Effect of dislocation pile-up on size-dependent yield strength in finite single-crystal micro-samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Bo; Shibutani, Yoji, E-mail: sibutani@mech.eng.osaka-u.ac.jp; Zhang, Xu

2015-07-07

Recent research has explained that the steeply increasing yield strength in metals depends on decreasing sample size. In this work, we derive a statistical physical model of the yield strength of finite single-crystal micro-pillars that depends on single-ended dislocation pile-up inside the micro-pillars. We show that this size effect can be explained almost completely by considering the stochastic lengths of the dislocation source and the dislocation pile-up length in the single-crystal micro-pillars. The Hall–Petch-type relation holds even in a microscale single-crystal, which is characterized by its dislocation source lengths. Our quantitative conclusions suggest that the number of dislocation sources andmore » pile-ups are significant factors for the size effect. They also indicate that starvation of dislocation sources is another reason for the size effect. Moreover, we investigated the explicit relationship between the stacking fault energy and the dislocation “pile-up” effect inside the sample: materials with low stacking fault energy exhibit an obvious dislocation pile-up effect. Our proposed physical model predicts a sample strength that agrees well with experimental data, and our model can give a more precise prediction than the current single arm source model, especially for materials with low stacking fault energy.« less

A Physical Basis for M s-Yield Scaling in Hard Rock and Implications for Late-Time Damage of the Source Medium

DOE PAGES

Patton, Howard John

2016-04-11

Surface wave magnitude M s for a compilation of 72 nuclear tests detonated in hard rock media for which yields and burial depths have been reported in the literature is shown to scale with yield W as a + b × log[W], where a = 2.50 ± 0.08 and b = 0.80 ± 0.05. While the exponent b is consistent with an M s scaling model for fully coupled, normal containment-depth explosions, the intercept a is offset 0.45 magnitude units lower than the model. The cause of offset is important to understand in terms of the explosion source. Hard rockmore » explosions conducted in extensional and compressional stress regimes show similar offsets, an indication that the tectonic setting in which an explosion occurs plays no role causing the offset. The scaling model accounts for the effects of source medium material properties on the generation of 20-s period Rayleigh wave amplitudes. Aided by thorough characterizations of the explosion and tectonic release sources, an extensive analysis of the 1963 October 26 Shoal nuclear test detonated in granite 27 miles southeast of Fallon NV shows that the offset is consistent with the predictions of a material damage source model related to non-linear stress wave interactions with the free surface. This source emits Rayleigh waves with polarity opposite to waves emitted by the explosion. The Shoal results were extended to analyse surface waves from the 1962 February 15 Hardhat nuclear test, the 1988 September 14 Soviet Joint Verification Experiment, and the anomalous 1979 August 18 northeast Balapan explosion which exhibits opposite polarity, azimuth-independent source component U1 compared to an explosion. Modelling these tests shows that Rayleigh wave amplitudes generated by the damage source are nearly as large as or larger than amplitudes from the explosion. As such, destructive interference can be drastic, introducing metastable conditions due to the sensitivity of reduced amplitudes to Rayleigh wave initial phase angles of the explosion and damage sources. This meta-stability is a likely source of scatter in M s-yield scaling observations. The agreement of observed scaling exponent b with the model suggests that the damage source strength does not vary much with yield, in contrast to explosions conducted in weak media where Ms scaling rates are greater than the model predicts, and the yield dependence of the damage source strength is significant. This difference in scaling behaviour is a consequence of source medium material properties.« less

A Physical Basis for M s-Yield Scaling in Hard Rock and Implications for Late-Time Damage of the Source Medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, Howard John

Surface wave magnitude M s for a compilation of 72 nuclear tests detonated in hard rock media for which yields and burial depths have been reported in the literature is shown to scale with yield W as a + b × log[W], where a = 2.50 ± 0.08 and b = 0.80 ± 0.05. While the exponent b is consistent with an M s scaling model for fully coupled, normal containment-depth explosions, the intercept a is offset 0.45 magnitude units lower than the model. The cause of offset is important to understand in terms of the explosion source. Hard rockmore » explosions conducted in extensional and compressional stress regimes show similar offsets, an indication that the tectonic setting in which an explosion occurs plays no role causing the offset. The scaling model accounts for the effects of source medium material properties on the generation of 20-s period Rayleigh wave amplitudes. Aided by thorough characterizations of the explosion and tectonic release sources, an extensive analysis of the 1963 October 26 Shoal nuclear test detonated in granite 27 miles southeast of Fallon NV shows that the offset is consistent with the predictions of a material damage source model related to non-linear stress wave interactions with the free surface. This source emits Rayleigh waves with polarity opposite to waves emitted by the explosion. The Shoal results were extended to analyse surface waves from the 1962 February 15 Hardhat nuclear test, the 1988 September 14 Soviet Joint Verification Experiment, and the anomalous 1979 August 18 northeast Balapan explosion which exhibits opposite polarity, azimuth-independent source component U1 compared to an explosion. Modelling these tests shows that Rayleigh wave amplitudes generated by the damage source are nearly as large as or larger than amplitudes from the explosion. As such, destructive interference can be drastic, introducing metastable conditions due to the sensitivity of reduced amplitudes to Rayleigh wave initial phase angles of the explosion and damage sources. This meta-stability is a likely source of scatter in M s-yield scaling observations. The agreement of observed scaling exponent b with the model suggests that the damage source strength does not vary much with yield, in contrast to explosions conducted in weak media where Ms scaling rates are greater than the model predicts, and the yield dependence of the damage source strength is significant. This difference in scaling behaviour is a consequence of source medium material properties.« less

