instability. I will present both observational and theoretical support for the precipitation mode in large galaxies and discuss how it can be implemented in cosmological simulations of galaxy evolution. Galaxy cluster cores are unique laboratories for studying the astrophysics of thermal instability and may be teaching us valuable lessons about how feedback works in galaxies spanning the entire mass spectrum.

  5. Precipitation interpolation in mountainous areas

    NASA Astrophysics Data System (ADS)

    Kolberg, Sjur

    2015-04-01

    Different precipitation interpolation techniques as well as external drift covariates are tested and compared in a 26000 km2 mountainous area in Norway, using daily data from 60 stations. The main method of assessment is cross-validation. Annual precipitation in the area varies from below 500 mm to more than 2000 mm. The data were corrected for wind-driven undercatch according to operational standards. While temporal evaluation produce seemingly acceptable at-station correlation values (on average around 0.6), the average daily spatial correlation is less than 0.1. Penalising also bias, Nash-Sutcliffe R2 values are negative for spatial correspondence, and around 0.15 for temporal. Despite largely violated assumptions, plain Kriging produces better results than simple inverse distance weighting. More surprisingly, the presumably 'worst-case' benchmark of no interpolation at all, simply averaging all 60 stations for each day, actually outperformed the standard interpolation techniques. For logistic reasons, high altitudes are under-represented in the gauge network. The possible effect of this was investigated by a) fitting a precipitation lapse rate as an external drift, and b) applying a linear model of orographic enhancement (Smith and Barstad, 2004). These techniques improved the results only marginally. The gauge density in the region is one for each 433 km2; higher than the overall density of the Norwegian national network. Admittedly the cross-validation technique reduces the gauge density, still the results suggest that we are far from able to provide hydrological models with adequate data for the main driving force.

  6. Dynamic Controls on Recent Increases in Northwest Greenland Coastal Precipitation

    NASA Astrophysics Data System (ADS)

    Wong, G. J.; Osterberg, E. C.; Hawley, R. L.; Courville, Z.; Ferris, D. G.; Howley, J. A.

    2015-12-01

    Arctic precipitation has been rising over recent decades, with implications for glacier mass balance, sea level rise, and thermohaline circulation via the freshening of the Arctic seas. Coastal instrumental data and proxy records in northwest (NW) Greenland indicate positive summer precipitation trends from 1952-2012 along with a long-term, significant (p < 0.05) summer warming trend. While the observed precipitation increase is likely due in part to Clausius-Clapeyron increases in vapor pressure, the dynamical mechanisms responsible for the increasing trend remain poorly understood. Here we use a 61-year record of precipitation from Thule Air Base in NW Greenland and NCEP/NCAR reanalysis data to identify atmospheric circulation patterns associated with enhanced precipitation in recent decades. We evaluate Thule precipitation-circulation relationships for the warm season (July-October [JASO]; 49% of annual precipitation) and cold season (December-February [DJF]; 20% of annual precipitation). Anomalously high precipitation in DJF and JASO is associated with enhanced southerly flow of warm, moist air and enhanced uplift (omega) in Northern Baffin Bay. Meridional flow in Baffin Bay is strongly correlated with the North Atlantic Oscillation (NAO). We observe enhanced southerly flow, uplift and Thule precipitation during negative NAO conditions in winter and to a weaker extent JASO. Based on this mechanism, the trend (p < 0.10) of declining annual NAO index values since 1981 is consistent with the rising trends in Thule annual precipitation over this interval. We find evidence that a NW Greenland ice core proxy record (2Barrel) has a diminished JASO seasonal bias compared with the coast, and thus a future, longer proxy record collected from the 2Barrel site would be well suited for capturing both summer and winter climate variability.

  7. The Effect of Bacterial Surfaces on Silica Precipitation

    NASA Astrophysics Data System (ADS)

    Yee, N.; Phoenix, V. R.; Konhauser, K. O.; Benning, L. G.

    2001-12-01

    Bacterial silicification is an important geological process in modern geothermal environments (e.g., New Zealand, Iceland, Japan). The precipitation of silica onto bacterial surfaces can affect microbial fossilization, chemical sediment formation, the porosity and permeability of crustal rocks, and silica transport in geothermal hot springs. Previous studies have suggested that active deposition of silica onto bacterial cells begins with the precipitation of heterogeneously nucleated aggregates of amorphous silica. However, the effect of bacteria on silica precipitation is poorly understood, and it is unclear if bacterial surfaces enhance the kinetics of silica precipitation or if the bacteria act as passive precipitation surfaces. In this study, we performed silica precipitation experiments with the filamentous cyanobacteria Calothrix sp. (strain KC97) to elucidate the rates and mechanisms of silicate biomineralization. Batch experiments were conducted as a function of time, Si saturation states, temperature, pH and Fe concentrations. Experiments at both undersaturated and supersaturated conditions indicate that Si-bacteria interactions are weak, and that minimal bacterial silica sorption/precipitation occurs. In supersaturated solutions, abotic polymerization rates are rapid and at the times scales of our experiments (1-300 hours) the presence of bacteria does not enhance silica nucleation or monomeric silica polymerization. However, the presence of Fe-coated bacteria significantly increases silica sorption/precipitation rates, and the extent of Si sorption/precipitation increases with increasing Fe concentrations. Fe precipitation experiments performed without Si indicate that iron precipitation onto bacterial surfaces occurs very rapidly and significantly faster than abotic controls. The experimental data suggest that in the presence of Fe, bacterial silicification occurs as a two step process: 1) Fe precipitates onto bacterial cells via heterogeneous surface

  8. Total Precipitable Water

    SciTech Connect

    2012-01-01

    The simulation was performed on 64K cores of Intrepid, running at 0.25 simulated-years-per-day and taking 25 million core-hours. This is the first simulation using both the CAM5 physics and the highly scalable spectral element dynamical core. The animation of Total Precipitable Water clearly shows hurricanes developing in the Atlantic and Pacific.

  9. Global precipitation measurement (GPM)

    NASA Astrophysics Data System (ADS)

    Neeck, Steven P.; Flaming, Gilbert M.; Adams, W. James; Smith, Eric A.

    2001-12-01

    The National Aeronautics and Space Administration (NASA) is studying options for future space-based missions for the EOS Follow-on Era (post 2003), building upon the measurements made by Pre-EOS and EOS First Series Missions. One mission under consideration is the Global Precipitation Measurement (GPM), a cooperative venture of NASA, Japan, and other international partners. GPM will capitalize on the experience of the highly successful Tropical Rainfall Measurement Mission (TRMM). Its goal is to extend the measurement of rainfall to high latitudes with high temporal frequency, providing a global data set every three hours. A reference concept has been developed consisting of an improved TRMM-like primary satellite with precipitation radar and microwave radiometer to make detailed and accurate estimates of the precipitation structure and a constellation of small satellites flying compact microwave radiometers to provide the required temporal sampling of highly variable precipitation systems. Considering that DMSP spacecraft equipped with SSMIS microwave radiometers, successor NPOESS spacecraft equipped with CMIS microwave radiometers, and other relevant international systems are expected to be in operation during the timeframe of the reference concept, the total number of small satellites required to complete the constellation will be reduced. A nominal plan is to begin implementation in FY'03 with launches in 2007. NASA is presently engaged in advanced mission studies and advanced instrument technology development related to the mission.

  10. Calcium precipitate induced aerobic granulation.

    PubMed

    Wan, Chunli; Lee, Duu-Jong; Yang, Xue; Wang, Yayi; Wang, Xingzu; Liu, Xiang

    2015-01-01

    Aerobic granulation is a novel biotechnology for wastewater treatment. This study refined existing aerobic granulation mechanisms as a sequencing process including formation of calcium precipitate under alkaline pH to form inorganic cores, followed by bacterial attachment and growth on these cores to form the exopolysaccharide matrix. Mature granules comprised an inner core and a matrix layer and a rim layer with enriched microbial strains. The inorganic core was a mix of different crystals of calcium and phosphates. Functional strains including Sphingomonas sp., Paracoccus sp. Sinorhizobium americanum strain and Flavobacterium sp. attached onto the cores. These functional strains promote c-di-GMP production and the expression by Psl and Alg genes for exopolysaccharide production to enhance formation of mature granules.

  11. Precipitation-runoff modeling system; user's manual

    USGS Publications Warehouse

    Leavesley, G.H.; Lichty, R.W.; Troutman, B.M.; Saindon, L.G.

    1983-01-01

    The concepts, structure, theoretical development, and data requirements of the precipitation-runoff modeling system (PRMS) are described. The precipitation-runoff modeling system is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and groundwater recharge. Parameter-optimization and sensitivity analysis capabilites are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model system enhancement and hydrologic modeling research and development. (Author 's abstract)

  12. Temperature sensitivity of extreme precipitation events in the south-eastern Alpine forelands

    NASA Astrophysics Data System (ADS)

    Schroeer, Katharina; Kirchengast, Gottfried

    2016-04-01

    How will convective precipitation intensities and patterns evolve in a warming climate on a regional to local scale? Studies on the scaling of precipitation intensities with temperature are used to test observational and climate model data against the hypothesis that the change of precipitation with temperature will essentially follow the Clausius-Clapeyron (CC) equation, which corresponds to a rate of increase of the water holding capacity of the atmosphere by 6-7 % per Kelvin (CC rate). A growing number of studies in various regions and with varying approaches suggests that the overall picture of the temperature-precipitation relationship is heterogeneous, with scaling rates shearing off the CC rate in both upward and downward directions. In this study we investigate the temperature scaling of extreme precipitation events in the south-eastern Alpine forelands of Austria (SEA) based on a dense rain gauge net of 188 stations, with sub-daily precipitation measurements since about 1990 used at 10-min resolution. Parts of the study region are European hot-spots for severe hailstorms and the region, which is in part densely populated and intensively cultivated, is generally vulnerable to climate extremes. Evidence on historical extremely heavy short-time and localized precipitation events of several hundred mm of rain in just a few hours, resulting in destructive flash flooding, underline these vulnerabilities. Heavy precipitation is driven by Mediterranean moisture advection, enhanced by the orographic lifting at the Alpine foothills, and hence trends in positive sea surface temperature anomalies might carry significant risk of amplifying future extreme precipitation events. In addition, observations from the highly instrumented subregion of south-eastern Styria indicate a strong and robust long-term warming trend in summer of about 0.7°C per decade over 1971-2015, concomitant with a significant increase in the annual number of heat days. The combination of these

  13. Soil moisture-precipitation coupling: observations question an impact on precipitation occurrence in North America

    NASA Astrophysics Data System (ADS)

    Guillod, Benoit P.; Orlowsky, Boris; Miralles, Diego; Dolman, Han; Reichstein, Markus; Teuling, Adriaan J.; Van den Hurk, Bart; Buchmann, Nina; Seneviratne, Sonia I.

    2013-04-01

    The coupling between soil moisture and convective precipitation through indirect mechanisms (e.g. boundary-layer growth and convection triggering) remains a key challenge out of numerous aspects on the interactions between the land surface and precipitation. In particular, how surface turbulent fluxes (sensible, latent heat fluxes and their partitioning) impact the occurrence of rainfall is poorly understood, due to the number and diversity of the processes involved. Here we explore the relationship between Evaporative Fraction (EF) and precipitation occurrence on the daily time scale. We apply a recently developed method (Findell et al., 2011) to observational data in North America: EF derived from FLUXNET sites and from GLEAM (satellite-based estimates), and radar precipitation data from NEXRAD. We then compare the resulting estimate of land-precipitation coupling to the NARR reanalysis (North American Regional Reanalysis). While a strong relationship is found in NARR, observations do not confirm a strong impact of EF on precipitation occurrence (i.e., no significant coupling is found). Further analyses show that, while precipitation data from NARR and NEXRAD agree well, EF data from the different sources differ widely and lead to different coupling. This questions the existence of a positive coupling between EF and precipitation occurrence in North America and highlights the need for more reliable datasets of high spatial and temporal resolution to fully quantify the strength of such land-surface atmosphere coupling. References: Findell, K. L., P. Gentine, B. R. Lintner, and C. Kerr. 2011. Probability of afternoon precipitation in eastern United States and Mexico enhanced by high evaporation. Nature Geosci, 4, 434-439.

  14. A statistically based seasonal precipitation forecast model with automatic predictor selection and its application to central and south Asia

    NASA Astrophysics Data System (ADS)

    Gerlitz, Lars; Vorogushyn, Sergiy; Apel, Heiko; Gafurov, Abror; Unger-Shayesteh, Katy; Merz, Bruno

    2016-11-01

    The study presents a statistically based seasonal precipitation forecast model, which automatically identifies suitable predictors from globally gridded sea surface temperature (SST) and climate variables by means of an extensive data-mining procedure and explicitly avoids the utilization of typical large-scale climate indices. This leads to an enhanced flexibility of the model and enables its automatic calibration for any target area without any prior assumption concerning adequate predictor variables. Potential predictor variables are derived by means of a cell-wise correlation analysis of precipitation anomalies with gridded global climate variables under consideration of varying lead times. Significantly correlated grid cells are subsequently aggregated to predictor regions by means of a variability-based cluster analysis. Finally, for every month and lead time, an individual random-forest-based forecast model is constructed, by means of the preliminary generated predictor variables. Monthly predictions are aggregated to running 3-month periods in order to generate a seasonal precipitation forecast. The model is applied and evaluated for selected target regions in central and south Asia. Particularly for winter and spring in westerly-dominated central Asia, correlation coefficients between forecasted and observed precipitation reach values up to 0.48, although the variability of precipitation rates is strongly underestimated. Likewise, for the monsoonal precipitation amounts in the south Asian target area, correlations of up to 0.5 were detected. The skill of the model for the dry winter season over south Asia is found to be low. A sensitivity analysis with well-known climate indices, such as the El Niño- Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO) and the East Atlantic (EA) pattern, reveals the major large-scale controlling mechanisms of the seasonal precipitation climate for each target area. For the central Asian target areas, both

  15. Uncertainties in Arctic Precipitation

    NASA Astrophysics Data System (ADS)

    Majhi, I.; Alexeev, V. A.; Cherry, J. E.; Cohen, J. L.; Groisman, P. Y.

    2012-12-01

    Arctic precipitation is riddled with measurement biases; to address the problem is imperative. Our study focuses on comparison of various datasets and analyzing their biases for the region of Siberia and caution that is needed when using them. Five sources of data were used ranging from NOAA's product (RAW, Bogdanova's correction), Yang's correction technique and two reanalysis products (ERA-Interim and NCEP). The reanalysis dataset performed better for some months in comparison to Yang's product, which tends to overestimate precipitation, and the raw dataset, which tends to underestimate. The sources of bias vary from topography, to wind, to missing data .The final three products chosen show higher biases during the winter and spring season. Emphasis on equations which incorporate blizzards, blowing snow and higher wind speed is necessary for regions which are influenced by any or all of these factors; Bogdanova's correction technique is the most robust of all the datasets analyzed and gives the most reasonable results. One of our future goals is to analyze the impact of precipitation uncertainties on water budget analysis for the Siberian Rivers.

  16. Stimulation of Indigenous Carbonate Precipitating Bacteria for Ground Improvement

    NASA Astrophysics Data System (ADS)

    Rajasekar, Adharsh; Moy, Charles K. S.; Wilkinson, Stephen

    2017-05-01

    Calcite minerals are precipitated in soil through biomineralisation which can be either organic or inorganic in nature. Biomineralisation can be employed to improve ground conditions in its natural state. Usually, studies of applied biomineralisation are highly interdisciplinary involving expertise from engineers, chemists and microbiologists. In this paper, we study the potential of biomineralisation from indigenous bacteria present in soil. The soil samples were collected from a high permeable zone and the bacteria that inhabit the soil were stimulated at a temperature of 15°C. A cementation solution consisting of 500mM calcium chloride, urea and nutrient broth at a pH of 7.5 was added to the soil samples. Inorganic precipitation was found to be dominant and was more efficient when compared to organic precipitation. Carbonate precipitation data indicated that inorganic precipitation were 1.37 times better at carbonate formation in comparison to organic precipitation. Scanning Electron Microscopy analysis identified cementation bonds formed between soil particles. It was deducted that organic precipitation is dependent on temperature, and may take an extended time at such low temperature. The preliminary data presented in this paper suggests that the implementation of biomineralisation with in-situ microbes is promising but requires further laboratory and field investigation before being considered for engineering application.

  17. Assimilating the Global Precipitation Measurement (GPM) Estimates in the Canadian Precipitation Analysis (CaPA) Over North America.

    NASA Astrophysics Data System (ADS)

    Boluwade, A.; Rasmussen, P. F.; Stadnyk, T. A.; Fortin, V.; Guy, R.

    2015-12-01

    The importance of precipitation measurement using estimates from satellite products cannot be over emphasized. Observations from space using sensors mounted on satellites cover wider areas and provide high spatial and temporal resolution. The estimates derived from this process are very useful in integrated hydrologic modeling, weather forecasting and monitoring landslides, droughts and floods, etc. Example of a satellite precipitation product is the Tropical Rainfall Measurement Mission (TRMM) and Global Precipitation Mission (GPM). TRMM was primarily designed to measure heavy-to-moderate rainfall over tropical and subtropical regions. GPM was designed to extend, enhance, and improve TRMM precipitation data. The primary objective of this study is the assimilation GPM satellite based precipitation estimates into the Canadian Precipitation Analysis (CaPA). CaPA combines the Global Environmental Multi-Scale model (GEM) dataset and observed precipitation from monitoring stations to provide precipitation estimates at 6hr and 24hr time steps and spatial resolution of 10km covering North America. In the result, we used the Equitable Threat Score (ETS) as performance evaluation. GPM assimilation provides higher skill (ETS) at precipitation values below 3mm while being used as additional data source. GPM has better skill as background field at precipitation value above 3mm.

  18. Illinois Precipitation Research: A Focus on Cloud and Precipitation Modification.

    NASA Astrophysics Data System (ADS)

    Changnon, Stanley A.; Czys, Robert R.; Scott, Robert W.; Westcott, Nancy E.

    1991-05-01

    At the heart of the 40-year atmospheric research endeavors of the Illinois State Water Survey have been studies to understand precipitation processes in order to learn how precipitation is modified purposefully and accidentally, and to measure the physical and socio-economic consequences of cloud and precipitation modification. Major field and laboratory activities of past years or briefly treated as a basis for describing the key findings of the past ten years. Recent studies of inadvertent and purposeful cloud and rain modification and their effects are emphasized, including a 1989 field project conducted in Illinois and key findings from an on-going exploratory experiment addressing cloud and rain modification. Results are encouraging for the use of dynamic seeding on summer cumuliform clouds of the Midwest.Typical in-cloud results at 10°C reveal multiple updrafts that tend to be filled with large amounts of supercooled drizzle and raindrops. Natural ice production is vigorous, and initial concentrations are larger than expected from ice nuclei. However, natural ice production is not so vigorous as to preclude opportunities for seeding. Radar-based studies of such clouds reveal that their echo cores usually can be identified prior to desired seeding times, which is significant for the evaluation of their behavior. Cell characteristics show considerable variance under different types of meteorological conditions. Analysis of cell mergers reveals that under conditions of weak vertical shear, mid-level intercell flow at 4 km occurs as the reflectivity bridge between cells rapidly intensifies. The degree of intensification of single-echo cores after they merge is strongly related to the age and vigor of the cores before they join. Hence, cloud growth may be enhanced if seeding can encourage echo cores to merge at critical times. Forecasting research has developed a technique for objectively distinguishing between operational seeding and nonoperational days and for

  19. Drug precipitation-permeation interplay: supersaturation in an absorptive environment.

    PubMed

    Bevernage, Jan; Brouwers, Joachim; Annaert, Pieter; Augustijns, Patrick

    2012-10-01

    The present study investigated the interplay between supersaturation, absorption, precipitation, and excipient-mediated precipitation inhibition by comparing classic precipitation assessment in a non-absorption environment with precipitation/permeation assessment in an absorption environment. Loviride and HPMC-E5 were selected as poorly soluble model drug and precipitation inhibitor, respectively. To investigate supersaturation in an absorptive environment, supersaturation was induced at different degrees (DS), using a solvent shift method, in shaken Caco-2 Transwell® inserts containing fasted state simulated intestinal fluid (FaSSIF); to simulate a non-absorption environment, the inserts were parafilm-sealed and did not contain a cell monolayer. Donor and acceptor compartments were sampled as a function of time to determine precipitation kinetics and transport, respectively. In absence of precipitation, loviride transport increased proportionally with the initial DS; however, precipitation limited the supersaturation-induced transport enhancement. Loviride precipitation was found to be less extensive in an absorption environment compared to a non-absorption environment. As a result, the optimal DS obtained in a non-absorption environment (highest amount maintained in solution) did not correlate with the highest transport in an absorption environment. In addition, the impact of HPMC-E5 on loviride transport was inferior to its precipitation inhibitory capacity observed in a non-absorption environment. For the first time, the present study explicitly demonstrated that implementation of permeation in precipitation assays is critical to predict the impact of supersaturation, precipitation, and precipitation inhibition on the absorption of poorly soluble drugs. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Preliminary considerations concerning actinide solubilities

    SciTech Connect

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  1. Magnetite seeded precipitation of phosphate.