Microstructural probing of ferritic/martensitic steels using internal transmutation-based positron source

NASA Astrophysics Data System (ADS)

Krsjak, Vladimir; Dai, Yong

2015-10-01

This paper presents the use of an internal 44Ti/44Sc radioisotope source for a direct microstructural characterization of ferritic/martensitic (f/m) steels after irradiation in targets of spallation neutron sources. Gamma spectroscopy measurements show a production of ∼1MBq of 44Ti per 1 g of f/m steels irradiated at 1 dpa (displaced per atom) in the mixed proton-neutron spectrum at the Swiss spallation neutron source (SINQ). In the decay chain 44Ti → 44Sc → 44Ca, positrons are produced together with prompt gamma rays which enable the application of different positron annihilation spectroscopy (PAS) analyses, including lifetime and Doppler broadening spectroscopy. Due to the high production yield, long half-life and relatively high energy of positrons of 44Ti, this methodology opens up new potential for simple, effective and inexpensive characterization of radiation induced defects in f/m steels irradiated in a spallation target.

Probabilistic tsunami hazard assessment at Seaside, Oregon, for near-and far-field seismic sources

USGS Publications Warehouse

Gonzalez, F.I.; Geist, E.L.; Jaffe, B.; Kanoglu, U.; Mofjeld, H.; Synolakis, C.E.; Titov, V.V.; Areas, D.; Bellomo, D.; Carlton, D.; Horning, T.; Johnson, J.; Newman, J.; Parsons, T.; Peters, R.; Peterson, C.; Priest, G.; Venturato, A.; Weber, J.; Wong, F.; Yalciner, A.

2009-01-01

The first probabilistic tsunami flooding maps have been developed. The methodology, called probabilistic tsunami hazard assessment (PTHA), integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment (PSHA). Application of the methodology to Seaside, Oregon, has yielded estimates of the spatial distribution of 100- and 500-year maximum tsunami amplitudes, i.e., amplitudes with 1% and 0.2% annual probability of exceedance. The 100-year tsunami is generated most frequently by far-field sources in the Alaska-Aleutian Subduction Zone and is characterized by maximum amplitudes that do not exceed 4 m, with an inland extent of less than 500 m. In contrast, the 500-year tsunami is dominated by local sources in the Cascadia Subduction Zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km. The primary sources of uncertainty in these results include those associated with interevent time estimates, modeling of background sea level, and accounting for temporal changes in bathymetry and topography. Nonetheless, PTHA represents an important contribution to tsunami hazard assessment techniques; viewed in the broader context of risk analysis, PTHA provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard, which can then be combined with vulnerability and exposure to yield estimates of tsunami risk. Copyright 2009 by the American Geophysical Union.

Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my

2015-07-22

Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) andmore » proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.« less

(R)-3-hydroxyacyl-ACP:CoA transacylase of Pseudomonas chlororaphis: gene cloning, characterization and knock-out on PHA and rhamnolipid syntheses

USDA-ARS?s Scientific Manuscript database

Pseudomonas chlororaphis is a useful microorganism capable of producing polyhydroxyalkanoate (PHA) biopolymer and rhamnolipid (RL) biosurfactants by using carbon- and nitrogen-sources derived from renewable feedstocks as substrates of fermentation. We are interested in increasing the yield of RL pr...

NICOLAU: compact unit for photometric characterization of automotive lighting from near-field measurements

NASA Astrophysics Data System (ADS)

Royo, Santiago; Arranz, Maria J.; Arasa, Josep; Cattoen, Michel; Bosch, Thierry

2005-02-01

The present works depicts a measurement technique intended to enhance the characterization procedures of the photometric emissions of automotive headlamps, with potential applications to any light source emission, either automotive or non-automotive. A CCD array with a precisely characterized optical system is used for sampling the luminance field of the headlamp just a few centimetres in front of it, by combining deflectometric techniques (yielding the direction of the light beams) and photometric techniques (yielding the energy travelling in each direction). The CCD array scans the measurement plane using a self-developed mechanical unit and electronics, and then image-processing techniques are used for obtaining the photometric behaviour of the headlamp in any given plane, in particular in the plane and positions required by current normative, but also on the road, on traffic signs, etc. An overview of the construction of the system, of the considered principle of measurement, and of the main calibrations performed on the unit is presented. First results concerning relative measurements are presented compared both to reference data from a photometric tunnel and from a plane placed 5m away from the source. Preliminary results for the absolute photometric calibration of the system are also presented for different illumination beams of different headlamps (driving and passing beam).