    PubMed

    Karapinar, Nuray; Hoffmann, Erhard; Hahn, Hermann H

    2004-07-01

    Seeded precipitation of Ca phosphate on magnetite mineral (Fe3O4) surfaces was investigated using a Jar Test system in supersaturated solutions at 20 degrees C and ionic strength 0.01 mol l(-1) with relative super saturation, 12.0-20.0 for HAP. pH of the solution, initial phosphorus concentration and molar Ca/P ratio were investigated as the main parameters, which effect the seeded precipitation of Ca phosphate. Results showed that there is no pronounced effect of magnetite seed, neither positive nor negative on the amount of calcium phosphate precipitation. pH was found to be the main parameter that determines the phosphate precipitated onto the seed surface. Increasing of the pH of precipitation reaction was resulted in the decrease in percentage amount of phosphate precipitated onto seed surfaces to total precipitation (magnetite seeded precipitation efficiency). It was concluded that the pH dependence of magnetite-seeded precipitation should be considered in the light of its effect on the supersaturated conditions of solution. Saturation index (SI) of solution with respect to the precipitate phase was considered the driving force for the precipitation. A simulation programme PHREEQC (Version 2) was employed to calculate the Saturation-index with respect to hydroxyapatite (HAP) of the chemically defined precipitation system. It was found a good relationship between SI of solution with respect to HAP and the magnetite seeded precipitation efficiency, a second order polynomial function. Results showed that more favorable solution conditions for precipitation (higher SI values of solution) causes homogenous nucleation whereas heterogeneous nucleation led to a higher magnetite seeded precipitation efficiency.

  2. Image enhancements of Landsat 8 (OLI) and SAR data for preliminary landslide identification and mapping applied to the central region of Kenya

    NASA Astrophysics Data System (ADS)

    Mwaniki, M. W.; Kuria, D. N.; Boitt, M. K.; Ngigi, T. G.

    2017-04-01

    Image enhancements lead to improved performance and increased accuracy of feature extraction, recognition, identification, classification and hence change detection. This increases the utility of remote sensing to suit environmental applications and aid disaster monitoring of geohazards involving large areas. The main aim of this study was to compare the effect of image enhancement applied to synthetic aperture radar (SAR) data and Landsat 8 imagery in landslide identification and mapping. The methodology involved pre-processing Landsat 8 imagery, image co-registration, despeckling of the SAR data, after which Landsat 8 imagery was enhanced by Principal and Independent Component Analysis (PCA and ICA), a spectral index involving bands 7 and 4, and using a False Colour Composite (FCC) with the components bearing the most geologic information. The SAR data were processed using textural and edge filters, and computation of SAR incoherence. The enhanced spatial, textural and edge information from the SAR data was incorporated to the spectral information from Landsat 8 imagery during the knowledge based classification. The methodology was tested in the central highlands of Kenya, characterized by rugged terrain and frequent rainfall induced landslides. The results showed that the SAR data complemented Landsat 8 data which had enriched spectral information afforded by the FCC with enhanced geologic information. The SAR classification depicted landslides along the ridges and lineaments, important information lacking in the Landsat 8 image classification. The success of landslide identification and classification was attributed to the enhanced geologic features by spectral, textural and roughness properties.

  3. Measurement of Global Precipitation

    NASA Technical Reports Server (NTRS)

    Flaming, Gilbert Mark

    2004-01-01

    The Global Precipitation Measurement (GPM) Program is an international cooperative effort whose objectives are to (a) obtain increased understanding of rainfall processes, and (b) make frequent rainfall measurements on a global basis. The National Aeronautics and Space Administration (NASA) of the United States and the Japanese Aviation and Exploration Agency (JAXA) have entered into a cooperative agreement for the formulation and development of GPM. This agreement is a continuation of the partnership that developed the highly successful Tropical Rainfall Measuring Mission (TRMM) that was launched in November 1997; this mission continues to provide valuable scientific and meteorological information on rainfall and the associated processes. International collaboration on GPM from other space agencies has been solicited, and discussions regarding their participation are currently in progress. NASA has taken lead responsibility for the planning and formulation of GPM, Key elements of the Program to be provided by NASA include a Core satellite bus instrumented with a multi-channel microwave radiometer, a Ground Validation System and a ground-based Precipitation Processing System (PPS). JAXA will provide a Dual-frequency Precipitation Radar for installation on the Core satellite and launch services. Other United States agencies and international partners may participate in a number of ways, such as providing rainfall measurements obtained from their own national space-borne platforms, providing local rainfall measurements to support the ground validation activities, or providing hardware or launch services for GPM constellation spacecraft. This paper will present an overview of the current planning for the GPM Program, and discuss in more detail the status of the lead author's primary responsibility, development and acquisition of the GPM Microwave Imager.

  4. Accurate evaluation of axillary sentinel lymph node metastasis using contrast-enhanced ultrasonography with Sonazoid in breast cancer: a preliminary clinical trial.

    PubMed

    Matsuzawa, Fumihiko; Omoto, Kiyoka; Einama, Takahiro; Abe, Hironori; Suzuki, Takashi; Hamaguchi, Jun; Kaga, Terumi; Sato, Mami; Oomura, Masako; Takata, Yumiko; Fujibe, Ayako; Takeda, Chie; Tamura, Etsuya; Taketomi, Akinobu; Kyuno, Kenichi

    2015-01-01

    Breast cancer is the most common type of cancer in women. The 5-year survival rate in patients with breast cancer ranges from 74 to 82 %. Sentinel lymph node biopsy has become an alternative to axillary lymph node dissection for nodal staging. We evaluated the detection of the sentinel lymph node and metastasis of the lymph node using contrast enhanced ultrasonography with Sonazoid. Between December 2013 and May 2014, 32 patients with operable breast cancer were enrolled in this study. We evaluated the detection of axillary sentinel lymph nodes and the evaluation of axillary lymph nodes metastasis using contrast enhanced computed tomography, color Doppler ultrasonography and contrast enhanced ultrasonography with Sonazoid. All the sentinel lymph nodes were identified, and the sentinel lymph nodes detected by contrast enhanced ultrasonography with Sonazoid corresponded with those detected by computed tomography lymphography and indigo carmine method. The detection of metastasis based on contrast enhanced computed tomography were sensitivity 20.0 %, specificity 88.2 %, PPV 60.0 %, NPV 55.6 %, accuracy 56.3 %. Based on color Doppler ultrasonography, the results were sensitivity 36.4 %, specificity 95.2 %, PPV 80.0 %, NPV 74.1 %, accuracy 75.0 %. Based on contrast enhanced ultrasonography with Sonazoid, the results were sensitivity 81.8 %, specificity 95.2 %, PPV 90.0 %, NPV 90.9 %, accuracy 90.6 %. The results suggested that contrast enhanced ultrasonography with Sonazoid was the most accurate among the evaluations of these modalities. In the future, we believe that our method would take the place of conventional sentinel lymph node biopsy for an axillary staging method.

  5. DISSOLUTION OF LANTHANUM FLUORIDE PRECIPITATES

    DOEpatents

    Fries, B.A.

    1959-11-10

    A plutonium separatory ore concentration procedure involving the use of a fluoride type of carrier is presented. An improvement is given in the derivation step in the process for plutonium recovery by carrier precipitation of plutonium values from solution with a lanthanum fluoride carrier precipitate and subsequent derivation from the resulting plutonium bearing carrier precipitate of an aqueous acidic plutonium-containing solution. The carrier precipitate is contacted with a concentrated aqueous solution of potassium carbonate to effect dissolution therein of at least a part of the precipitate, including the plutonium values. Any remaining precipitate is separated from the resulting solution and dissolves in an aqueous solution containing at least 20% by weight of potassium carbonate. The reacting solutions are combined, and an alkali metal hydroxide added to a concentration of at least 2N to precipitate lanthanum hydroxide concomitantly carrying plutonium values.

  6. Precipitation Extremes Under Climate Change.

    PubMed

    O'Gorman, Paul A

    The response of precipitation extremes to climate change is considered using results from theory, modeling, and observations, with a focus on the physical factors that control the response. Observations and simulations with climate models show that precipitation extremes intensify in response to a warming climate. However, the sensitivity of precipitation extremes to warming remains uncertain when convection is important, and it may be higher in the tropics than the extratropics. Several physical contributions govern the response of precipitation extremes. The thermodynamic contribution is robust and well understood, but theoretical understanding of the microphysical and dynamical contributions is still being developed. Orographic precipitation extremes and snowfall extremes respond differently from other precipitation extremes and require particular attention. Outstanding research challenges include the influence of mesoscale convective organization, the dependence on the duration considered, and the need to better constrain the sensitivity of tropical precipitation extremes to warming.

  7. Global salinity predictors of western United States precipitation

    NASA Astrophysics Data System (ADS)

    Liu, T.; Schmitt, R. W.; Li, L.

    2016-12-01

    Moisture transport from the excess of evaporation over precipitation in the global ocean drives terrestrial precipitation patterns. Sea surface salinity (SSS) is sensitive to changes in ocean evaporation and precipitation, and therefore, to changes in the global water cycle. We use the Met Office Hadley Centre EN4.2.0 SSS dataset to search for teleconnections between autumn-lead seasonal salinity signals and winter precipitation over the western United States. NOAA CPC Unified observational US precipitation in winter months is extracted from bounding boxes over the northwest and southwest and averaged. Lead autumn SON SSS in ocean areas that are relatively highly correlated with winter DJF terrestrial precipitation are filtered by a size threshold and treated as individual predictors. After removing linear trends from the response and explanatory variables and accounting for multiple collinearity, we use best subsets regression and the Bayesian information criterion (BIC) to objectively select the best model to predict terrestrial precipitation using SSS and SST predictors. The combination of autumn SSS and SST predictors can skillfully predict western US winter terrestrial precipitation (R2 = 0.51 for the US Northwest and R2 = 0.7 for the US Southwest). In both cases, SSS is a better predictor than SST. Thus, incorporating SSS can greatly enhance the accuracy of existing precipitation prediction frameworks that use SST-based climate indices and by extension improve watershed management.

  8. Urease activity in microbiologically-induced calcite precipitation.

    PubMed

    Bachmeier, Keri L; Williams, Amy E; Warmington, John R; Bang, Sookie S

    2002-02-14

    The role of microbial urease in calcite precipitation was studied utilizing a recombinant Escherichia coli HB101 containing a plasmid, pBU11, that encodes Bacillus pasteurii urease. The calcite precipitation by E. coli HB101 (pBU11) was significant although its precipitation level was not as high as that by B. pasteurii. Addition of low concentrations (5-100 microM) of nickel, the cofactor of urease, to the medium further enhanced calcite precipitation by E. coli (pBU11). Calcite precipitation induced by both B. pasteurii and E. coli (pBU11) was inhibited in the presence of a urease inhibitor, acetohydroxamic acid (AHA). These observations on the recombinant urease have confirmed that urease activity is essential for microbiologically-induced calcite precipitation. Partially purified B. pasteurii urease was immobilized in polyurethane (PU) foam to compare the efficacy of calcite precipitation between the free and immobilized enzymes. The immobilized urease showed higher K(m) and lower V(max) values, which were reflected by a slower overall calcite precipitation. However, scanning electron micrographs (SEM) identified that the calcite precipitation occurred throughout the matrices of polyurethane. Furthermore, PU-immobilized urease retained higher enzymatic activities at high temperatures and in the presence of a high concentration of pronase, indicating that immobilization protects the enzyme activity from environmental changes.

  9. Potential Impacts of Pollution Aerosol and Dust Acting As Cloud-Nucleating Aerosol on Precipitation in the Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Jha, V.; Cotton, W. R.; Carrio, G. G.

    2014-12-01

    The southwest US has huge demands on water resources. The Colorado River Basin (CRB) is potentially affected by anthropogenic aerosol pollution and dust acting as cloud-nucleating aerosol as well as impacting snowpack albedo.The specific objective of this research is to quantify the impacts of both dust and pollution aerosols on wintertime precipitation in the Colorado Mountains for the years 2005-2006. We examine the combined effects of anthropogenic pollution aerosol and dust serving as cloud condensation nuclei (CCN), ice nuclei (IN) and giant CCN(GCCN) on precipitation in the CRB. Anthropogenic pollution can enhance droplet concentrations, and decrease collision and coalescence and ice particle riming largely via the "spillover" effect. Dust can serve as IN and enhance precipitation in wintertime orographic clouds. Dust coated with sulfates or originating over dry lake beds can serve as GCCN which when wetted can result in larger cloud droplets and thereby enhance the warm-rain collision and coalescence process and ice particle riming. But smaller dust particles coated with sulfates, can decrease collision and coalescence and ice particle riming similar to anthropogenic pollution aerosols. The Colorado State University (CSU) Regional Atmospheric Modeling System (RAMS) version 6.0 is used for this study. RAMS was modified to ingest GEOS-CHEM output data and periodically update aerosol fields. GEOS-CHEM is a chemical transport model which uses assimilated meteorological data from the NASA Goddard Earth Observation System (GEOS). The aerosol data comprise a sum of hydrophobic and hydrophilic black carbon and organic aerosol, hydrophilic SOAs, hydrocarbon oxidation and inorganic aerosols (nitrate, sulfate and ammonium). In addition, a RAMS-based dust source and transport model is used. Preliminary analysis suggests pollution dominates over dust resulting in a decrease in precipitation via the spillover effect. Dust serving as GCCN and IN tend to enhance ice

  10. Improving Groundwater Predictions using Seasonal Precipitation Forecasts

    NASA Astrophysics Data System (ADS)

    Almanaseer, N.; Arumugam, S.; Bales, J. D.

    2011-12-01

    This research aims to evaluate the utility of precipitation forecasts in improving groundwater and streamflow predictions at seasonal and monthly time scales using statistical modeling techniques. For this purpose, we select ten groundwater wells from the Groundwater Climate Response Network (GCRN) and nine streamgauges from the Hydro-Climatic Data Network (HCDN) to represent groundwater and surface water variability with minimal anthropogenic influences over Flint River Basin (FRB) in Georgia, U.S. Preliminary analysis shows significant correlation between precipitation forecasts over FRB with observed precipitation (P), streamflow discharges (Q) and depth to groundwater (G). Three statistical models are developed using principle component regression (PCR) and canonical correlation analysis (CCA) with leave-5-out cross-validation to predict winter (JFM) and spring (AMJ) as well as monthly (Jan through Jun) groundwater and streamflow for the selected sites. The three models starts at the end of Dec and uses Oct, Nov and Dec (OND) observed records to predict 2-seasons and 6-months ahead. Model-1 is the "null model" that does not include precipitation forecasts as predictors. It is developed using PCR to predict seasonal and monthly Q and G independently based on previous (Oct. Nov. and Dec; OND) observations of Q or G at a given site without using climate information. Model predictands are JFM, AMJ for seasonal and Jan. through Jun for monthly. Model-2 is also developed using PCR, but it uses the issued at January precipitation forecasts from nine ECHAM 4.5 grid points as additional predictors. Model-3 is developed using CCA and it aims to integrate additional information on the predictands (i.e., groundwater) from adjacent basins to improve the prediction. Model-3 is designed to evaluate the role of climate versus the role groundwater and surface water flows in the selected basins. Finally, comparisons between the three models for each site and across the sites

  11. Passive Microwave Precipitation Detection Biases: Relationship to Environment

    NASA Astrophysics Data System (ADS)

    Viramontez, A.; Rapp, A. D.

    2015-12-01

    Accurate satellite precipitation estimates are essential for understanding the long-term variability in the global hydrologic cycle and for constraining global climate models. Spaceborne precipitation estimates depend heavily on passive microwave remote sensors due to the large spatial coverage and long record of observations available from such sensors; however, light precipitation is frequently undetected or underestimated by passive microwave rainfall retrievals. Observations from the CloudSat Profiling Radar (CPR) and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) provide a unique opportunity for long-term collocated precipitation measurements from passive microwave sensors and an active radar with sensitivity to very light precipitation that can be used to assess the precipitation detection biases. For this study, collocated measurements from AMSR-E and CloudSat during 2008 will be used to identify environments where AMSR-E underestimates precipitation. Environmental variables from the ECMWF Reanalysis (ERA-Interim) will be used to understand the characteristics of the large-scale and thermodynamic environments associated with AMSR-E precipitation biases. A preliminary comparison of CPR rain rates and AMSR-E Level-2B rain rates show a large fraction of rain missed by AMSR-E, with nearly 80% of missed light rain in regions with SSTs below 25°C. This is consistent with prior studies showing large detection biases in regions of large-scale subsidence. The relationship between precipitation biases and other factors such as 2 m air temperature, column water vapor, lower tropospheric stability, and vertical velocity will be explored.

  12. Precipitation responses to radiative effects of ice clouds: A cloud-resolving modeling study of a pre-summer torrential precipitation event

    NASA Astrophysics Data System (ADS)

    Shen, Xinyong; Huang, Wenyan; Guo, Chunyan; Jiang, Xiaocen

    2016-10-01

    The precipitation responses to the radiative effects of ice clouds are investigated through analysis of five-day and horizontally averaged data from 2D cumulus ensemble model experiments of a pre-summer torrential precipitation event. The exclusion of the radiative effects of ice clouds lowered the precipitation rate through a substantial reduction in the decrease of hydrometeors when the radiative effects of water clouds were switched on, whereas it increased the precipitation rate through hydrometeor change from an increase to a decrease when the radiative effects of ice clouds were turned off. The weakened hydrometeor decrease was associated with the enhanced longwave radiative cooling mainly through the decreases in the melting of non-precipitating ice to non-precipitating water. The hydrometeor change from an increase to a decrease corresponded to the strengthened longwave radiative cooling in the upper troposphere through the weakened collection of non-precipitating water by precipitation water.

  13. Simulations of Precipitation Variability over the Upper Rio Grande Basin

    SciTech Connect

    Costigan, Keeley R.; Bossert, James E.; Langley, David L.

    1997-12-31

    In this research, we study Albuquerque`s water and how it may be affected by changes in the regional climate, as manifested by variations in Rio Grande water levels. To do this, we rely on the use of coupled atmospheric, runoff, and ground water models. Preliminary work on the project has focused on uncoupled simulations of the aquifer beneath Albuquerque and winter precipitation simulations of the upper Rio Grande Basin. The latter is discussed in this paper.

  14. Analysis of Contrast-Enhanced Ultrasound Perfusion Patterns and Time-Intensity Curves for Metastatic Lymph Nodes From Lung Cancer: Preliminary Results.

    PubMed

    Yin, Shanshan; Cui, Qiuli; Wang, Song; Fan, Zhihui; Yan, Kun

    2017-09-06

    To retrospectively summarize the similarities and differences in contrast-enhanced ultrasound (US) findings for lymph node metastasis from adenocarcinoma, squamous carcinoma, and small cell lung cancer. Patients who had received contrast-enhanced US examinations and had a histologic diagnosis of supraclavicular lymph node metastasis from lung cancer were included. The perfusion patterns on contrast-enhanced US images and time-intensity curve parameters were analyzed for the different pathologic types. The microvascular density and microvascular diameter were evaluated. Totally, 61 patients were enrolled in this study, including 26 cases with lung squamous carcinoma, 26 with lung adenocarcinoma, and 9 with small cell lung cancer. Contrast-enhanced US perfusion showed no significant differences in enhancement uniformity during the arterial phase and in the presence of unenhanced areas of metastatic lymph nodes with the 3 different pathologic origins (P > .05), but fewer unenhanced areas could be seen in metastatic lymph nodes from adenocarcinoma. The analysis of the time-intensity curve parameters showed that there were significant differences in the peak intensity between metastatic lymph nodes from lung squamous carcinoma and lung adenocarcinoma (P < .05). The microvascular density of metastatic lymph nodes from adenocarcinoma was significantly higher than that of metastatic lymph nodes from squamous carcinoma and small cell lung cancer (P < .001; P = .0444), whereas the microvascular diameter of metastatic lymph nodes from adenocarcinoma was significantly smaller than that from squamous carcinoma and small cell lung cancer (P = .0277; P < .001). Effects of the pathologic diagnosis should be considered when analyzing quantitative parameters of metastatic lymph nodes during contrast-enhanced US examinations, even in the same organ. © 2017 by the American Institute of Ultrasound in Medicine.

  15. Fishtail Effect Due To Silver Influenced Sub-precipitate Microstructure in YBCO/Ag Superconducting Composites

    NASA Astrophysics Data System (ADS)

    Parthasarathy, R.; Kumar, N. Devendra; Bai, V. Seshu

    2011-07-01

    We report the existence of a sub-precipitate microstructure and the resulting fishtail effect in YBCO/Ag superconducting composites fabricated by Seeded Infiltration and Growth Processing. The SEM micrographs reveal sub-precipitate microstructure in the form of precipitates of size less than 100 nm within the larger non-superconducting Y-211 precipitates that contributes to the enhancement of Jc in the form of secondary peak effect at lower fields.

  16. Magnetospheric particle precipitation at Titan

    NASA Astrophysics Data System (ADS)

    Royer, Emilie; Esposito, Larry; Crary, Frank; Wahlund, Jan-Erik

    2017-04-01

    Although solar XUV radiation is known to be the main source of ionization in Titan's upper atmosphere around 1100 km of altitude, magnetospheric particle precipitation can also account for about 10% of the ionization process. Magnetospheric particle precipitation is expected to be the most intense on the nightside of the satelllite and when Titan's orbital position around Saturn is the closest to Noon Saturn Local Time (SLT). In addition, on several occasion throughout the Cassini mission, Titan has been observed while in the magnetosheath. We are reporting here Ultraviolet (UV) observations of Titan airglow enhancements correlated to these magnetospheric changing conditions occurring while the spacecraft, and thus Titan, are known to have crossed Saturn's magnetopause and have been exposed to the magnetosheath environnment. Using Cassini-Ultraviolet Imaging Spectrograph (UVIS) observations of Titan around 12PM SLT as our primary set of data, we present evidence of Titan's upper atmosphere response to a fluctuating magnetospheric environment. Pattern recognition software based on 2D UVIS detector images has been used to retrieve observations of interest, looking for airglow enhancement of a factor of 2. A 2D UVIS detector image, created for each UVIS observation of Titan, displays the spatial dimension of the UVIS slit on the x-axis and the time on the y-axis. In addition, data from the T32 flyby and from April 17, 2005 from in-situ Cassini instruments are used. Correlations with data from simultaneous observations of in-situ Cassini instruments (CAPS, RPWS and MIMI) has been possible on few occasions and events such as electron burst and reconnections can be associated with unusual behaviors of the Titan airglow. CAPS in-situ measurements acquired during the T32 flyby are consistent with an electron burst observed at the spacecraft as the cause of the UV emission. Moreover, on April 17, 2005 the UVIS observation displays feature similar to what could be a

  17. Visual-spatial memory may be enhanced with theta burst deep brain stimulation of the fornix: a preliminary investigation with four cases.

    PubMed

    Miller, Jonathan P; Sweet, Jennifer A; Bailey, Christopher M; Munyon, Charles N; Luders, Hans O; Fastenau, Philip S

    2015-07-01

    Memory loss after brain injury can be a source of considerable morbidity, but there are presently few therapeutic options for restoring memory function. We have previously demonstrated that burst stimulation of the fornix is able to significantly improve memory in a rodent model of traumatic brain injury. The present study is a preliminary investigation with a small group of cases to explore whether theta burst stimulation of the fornix might improve memory in humans. Four individuals undergoing stereo-electroencephalography evaluation for drug-resistant epilepsy were enrolled. All participants were implanted with an electrode into the proximal fornix and dorsal hippocampal commissure on the language dominant (n = 3) or language non-dominant (n = 1) side, and stimulation of this electrode reliably produced a diffuse evoked potential in the head and body of the ipsilateral hippocampus. Each participant underwent testing of verbal memory (Rey Auditory-Verbal Learning Test), visual-spatial memory (Medical College of Georgia Complex Figure Test), and visual confrontational naming (Boston Naming Test Short Form) once per day over at least two consecutive days using novel test forms each day. For 50% of the trials, the fornix electrode was continuously stimulated using a burst pattern (200 Hz in 100 ms trains, five trains per second, 100 µs, 7 mA) and was compared with sham stimulation. Participants and examiners were blinded to whether stimulation was active or not, and the order of stimulation was randomized. The small sample size precluded use of inferential statistics; therefore, data were analysed using descriptive statistics and graphic analysis. Burst stimulation of the fornix was not perceived by any of the participants but was associated with a robust reversible improvement in immediate and delayed performance on the Medical College of Georgia Complex Figure Test. There were no apparent differences on either Rey Auditory-Verbal Learning Test or Boston Naming

  18. Preliminary study on the use of a silver oxide watch battery (1.5 V) for electrical enhancement of bone healing.

    PubMed

    Shokry, M

    1985-07-01

    A totally implantable watch battery (1.5 V) having 2 cathodes connected with 2 cortical screws of an osteosynthesis plate and one anode in the adjacent tissues gave positive results when used for enhancement of healing in experimentally fractured model.

  19. Precipitation in pores: A geochemical frontier

    SciTech Connect

    Stack, Andrew G.

    2015-07-29

    This article's purpose is to review some of the recent research in which geochemists have examined precipitation of solid phases in porous media, particularly in pores a few nanometers in diameter (nanopores). While this is a “review,” it is actually more forward-looking in that the list of things about this phenomenon that we do not know or cannot control at this time is likely longer than what we do know and can control. For example, there are three directly contradictory theories on how to predict how precipitation proceeds in a medium of varying pore size, as will be discussed below. The confusion on this subject likely stems from the complexity of the phenomenon itself: One can easily clog a porous medium by inducing a rapid, homogeneous precipitation directly from solution, or have limited precipitation occur that does not affect permeability or even porosity substantially. It is more difficult to engineer mineral precipitation in order to obtain a specific outcome, such as filling all available pore space over a targeted area for the purposes of contaminant sequestration. However, breakthrough discoveries could occur in the next five to ten years that enhance our ability to predict robustly and finely control precipitation in porous media by understanding how porosity and permeability evolve in response to system perturbations. These discoveries will likely stem (at least in part) from advances in our ability to 1) perform and interpret X-ray/neutron scattering experiments that reveal the extent of precipitation and its locales within porous media (Anovitz and Cole 2015, this volume), and 2) utilize increasingly powerful simulations to test concepts and models about the evolution of porosity and permeability as precipitation occurs (Steefel et al. 2015, this volume). A further important technique to isolate specific phenomena and understand reactivity is also microfluidics cell experiments that allow specific control of flow paths and fluid velocities

  20. Precipitation in pores: A geochemical frontier

    DOE PAGES

    Stack, Andrew G.

    2015-07-29

    This article's purpose is to review some of the recent research in which geochemists have examined precipitation of solid phases in porous media, particularly in pores a few nanometers in diameter (nanopores). While this is a “review,” it is actually more forward-looking in that the list of things about this phenomenon that we do not know or cannot control at this time is likely longer than what we do know and can control. For example, there are three directly contradictory theories on how to predict how precipitation proceeds in a medium of varying pore size, as will be discussed below.more » The confusion on this subject likely stems from the complexity of the phenomenon itself: One can easily clog a porous medium by inducing a rapid, homogeneous precipitation directly from solution, or have limited precipitation occur that does not affect permeability or even porosity substantially. It is more difficult to engineer mineral precipitation in order to obtain a specific outcome, such as filling all available pore space over a targeted area for the purposes of contaminant sequestration. However, breakthrough discoveries could occur in the next five to ten years that enhance our ability to predict robustly and finely control precipitation in porous media by understanding how porosity and permeability evolve in response to system perturbations. These discoveries will likely stem (at least in part) from advances in our ability to 1) perform and interpret X-ray/neutron scattering experiments that reveal the extent of precipitation and its locales within porous media (Anovitz and Cole 2015, this volume), and 2) utilize increasingly powerful simulations to test concepts and models about the evolution of porosity and permeability as precipitation occurs (Steefel et al. 2015, this volume). A further important technique to isolate specific phenomena and understand reactivity is also microfluidics cell experiments that allow specific control of flow paths and fluid

  1. Auroral helium precipitation.

    NASA Technical Reports Server (NTRS)

    Axford, W. I.; Chivers, H. J. A.; Eberhardt, P.; Geiss, J.; Buehler, F.

    1972-01-01

    Application of the metal foil sampling technique, which has been used to measure helium, neon, and argon fluxes in the solar wind, to the problem of measuring the fluxes of these gases in the auroral primary radiation. Aluminum and platinum foils have been flown into two bright auroras and have been recovered. The foils have been analyzed for helium and neon isotopes with a mass spectrometer; so far only He4 has been detected. In the first flight the precipitating flux of He4 with particle energies above about 1 keV was approximately 1,000,000 per sq cm per sec, and the backscattered flux was smaller by about a factor of 10. In the second flight the aurora was less bright, and the He4 fluxes were lower by a factor of about 2. A rough analysis suggests that the mean energy of the incident particles was greater than 3 keV.

  2. Auroral helium precipitation.

    NASA Technical Reports Server (NTRS)

    Axford, W. I.; Chivers, H. J. A.; Eberhardt, P.; Geiss, J.; Buehler, F.

    1972-01-01

    Application of the metal foil sampling technique, which has been used to measure helium, neon, and argon fluxes in the solar wind, to the problem of measuring the fluxes of these gases in the auroral primary radiation. Aluminum and platinum foils have been flown into two bright auroras and have been recovered. The foils have been analyzed for helium and neon isotopes with a mass spectrometer; so far only He4 has been detected. In the first flight the precipitating flux of He4 with particle energies above about 1 keV was approximately 1,000,000 per sq cm per sec, and the backscattered flux was smaller by about a factor of 10. In the second flight the aurora was less bright, and the He4 fluxes were lower by a factor of about 2. A rough analysis suggests that the mean energy of the incident particles was greater than 3 keV.

  3. Immunoaffinity centrifugal precipitation chromatography.

    PubMed

    Qi, Lin; Ito, Yoichiro

    2007-06-01

    Purification of proteins based on immunoaffinity has been performed using a solid support coated with antibody against the target proteins. The method requires immobilizing the antibody onto the solid support using protein A or G, and has a risk of adsorptive loss of target proteins onto the solid support. Centrifugal precipitation chromatography has been successfully used to purify enzymes, such as ketosteroid isomerase and hyaluronidase without the use of solid support. The purpose of this study is to demonstrate that immunoaffinity centrifugal precipitation chromatography is capable of isolating an antigen by exploiting antigen-antibody binding. The separation was initiated by filling both channels with 40% saturated ammonium sulfate (AS) of pH 4-4.5 followed by loading 20 microl of human plasma (National Institutes of Health blood bank) mixed with 2 mg of rabbit anti-HSA (human serum protein) antibody (Sigma). Then, the sample channel was eluted with water at 0.03 ml/min and AS channel with 40% AS solution of pH 4-4.5 at 1 ml/min until all non-binding components were eluted. Then, the releasing reagent (50% AS solution containing 0.5 M glycine and 10% ammonium hydroxide at pH 10) was introduced through the AS channel to release the target protein (HSA). The retained antibody was recovered by eluting the sample channel with water at 1 ml/min. A hollow fiber membrane device at the outlet (MicroKros, Spectrum, New Brunswick, NJ, USA) was provided on-line dialysis of the eluent before fractions were collected, so that the fractions could be analyzed by SDS-PAGE (sodium dodecyl sulfate - polyacrylamide gel electrophoresis) without further dialysis. The current method does not require immobilizing the antibody onto a matrix, which is used by the conventional immunoaffinity chromatography. This method ensures full recovery of the antigen and antibody, and it may be applied to purification of other proteins.

  4. Detection of Asian dust in California orographic precipitation

    NASA Astrophysics Data System (ADS)

    Ault, Andrew P.; Williams, Christopher R.; White, Allen B.; Neiman, Paul J.; Creamean, Jessie M.; Gaston, Cassandra J.; Ralph, F. Martin; Prather, Kimberly A.

    2011-08-01

    Aerosols impact the microphysical properties of clouds by serving as cloud condensation nuclei (CCN) and ice nuclei (IN). By modifying cloud properties, aerosols have the potential to alter the location and intensity of precipitation, but determining the magnitude and reproducibility of aerosol-induced changes to precipitation remains a significant challenge to experimentalists and modelers. During the CalWater Early Start campaign (22 February to 11 March 2009), a uniquely comprehensive set of atmospheric chemistry, precipitation, and meteorological measurements were made during two extratropical cyclones. These two storms showed enhanced integrated water vapor concentrations and horizontal water vapor transports due to atmospheric river conditions and, together, produced 23% of the annual precipitation and 38% of the maximum snowpack at California's Central Sierra Snow Lab (CSSL). Precipitation measurements of insoluble residues showed very different chemistry occurring during the two storms with the first one showing mostly organic species from biomass burning, whereas the second storm showed a transition from biomass burning organics to the dominance of Asian dust. As shown herein, the dust was transported across the Pacific during the second storm and became incorporated into the colder high-altitude precipitating orographic clouds over the Sierra Nevada. The second storm produced 1.4 times as much precipitation and increased the snowpack by 1.6 times at CSSL relative to the first storm. As described in previous measurement and modeling studies, dust can effectively serve as ice nuclei, leading to increased riming rates and enhanced precipitation efficiency, which ultimately can contribute to differences in precipitation. Future modeling studies will help deconvolute the meteorological, microphysical, and aerosol factors leading to these differences and will use CalWater's meteorological and aerosol observations to constrain the model-based interpretations

  5. Detection of Asian Dust in California Orographic Precipitation

    NASA Astrophysics Data System (ADS)

    Ault, A. P.; Williams, C. R.; White, A. B.; Neiman, P. J.; Creamean, J.; Gaston, C. J.; Ralph, F. M.; Prather, K. A.

    2011-12-01

    Aerosols impact the microphysical properties of clouds by serving as cloud condensation nuclei (CCN) and ice nuclei (IN). By modifying cloud properties, aerosols have the potential to alter the location and intensity of precipitation, but determining the magnitude and reproducibility of aerosol-induced changes to precipitation remains a significant challenge to experimentalists and modelers. During the CalWater Early Start campaign (22 February - 11 March 2009), a uniquely comprehensive set of atmospheric chemistry, precipitation, and meteorological measurements were made during two extratropical cyclones. These two storms showed enhanced integrated water vapor concentrations and horizontal water vapor transports due to atmospheric river conditions and, together, produced 23% of the annual precipitation and 38% of the maximum snowpack at California's Central Sierra Snow Lab (CSSL). Precipitation measurements of insoluble residues showed very different chemistry occurring during the two storms with the first one showing mostly organic species from biomass burning, whereas the second storm showed a transition from biomass burning organics to the dominance of Asian dust. As shown herein, the dust was transported across the Pacific during the second storm and became incorporated into the colder high altitude precipitating orographic clouds over the Sierra Nevada. The second storm produced 1.4 times as much precipitation and increased the snowpack by 1.6 times at CSSL relative to the first storm. As described in previous measurement and modeling studies, dust can effectively serve as ice nuclei, leading to increased riming rates and enhanced precipitation efficiency, which ultimately can contribute to differences in precipitation. Future modeling studies will help deconvolute the meteorological, microphysical, and aerosol factors leading to these differences, and will use CalWater's meteorological and aerosol observations to constrain the model-based interpretations

  6. ER-2 Observations of Precipitation Systems During TRMM-LBA

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald; Tian, Lin; Geerts, Bart

    1999-01-01

    The NASA ER-2 performed numerous flights over precipitation systems in Rondonia, Brazil. The ER-2 carried a payload including the ER-2 Doppler Radar (EDOP), the Advanced Microwave Precipitation Radiometer (AMPR), the Lightning Instrument Package, and other instruments. This presentation will overview the types of data sets collected during TRMM-LBA (Tropical Rainfall Measuring Mission Satellite-Large Scale Biosphere Atmosphere Experiment in Amazonia) with particular emphasis on EDOP measurements. Numerous cases of convection ranging from weak to very intense, were overflown by the ER-2. Two TRMM overpasses were coincident with ER-2 flights which allowed for intercomparisons between the Precipitation Radiometer (PR), EDOP, and the S-POL (S-band Polarimetric Radar) and TOGA (Tropical Oceans and Global Atmosphere) ground-based radars. Preliminary results from this comparison will be presented as well as initial selection of case studies and efforts involving vertical motions in convection.

  7. Electron Precipitation at Mars: Advancing Our Understanding with MAVEN

    NASA Astrophysics Data System (ADS)

    Al Noori, H.; Lillis, R. J.; Fillingim, M. O.

    2015-12-01

    Electrons from the solar wind enter the Martian upper atmosphere from space in a process known as electron precipitation. These electrons are confined to move along magnetic field lines and, when those field lines intersect the atmosphere, the electrons collide with atmospheric neutral particles, resulting in heating, dissociation, ionization and excitation of those neutrals. Electron precipitation is an important source of energy input to the Mars upper atmosphere, and is typically the dominant source on the nightside. Past observations from Mars Global Surveyor have characterized patterns of electron precipitation, but only at ~400 km and ~2 AM local time. The MAVEN mission and in particular the SWEA instrument, provides an opportunity to study the distribution of suprathermal electrons in near-Mars space, over a range of altitudes from 120-6000 km and at a range of local times. We will present preliminary observations of flux patterns of these electrons.

  8. Precipitation-Based ENSO Indices

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Curtis, Scott

    1998-01-01

    In this study gridded observed precipitation data sets are used to construct rainfall-based ENSO indices. The monthly El Nino and La Nina Indices (EI and LI) measure the steepest zonal gradient of precipitation anomalies between the equatorial Pacific and the Maritime Continent. This is accomplished by spatially averaging precipitation anomalies using a spatial boxcar filter, finding the maximum and minimum averages within a Pacific and Maritime Continent domain for each month, and taking differences. EI and LI can be examined separately or combined to produce one ENSO Precipitation Index (ESPI). ESPI is well correlated with traditional sea surface temperature and pressure indices, leading Nino 3.4. One advantage precipitation indices have over more conventional indices, is describing the strength and position of the Walker circulation. Examples are given of tracking the impact of ENSO events on the tropical precipitation fields.

  9. National Acid Precipitation Assessment Plan

    SciTech Connect

    Not Available

    1982-06-01

    The Acid Precipitation Act of 1980 (Title VII of The Energy Security Act of 1980 - P.L. 96-294) established the Interagency Task Force on Acid Precipitation to develop and implement a comprehensive National Acid Precipitation Assessment Program. The Act requires the Task Force to produce a National Plan for the ten-year research program; this document is that Plan. The purpose of the National Acid Precipitation Assessment Program is to increase our understanding of the causes and effects of acid precipitation. The National Program includes research, monitoring and assessment activities that emphasize the timely development of a firmer scientific basis for decision making. This program of policy-oriented research issues Annual Reports describing research progress and the current state of knowledge about acid precipitation and its implications. The first Annual Report to the President and the Congress was issued in January 1982.

  10. (+)-N-allylnormetazocine enhances N-acetyltransferase activity and melatonin synthesis: preliminary evidence for a functional role of sigma receptors in the rat pineal gland.

    PubMed

    Steardo, L; Monteleone, P; d'Istria, M; Serino, I; Maj, M; Cuomo, V

    1995-11-01

    In the present study, to evaluate the role that sigma receptors play in the physiology of the pineal gland, we assessed the effects of the sigma receptor ligand (+)-N-allylnormetazocine on the gland activity during either the day or the night. As compared to saline, (+)-N-allylnormetazocine enhanced the physiological increases in both pineal N-acetyltransferase (NAT) activity and melatonin content at night, but it did not affect the biosynthetic activity of the gland during the day. Moreover, (+)-N-allylnormetazocine potentiated the enhancement of NAT activity and pineal melatonin content induced by isoproterenol administration during the day. The nocturnal stimulation of pineal NAT activity and melatonin levels by (+)-N-allylnormetazocine was prevented by pretreatment with rimcazole, a specific sigma receptor antagonist. These results demonstrate that sigma receptor activation by (+)-N-allylnormetazocine is not able, by itself, to stimulate pineal melatonin production, whereas it potentiates the biosynthetic activity of the pineal gland when this is stimulated noradrenergically.

  11. ARM Cloud Aerosol Precipitation Experiment (ACAPEX) Science Plan

    SciTech Connect

    Leung, L. R.; Prather, K.; Ralph, R.; Rosenfeld, D.; Spackman, R.; DeMott, P.; Fairall, C.; Fan, J.; Hagos, S.; Hughes, M.; Long, C.; Rutledge, S.; Waliser, D.; Wang, H.

    2014-09-01

    The western U.S. receives precipitation predominantly during the cold season when storms approach from the Pacific Ocean. The snowpack that accumulates during winter storms provides about 70-90% of water supply for the region. Understanding and modeling the fundamental processes that govern the large precipitation variability and extremes in the western U.S. is a critical test for the ability of climate models to predict the regional water cycle, including floods and droughts. Two elements of significant importance in predicting precipitation variability in the western U.S. are atmospheric rivers and aerosols. Atmospheric rivers (ARs) are narrow bands of enhanced water vapor associated with the warm sector of extratropical cyclones over the Pacific and Atlantic oceans. Because of the large lower-tropospheric water vapor content, strong atmospheric winds and neutral moist static stability, some ARs can produce heavy precipitation by orographic enhancement during landfall on the U.S. West Coast. While ARs are responsible for a large fraction of heavy precipitation in that region during winter, much of the rest of the orographic precipitation occurs in post-frontal clouds, which are typically quite shallow, with tops just high enough to pass the mountain barrier. Such clouds are inherently quite susceptible to aerosol effects on both warm rain and ice precipitation-forming processes.

  12. Preliminary experimental results of Sewage Sludge (SS) Co-digestion with Palm Oil Mill Effluent (POME) for Enhanced Biogas Production in Laboratory Scale Anaerobic Digester

    NASA Astrophysics Data System (ADS)

    Sivasankari, R.; Kumaran, P.; Normanbhay, Saifuddin; Halim Shamsuddin, Abd

    2013-06-01

    An investigation on the feasibility of co-digesting Sewage Sludge with Palm Oil Mill Effluent for enhancing the biogas production and the corresponding effect of the co-digestion substrate ratio on the biogas production has been evaluated. Anaerobic co-digestion of POME with SS was performed at ratios of 100:0, 70:30, 60:40 and 0:100 to find the optimum blend required for enhanced waste digestion and biogas production. Single stage batch digestion was carried out for 12 days in a laboratory scale anaerobic digester. Co-digestion of sludge's at the 70:30 proportion resulted in optimal COD and C: N ratio which subsequently recorded the highest performance with regards to biogas production at 28.1 L's compared to the 1.98 L's of biogas produced from digestion of SS alone. From the results obtained, it is evident that co-digestion of POME and SS is an attractive option to be explored for enhancement of biogas production in anaerobic digesters.

  13. Assessment of myocardial perfusion and viability from routine contrast-enhanced 16-detector-row computed tomography of the heart: preliminary results.

    PubMed

    Nikolaou, Konstantin; Sanz, Javier; Poon, Michael; Wintersperger, Bernd J; Ohnesorge, Bernd; Rius, Teresa; Fayad, Zahi A; Reiser, Maximilian F; Becker, Christoph R

    2005-05-01

    To assess the diagnostic accuracy of 16-detector-row computed tomography (16DCT) of the heart in the assessment of myocardial perfusion and viability in comparison to stress perfusion magnetic resonance imaging (SP-MRI) and delayed-enhancement magnetic resonance imaging (DE-MRI). A number of 30 patients underwent both 16DCT and MRI of the heart. Contrast-enhanced 16DCT data sets were reviewed for areas of myocardium with reduced attenuation. Both CT and MRI data were examined by independent reviewers for the presence of myocardial perfusion defects or myocardial infarctions (MI). Volumetric analysis of the hypoperfusion areas in CT and the infarct sizes in DE-MRI were performed. According to MRI, myocardial infarctions were detected in 11 of 30 cases, and perfusion defects not corresponding to an MI were detected in six of 30 patients. CTA was able to detect ten of 11 MI correctly (sensitivity 91%, specificity 79%, accuracy 83%), and detected three of six hypoperfusions correctly (sensitivity 50%, specificity 92%, accuracy 79%). Assessing the volume of perfusion defects correlating to history of MI on the CT images, a systematic underestimation of the true infarct size as compared to the results of DE-MRI was found (P<0.01). Routine, contrast-enhanced 16-detector row CT of the heart can detect chronic myocardial infarctions in the majority of cases, but ischemic perfusion defects are not reliably detected under resting conditions.

  14. Application of Gis Technology for the Precipitation Mapping

    NASA Astrophysics Data System (ADS)

    Dyras, I.; Serafin-Rek, D.

    2003-04-01

    Precipitation is one of the most variable meteorological parameters in time and space. The standard surface measurement network provides a very localised information about the precipitation. The satellite, radar observations and Numerical Weather Prediction (NWP) models provide the continuous information on the state of the atmosphere, however, with the much lower resolution. Combining these data into one system allows analysing the data from different sources in order to estimate the precipitation intensity and range. The paper presents the works undertaken for the Central Europe region for the stratiform and convective precipitation. The analysis results are prepared in the form of maps of precipitation intensity and range. The satellite data available from an Advanced Microwave Sounding Unit (AMSU) on board of NOAA-15, 16 and 17 satellites enhanced the possibilities of the new meteorological precipitation related products derivation. The products such as Rain Rate (RR), Scattering Index (SI), Total Precipitation Water (TPW), Precipitation Probability (PP) and Liquid Water Path (LWP) were prepared basing on the regression algorithms. The data from spring and summer seasons in 2001 and 2002 were used. The temperature and precipitation thematic layers are created from the NWP model grid data. Also SYNOP and TEMP data are converted into thematic coverages. The progress in GIS technology application for NOAA/AMSU microwave derived products preparation and visualization in the Satellite Research Department in Poland was accomplished. The developed system allows displaying the rain field forecasted by the NWP model Aladin and the precipitation observed with the satellite data and other ancillary information. The maps of precipitation with additional geographical data and administrative boundaries are available for the weather forecasting units via Intranet. It is planned to make images available on the web for external customers. Radar and lightning data as well as

  15. Dissolved Organic Carbon In Precipitation At A Coastal Rural Site

    NASA Astrophysics Data System (ADS)

    Liptzin, D.; Daley, M.; Sive, B. C.; Talbot, R. W.; McDowell, W. H.

    2013-12-01

    Dissolved organic carbon (DOC) is a ubiquitous component of precipitation. This DOC is a complex mixture of compounds from biogenic and anthropogenic sources. The amount and chemistry of the DOC in precipitation has been studied for a variety of reasons: as a source of acidity, as a source of C to marine and terrestrial ecosystems, or to track the fate of individual compounds or pollutants. In most cases, past studies have focused on particular compounds or a limited number of precipitation events. Very little is known about the temporal trends in DOC or the relationship between DOC and other constituents of precipitation. We collected precipitation events for more than five years at a rural coastal site in New Hampshire. We evaluated the seasonal patterns and compared the DOC concentrations to other typical measures of the wet atmospheric deposition (ammonium, nitrate, sulfate, and chloride). In addition, we compared the DOC in precipitation to the concentrations of various organic constituents of the atmosphere. The volume weighted mean C concentration was 0.75 mg C/L with concentrations in the summer significantly higher than in the other three seasons. The DOC concentration was most strongly associated with ammonium concentrations (r=0.81), but was also significantly related to nitrate (r=0.50) and sulfate (r=0.63) concentrations. There was no significant association between DOC and chloride concentrations. Preliminary regression tree analysis suggests that the DOC concentration in precipitation was best predicted by the atmospheric concentration of methyl vinyl ketone, an oxidation product of isoprene. These results suggest that both terrestrial biogenic and anthropogenic sources may be important precursors to the C removed from the atmosphere during precipitation events.

  16. Magnesium carbonate precipitate strengthened aerobic granules.

    PubMed

    Lee, Duu-Jong; Chen, Yu-You

    2015-05-01

    Aerobic granules were precipitated internally with magnesium carbonate to enhance their structural stability under shear. The strengthened granules were tested in continuous-flow reactors for 220 days at organic loadings of 6-39 kg/m(3)/day, hydraulic retention times of 0.44-19 h, and temperatures of 10 or 28°C. The carbonate salt had markedly improved the granule strength without significant changes in granule morphology or microbial communities (with persistent strains Streptomyces sp., Rhizobium sp., Brevundimonas sp., and Nitratireductor sp.), or sacrifice in biological activity for organic degradation. MgCO3 precipitated granules could be used in continuous-flow reactor for wastewater treatment at low cost and with easy processing efforts.

  17. The Environmental Influence on Tropical Cyclone Precipitation.

    NASA Astrophysics Data System (ADS)

    Rodgers, Edward B.; Baik, Jong-Jin; Pierce, Harold F.

    1994-05-01

    The intensity, spatial, and temporal changes in precipitation were examined in three North Atlantic hurricanes during 1989 (Dean, Gabrielle, and Hugo) using precipitation estimates made from Special Sensor Microwave/Imager (SSM/I) measurements. In addition, analyses from a barotropic hurricane forecast model and the European Centre for Medium-Range Weather Forecast model were used to examine the relationship between the evolution of the precipitation in these tropical cyclones and external forcing. The external forcing parameters examined were 1) mean climatological sea surface temperatures, 2) vertical wind shear, 3) environmental tropospheric water vapor flux, and 4) upper-tropospheric eddy relative angular momentum flux convergence.The analyses revealed that 1) the SSM/I precipitation estimates were able to delineate and monitor convective ring cycles similar to those observed with land-based and aircraft radar and in situ measurements; 2) tropical cyclone intensification was observed to occur when these convective rings propagated into the inner core of these systems (within 111 km of the center) and when the precipitation rates increased; 3) tropical cyclone weakening was observed to occur when these inner-core convective rings dissipated; 4) the inward propagation of the outer convective rings coincided with the dissipation of the inner convective rings when they came within 55 km of each other; 5) in regions with the combined warm sea surface temperatures (above 26°C) and low vertical wind shear (less than 5 m s1), convective rings outside the region of strong lower-tropospheric inertial stability could be initiated by strong surges of tropospheric moisture, while convective rings inside the region of strong lower-tropospheric inertial stability could be enhanced by upper-tropospheric eddy relative angular momentum flux convergence.

  18. The environmental influence on tropical cyclone precipitation

    NASA Technical Reports Server (NTRS)

    Rodgers, Edward B.; Baik, Jong-Jin; Pierce, Harold F.

    1994-01-01

    The intensity, spatial, and temporal changes in precipitation were examined in three North Atlantic hurricanes during 1989 (Dean, Gabrielle, and Hugo) using precipitation estimates made from Special Sensor Microwave/Imager (SSM/I) measurements. In addition, analyses from a barotropic hurricane forecast model and the European Centre for Medium-Range Weather Forecast model were used to examine the relationship between the evolution of the precipitation in these tropical cyclones and external forcing. The external forcing parameters examined were (1) mean climatological sea surface temperatures, (2) vertical wind shear, (3) environmental tropospheric water vapor flux, and (4) upper-tropospheric eddy relative angular momentum flux convergence. The analyses revealed that (1) the SSM/I precipitation estimates were able to delineate and monitor convective ring cycles similar to those observed with land-based and aircraft radar and in situ measurements; (2) tropical cyclone intensification was observed to occur when these convective rings propagated into the inner core of these systems (within 111 km of the center) and when the precipitation rates increased; (3) tropical cyclone weakening was observed to occur when these inner-core convective rings dissipated; (4) the inward propagation of the outer convective rings coincided with the dissipation of the inner convective rings when they came within 55 km of each other; (5) in regions with the combined warm sea surface temperatures (above 26 C) and low vertical wind shear (less than 5 m/s), convective rings outside the region of strong lower-tropospheric inertial stability could be initiated by strong surges of tropospheric moisture, while convective rings inside the region of strong lower-tropospheric inertial stability could be enhanced by upper-tropospheric eddy relative angular momentum flux convergence.

  19. Quantification of asphaltene precipitation by scaling equation

    NASA Astrophysics Data System (ADS)

    Janier, Josefina Barnachea; Jalil, Mohamad Afzal B. Abd.; Samin, Mohamad Izhar B. Mohd; Karim, Samsul Ariffin B. A.

    2015-02-01

    Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir conditions. Two conditions were followed in the conduct of the experiment. Firstly, a 45cc light crude oil was mixed with 18cc (40%) of CO2 and secondly, the same amount of crude oil sample was mixed with 27cc (60%) of CO2. Results showed that for a 45cc crude oil sample combined with 18cc (40%) of CO2 gas indicated a saturation pressure of 1498.37psi and asphaltene onset point was 1620psi. Then for the same amount of crude oil combined with 27cc (60%) of CO2, the saturation pressure was 2046.502psi and asphaltene onset point was 2230psi. The derivation of the scaling equation considered reservoir temperature, pressure, bubble point pressure, mole percent of the precipitant the injected gas CO2, and the gas molecular weight. The scaled equation resulted to a third order polynomial that can be used to quantify the amount of asphaltene in crude oil.

  20. Precipitation controls isoprene emissions from tropical ecosystems

    NASA Astrophysics Data System (ADS)

    Potosnak, M. J.; Gatti, L. V.; Guenther, A. B.; Karl, T.; Trostdorf, C. R.; Martins, W. C.; Rinne, H. J.; Yamazaki, A.

    2003-12-01

    Isoprene emissions from tropical regions account for a majority of isoprene produced globally. Current estimates of global isoprene emissions use meteorological inputs (temperature and light), ecosystem leaf area, and a time invariant, ecosystem specific emissions factor. This approach has been verified to work well for deciduous mid-latitude forests, but the approach has not been tested for tropical ecosystems where seasonality is induced by precipitation. Recent flux studies at two field stations in the tropics found strong effects of precipitation regime (dry vs. wet season) on isoprene emissions. A flux study conducted during the wet season (October 1999) at the La Selva Biological Station (10° 26' N, 83° 59' W, precipitation 4000 mm yr{-1}) found whole system isoprene emissions rates between 2--10 mg C m-2 h-1, while a second campaign during the dry season (April 2003) found values ranging 8--16 mg C m-2 h-1. This difference could not be explained by changes in ambient temperature or light using established emissions algorithms. The second field site near Santarém, Brazil in the Floresta Nacional do Tapajós (2° 51' S, 54° 58' W, precipitation 2000 mm yr{-1}), part of the Large scale Biosphere-atmosphere experiment in Amazônia (LBA), showed a similar pattern. Additionally, a 13 month isoprene concentration record at this station found a 4 fold increase during the dry season. Application of a one dimensional chemistry model predicts a similar change in isoprene source strength. A standard emission model using temperature and light could not account for these seasonal changes, but adding an empirical term that accounted for previous precipitation greatly enhanced the fit.

  1. Sparse Downscaling and Adaptive Fusion of Multi-sensor Precipitation

    NASA Astrophysics Data System (ADS)

    Ebtehaj, M.; Foufoula, E.

    2011-12-01

    The past decades have witnessed a remarkable emergence of new sources of multiscale multi-sensor precipitation data including data from global spaceborne active and passive sensors, regional ground based weather surveillance radars and local rain-gauges. Resolution enhancement of remotely sensed rainfall and optimal integration of multi-sensor data promise a posteriori estimates of precipitation fluxes with increased accuracy and resolution to be used in hydro-meteorological applications. In this context, new frameworks are proposed for resolution enhancement and multiscale multi-sensor precipitation data fusion, which capitalize on two main observations: (1) sparseness of remotely sensed precipitation fields in appropriately chosen transformed domains, (e.g., in wavelet space) which promotes the use of the newly emerged theory of sparse representation and compressive sensing for resolution enhancement; (2) a conditionally Gaussian Scale Mixture (GSM) parameterization in the wavelet domain which allows exploiting the efficient linear estimation methodologies, while capturing the non-Gaussian data structure of rainfall. The proposed methodologies are demonstrated using a data set of coincidental observations of precipitation reflectivity images by the spaceborne precipitation radar (PR) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite and ground-based NEXRAD weather surveillance Doppler radars. Uniqueness and stability of the solution, capturing non-Gaussian singular structure of rainfall, reduced uncertainty of estimation and efficiency of computation are the main advantages of the proposed methodologies over the commonly used standard Gaussian techniques.

  2. High-resolution blood-pool-contrast-enhanced MR angiography in glioblastoma: tumor-associated neovascularization as a biomarker for patient survival. A preliminary study.

    PubMed

    Puig, Josep; Blasco, Gerard; Daunis-I-Estadella, Josep; Alberich-Bayarri, Angel; Essig, Marco; Jain, Rajan; Remollo, Sebastián; Hernández, David; Puigdemont, Montserrat; Sánchez-González, Javier; Mateu, Gloria; Wintermark, Max; Pedraza, Salvador

    2016-01-01

    The objective of the study was to determine whether tumor-associated neovascularization on high-resolution gadofosveset-enhanced magnetic resonance angiography (MRA) is a useful biomarker for predicting survival in patients with newly diagnosed glioblastomas. Before treatment, 35 patients (25 men; mean age, 64 ± 14 years) with glioblastoma underwent MRI including first-pass dynamic susceptibility contrast (DSC) perfusion and post-contrast T1WI sequences with gadobutrol (0.1 mmol/kg) and, 48 h later, high-resolution MRA with gadofosveset (0.03 mmol/kg). Volumes of interest for contrast-enhancing lesion (CEL), non-CEL, and contralateral normal-appearing white matter were obtained, and DSC perfusion and DWI parameters were evaluated. Prognostic factors were assessed by Kaplan-Meier survival and Cox proportional hazards model. Eighteen (51.42 %) glioblastomas were hypervascular on high-resolution MRA. Hypervascular glioblastomas were associated with higher CEL volume and lower Karnofsky score. Median survival rates for patients with hypovascular and hypervascular glioblastomas treated with surgery, radiotherapy, and chemotherapy were 15 and 9.75 months, respectively (P < 0.001). Tumor-associated neovascularization was the best predictor of survival at 5.25 months (AUC = 0.794, 81.2 % sensitivity, 77.8 % specificity, 76.5 % positive predictive value, 82.4 % negative predictive value) and yielded the highest hazard ratio (P < 0.001). Tumor-associated neovascularization detected on high-resolution blood-pool-contrast-enhanced MRA of newly diagnosed glioblastoma seems to be a useful biomarker that correlates with worse survival.

  3. Preliminary Results on FeCrAl Alloys in the As-received and Welded State Designed to Have Enhanced Weldability and Radiation Tolerance

    SciTech Connect

    Field, Kevin G.; Gussev, Maxim N.; Hu, Xunxiang; Yamamoto, Yukinori

    2015-09-30

    The present report summarizes and discusses the recent results on developing a modern, nuclear grade FeCrAl alloy designed to have enhanced radiation tolerance and weldability. The alloys used for these investigations are modern FeCrAl alloys based on a Fe-13Cr-5Al-2Mo-0.2Si-0.05Y alloy (in wt.%, designated C35M). Development efforts have focused on assessing the influence of chemistry and microstructure on the fabricability and performance of these newly developed alloys. Specific focus was made to assess the weldability, thermal stability, and radiation tolerance.

  4. Cloning, overexpression, purification and preliminary X-ray analysis of the protein kinase domain of enhanced disease resistance 1 (EDR1) from Arabidopsis thaliana

    PubMed Central

    Kaljunen, Heidi; Panneerselvam, Saravanan; Mueller-Dieckmann, Jochen

    2014-01-01

    Enhanced disease resistance 1 is a member of the Raf-like mitogen-activated protein kinase kinase kinase (MAPKKK) family that negatively regulates disease resistance, ethylene-induced senescence and programmed cell death in response to both abiotic and biotic stresses. A catalytically inactive form of the EDR1 kinase domain was successfully cloned, expressed, purified and crystallized. Crystallization was conducted in the presence of the ATP analogue AMP-PNP. The crystals belonged to space group P3221 and contained two molecules in the asymmetric unit. The crystals diffracted X-rays to 2.55 Å resolution. PMID:25005098

  5. A preliminary look at AVE-SESAME 3 conducted on 25-26 April 1979

    NASA Technical Reports Server (NTRS)

    Williams, S. F.; Horvath, N.; Turner, R. E.

    1980-01-01

    General weather conditions, including synoptic maps, radar reports, satellite photographs, precipitation areas and amounts, and a summary of severe weather reports are presented. These data provide researchers a preliminary look at conditions during the AVE-SESAME 3 period.

  6. Modeling of asphaltene and wax precipitation

    SciTech Connect

    Chung, F.; Sarathi, P.; Jones, R.

    1991-01-01

    This research project was designed to focus on the development of a predictive technique for organic deposition during gas injection for petroleum EOR. A thermodynamic model has been developed to describe the effects of temperature, pressure, and composition on asphaltene precipitation. The proposed model combines regular solution theory with Flory-Huggins polymer solutions theory to predict maximum volume fractions of asphaltene dissolved in oil. The model requires evaluation of vapor-liquid equilibria, first using an equation of state followed by calculations of asphaltene solubility in the liquid-phase. A state-of-the-art technique for C{sub 7+} fraction characterization was employed in developing this model. The preliminary model developed in this work was able to predict qualitatively the trends of the effects of temperature, pressure, and composition. Since the mechanism of paraffinic wax deposition is different from that of asphaltene deposition, another thermodynamic model based on the solid-liquid solution theory was developed to predict the wax formation. This model is simple and can predict the wax appearance temperature with reasonable accuracy. Accompanying the modeling work, experimental studies were conducted to investigate the solubility of asphaltene in oil land solvents and to examine the effects of oil composition, CO{sub 2}, and solvent on asphaltene precipitation and its properties. This research focused on the solubility reversibility of asphaltene in oil and the precipitation caused by CO{sub 2} injection at simulated reservoir temperature and pressure conditions. These experiments have provided many observations about the properties of asphaltenes for further improvement of the model, but more detailed information about the properties of asphaltenes in solution is needed for the development of more reliable asphaltene characterization techniques. 50 refs., 8 figs., 7 tabs.

  7. Improving Precipitation Forecast for Canadian Catchments

    NASA Astrophysics Data System (ADS)

    Jha, S. K.; Shrestha, D. L.; Walford, C.; Leong, D. N. S.; Friesenhan, E.; Campbell, D.; Rasmussen, P. F.

    2016-12-01

    In Canada, floods occur frequently along large river systems, causing devastation to lives and infrastructure. Flooding in Canada is often caused by heavy rainfall during the snowmelt period. The flood forecast centres are responsible for providing advanced flood warnings and rely heavily on forecasted precipitation from numerical weather prediction (NWP) model outputs produced by Environment Canada and the National Oceanic and Atmospheric Administration. The uncertainties in NWP model output are enhanced by physiography and orographic effects over diverse landscapes, particularly in the western catchments of Canada. Therefore, post-processing of NWP model output is necessary to obtain better forecasts of rainfall amount, location, timing, and intensity; and to reliably quantify forecast uncertainty. The Rainfall Post Processing (RPP) approach (Robertson et al., 2013) has been successfully applied recently to remove rainfall forecast bias and quantify forecast uncertainty from NWP models in Australian catchments (Shrestha et al., 2015). In principle, the RPP method can be applied to other regions (e.g. cold regions) but has not been tested yet. In this study we will evaluate the performance of the RPP for improving the precipitation forecast in southern catchments in Alberta and British Columbia. The RPP relates raw quantitative precipitation forecasts and observed precipitation using a Bayesian joint probability (BJP) modeling approach, followed by the Schaake shuffle. Precipitation forecasts were analysed from two NWP models, Global Ensemble Forecasting System and Global Deterministic Prediction System. Observed data was collected from the provincial river forecast centres. The study period from Jan 2012 to Dec 2015 covered major flood events in Calgary, Alberta, and floods in coastal watersheds in British Columbia. Rain-gauge observations and forecast grid points were interpolated to obtain an aerial average precipitation in subareas to force the hydrological

  8. Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion.

    PubMed

    Paltiel, H J; Padua, H M; Gargollo, P C; Cannon, G M; Alomari, A I; Yu, R; Clement, G T

    2011-04-07

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

  9. Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion

    NASA Astrophysics Data System (ADS)

    Paltiel, H. J.; Padua, H. M.; Gargollo, P. C.; Cannon, G. M., Jr.; Alomari, A. I.; Yu, R.; Clement, G. T.

    2011-04-01

    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

  10. A newly anti-Streptococcus suis bacteriocin producing strain from unweaned piglets fecal matter: isolation, preliminary identification, and optimization of medium composition for enhanced bacteriocin production.

    PubMed

    Zhang, Xiangmei; Chang, Xiaoyuan; Liu, Guorong; Wu, Pengpeng; Li, Pinglan

    2012-01-01

    A newly isolated anti-Streptococcus suis bacteriocin-producing strain LPL1-5 was obtained from healthy unweaned piglets' fecal matter, and was designated as Lactobacillus pentosus LPL1-5 based on morphology, biochemical properties, and 16S rDNA sequencing analysis. The medium composition for enhanced bacteriocin production by L. pentosus LPL1-5 was optimized by statistical methodology. Yeast extract, K(2)HPO(4)·3H(2)O, and MnSO(4)·H(2)O were identified as significant components influencing pentocin LPL1-5 production using the Plackett-Burman method. Response surface methodology was applied for further optimization. The concentrations of medium components for enhanced pentocin LPL1-5 production were as follows (g/L): lactose 20.00, tryptone 10.00, beef extract 10.00, yeast extract 14.00, MnSO(4)·H(2)O 0.84, K(2)HPO(4)·3H(2)O 4.92, triammonium citrate 2.00, Na-acetate 5.00, MgSO(4)·7H(2)O 0.58, Tween 80 1.00. Under the optimized condition, a value of 3154.65 ± 27.93 IU/mL bacteriocin activity was achieved, which was 4.2-fold that of the original medium.

  11. Orographic precipitation, wind-blown snow, and landscape evolution in glaciated mountain ranges

    NASA Astrophysics Data System (ADS)

    Brocklehurst, S. H.; Rowan, A. V.; Plummer, M. A.; Foster, D.; Schultz, D. M.; MacGregor, K. R.

    2011-12-01

    than at the range scale. Rapid rock uplift and significant glacial erosion of the north-south Teton Range, Wyoming, has created some of the highest relief in the conterminous US. While an initial topographic asymmetry would have arisen from the tectonic gradient imposed by the extensional Teton Fault on the east side of the range, the topographic asymmetry would have been exaggerated by feedbacks associated with glacial erosion. Slowly-falling snow would have been advected further into the range by prevailing westerlies, which would also have redistributed fallen snow from the subdued topography typical of the headwaters of west-draining basins. Greater topographic shading and cover by rock debris would have mitigated ablation of eastern glaciers bounded by high valley walls. Glacier size, ice flux and erosion would therefore have been enhanced in eastern-draining basins, though only the largest glaciers were capable of eroding at rates that kept pace with rock uplift. Preliminary numerical modelling results are consistent with these inferences of the importance of orographic precipitation and wind-blown snow based on topographic analysis.

  12. Acid precipitation and forest soils

    Treesearch

    C. O. Tamm

    1976-01-01

    Many soil processes and properties may be affected by a change in chemical climate such as that caused by acidification of precipitation. The effect of additions of acid precipitation depends at first on the extent to which this acid is really absorbed by the soil and on the changes in substances with actual or potential acidity leaving the soil. There is for instance...

  13. Resistivity Problems in Electrostatic Precipitation

    ERIC Educational Resources Information Center

    White, Harry J.

    1974-01-01

    The process of electrostatic precipitation has ever-increasing application in more efficient collection of fine particles from industrial air emissions. This article details a large number of new developments in the field. The emphasis is on high resistivity particles which are a common cause of poor precipitator performance. (LS)

  14. An economical storage precipitation gage

    Treesearch

    Raymond D. Ratliff; Jack N. Reppert

    1965-01-01

    Describes how to make an economical "can-cone"-type storage precipitation gage, based on one originally designed by the California Department of Water Resources. The cone was modified by including an inner skirt to prevent loss of water between the cone and can. Periodic records of precipitation are obtained by stick measurement. Five complete cones cost $120...

  15. Precipitation in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  16. Precipitation in the Solar System

    ERIC Educational Resources Information Center

    McIntosh, Gordon

    2007-01-01

    As an astronomy instructor, I am always looking for commonly observed Earthly experiences to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote a short TPT article on frost. This paper is on the related phenomena of precipitation. Precipitation, so common on most of the Earth's…

  17. Precipitation Process and Apparatus Therefor

    DOEpatents

    Stang, Jr, L C

    1950-12-05

    This invention concerns an apparatus for remotely-controlled precipitation and filtration operations. Liquid within a precipitation chamber is maintained above a porous member by introducing air beneath the member; pressure beneath the porous member is reduced to suck the liquid through the member and effect filtration.

  18. Encoding information into precipitation structures

    NASA Astrophysics Data System (ADS)

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan

    2008-12-01

    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A+ + B- → C reaction-diffusion processes. Our main result, based on simulating the reaction-diffusion-precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm.

  19. Computer-enhanced interventions for drug use and HIV risk in the emergency room: preliminary results on psychological precursors of behavior change.

    PubMed

    Bonar, Erin E; Walton, Maureen A; Cunningham, Rebecca M; Chermack, Stephen T; Bohnert, Amy S B; Barry, Kristen L; Booth, Brenda M; Blow, Frederic C

    2014-01-01

    This article describes process data from a randomized controlled trial among 781 adults recruited in the emergency department who reported recent drug use and were randomized to: intervener-delivered brief intervention (IBI) assisted by computer, computerized BI (CBI), or enhanced usual care (EUC). Analyses examined differences between baseline and post-intervention on psychological constructs theoretically related to changes in drug use and HIV risk: importance, readiness, intention, help-seeking, and confidence. Compared to EUC, participants receiving the IBI significantly increased in confidence and intentions; CBI patients increased importance, readiness, confidence, and help-seeking. Both groups increased relative to the EUC in likelihood of condom use with regular partners. Examining BI components suggested that benefits of change and tools for change were associated with changes in psychological constructs. Delivering BIs targeting drug use and HIV risk using computers appears promising for implementation in healthcare settings. This trial is ongoing and future work will report behavioral outcomes.

  20. Care and Respect for Elders in Emergencies program: a preliminary report of a volunteer approach to enhance care in the emergency department.

    PubMed

    Sanon, Martine; Baumlin, Kevin M; Kaplan, Shari Sirkin; Grudzen, Corita R

    2014-02-01

    Older adults who present to an emergency department (ED) generally have more-complex medical conditions with complicated care needs and are at high risk for preventable adverse outcomes during their ED visit. The Care and Respect for Elders with Emergencies (CARE) volunteer initiative is a geriatric-focused volunteer program developed to help prevent avoidable complications such as falls, delirium and use of restraints, and functional decline in vulnerable elders in the ED. The CARE program consists of bedside volunteer interventions ranging from conversation to various short activities designed to engage and reorient high-risk, older, unaccompanied individuals in the ED. This article describes the development and characteristics of the CARE program, the services provided, the experiences of the elderly patients and their volunteers, and the growth of the program over time. CARE volunteers provide elders with the additional attention needed in an often chaotic, unfamiliar environment by enhancing their care, improving satisfaction, and preventing potential decline.

  1. Evaluation of contrast-enhanced ultrasonography for hepatocellular carcinoma prior to and following stereotactic body radiation therapy using the CyberKnife® system: A preliminary report.

    PubMed

    Shiozawa, Kazue; Watanabe, Manabu; Ikehara, Takashi; Kobayashi, Kojiro; Ochi, Yuta; Suzuki, Yuta; Fuchinoue, Kazuhiro; Yoneda, Masataka; Kenmochi, Takeshi; Okubo, Yusuke; Mori, Takayuki; Makino, Hiroyuki; Tsukamoto, Nobuhiro; Igarashi, Yoshinori; Sumino, Yasukiyo

    2016-01-01

    The CyberKnife® is expected to be a novel local treatment for hepatocellular carcinoma (HCC), however, a long-term follow-up using dynamic computed tomography and magnetic resonance imaging is required to determine the effect of treatment in a number of the affected patients. Therefore, there is a requirement to evaluate procedures for early determination of the effect of CyberKnife treatment. The present study aimed to evaluate the changes in the hemodynamics of the tumors and the hepatic parenchyma surrounding the tumor prior to and following CyberKnife treatment for HCC. A total of 4 HCC patients were enrolled in this study. These patients underwent CyberKnife treatment and were evaluated by image analysis prior to and following treatment using contrast-enhanced ultrasonography (CEUS) with Sonazoid. CEUS was performed prior to treatment, at 2 and 4 weeks post-treatment, and every 4 weeks thereafter for as long as possible. The dynamics of the enhancement of the tumor and the hepatic parenchyma surrounding the tumor in the vascular phase, and the presence or absence of a hypoechoic area in the hepatic parenchyma surrounding the tumor in the post-vascular phase were assessed. Results showed that: i) In the patient with earlier changes, hemodynamic changes were evident in the tumor at 4 weeks and in the hepatic parenchyma surrounding the tumor at 2 weeks post-treatment, respectively; ii) the tumor showed hypoenhancement in all patients; and iii) with regard to findings in the hepatic parenchyma surrounding the tumor, strong hyperenhancement appeared in the vascular phase initially, followed by a hypoechoic area in the post-vascular phase. Evaluation of the hemodynamics of tumors and hepatic parenchyma surrounding the tumor using CEUS with Sonazoid may be therapeutically applicable, as it is less invasive than dynamic computed tomography (CT) and provides an early evaluation of the effectiveness of CyberKnife treatment.

  2. in situ Calcite Precipitation for Contaminant Immobilization

    SciTech Connect

    Yoshiko Fujita; Robert W. Smith

    2009-08-01

    in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at

  3. Precipitation Response to Land Cover Changes in the Netherlands

    NASA Astrophysics Data System (ADS)

    Daniels, E.; Lenderink, G.; Hutjes, R. W. A.; Holtslag, A. A.

    2015-12-01

    Precipitation has increased by 25% over the last century in the Netherlands. In this period, conversion of peat areas into grassland, expansion of urban areas, and the creation of new land in Lake Ijssel were the largest land cover changes. Both station data analysis (Daniels et al. 2014) and high-resolution (2.5 km) simulations with the atmospheric Weather Research and Forecasting (WRF) model suggest that the observed increase in precipitation is not due to these land cover changes. Instead, the change from historical (1900) to present (2000) land cover decreases precipitation in WRF (Figure). However, WRF seems to be very sensitive to changes in evapotranspiration. The creation of new land and the expansion of urban areas are similar from a moisture perspective, since they locally decrease evapotranspiration, and therefore affect the soil moisture-precipitation feedback mechanism. In our simulations, the resulting feedback is always positive, as a reduction in evapotranspiration causes a reduction of precipitation. There is a difference between urban areas and land in WRF however. Over urban areas, the planetary boundary layer (PBL) height increases more than the lifting condensation level (LCL), and the potential to trigger precipitation hereby increases. This in turn decreases the strength, but not sign, of the soil moisture-precipitation feedback. WRF is therefore unable to reproduce the observed precipitation enhancement downwind of urban areas. In all, it seems the sensitivity of WRF to changes in surface moisture might be too high and this questions the applicability of the model to investigate land cover changes. Daniels, E. E., G. Lenderink, R. W. A. Hutjes, and A. A. M. Holtslag, 2014: Spatial precipitation patterns and trends in The Netherlands during 1951-2009. International Journal of Climatology, 34, 1773-1784. Figure: Composite summer precipitation (mm) based on 19 single day cases (a), showing the decreases resulting from changing present to

  4. Estimation of continental precipitation recycling

    NASA Technical Reports Server (NTRS)

    Brubaker, Kaye L.; Entekhabi, Dara; Eagleson, P. S.

    1993-01-01

    The total amount of water that precipitates on large continental regions is supplied by two mechanisms: 1) advection from the surrounding areas external to the region and 2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the continental area. The degree to which regional precipitation is supplied by recycled moisture is a potentially significant climate feedback mechanism and land surface-atmosphere interaction, which may contribute to the persistence and intensification of droughts. Gridded data on observed wind and humidity in the global atmosphere are used to determine the convergence of atmospheric water vapor over continental regions. A simplified model of the atmospheric moisture over continents and simultaneous estimates of regional precipitation are employed to estimate, for several large continental regions, the fraction of precipitation that is locally derived. The results indicate that the contribution of regional evaporation to regional precipitation varies substantially with location and season. For the regions studied, the ratio of locally contributed to total monthly precipitation generally lies between 0. 10 and 0.30 but is as high as 0.40 in several cases.

  5. Estimation of continental precipitation recycling

    NASA Technical Reports Server (NTRS)

    Brubaker, Kaye L.; Entekhabi, Dara; Eagleson, P. S.

    1993-01-01

    The total amount of water that precipitates on large continental regions is supplied by two mechanisms: 1) advection from the surrounding areas external to the region and 2) evaporation and transpiration from the land surface within the region. The latter supply mechanism is tantamount to the recycling of precipitation over the continental area. The degree to which regional precipitation is supplied by recycled moisture is a potentially significant climate feedback mechanism and land surface-atmosphere interaction, which may contribute to the persistence and intensification of droughts. Gridded data on observed wind and humidity in the global atmosphere are used to determine the convergence of atmospheric water vapor over continental regions. A simplified model of the atmospheric moisture over continents and simultaneous estimates of regional precipitation are employed to estimate, for several large continental regions, the fraction of precipitation that is locally derived. The results indicate that the contribution of regional evaporation to regional precipitation varies substantially with location and season. For the regions studied, the ratio of locally contributed to total monthly precipitation generally lies between 0. 10 and 0.30 but is as high as 0.40 in several cases.

  6. Preliminary report: comparison of 980-nm, 808-nm diode laser enhanced with indocyanine green to the Nd:YAG laser applied to equine respiratory tissue

    NASA Astrophysics Data System (ADS)

    Tate, Lloyd P.; Blikslager, Anthony T.; Campbell, Nigel B.

    2001-05-01

    The Neodynium: Yttrium Aluminum Garnet (Nd:YAG) laser has been the mainstay of performing upper respiratory laser surgery in the equine since 1984. The 808-nm diode laser has also been applied transendoscopically as well as the 980-nm diode laser over recent years. It has been shown that Indocyanine Green (ICG) enhances the performance of the 808- nm laser because it is absorbed at 810 nm of light. The 808- nm laser's tissue interaction combined with ICG is equivalent to or greater than the Nd:YAG laser's cutting ability. The 980-nm diode laser performance was similar to that of the Nd:YAG as determined by the parameters of this study. This study compared the depths and widths of penetration achieved with the 808-nm diode laser after intravenous injection of ICG on equine respiratory tissue. It also compared depths and widths of penetration achieved by the non-contact application of the 980-nm diode laser delivering the same energy of 200 joules. The depths and widths of penetration of both diode lasers were compared to themselves and to the Nd:YAG laser with all factors remaining constant.

  7. Comparison of Contrast-Enhanced Ultrasound and Computed Tomography in Classifying Endoleaks After Endovascular Treatment of Abdominal Aorta Aneurysms: Preliminary Experience

    SciTech Connect

    Carrafiello, Gianpaolo Lagana, Domenico; Recaldini, Chiara; Mangini, Monica; Bertolotti, Elena; Caronno, Roberto; Tozzi, Matteo; Piffaretti, Gabriele; Annibale Genovese, Eugenio; Fugazzola, Carlo

    2006-12-15

    The purpose of the study was to assess the effectiveness of contrast-enhanced ultrasonography (CEUS) in endoleak classification after endovascular treatment of an abdominal aortic aneurysm compared to computed tomography angiography (CTA). From May 2001 to April 2003, 10 patients with endoleaks already detected by CTA underwent CEUS with Sonovue (registered) to confirm the CTA classification or to reclassify the endoleak. In three conflicting cases, the patients were also studied with conventional angiography. CEUS confirmed the CTA classification in seven cases (type II endoleaks). Two CTA type III endoleaks were classified as type II using CEUS and one CTA type II endoleak was classified as type I by CEUS. Regarding the cases with discordant classification, conventional angiography confirmed the ultrasound classification. Additionally, CEUS documented the origin of type II endoleaks in all cases. After CEUS reclassification of endoleaks, a significant change in patient management occurred in three cases. CEUS allows a better attribution of the origin of the endoleak, as it shows the flow in real time. CEUS is more specific than CTA in endoleak classification and gives more accurate information in therapeutic planning.

  8. A CT-ultrasound-coregistered augmented reality enhanced image-guided surgery system and its preliminary study on brain-shift estimation

    NASA Astrophysics Data System (ADS)

    Huang, C. H.; Hsieh, C. H.; Lee, J. D.; Huang, W. C.; Lee, S. T.; Wu, C. T.; Sun, Y. N.; Wu, Y. T.

    2012-08-01

    With the combined view on the physical space and the medical imaging data, augmented reality (AR) visualization can provide perceptive advantages during image-guided surgery (IGS). However, the imaging data are usually captured before surgery and might be different from the up-to-date one due to natural shift of soft tissues. This study presents an AR-enhanced IGS system which is capable to correct the movement of soft tissues from the pre-operative CT images by using intra-operative ultrasound images. First, with reconstructing 2-D free-hand ultrasound images to 3-D volume data, the system applies a Mutual-Information based registration algorithm to estimate the deformation between pre-operative and intra-operative ultrasound images. The estimated deformation transform describes the movement of soft tissues and is then applied to the pre-operative CT images which provide high-resolution anatomical information. As a result, the system thus displays the fusion of the corrected CT images or the real-time 2-D ultrasound images with the patient in the physical space through a head mounted display device, providing an immersive augmented-reality environment. For the performance validation of the proposed system, a brain phantom was utilized to simulate brain-shift scenario. Experimental results reveal that when the shift of an artificial tumor is from 5mm ~ 12mm, the correction rates can be improved from 32% ~ 45% to 87% ~ 95% by using the proposed system.

  9. Tracer kinetic analysis of dynamic contrast-enhanced MRI and CT bladder cancer data: A preliminary comparison to assess the magnitude of water exchange effects.

    PubMed

    Bains, Lauren J; McGrath, Deirdre M; Naish, Josephine H; Cheung, Susan; Watson, Yvonne; Taylor, M Ben; Logue, John P; Parker, Geoffrey J M; Waterton, John C; Buckley, David L

    2010-08-01

    The purpose of this study was to determine the impact of water exchange on tracer kinetic parameter estimates derived from T(1)-weighted dynamic contrast-enhanced (DCE)-MRI data using a direct quantitative comparison with DCE-CT. Data were acquired from 12 patients with bladder cancer who underwent DCE-CT followed by DCE-MRI within a week. A two-compartment tracer kinetic model was fitted to the CT data, and two versions of the same model with modifications to account for the fast exchange and no exchange limits of water exchange were fitted to the MR data. The two-compartment tracer kinetic model provided estimates of the fractional plasma volume (v(p)), the extravascular extracellular space fraction (v(e)), plasma perfusion (F(p)), and the microvascular permeability surface area product. Our findings suggest that DCE-CT is an appropriate reference for DCE-MRI in bladder cancers as the only significant difference found between CT and MR parameter estimates were the no exchange limit estimates of v(p) (P = 0.002). These results suggest that although water exchange between the intracellular and extravascular-extracellular space has a negligible effect on DCE-MRI, vascular-extravascular-extracellular space water exchange may be more important.

  10. Incorporating Contrast-Enhanced Ultrasound into the BI-RADS Scoring System Improves Accuracy in Breast Tumor Diagnosis: A Preliminary Study in China.

    PubMed

    Xiao, Xiaoyun; Dong, Licong; Jiang, Qiongchao; Guan, Xiaofeng; Wu, Huan; Luo, Baoming

    2016-11-01

    The aim of the study was to develop a scoring model incorporating the Breast Imaging Reporting and Data System (BI-RADS) and the contrast-enhanced ultrasound (CEUS) scoring system to differentiate between malignant and benign breast lesions. A total of 524 solid breast masses in 490 consecutive patients were evaluated with conventional US and CEUS in this prospective study. Each lesion was scored according to BI-RADS, CEUS, and CEUS-rerated BI-RADS. The diagnostic specificity, sensitivity and accuracy of BI-RADS were 77.9%, 88.9% and 84.0%, respectively, and the area under the receiver operating characteristic curve was 0.834. The corresponding values for rerated BI-RADS were 82.1%, 96.9%, 90.3% and 0.895. The area under the receiver operating characteristic curve of BI-RADS alone was significantly smaller than that of CEUS and the rerated BI-RADS (p = 0.008 compared with CEUS, p = 0.002 compared with rerated BI-RADS). This study indicates that rerating BI-RADS with the CEUS scoring system improves its diagnostic accuracy.

  11. Deep vein thrombosis using noncontrast-enhanced MR venography with electrocardiographically gated three-dimensional half-Fourier FSE: preliminary experience.

    PubMed

    Ono, Atsushi; Murase, Kenya; Taniguchi, Toshitaka; Shibutani, Osamu; Takata, Satoru; Kobashi, Yasuyuki; Miyazaki, Mitsue

    2009-04-01

    Three noncontrast-enhanced MR venography techniques are presented for assessing deep vein thrombosis (DVT) at 0.5 T in patients with metallic implants. Two cardiac-gated 3D half-Fourier FSE fresh blood imaging sequences with flow-refocusing pulses (FR-FBI) in the read-out (RO) direction and without FR pulses (non-FR-FBI) were developed for slower-flowing blood. For faster flowing blood, a swap phase-encode arterial double-subtraction elimination (SPADE) technique was developed. The three techniques were assessed both quantitatively using signal-to-noise (SNR) and contrast-noise-ratio (CNR) measurements and qualitatively by subjective image analysis in 15 volunteers. SPADE was compared to FR-FBI in the pelvic veins and FR-FBI was compared to non-FR-FBI in the thigh and calf veins. Both SPADE and FR-FBI techniques produced significantly higher SNRs, CNRs, and image quality in each comparative study (P<0.001). Five patients with metallic implants and confirmed DVT underwent SPADE (pelvic veins) and FR-FBI (thigh and calf veins) examinations and the results were compared to conventional venography. The SPADE and FR-FBI images showed all DVTs from all five patients without interference from implant susceptibility artifacts. The excellent image quality produced by both SPADE and FR-FBI throughout peripheral vasculature demonstrates their promise for detecting DVT in postsurgery patients.

  12. Dynamic contrast-enhanced MRI as a valuable non-invasive tool to evaluate tissue perfusion of free flaps: Preliminary results.

    PubMed

    Fellner, Claudia; Jung, Ernst M; Prantl, Lukas

    2010-01-01

    Early detection of a compromised circulation of free flaps and an immediate revision may lead to higher rates of flap salvage. The aim of this study was to evaluate the perfusion of the entire flap using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). DCE was performed in 11 patients after flap transplantation using an optimized 3D gradient echo sequence to cover the whole flap. The percentage increase of signal intensity over time was evaluated for the free flap as well as for a reference tissue. Furthermore, normalized signal increase was calculated as the ratio of signal increase within the flaps to the signal increase in the reference tissue. Signal increase in free flaps and reference tissue was compared using the Wilcoxon-test (p < 0.05), normalized signal increase in normally perfused (n = 9) and in flaps with compromised perfusion (n = 2) using Mann-Whitney-test (p < 0.05). Signal increase within normally perfused flaps was similar to the reference tissue. In flaps with compromised perfusion the increase was significantly lower than in reference tissue. Normalized signal increase in adequately perfused flaps and flaps with compromised perfusion also showed a significant difference. DCE MRI may be a valuable non-invasive tool to evaluate tissue perfusion of the complete free flap.

  13. Extreme precipitation events and related weather patterns over Iraq

    NASA Astrophysics Data System (ADS)

    raheem Al-nassar, Ali; Sangrà, Pablo; Alarcón, Marta

    2016-04-01

    This study aims to investigate the extreme precipitation events and the associated weather phenomena in the Middle East and particularly in Iraq. For this purpose we used Baghdad daily precipitation records from the Iraqi Meteorological and Seismology Organization combined with ECMWF (ERA-Interim) reanalysis data for the period from January 2002 to December 2013. Extreme events were found statistically at the 90% percentile of the recorded precipitation, and were highly correlated with hydrological flooding in some cities of Iraq. We identified fifteen extreme precipitation events. The analysis of the corresponding weather patterns (500 hPa and 250 hPa geopotential and velocity field distribution) indicated that 5 events were related with cut off low causing the highest precipitation (180 mm), 3 events related with rex block (158 mm), 3 events related with jet streak occurrence (130 mm) and 4 events related with troughs (107 mm). . Five of these events caused flash floods and in particular one of them related with a rex block was the most dramatic heavy rain event in Iraq in 30 years. We investigated for each case the convective instability and dynamical forcing together with humidity sources. For convective instability we explored the distribution of the K index and SWEAT index. For dynamical forcing we analyzed at several levels Q vector, divergence, potential and relative vorticity advection and omega vertical velocity. Source of humidity was investigated through humidity and convergence of specific humidity distribution. One triggering factor of all the events is the advection and convergence of humidity from the Red Sea and the Persian Gulf. Therefore a necessary condition for extreme precipitation in Iraq is the advection and convergence of humidity from the Red Sea and Persian Gulf. Our preliminary analysis also indicates that extreme precipitation events are primary dynamical forced playing convective instability a secondary role.

  14. Passive microwave precipitation detection biases: Relationship to cloud morphology

    NASA Astrophysics Data System (ADS)

    Marter, R. E.; Rapp, A. D.

    2015-12-01

    Accurate measurement of the Earth's hydrologic cycle requires a more precise understanding of precipitation accumulation and intensity on a global scale. While there is a long record of passive microwave satellite measurements, passive microwave rainfall retrievals often fail to detect light precipitation or have light rain intensity biases because they cannot differentiate between emission from cloud and rain water. Previous studies have shown that AMSR-E significantly underestimates rainfall occurrence and volume compared to CloudSat. This underestimation totals just below 0.6 mm/day quasi-globally (60S-60N), but there are larger regional variations related to the dominant cloud regime. This study aims to use Moderate Resolution Imaging Spectroradiometer (MODIS) and the 94-GHz CloudSat Cloud Profiling Radar (CPR), which has a high sensitivity to light rain, with the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) observations, to help better characterize the properties of clouds that lead to passive microwave rainfall detection biases. CPR cloud and precipitation retrievals. AMSR-E Level-2B Goddard Profiling 2010 Algorithm (GPROF 2010) rainfall retrievals, and MODIS cloud properties were collocated and analyzed for 2008. Results are consistent with past studies and show large passive microwave precipitation detection biases compared to CloudSat in stratocumulus and shallow cumulus regimes. A preliminary examination of cases where AMSR-E failed to detect precipitation detected by CloudSat shows that over 50% of missed warm precipitation occurs in clouds with top heights below 2 km. MODIS cloud microphysical and macrophysical properties, such as optical thickness, particle effective radius, and liquid water path will be analyzed when precipitation is detected by CloudSat and missed by AMSR-E. The overall goal is to understand how cloud morphology relates to detection biases.

  15. Inhibition of nickel precipitation by organic ligands

    SciTech Connect

    Hu, H.L.; Nikolaidis, N.P.; Grasso, D.

    1996-11-01

    Wastewaters from electroplating are very complex due to the composition of the plating baths. A nickel plating bath typically consists of a nickel source (nickel chloride or nickel sulfate), complexing agents to solubilize nickel ions controlling their concentration in the solution, buffering agents to maintain pH, brighteners to improve brightness of the plated metal, stabilizers (inhibitors) to prevent undesired reactions, accelerators to enhance speed of reactions, wetting agents to reduce surface tension at the metal surface, and reducing agents (only for electroless nickel plating) to supply electrons for reduction of the nickel. Alkaline precipitation is the most common method of recovering nickel from wastewaters. However, organic constituents found in the wastewaters can mask or completely inhibit the precipitation of nickel. The objective of this study was to conduct an equilibrium study to explore the inhibition behavior of various organic ligands on nickel precipitation. This will lay the groundwork for development of technologies efficacious in the treatment of complexed nickel. The organic ligands used in this study are EDTA, triethanolamine (TEA), gluconate, and tartrate.

  16. Oxygen precipitation behavior in heavily arsenic doped silicon crystals

    NASA Astrophysics Data System (ADS)

    Haringer, Stephan; Gambaro, Daniela; Porrini, Maria

    2017-01-01

    Silicon crystals containing different levels of arsenic concentration and oxygen content were grown, and samples were taken at various positions along the crystal, to study the influence of three main factors, i.e. the initial oxygen content, the dopant concentration and the thermal history, on the nucleation of oxygen precipitates during crystal growth and cooling in the puller. The crystal thermal history was reconstructed by means of computer modeling, simulating the temperature distribution in the crystal at several growth stages. The oxygen precipitation was characterized after a thermal cycle of 4 h at 800 °C for nuclei stabilization +16 h at 1000 °C for nuclei growth. Oxygen precipitates were counted under microscope on the cleaved sample surface after preferential etching. Lightly doped silicon samples were also included, as reference. Our results show that even in heavily arsenic doped silicon the oxygen precipitation is a strong function of the initial oxygen concentration, similar to what has been observed for lightly doped silicon. In addition, a precipitation retardation effect is observed in the arsenic doped samples when the dopant concentration is higher than 1.7×1019 cm-3 compared to lightly doped samples with the same initial oxygen content and crystal thermal history. Finally, a long permanence time of the crystal in the temperature range between 450 °C and 750 °C enhances the oxygen precipitation, showing that this is an effective temperature range for oxygen precipitation nucleation in heavily arsenic doped silicon.

  17. Assessment of changes in vascularity and blood volume in canine sarcomas and squamous cell carcinomas during fractionated radiation therapy using quantified contrast-enhanced power Doppler ultrasonography: a preliminary study.

    PubMed

    Ohlerth, Stefanie; Bley, Carla Rohrer; Laluhová, Dagmar; Roos, Malgorzata; Kaser-Hotz, Barbara

    2010-10-01

    Radiation therapy does not only target tumour cells but also affects tumour vascularity. In the present study, changes in tumour vascularity and blood volume were investigated in five grade 1 oral fibrosarcomas, eight other sarcomas (non-oral soft tissue and bone sarcomas) and 12 squamous cell carcinomas in dogs during fractionated radiation therapy (total dose, 45-56 Gy). Contrast-enhanced power Doppler ultrasound was performed before fraction 1, 3, 6, 8, 10, 12, 14 and 15 or 16 (sarcomas) or 17 (squamous cell carcinomas). Prior to treatment, median vascularity and blood volume were significantly higher in squamous cell carcinomas (P=0.0005 and 0.001), whereas measurements did not differ between oral fibrosarcomas and other sarcomas (P=0.88 and 0.999). During the course of radiation therapy, only small, non-significant changes in vascularity and blood volume were observed in all three tumour histology groups (P=0.08 and P=0.213), whereas median tumour volume significantly decreased until the end of treatment (P=0.04 for fibrosarcomas and other sarcomas, P=0.008 for squamous cell carcinomas). It appeared that there was a proportional decrease in tumour volume, vascularity and blood volume. Doppler measurements did not predict progression free interval or survival in any of the three tumour groups (P=0.06-0.86). However, the number of tumours investigated was small and therefore, the results can only be considered preliminary.

  18. Geochemical effects of CO2 injection on produced water chemistry at an enhanced oil recovery site in the Permian Basin of northwest Texas, USA: Preliminary geochemical and Li isotope results

    NASA Astrophysics Data System (ADS)

    Pfister, S.; Gardiner, J.; Phan, T. T.; Macpherson, G. L.; Diehl, J. R.; Lopano, C. L.; Stewart, B. W.; Capo, R. C.

    2014-12-01

    Injection of supercritical CO2 for enhanced oil recovery (EOR) presents an opportunity to evaluate the effects of CO2 on reservoir properties and formation waters during geologic carbon sequestration. Produced water from oil wells tapping a carbonate-hosted reservoir at an active EOR site in the Permian Basin of Texas both before and after injection were sampled to evaluate geochemical and isotopic changes associated with water-rock-CO2 interaction. Produced waters from the carbonate reservoir rock are Na-Cl brines with TDS levels of 16.5-34 g/L and detectable H2S. These brines are potentially diluted with shallow groundwater from earlier EOR water flooding. Initial lithium isotope data (δ7Li) from pre-injection produced water in the EOR field fall within the range of Gulf of Mexico Coastal sedimentary basin and Appalachian basin values (Macpherson et al., 2014, Geofluids, doi: 10.1111/gfl.12084). Pre-injection produced water 87Sr/86Sr ratios (0.70788-0.70795) are consistent with mid-late Permian seawater/carbonate. CO2 injection took place in October 2013, and four of the wells sampled in May 2014 showed CO2 breakthrough. Preliminary comparison of pre- and post-injection produced waters indicates no significant changes in the major inorganic constituents following breakthrough, other than a possible drop in K concentration. Trace element and isotope data from pre- and post-breakthrough wells are currently being evaluated and will be presented.

  19. Precipitation Measurements from Space: The Global Precipitation Measurement Mission

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2007-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to bc launched in the early next decade.

  20. Precipitation Measurements from Space: The Global Precipitation Measurement Mission

    NASA Technical Reports Server (NTRS)

    Hou, Arthur Y.

    2007-01-01

    Water is fundamental to the life on Earth and its phase transition between the gaseous, liquid, and solid states dominates the behavior of the weather/climate/ecological system. Precipitation, which converts atmospheric water vapor into rain and snow, is central to the global water cycle. It regulates the global energy balance through interactions with clouds and water vapor (the primary greenhouse gas), and also shapes global winds and dynamic transport through latent heat release. Surface precipitation affects soil moisture, ocean salinity, and land hydrology, thus linking fast atmospheric processes to the slower components of the climate system. Precipitation is also the primary source of freshwater in the world, which is facing an emerging freshwater crisis in many regions. Accurate and timely knowledge of global precipitation is essential for understanding the behavior of the global water cycle, improving freshwater management, and advancing predictive capabilities of high-impact weather events such as hurricanes, floods, droughts, and landslides. With limited rainfall networks on land and the impracticality of making extensive rainfall measurements over oceans, a comprehensive description of the space and time variability of global precipitation can only be achieved from the vantage point of space. This presentation will examine current capabilities in space-borne rainfall measurements, highlight scientific and practical benefits derived from these observations to date, and provide an overview of the multi-national Global Precipitation Measurement (GPM) Mission scheduled to bc launched in the early next decade.

  1. Door‐to‐Puncture: A Practical Metric for Capturing and Enhancing System Processes Associated With Endovascular Stroke Care, Preliminary Results From the Rapid Reperfusion Registry

    PubMed Central

    Sun, Chung‐Huan J.; Ribo, Marc; Goyal, Mayank; Yoo, Albert J.; Jovin, Tudor; Cronin, Carolyn A.; Zaidat, Osama; Nogueira, Raul; Nguyen, Thanh; Hussain, M. Shazam; Menon, Bijoy K.; Mehta, Brijesh; Jindal, Gaurav; Horev, Anat; Norbash, Alexander; Leslie‐Mazwi, Thabele; Wisco, Dolora; Gupta, Rishi

    2014-01-01

    Background In 2011, the Brain Attack Coalition proposed door‐to‐treatment times of 2 hours as a benchmark for patients undergoing intra‐arterial therapy (IAT). We designed the Rapid Reperfusion Registry to capture the percentage of stroke patients who meet the target and its impact on outcomes. Methods and Results This is a retrospective analysis of anterior circulation patients treated with IAT within 9 hours of symptom onset. Data was collected from December 31, 2011 to December 31, 2012 at 2 centers and from July 1, 2012 to December 31, 2012 at 7 centers. Short “Door‐to‐Puncture” (D2P) time was hypothesized to be associated with good patient outcomes. A total of 478 patients with a mean age of 68±14 years and median National Institutes of Health Stroke Scale (NIHSS) of 18 (IQR 14 to 21) were analyzed. The median times for IAT delivery were 234 minutes (IQR 163 to 304) for “last known normal‐to‐groin puncture” time (LKN‐to‐GP) and 112 minutes (IQR 68 to 176) for D2P time. The overall good outcome rate was 39.7% for the entire cohort. In a multivariable model adjusting for age, NIHSS, hypertension, diabetes, reperfusion status, and symptomatic hemorrhage, both short LKN‐to‐GP (OR 0.996; 95% CI [0.993 to 0.998]; P<0.001) and short D2P times (OR 0.993, 95% CI [0.990 to 0.996]; P<0.001) were associated with good outcomes. Only 52% of all patients in the registry achieved the targeted D2P time of 2 hours. Conclusions The time interval of D2P presents a clinically relevant time frame by which system processes can be targeted to streamline the delivery of IAT care nationally. At present, there is much opportunity to enhance outcomes through reducing D2P. PMID:24772523

  2. Inducing mineral precipitation in groundwater by addition of phosphate

    PubMed Central

    2011-01-01

    bacterial cells appears to be associated with delayed HAP precipitation, changes in the lattice parameters, and reduced incorporation of trace elements as compared to cell-free systems. Schemes to remediate groundwater contaminated with trace metals that are based on enhanced phosphate mineral precipitation may need to account for these phenomena, particularly if the remediation approach relies on enhancement of in situ microbial populations. PMID:22029908

  3. Comparison Of Downscaled CMIP5 Precipitation Datasets For Projecting Changes In Extreme Precipitation In The San Francisco Bay Area.

    NASA Technical Reports Server (NTRS)

    Milesi, Cristina; Costa-Cabral, Mariza; Rath, John; Mills, William; Roy, Sujoy; Thrasher, Bridget; Wang, Weile; Chiang, Felicia; Loewenstein, Max; Podolske, James

    2014-01-01

    Water resource managers planning for the adaptation to future events of extreme precipitation now have access to high resolution downscaled daily projections derived from statistical bias correction and constructed analogs. We also show that along the Pacific Coast the Northern Oscillation Index (NOI) is a reliable predictor of storm likelihood, and therefore a predictor of seasonal precipitation totals and likelihood of extremely intense precipitation. Such time series can be used to project intensity duration curves into the future or input into stormwater models. However, few climate projection studies have explored the impact of the type of downscaling method used on the range and uncertainty of predictions for local flood protection studies. Here we present a study of the future climate flood risk at NASA Ames Research Center, located in South Bay Area, by comparing the range of predictions in extreme precipitation events calculated from three sets of time series downscaled from CMIP5 data: 1) the Bias Correction Constructed Analogs method dataset downscaled to a 1/8 degree grid (12km); 2) the Bias Correction Spatial Disaggregation method downscaled to a 1km grid; 3) a statistical model of extreme daily precipitation events and projected NOI from CMIP5 models. In addition, predicted years of extreme precipitation are used to estimate the risk of overtopping of the retention pond located on the site through simulations of the EPA SWMM hydrologic model. Preliminary results indicate that the intensity of extreme precipitation events is expected to increase and flood the NASA Ames retention pond. The results from these estimations will assist flood protection managers in planning for infrastructure adaptations.

  4. Immobilization of bile salt hydrolase enzyme on mesoporous SBA-15 for co-precipitation of cholesterol.

    PubMed

    Bhange, Pallavi; Sridevi, N; Bhange, Deu S; Prabhune, Asmita; Ramaswamy, Veda

    2014-02-01

    We describe herein a simple and effective strategy for immobilization of bile salt hydrolase enzyme by grafting glutaraldehyde groups inside channels of APTES functionalized SBA-15. The increase in glutaraldehyde concentration prevents leakage of enzyme but showed a steep decrease in enzyme activity in the immobilized matrix. So the degree of cross-linking should be the minimum possible to ensure sufficient stability without loss of activity. Cross-linking carried out with 0.1% glutaraldehyde concentration showed the highest activity, so this was used in all further experiments. Physico-chemical characterizations of the immobilized enzyme were carried out by XRD, N2 adsorption, TEM, FTIR and (29)Si CP-MAS NMR techniques. Immobilized BSH exhibits enhanced stability over a wide pH (3-11) and temperature range (40-80 °C) and retains an activity even after recycling experiments and six months of storage. From our in vivo research experiment toward co-precipitation of cholesterol, we have shown that immobilized BSH enzyme may be the promising catalyst for the reduction of serum cholesterol levels in our preliminary investigation. Enhancement in pH stability at the extreme side of pH may favor the use of immobilized BSH enzyme for drug delivery purpose to with stand extreme pH conditions in the gastrointestinal conditions.

  5. Preliminary assessment of dynamic contrast-enhanced CT implementation in pretreatment FDG-PET/CT for outcome prediction in head and neck tumors.

    PubMed

    Abramyuk, Andrij; Wolf, Gunter; Shakirin, Georgy; Haberland, Ulrike; Tokalov, Sergey; Koch, Arne; Appold, Steffen; Zöphel, Klaus; Abolmaali, Nasreddin

    2010-09-01

    Recently published data show some controversy concerning the impact of [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in predicting head and neck tumors (HNT) outcome. Assessment of tumor blood supply parameters using dynamic contrast-enhanced CT (DCE-CT) may deliver additional information concerning this important question. To evaluate the contribution of DCE-CT implemented in pretherapeutic FDG-PET/CT protocol for prognosis prediction in patients with HNT. Ten consecutive patients (median age 50 years, range 47-74 years) with histologically proven HNT underwent FDG-PET/CT with DCE-CT before treatment. FDG uptake was measured by maximum standardized uptake value (SUV(max)). Relative tumor blood volume (rTBV) was determined from DCE-CT using Patlak analysis. Intratumoral heterogeneity was assessed by means of lacunarity analysis. Obtained values were compared with time-to-progression and overall survival. PET and DCE-CT images were compared on a pixel-by-pixel basis using Pearson coefficient of correlation. Three patients with lower FDG uptake (SUV(max): 8+/-1) and five patients with higher FDG uptake (SUV(max): 15+/-4, P=0.004) were free of local recurrence for 24 months. Two groups of patients with significantly differing lower (group A: 0.37+/-0.02, n=6) and higher (group B: 0.52+/-0.01, n=4; P<0.01), tumor heterogeneity (lacunarity) were identified. Corresponding mean rTBV was higher in group A (9.6+/-1.8 ml/100 ml) than in group B (6.2+/-0.6 ml/100 ml). All six patients with homogeneous tumor blood supply (lower lacunarity) and higher rTBV were free of local recurrence during 24 months, while two of four patients with heterogeneous tumor blood supply (higher lacunarity) and lower rTBV died during follow-up due to tumor relapse. A weak correlation between FDG-PET and DCE-CT rTBV was observed (R(2)=0.1). FDG-PET/CT and DCT-CT are complementary methods for surveillance assessment in patients with HNT. Implementation of DCE

  6. Estimation of Thermodynamic and Dynamic Contribution on Regional Precipitation Intensity and Frequency Changes under Global Warming

    NASA Astrophysics Data System (ADS)

    Chen, C.-A.; Chou, C.; Chen, C.-T.

    2012-04-01

    From global point of view, an increased tendency of mean precipitation, which is associated with a shift toward more intense and extreme precipitation, has been found in observations and global warming simulations. However, changes in regional precipitation might be different due to contributions of thermodynamic and dynamic components. It implies that changes in regional rainfall intensity and frequency, which is connected to regional mean precipitation changes, should be more complicated under global warming. To understand how regional intensity and frequency will change under global warming, the global warming simulations from the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset in the A1B scenario were examined in this study. Over regions with increased mean precipitation, positive precipitation anomaly is usually contributed by more frequent heavy rain and enhanced rainfall intensity, even though there are less light rain events in the future. On the other hand, over regions with decreased mean precipitation, negative precipitation anomaly is associated with decreases in frequency for almost every rain events and weakened rainfall intensity, even though there are more very heavy and light rain events. The thermodynamic component is uniform in different regions, and tends to enhance precipitation frequency and intensity, while the dynamic component varies with regions, and can either enhance or reduce precipitation frequency and intensity.

  7. IMPACT OF TRMM PRECIPITATION ON CPTEC’S RPSAS ANALYSIS

    NASA Astrophysics Data System (ADS)

    Herdies, D. L.; Bastarz, C. F.; Fernandez, J. P.

    2009-12-01

    In this work a data assimilation study was performed to assess the impact of estimated precipitation from TRMM (Tropical Rainfall Measuring Mission) on the CPTEC (Centro de Previsão de Tempo e Estudos Climáticos at Brasil) RPSAS (Regional Physical-space Statistical Analysis System) analyses and the Eta model forecast over the region of La Plata Basin, during a case o MCC (Mesoscale Convective Complex) occurred between 22th and 23th January 2003. The data assimilation system RPSAS and the mesoscale regional Eta model (both with 20km of spatial resolution) were run together with and without the TRMM precipitation. Is this study the assimilation of precipitation is basically a nudging process and is performed during the first guess stage by the Eta model, like in the NCEP (National Centers for Environmental Predictions) EDAS (Eta Data Assimilation System) precipitation data assimilation. During this process the model adjusts the precipitation by comparing, at which grid point and at which time step, the model precipitation against the TRMM precipitation. Doing this some adjustments are made on the latent heat vertical profile, water vapor mixing ratio and relative humidity, by considering the Betts-Miller-Janjic convective parameterization. On the next step, the RPSAS produces an analysis which covers most of the South America and the adjacent oceans. From this analysis the Eta model produces 6h, 12h, 18h and 24h forecast. Data collected from the SALLJEX (South America Low Level Jet EXperiment) was used to compare the forecasts of the model and the CPTEC 40km Regional Reanalysis was used to compare with the RPSAS analyses. Some preliminary results show that the precipitation assimilation improves the first hours of the forecast (typically 6h). The variables verified were the zonal and meridional wind, geopotential height and the precipitation. The convective precipitation fields were improved, mainly over the 6h forecast. This is an important improvement because the

  8. The 2014 Silba Precipitation Extreme

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2015-04-01

    On 30 July 2014 a 24 h precipitation record of 218 mm was set at the island of Silba in the N-Adriatic Sea. The precipitation was of convective nature and significantly less precipitation was recorded only small distances away, at the coast of mainland Croatia. The event is reproduced numerically and discussed in terms of dynamics and predictability. On a large scale, the precipitation extreme was associated with a slow-moving upper tropospheric low that formed over the N-Atlantic several days earlier. At lower levels, there were humid mediterranean airmasses. On a smaller scale, there are indications that the extreme convection may have been triggered by an orographic disturbance.

  9. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  10. Silica Precipitation and Lithium Sorption

    SciTech Connect

    Jay Renew

    2015-09-20

    This file contains silica precipitation and lithium sorption data from the project. The silica removal data is corrected from the previous submission. The previous submission did not take into account the limit of detection of the ICP-MS procedure.

  11. Atmospheric science: Energy and precipitation

    NASA Astrophysics Data System (ADS)

    Donohoe, Aaron

    2016-12-01

    The latitude of the tropical rainbelt is constrained by the energy balance between hemispheres. An expansion of this theory that includes longitudinal variations of atmospheric heating can predict regional changes in tropical precipitation.

  12. WEATHER_Layered-Precipitable-Water

    Atmospheric Science Data Center

    2016-06-23

    ... TOVS (HIRS) clear sky radiances Radiosonde GPS (after 1995) AIRS Level 2 TPW and Layered PW Spatial ... Parameters:  Precipitable Water Order Data:  Earthdata Search:  Earthdata Search SCAR-B ...

  13. WEATHER_Total-Precipitable-Water

    Atmospheric Science Data Center

    2016-06-23

    ... TOVS (HIRS) clear sky radiances Radiosonde GPS (after 1995) AIRS Level 2 TPW and Layered PW Spatial ... Parameters:  Precipitable Water Order Data:  Earthdata Search:  Earthdata Search SCAR-B ...

  14. Evaluation of Coupled Precipitator Two

    SciTech Connect

    Stone, M.E.

    1999-11-08

    The offline testing of the Coupled Precipitator Two (CP-2) has been completed. The tests were conducted and are documented. The tests were conducted at an offline test rack near the Drain Tube Test Stand facility in 672-T.

  15. Identifying Anomality in Precipitation Processes

    NASA Astrophysics Data System (ADS)

    Jiang, P.; Zhang, Y.

    2014-12-01

    Safety, risk and economic analyses of engineering constructions such as storm sewer, street and urban drainage, and channel design are sensitive to precipitation storm properties. Whether the precipitation storm properties exhibit normal or anomalous characteristics remains obscure. In this study, we will decompose a precipitation time series as sequences of average storm intensity, storm duration and interstorm period to examine whether these sequences could be treated as a realization of a continuous time random walk with both "waiting times" (interstorm period) and "jump sizes" (average storm intensity and storm duration). Starting from this viewpoint, we will analyze the statistics of storm duration, interstorm period, and average storm intensity in four regions in southwestern United States. We will examine whether the probability distribution is temporal and spatial dependent. Finally, we will use fractional engine to capture the randomness in precipitation storms.

  16. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  17. Oceanic Precipitation Measurement - Surface Validation

    NASA Astrophysics Data System (ADS)

    Klepp, Christian

    2013-04-01

    State-of-the-art satellite derived and reanalysis based precipitation climatologies still show remarkably large differences in frequency, amount, intensity, variability and temporal behavior of precipitation over the oceans. Additionally so far appropriate in-situ validation instruments were not available for shipboard use. The uncertainties are largest for light precipitation within the ITCZ and subtropics and for cold season high-latitude precipitation including mix-phase and snowfall. Hence, a long-term issue on which IPWG and GPM-GV is urging more attention is the provision of high quality surface validation data in oceanic areas using innovative ship-based instruments. Precipitation studies would greatly benefit from systematic dataset collection and analysis as such data could also be used to constrain precipitation retrievals. To achieve this goal, the KlimaCampus and Max Planck Institute for Meteorology in Hamburg, Germany funded this project that uses automated shipboard optical disdrometers, called Eigenbrodt ODM470, that are capable of measuring liquid and solid precipitation using drop size distributions in minute intervals on moving ships with high accuracy even under high wind speeds and rough sea states. Since the project start in 2009 the statistical basis for a conclusive validation has significantly improved with comprehensive data collection of more than 3 million minutes of precipitation measurements onboard six ships. Currently, six ODM470 instrument systems are available of which three are long-term mounted onboard the German research icebreaker R/V Polarstern (Alfred Wegner Institut) since June 2010, on R/V Akademik Ioffe (P.P.Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia) since September 2010 and on R/V Maria S. Merian (Brise Research, University of Hamburg) since December 2011. Three instruments are used for additional short-term shipboard campaigns and intercomparison projects. The core regions for these

  18. Precipitation of DNA with Ethanol.

    PubMed

    Green, Michael R; Sambrook, Joseph

    2016-12-01

    DNA can be precipitated out of solution for the removal of salts and/or for resuspension in an alternative buffer. Either ethanol or isopropanol can be used to achieve this purpose; however, the use of ethanol is generally preferred. Cations, provided as salts, are typically included to neutralize the negative charge of the DNA phosphate backbone. This method describes ethanol precipitation of DNA in microcentrifuge tubes.

  19. Effect of Carbonaceous Aerosols on Clouds and Precipitation in Asia

    NASA Astrophysics Data System (ADS)

    v, V.; Wang, H.; Ganguly, D.; Minghuai, W.; Rasch, P. J.

    2010-12-01

    Carbonaceous aerosols enhance scattering and absorption of solar radiation (i.e., direct radiative effect) in the atmosphere and also affect clouds and precipitation through indirect effects, thus heating the atmosphere but reducing the amount of solar radiation that reaches the earth’s surface. These effects through dynamic feedbacks can also have remote impact over regions far away from their emission sources and hence demand special scientific attention. Previous modeling studies have revealed that large amount of anthropogenic carbonaceous aerosols over the Asian region can alter monsoon circulation and precipitation patterns and thereby influence its strength by varying degrees spatially. Most of the studies focused on the direct radiative effect of aerosols and their subsequent effect on monsoon precipitation. We evaluate the changes in clouds and precipitation in Asia due to carbonaceous aerosols using the community atmospheric model (CAM5) which accounts for not only aerosol direct effects, but also aerosol indirect effects on warm, mixed-phase and cirrus clouds. This study focuses on the precipitation efficiency with emphasis on aerosol indirect effects. In addition to carbonaceous aerosol emissions over Asia, the effect of emissions from other regions like North America, North Africa and Europe are also investigated for their influence on precipitation in the Asian region. In addition to the focus on the aerosol effect on monsoon, we also study the seasonality in aerosol induced changes to precipitation efficiency. We present the quantitative estimates of changes in precipitation efficiency related to changes in aerosol loading and compare them with those estimated from satellite observations, and further explore the potential role of aerosol indirect effects to changes in precipitation efficiency.

  20. NASA Dual Precipitation Radar Arrives at Goddard

    NASA Image and Video Library

    The Dual-frequency Precipitation Radar (DPR) built by the Japan Aerospace Exploration Agency (JAXA) for the Global Precipitation Measurement (GPM) mission's Core Observatory arrived on Friday, Marc...

  1. Effects of proton irradiation on nanocluster precipitation in ferritic steel containing fcc alloying additions

    SciTech Connect

    Zhang, Zhongwu; Liu, C T; Wang, Xun-Li; Miller, Michael K; Ma, Dong; Chen, Guang; Williams, J R; Chin, Bryan

    2012-01-01

    Newly-developed precipitate-strengthened ferritic steels with and without pre-existing nanoscale precipitates were irradiated with 4 MeV protons to a dose of ~5 mdpa at 50 C and subsequently examined by nanoindentation and atom probe tomography (APT). Irradiation-enhanced precipitation and coarsening of pre-existing nanoscale precipitates were observed. Copper partitions to the precipitate core along with a segregation of Ni, Al and Mn to the precipitate/matrix interface after both thermal aging and proton irradiation. Proton irradiation induces the precipitation reaction and coarsening of pre-existing nanoscale precipitates, and these results are similar to a thermal aging process. The precipitation and coarsening of nanoscale precipitates are responsible for the changes in hardness. The observation of the radiation-induced softening is essentially due to the coarsening of the pre-existing Cu-rich nanoscale precipitates. The implication of the precipitation on the embrittlement of reactor-pressure-vessel steels after irradiation is discussed.

  2. Stability of Grassland Communities to Altered Precipitation: A Meta-Analysis

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Shi, Z.; Collins, S. L.; Knapp, A.; Pockman, W.; Smith, M.

    2014-12-01

    Species-specific responses to changes in precipitation can alter plant community structure and composition potentially altering ecosystem functioning. The latter will further feed back to climate change. Here, we synthesized results from more than 50 experimental studies that either increased or decreased precipitation in grasslands to assess productivity responses of different species and plant functional types (PFT) as well as changes in community structure. Our results showed that increased precipitation enhanced aboveground net primary production (ANPP) of the dominant PFT but had no effect on ANPP of the subordinate species. Similarly, decreased precipitation reduced ANPP of the dominant species but not that of subordinate species. Individual C3 species were highly responsive to alterations in precipitation, but C4 species were not. Altered precipitation had no effect on species richness, evenness or diversity. Overall, ANPP and belowground net primary productivity (BNPP) responded to both increased and reduced precipitation, but relative responses of ANPP to increased precipitation diminished with increasing mean annual precipitation (MAP) whereas the relative responses to reduced precipitation did not change with MAP. BNPP responses to altered precipitation did not vary with MAP. Our findings suggest that the dominant PFT in grasslands can be used as a proxy for community responses in ecosystem biogeochemical models. Further, grassland community composition and structure appear to be relatively stable in response to alterations in precipitation of the duration and magnitude encompassed by these experiments.

  3. Advanced Microwave Precipitation Radiometer (AMPR) for remote observation of precipitation

    NASA Technical Reports Server (NTRS)

    Galliano, J. A.; Platt, R. H.

    1990-01-01

    The design, development, and tests of the Advanced Microwave Precipitation Radiometer (AMPR) operating in the 10 to 85 GHz range specifically for precipitation retrieval and mesoscale storm system studies from a high altitude aircraft platform (i.e., ER-2) are described. The primary goals of AMPR are the exploitation of the scattering signal of precipitation at frequencies near 10, 19, 37, and 85 GHz together to unambiguously retrieve precipitation and storm structure and intensity information in support of proposed and planned space sensors in geostationary and low earth orbit, as well as storm-related field experiments. The development of AMPR will have an important impact on the interpretation of microwave radiances for rain retrievals over both land and ocean for the following reasons: (1) A scanning instrument, such as AMPR, will allow the unambiguous detection and analysis of features in two dimensional space, allowing an improved interpretation of signals in terms of cloud features, and microphysical and radiative processes; (2) AMPR will offer more accurate comparisons with ground-based radar data by feature matching since the navigation of the ER-2 platform can be expected to drift 3 to 4 km per hour of flight time; and (3) AMPR will allow underflights of the SSM/I satellite instrument with enough spatial coverage at the same frequencies to make meaningful comparisons of the data for precipitation studies.

  4. Geostatistical Study of Precipitation on the Island of Crete

    NASA Astrophysics Data System (ADS)

    Agou, Vasiliki D.; Varouchakis, Emmanouil A.; Hristopulos, Dionissios T.

    2015-04-01

    Understanding and predicting the spatiotemporal patterns of precipitation in the Mediterranean islands is an important topic of research, which is emphasized by alarming long-term predictions for increased drought conditions [4]. The analysis of records from drought-prone areas around the world has demonstrated that precipitation data are non-Gaussian. Typically, such data are fitted to the gamma distribution function and then transformed into a normalized index, the so-called Standardized Precipitation Index (SPI) [5]. The SPI can be defined for different time scales and has been applied to data from various regions [2]. Precipitation maps can be constructed using the stochastic method of Ordinary Kriging [1]. Such mathematical tools help to better understand the space-time variability and to plan water resources management. We present preliminary results of an ongoing investigation of the space-time precipitation distribution on the island of Crete (Greece). The study spans the time period from 1948 to 2012 and extends over an area of 8 336 km2. The data comprise monthly precipitation measured at 56 stations. Analysis of the data showed that the most severe drought occurred in 1950 followed by 1989, whereas the wettest year was 2002 followed by 1977. A spatial trend was observed with the spatially averaged annual precipitation in the West measured at about 450mm higher than in the East. Analysis of the data also revealed strong correlations between the precipitation in the western and eastern parts of the island. In addition to longitude, elevation (masl) was determined to be an important factor that exhibits strong linear correlation with precipitation. The precipitation data exhibit wet and dry periods with strong variability even during the wet period. Thus, fitting the data to specific probability distribution models has proved challenging. Different time scales, e.g. monthly, biannual, and annual have been investigated. Herein we focus on annual

  5. The effects of auroral precipitation on atmospheric nitric oxide concentration

    NASA Astrophysics Data System (ADS)

    Jones, S.; Lessard, M.; Fritz, B.

    2016-12-01

    The Pulsating Auroral Nitric Oxide Production in the Lower Ionosphere (PANOPLI) project addresses a science problem that has strong implications regarding the question of how solar variability may be related to climate change and terrestrial weather. Pulsating aurora is the ideal choice for studying auroral NO production since this type of aurora is caused by tens of keV electron precipitation (which is known to produce enhancements in thermospheric NO) and is a frequently occurring and long lasting phenomenon resulting in widespread auroral luminosity. The pulsating auroral precipitation results in a large transfer of power from the magnetosphere to the ionosphere-thermosphere and may be a significant contributor to thermospheric NO production, which is dependent on the energy flux and duration of the auroral precipitation. PANOPLI makes use of ground-based riometer measurements to characterize the electron precipitation causing pulsating aurora and determine the effects of pulsating aurora on the theremosphere-mesosphere NO reservoir. The inferred precipitating electron distribution function is input to a model to calculate the expected NO enhancement for comparison with NO enhancements inferred from ground-based Fabry-Perot interferometer measurements. This problem is particularly important because NO produced at low enough altitudes can transport downward to the stratosphere and chemically react with ozone causing depletion. Therefore, this work is a vital first step in quantifying the auroral contribution to ozone depletion. Previous studies have shown that the auroral contribution to atmospheric chemistry can be significant, with up to 60% of ozone depletion enhancements (above background levels) at 35-40 km altitude due to energetic electron precipitation (Randall et al., 2005).

  6. Non-precipitating cumulus cloud study

    SciTech Connect

    Alkezweeny, A.J.

    1984-10-01

    This document describes the field experiment that was conducted in Kentucky during the period from July 20 to August 24, 1983. The objectives were to determine the vertical transport of acidic pollutants by cumulus convection and formation of acidic substances in non-precipitating clouds. The study is a research component of Task Group C (Atmospheric Processes) of the National Acid Precipitation Assessment Program. To examine the vertical transport, an SF/sub 6/ tracer was released from one aircraft, sampled by another aircraft, and sampled on the ground. The results show that pollutants from the boundary layer are lifted to the cloud layer. From there, they are intermittently transported both to the ground and to higher elevations, possibly in the vertical updrafts of towering cumulus clouds. A series of instrumented aircraft flights around the clouds were conducted to study the formation of acidic aerosols. The concentrations of SO/sub 2/, SO/sub 4/, NO/sub 3/, NH/sub 4/, NH/sub 3/, HNO/sub 3/ and trace metals were measured by filter techniques. Furthermore, NO/sub x/, O/sub 3/, light scattering, and basic meteorological parameters were measured in real-time. Detailed chemical composition of aerosols and NH/sub 3/ was also measured on the ground. Preliminary results show that the molar ratio of SO/sub 2//SO/sub 2/ + SO/sub 4/) at cloud tops is higher than at cloud bases. This indicates that sulfate aerosols were formed in the clouds. The NH/sub 3/ concentration shows higher values at nighttime than daytime and decreases sharply with increasing altitude. 3 references.

  7. Assessment of precipitate formation on interaction of irrigants used in different combinations: an in vitro study.

    PubMed

    Shenoy, Amarnath; Bolla, Nagesh; Sarath, Raj K; Ram, C H Sunil

    2013-01-01

    Irrigants play an essential role in the successful debridement and disinfection of pulp space. Various combination of irrigants used during root canal treatment enhance their efficacy, but some form precipitates which affects the diffusion of intracanal medicaments and the seal of the obturated root canal. To evaluate the combination of various irrigants whether it forms the precipitate and also to quantify the amount of precipitate formed. Five different irrigants were taken in ten test tubes each having the combination of two irrigants and observed for 2 min for precipitate formation. One-way-ANOVA test revealed more amounts of precipitate with 2% Chlorhexidine (CHX) 5% Tulsi followed by 2% CHX, 5% Neem and 3% Sodium hypochlorite 2% CHX. Precipitate formation is seen more with the 2% CHX-5% Neem followed by 2% CHX-5% Tulsi when compared with the control group. When these combinations of irrigants were used, intermediate flushes of saline or distilled water reduced the amount of precipitate.

  8. Scanning infrared microscopy investigation of copper precipitation in cast multicrystalline silicon

    NASA Astrophysics Data System (ADS)

    Xi, Zhenqiang; Yang, Deren; Moeller, H. J.

    2006-01-01

    The behavior of copper precipitation in cast multicrystalline silicon (mc-Si) annealed at different temperatures under air cooling (30 K/s) or slow cooling (0.3 K/s) was investigated by scanning infrared microscopy (SIRM). Comparing to Czochralski-grown silicon (Cz-Si), copper precipitated more easily in mc-Si, and the lowest temperature of copper precipitation in mc-Si was about 700 °C, lower than that in Cz-Si. It was also observed that copper preferably precipitated on grain boundaries so that near the grain boundaries the denuded zone formed. The results indicate that the defects including dislocations, grain boundaries and microdefects, as the heteronucleation sites, enhanced copper precipitation. Moreover, cooling rates had a great influence on the copper precipitation, especially at lower annealing temperatures. Generally air cooling led to the formation of high density of copper-precipitate colonies.

  9. Chemical Data for Precipitate Samples

    USGS Publications Warehouse

    Foster, Andrea L.; Koski, Randolph A.

    2008-01-01

    During studies of sulfide oxidation in coastal areas of Prince William Sound in 2005, precipitate samples were collected from onshore and intertidal locations near the Ellamar, Threeman, and Beatson mine sites (chapter A, fig. 1; table 7). The precipitates include jarosite and amorphous Fe oxyhydroxide from Ellamar, amorphous Fe oxyhydroxide from Threeman, and amorphous Fe oxyhydroxide, ferrihydrite, and schwertmannite from Beatson. Precipitates occurring in the form of loose, flocculant coatings were harvested using a syringe and concentrated in the field by repetitive decanting. Thicker accumulations were either scraped gently from rocks using a stainless steel spatula or were scooped directly into receptacles (polyethylene jars or plastic heavy-duty zippered bags). Most precipitate samples contain small amounts of sedimentary detritus. With three jarosite-bearing samples from Ellamar, an attempt was made to separate the precipitate from the heavy-mineral fraction of the sediment. In this procedure, the sample was stirred in a graduated cylinder containing deionized water. The jarosite-rich suspension was decanted onto analytical filter paper and air dried before analysis. Eleven precipitate samples from the three mine sites were analyzed in laboratories of the U.S. Geological Survey (USGS) in Denver, Colorado (table 8). Major and trace elements were determined by inductively coupled plasma-mass spectrometry following multiacid (HCl-HNO3-HClO4-HF) digestion (Briggs and Meier, 2002), except for mercury, which was analyzed by cold-vapor atomic absorption spectroscopy (Brown and others, 2002a). X-ray diffraction (XRD) analyses were performed on powdered samples (<200 mesh) by S. Sutley of the USGS. Additional details regarding sample preparation and detection limits are found in Taggert (2002). Discussions of the precipitate chemistry and associated microbial communities are presented in Koski and others (2008) and Foster and others (2008), respectively.

  10. Nanocrystalline Zn1-x Co0.5xNi0.5x Fe2O4 ferrites: Fabrication via co-precipitation route with enhanced magnetic and electrical properties

    NASA Astrophysics Data System (ADS)

    Hassan, Amna; Azhar Khan, Muhammad; Shahid, Muhammad; Asghar, M.; Shakir, Imran; Naseem, Shahzad; Riaz, Saira; Farooq Warsi, Muhammad

    2015-11-01

    Co and Ni substituted znic ferrite nanoparticles (Zn1-xCo0.5xNi0.5xFe2O4) (0.00≤x≥0.75) were synthesized by co-precipitation method. X-ray diffraction and Fourier transform infrared spectroscopy confirmed the single phase spinel structure. The lattice constant decreased with the increased Co and Ni contents. The bulk density was found less as compared to the X-ray density and this difference was explained in terms of porosity. The crystallite size was calculated by Scherrer's formula and found in the range 20-50 nm. Two prominent stretching bands were observed in FTIR spectra around 400-600 cm-1. These two bands confirmed the spinel structure of the prepared nanoparticles. The saturation magnetization was found to increase upto x=0.60 from 1.31 emu/g to 81.2 emu/g then it decreased for x=0.75 to the value of 75.1 emu/g. The coercivity and retentivity were found in the range 35.36-226.125 Oe and 0.0135-19.8 emu/g, respectively. Dielectric parameters were decreased with the increased Ni-Co contents. About nine fold increase in the DC-electrical resistivity was obtained for the Zn0.25Co0.375Ni0.375Fe2O4 (2.8979×1010 Ω cm) as compared to the ZnFe2O4 (0.2974×1010 Ω cm) nanoparticles.

  11. The Global Precipitation Measurement Mission

    NASA Astrophysics Data System (ADS)

    Jackson, Gail

    2014-05-01

    The Global Precipitation Measurement (GPM) mission's Core satellite, scheduled for launch at the end of February 2014, is well designed estimate precipitation from 0.2 to 110 mm/hr and to detect falling snow. Knowing where and how much rain and snow falls globally is vital to understanding how weather and climate impact both our environment and Earth's water and energy cycles, including effects on agriculture, fresh water availability, and responses to natural disasters. The design of the GPM Core Observatory is an advancement of the Tropical Rainfall Measuring Mission (TRMM)'s highly successful rain-sensing package [3]. The cornerstone of the GPM mission is the deployment of a Core Observatory in a unique 65o non-Sun-synchronous orbit to serve as a physics observatory and a calibration reference to improve precipitation measurements by a constellation of 8 or more dedicated and operational, U.S. and international passive microwave sensors. The Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will provide measurements of 3-D precipitation structures and microphysical properties, which are key to achieving a better understanding of precipitation processes and improving retrieval algorithms for passive microwave radiometers. The combined use of DPR and GMI measurements will place greater constraints on possible solutions to radiometer retrievals to improve the accuracy and consistency of precipitation retrievals from all constellation radiometers. Furthermore, since light rain and falling snow account for a significant fraction of precipitation occurrence in middle and high latitudes, the GPM instruments extend the capabilities of the TRMM sensors to detect falling snow, measure light rain, and provide, for the first time, quantitative estimates of microphysical properties of precipitation particles. The GPM Core Observatory was developed and tested at NASA

  12. Are hourly precipitation extremes increasing faster than daily precipitation extremes?

    NASA Astrophysics Data System (ADS)

    Barbero, Renaud; Fowler, Hayley; Blenkinsop, Stephen; Lenderink, Geert

    2016-04-01

    Extreme precipitation events appear to be increasing with climate change in many regions of the world, including the United States. These extreme events have large societal impacts, as seen during the recent Texas-Oklahoma flooding in May 2015 which caused several billion in damages and left 47 deaths in its path. Better understanding of past changes in the characteristics of extreme rainfall events is thus critical for reliable projections of future changes. Although it has been documented in several studies that daily precipitation extremes are increasing across parts of the contiguous United States, very few studies have looked at hourly extremes. However, this is of primary importance as recent studies on the temperature scaling of extreme precipitation have shown that increases above the Clausius-Clapeyron (~ 7% °C-1) are possible for hourly precipitation. In this study, we used hourly precipitation data (HPD) from the National Climatic Data Center and extracted more than 1,000 stations across the US with more than 40 years of data spanning the period 1950-2010. As hourly measurements are often associated with a range of issues, the data underwent multiple quality control processes to exclude erroneous data. While no significant changes were found in annual maximum precipitation using both hourly and daily resolution datasets, significant increasing trends in terms of frequency of episodes exceeding present-day 95th percentiles of wet hourly/daily precipitation were observed across a significant portion of the US. The fraction of stations with significant increasing trends falls outside the confidence interval range during all seasons but the summer. While less than 12% of stations exhibit significant trends at the daily scale in the wintertime, more than 45% of stations, mostly clustered in central and Northern United States, show significant increasing trends at the hourly scale. This suggests that short-duration storms have increased faster than daily

  13. Dust particles precipitation in AC/DC electrostatic precipitator

    NASA Astrophysics Data System (ADS)

    Jaworek, A.; Marchewicz, A.; Krupa, A.; Sobczyk, A. T.; Czech, T.; Antes, T.; Śliwiński, Ł.; Kurz, M.; Szudyga, M.; Rożnowski, W.

    2015-10-01

    Submicron and nanoparticles removal from flue or exhaust gases remain still a challenge for engineers. The most effective device used for gas cleaning in power plants or industry is electrostatic precipitator, but its collection efficiency steeply decreases for particles smaller than 1 micron. In this paper, fractional collection efficiency of two-stage electrostatic precipitator comprising of alternating electric field charger and DC supplied parallel-plate collection stage has been investigated. The total number collection efficiency for PM2.5 particles was higher than 95% and mass collection efficiency >99%. Fractional collection efficiency for particles between 300 nm and 1 μm was >95%.

  14. Towards Quantitative Ocean Precipitation Validation

    NASA Astrophysics Data System (ADS)

    Klepp, C.; Bakan, S.; Andersson, A.

    2009-04-01

    A thorough knowledge of global ocean precipitation is an indispensable prerequisite for the understanding and successful modelling of the global climate system as it is an important component of the water cycle. However, reliable detection of quantitative precipitation over the global oceans, especially at high latitudes during the cold season remains a challenging task for remote sensing and model based estimates. Quantitative ship validation data using reliable instruments for measuring rain and snowfall hardly exist but are highly demanded for ground validation of such products. The satellite based HOAPS (Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data) climatology contains fields of precipitation, evaporation and the resulting freshwater flux along with 12 additional atmospheric parameters over the global ice-free ocean between 1987 and 2005. Except for the NOAA Pathfinder SST, all basic state variables are calculated from SSM/I passive microwave radiometer measurements. HOAPS contains three main data subsets that originate from one common pixel-level data source. Gridded 0.5 degree monthly, pentad and twice daily data products are freely available from www.hoaps.org. Especially for North Atlantic mid-latitude mix-phase precipitation, the HOAPS precipitation retrieval has been investigated in some depth. This analysis revealed that the HOAPS retrieval qualitatively well represents cyclonic and intense mesoscale precipitation in agreement with ship observations and Cloudsat data, while GPCP, ECMWF forecast, ERA-40 and regional model data miss mesoscale precipitation substantially. As the differences between the investigated data sets are already large under mix-phase precipitation conditions, further work is carried out on snowfall validation during the cold season at high-latitudes. A Norwegian Sea field campaign in winter 2005 was carried out using an optical disdrometer capable of measuring quantitative amounts of snowfall over the ocean

  15. Simulation of Orographically-Driven Precipitation in Southern California

    NASA Astrophysics Data System (ADS)

    Carpenter, T. M.; Georgakakos, K. P.

    2008-12-01

    The proximity of the Pacific Ocean to the Transverse and Peninsular Mountain Ranges of coastal Southern California may lead to significant, orographically-enhanced precipitation in the region. With abundant moisture, such as evidenced in Pineapple Express events or atmospheric rivers, this precipitation may lead to other hydrologic hazards as flash flooding, landslides or debris flows. Available precipitation observation networks are relatively sparse in the mountainous regions and often do not capture the spatial variation of these events with high resolution. This study aims to simulate the topographically-driven precipitation over Southern California with high spatial resolution using a simplified orographic precipitation model. The model employs potential theory flow to estimate steady state three-dimensional wind fields for given free stream velocity forcing winds, atmospheric moisture advection, and cloud and precipitation microphysics proposed by Kessler (1969). The advantage of this modeling set-up is the computational efficiency as compared to regional mesoscale models such as the MM5. For this application, the Southern California region, comprised of the counties of Santa Barbara, Ventura, Los Angeles, Orange, and San Diego, and portions of San Bernardino and Riverside counties, are modeled at a 3-km resolution. The orographic precipitation model is forced by free stream wind velocities given by the 700mb winds from the NCEP Reanalysis I dataset. Atmospheric moisture initial conditions are defined also by the NCEP Reanalysis I dataset, and updated 4x- daily with the available 6-hourly NCEP Reanalysis forcing. This paper presents a comparison of the simulated precipitation to observations for over a variety of spatial scales and over the historical wet season periods from October 2000 to April 2005. The comparison is made over several performance measurements including (a) the occurrence/non-occurrence of precipitation, (b) overall bias and correlation, (c

  16. Co-removal of hexavalent chromium during copper precipitation.

    PubMed

    Sun, J; Huang, J C

    2002-01-01

    In our recent study using the nucleated precipitation technology to treat plating wastewater, it was found that about one half of hexavalent chromium was co-removed with copper, nickel and zinc. Since hexavalent chromium could not react with either hydroxide or carbonate to from precipitates, this study was undertaken to evaluate the mechanism(s) involved in the chromium co-removal. Batch tests were conducted with synthetic solutions containing either only copper or both copper and hexavalent chromium. Metal precipitation was induced by adding Na2CO3 to different pH, and the quantitative removal of copper and chromium was determined. Besides, the [Cr]/[Cu] molar ratio of produced precipitates were also assessed in conjunction with the EDAX analysis to determine their compositions. Experimental results indicate that for pure copper solution, precipitation begins at pH 6.0, and completes at pH 7.0. The chemical forms of the precipitates are copper carbonates [CuCO3 x Cu(OH)2 and CuCO3 x 2Cu(OH)2]. On the other hand, in a bi-metal solution of copper plus chromium, precipitation of copper begins at about pH 5.0, and copper precipitation is always accompanied by some chromium removal. From the removal stoichiometry of the two metals, it is found that at low pH, the co-removal is a result of "co-precipitation" which results in the formation of CuCrO4 crystallites. Once such crystallites are formed, they provide a heterogeneous environment which enhances an early formation of copper carbonate at a lower pH (below 5.5). It is further found that once copper carbonate precipitates are produced, the remaining soluble will precipitate in such form, and at this stage further removal of copper is no longer accompanied by additional chromium removal. The test data also reflect that the produced copper carbonates are positively charged, as verified by zeta potential measurement, at pH below 7.5. Thus they are able to adsorb some anionic chromium (existing as chromate) through

  17. Detecting human influence in observed changes in precipitation

    NASA Astrophysics Data System (ADS)

    Polson, Debbie; Hegerl, Gabriele; Bollasina, Massimo; Wilcox, Laura; Zhang, Xuebin; Osborn, Timothy; Balan Sarojini, Beena

    2015-04-01

    Human induced changes to the precipitation could cause some of the most serious impacts of climate change, with potential consequences for water resources, health, agriculture and ecosystems. However, quantifying and understanding the drivers of changes to precipitation is challenging due to its large spatial and temporal variability, the lack of long-term observational records over much of the globe and the counteracting affects of greenhouse gases and aerosols. Nevertheless, detection and attribution studies have shown that human influence has changed both global and regional precipitation over the latter half of the 20th century. Using climates models to derive fingerprints of external forcing, we are able to show that greenhouse gas warming has driven large scale changes in precipitation. Greenhouse gas forcing is detectable in observed changes to zonal mean precipitation over land (Polson et al., 2012a). It has also been shown to have caused the intensification of the water cycle, enhancing existing patterns of the precipitation in the tropics and subtropics, over both land and ocean (Polson et al., 2012b). While at global scales, the influence of greenhouse gases is detectable in observations, separating the response of precipitation to anthropogenic aerosol forcing is more difficult. However, in some regions the influence of aerosols dominate, making it possible to detect aerosol forcing. Observed precipitation in the monsoon regions underwent substantial changes during the second half of the twentieth century, with drying from the 1950s to mid-1980s and increasing precipitation in recent decades. Climate model simulations are used to derive fingerprints of individual climate forcings (i.e., greenhouse gas, anthropogenic aerosol, and natural) and detection and attribution methods applied to determine which, if any, have driven these changes to monsoon precipitation. Even when accounting for internal variability of the climate, a clear signal of anthropogenic

  18. Solar wind precipitation on Mars

    NASA Astrophysics Data System (ADS)

    Stenberg, G.; Dieval, C.; Nilsson, H.; Kallio, E.; Barabash, S.; Futaana, Y.; Shematovich, V.; Bisikalo, D.

    2011-10-01

    We have found that solar wind particles frequently precipitate onto the atmosphere of Mars [1,2]. The precipitating particles contribute to the energy and matter flux into the ionosphere. We use ion data from the ASPERA-3 instrument onboard Mars Express to investigate the precipitation patterns, processes and the total transfer of energy and matter from the solar wind to the atmosphere. The main reason for the proton and alpha particle precipitation is likely the large gyroradii of hot particles compared to the size of the induced magnetosphere/magnetic barrier. We find that the particle penetration depends on the direction of the convection electric field in the solar wind but that the crustal magnetic fields have very little influence. The total energy flux is low compared to the solar radiation heating on the dayside, but a significant energy source on the nightside. We also believe that the solar wind alphaparticles precipitating into the atmosphere is an important source of the neutral helium in the Martian atmosphere. We combine our observations with computer modeling [3,4]. We have applied a Direct Simulation Monte Carlo method to solve the kinetic equation for the H/H+ transport in the upper Martian atmosphere including CO2, N2 and O. We conclude that the induced magnetic field around Mars plays the crucial role in the transport of charged particles in the upper atmosphere, and it determines the energy deposition of the solar wind.

  19. How much sediment have we added to a floodplain? Preliminary results of using contaminated sediments to tease out enhanced deposition to a floodplain of the lower Meramec River, MO

    NASA Astrophysics Data System (ADS)

    Pearson, A.; Hanes, D. M.

    2016-12-01

    Lead mining began between 1742 and 1762 within the "Old Lead Belt" of southern Missouri, located within the Big River watershed, and was the largest producer of lead worldwide from 1869 to 1972 extracting millions of tons of ore and depositing the waste products directly into the Big River in some cases and storing them immediately adjacent to the stream in others. The addition of tons of sediment to the stream system via mining has resulted in massive slugs of sediment moving down the Big River. In addition to coarse grained waste products undocumented amounts of contaminated mud sized sediments were added to the Big River and allowed to deposit downstream. Elevated lead levels (> 100 ppm) are documented within mud drapes on floodplains of the lower Meramec River after recent overbank deposition following storm events, indicating that mud sized contaminated sediment is currently being supplied to the lower Meramec River, a tributary of the Mississippi River. We conducted coring on a floodplain 19 km downstream of the confluence of the Big River and Meramec River in order to document the amount of contaminated sediment that has been historically added to a single floodplain of the lower Meramec River. The sediment samples taken from the cores were analyzed with a combination of ICP-MS and pXRF to characterize the maximum depth of lead contamination and estimate the amount of enhanced deposition experienced on a single lower Meramec River floodplain. Preliminary results show that the top 60 cm of Castlewood State Park floodplain contain lead contaminated sediments as high as 334 ppm and the floodplain has levels of lead in excess of 1000 ppm at 4 m depth in locations, suggesting that up to 4 m of deposition has occurred at a lower Meramec River floodplain since the onset of lead mining within the "Old Lead Belt." Further work will result in better constraints for the timing of this contaminated sediment and the extent deposition along the lower Meramec River.

  20. Plasma precipitation and neutral particle emission at Ganymede

    NASA Astrophysics Data System (ADS)

    Massetti, S.; Milillo, A.; Mura, A.; Orsini, S.; Plainaki, C.; Mangano, V.

    2012-04-01

    Ganymede, the largest moon of Jupiter is characterized by a tiny magnetosphere produced by an intrinsic magnetic moment; it is linked to the Jovian magnetosphere and embedded in its energetic plasma environment. In addition, since the plasma co-rotating with Jupiter impinges on Ganymede trailing side at subsonic speed, there is no bow-shock formation. Here we present preliminary results of Monte Carlo simulations aimed to evaluate the expected ion precipitation onto the polar caps of Ganymede, by means of the magnetic and electric fields derived by a global magnetohydrodynamic (MHD) model that realistically describe Ganymede's magnetospheric environment. We discuss precipitation pattern differences between the simulated ion species (H+, O+ and S+) at different energies in the range 10-100 keV. Plasma precipitating onto the surface of Ganymede modifies it both physically (via ion sputtering) and chemically (via radiolysis). Directly sputtered H2O molecules as well as products of H2O decomposition, that may recombine and produce diverse molecules, such as O2 and H2 are released. The yields of these processes have been estimated by means of accurate function that includes the dependence of the release on impacting ion species and energy as well as on the moon's surface temperature. In this study we attempted to isolate the temperature dependent part of this yield function and to assign it exclusively to the chemical processes taking place on ice and to the subsequent release of new molecules. In this way we make a rough preliminary distinction between the sputtering and radiolysis exospheric contributions. In our estimations we take into account also the energy spectra of precipitating plasma. A MonteCarlo model has been used to simulate the neutral density of escaping particles. Here we present results in terms of density and fluxes.

  1. Spatial and temporal variability of Antarctic precipitation from atmospheric methods

    SciTech Connect

    Cullather, R.L.; Bromwich, D.H.; Van Woert, M.L.

    1998-03-01

    The spatial and temporal variability of net precipitation (precipitation minus evaporation/sublimation) for Antarctica derived from the European Centre for Medium-Range Weather Forecasts operational analyses via the atmospheric moisture budget is assessed in comparison to a variety of glaciological and meteorological observations and datasets. For the 11-yr period 1985-95, the average continental value is 151 mm yr{sup {minus}1} water equivalent. Large regional differences with other datasets are identified, and the sources of error are considered. Interannual variability in the Southern Ocean storm tracks is found to be an important mechanism for enhanced precipitation minus evaporation (P-E) in both east and west Antarctica. In relation to the present findings, an evaluation of the rawinsonde method for estimating net precipitation in east Antarctica is conducted. Estimates of P-E using synthetic rawinsondes derived from the analyses are found to compare favorably to glaciological estimates. A significant upward trend of 2.4 mm yr{sup {minus}1} is found for the Antarctic continent that is consistent with findings from the National Centers for Environmental Prediction, formerly the National Meteorological Center, and the National Center for Atmospheric Research Reanalysis precipitation dataset. Despite large regional discrepancies, the general agreement on the main features of Antarctic precipitation between studies suggests that a threshold has been reached, where the assessment of the smaller terms including evaporation/sublimation and drift snow loss is required to explain the differences. 76 refs., 24 figs., 1 tab.

  2. Soil moisture impacts on convective precipitation in Oklahoma

    NASA Astrophysics Data System (ADS)

    Ford, Trenton W.

    Soil moisture is vital to the climate system, as root zone soil moisture has a significant influence on evapotranspiration rates and latent and sensible heat exchange. Through the modification of moisture flux from the land surface to the atmosphere, soil moisture can impact regional temperature and precipitation. Despite a wealth of studies examining land-atmosphere interactions, model and observation-driven studies show conflicting results with regard to the sign and strength of soil moisture feedback to precipitation, particularly in the Southern Great Plains of the United States. This research provides observational evidence for a preferential dry (or negative) soil moisture feedback to precipitation in Oklahoma. The ability of soil moisture to impact the location and occurrence of afternoon convective precipitation is constrained by synoptic-scale atmospheric circulation and resulting mid- and low-level wind patterns and sensible and latent heat flux. Overall, the preference for precipitation initiation over dry soils is enhanced when regional soil moisture gradients exhibit a weakened east to west, wet to dry pattern. Based on these results, we conclude that soil moisture can modify atmospheric conditions potentially leading to convective initiation. However, the land surface feedback signal is weak at best, suggesting that regional-scale circulation is the dominant driver of warm season precipitation in the Southern Great Plains.

  3. Influence of Precipitation Regime on Microbial Decomposition Patterns in Semi-Arid Ecosystems

    NASA Astrophysics Data System (ADS)

    Feris, K. P.; Jilek, C.; Huber, D. P.; Reinhardt, K.; deGraaff, M.; Lohse, K.; Germino, M.

    2011-12-01

    In water-limited semi-arid sagebrush steppe ecosystems predicted changes in climate may manifest as a shift from historically winter/snow-dominated precipitation regimes to one dominated by spring rains. In these ecosystems soil microorganisms play a vital role in linking the effects of water availability and plant productivity to biogeochemical cycling. Patterns of soil microbial catalyzed organic matter decomposition patters (i.e. patterns of extracellular enzyme activity (EEA)) are thought to depend upon the quantity and quality of soil organic matter (SOM), pH, and mean annual precipitation (Sinsabaugh, 2008), and less on the timing and magnitude of precipitation. However, sagebrush-steppe plant communities respond strongly to changes in the timing and magnitude of precipitation, and preliminary findings by our group suggest that corresponding changes in SOM quantity, quality, N-cycle dynamics, and soil structure are occurring. Therefore, we hypothesized: 1) Shifts in the timing and magnitude of precipitation would indirectly affect soil microbial decomposition patterns via responses in the plant community structure; and 2) Changes in precipitation patterns can directly affect soil microbial community structure and function, in effect uncoupling the interaction between plant community structure and soil community structure. We tested our hypotheses by determining the influence of experimentally manipulated timing and magnitude of precipitation on soil microbial EEA using stand