The characterization and evaluation of accidental explosions

NASA Technical Reports Server (NTRS)

Strehlow, R. A.; Baker, W. E.

1975-01-01

Accidental explosions are discussed from a number of viewpoints. First, all accidental explosions, intentional explosions and natural explosions are characterized by type. Second, the nature of the blast wave produced by an ideal (point source or HE) explosion is discussed to form a basis for describing how other explosion processes yield deviations from ideal blast wave behavior. The current status blast damage mechanism evaluation is also discussed. Third, the current status of our understanding of each different category of accidental explosions is discussed in some detail.

Active sensing: An innovative tool for evaluating grain yield and nitrogen use efficiency of multiple wheat genotypes

NASA Astrophysics Data System (ADS)

Naser, Mohammed Abdulridha

Precision agricultural practices have significantly contributed to the improvement of crop productivity and profitability. Remote sensing based indices, such as Normalized Difference Vegetative Index (NDVI) have been used to obtain crop information. It is used to monitor crop development and to provide rapid and nondestructive estimates of plant biomass, nitrogen (N) content and grain yield. Remote sensing tools are helping improve nitrogen use efficiency (NUE) through nitrogen management and could also be useful for high NUE genotype selection. The objectives of this study were: (i) to determine if active sensor based NDVI readings can differentiate wheat genotypes, (ii) to determine if NDVI readings can be used to classify wheat genotypes into grain yield productivity classes, (iii) to identify and quantify the main sources of variation in NUE across wheat genotypes, and (iv) to determine if normalized difference vegetation index (NDVI) could characterize variability in NUE across wheat genotypes. This study was conducted in north eastern Colorado for two years, 2010 and 2011. The NDVI readings were taken weekly during the winter wheat growing season from March to late June, in 2010 and 2011 and NUE were calculated as partial factor productivity and as partial nitrogen balance at the end of the season. For objectives i and ii, the correlation between NDVI and grain yield was determined using Pearson's product-moment correlation coefficient (r) and linear regression analysis was used to explain the relationship between NDVI and grain yield. The K-means clustering algorithm was used to classify mean NDVI and mean grain yield into three classes. For objectives iii and iv, the parameters related to NUE were also calculated to measure their relative importance in genotypic variation of NUE and power regression analysis between NDVI and NUE was used to characterize the relationship between NDVI and NUE. The results indicate more consistent association between grain yield and NDVI and between NDVI and NUE later in the season, after anthesis and during mid-grain filling stage under dryland and a poor association in wheat grown in irrigated conditions. The results suggest that below saturation of NDVI values (about 0.9), (i.e. prior to full canopy closure and after the beginning of senescence or most of the season under dryland conditions) NDVI could assess grain yield and NUE. The results also indicate that nitrogen uptake efficiency was the main source of variation of NUE among genotypes grown in site-years with lower yield. Overall, results from this study demonstrate that NDVI readings successfully classified wheat genotypes into grain yield classes across dryland and irrigated conditions and characterized variability in NUE across wheat genotypes.

Joint spectral characterization of photon-pair sources

NASA Astrophysics Data System (ADS)

Zielnicki, Kevin; Garay-Palmett, Karina; Cruz-Delgado, Daniel; Cruz-Ramirez, Hector; O'Boyle, Michael F.; Fang, Bin; Lorenz, Virginia O.; U'Ren, Alfred B.; Kwiat, Paul G.

2018-06-01

The ability to determine the joint spectral properties of photon pairs produced by the processes of spontaneous parametric downconversion (SPDC) and spontaneous four-wave mixing (SFWM) is crucial for guaranteeing the usability of heralded single photons and polarization-entangled pairs for multi-photon protocols. In this paper, we compare six different techniques that yield either a characterization of the joint spectral intensity or of the closely related purity of heralded single photons. These six techniques include: (i) scanning monochromator measurements, (ii) a variant of Fourier transform spectroscopy designed to extract the desired information exploiting a resource-optimized technique, (iii) dispersive fibre spectroscopy, (iv) stimulated-emission-based measurement, (v) measurement of the second-order correlation function ? for one of the two photons, and (vi) two-source Hong-Ou-Mandel interferometry. We discuss the relative performance of these techniques for the specific cases of a SPDC source designed to be factorable and SFWM sources of varying purity, and compare the techniques' relative advantages and disadvantages.

Machine characterization and benchmark performance prediction

NASA Technical Reports Server (NTRS)

Saavedra-Barrera, Rafael H.

1988-01-01

From runs of standard benchmarks or benchmark suites, it is not possible to characterize the machine nor to predict the run time of other benchmarks which have not been run. A new approach to benchmarking and machine characterization is reported. The creation and use of a machine analyzer is described, which measures the performance of a given machine on FORTRAN source language constructs. The machine analyzer yields a set of parameters which characterize the machine and spotlight its strong and weak points. Also described is a program analyzer, which analyzes FORTRAN programs and determines the frequency of execution of each of the same set of source language operations. It is then shown that by combining a machine characterization and a program characterization, we are able to predict with good accuracy the run time of a given benchmark on a given machine. Characterizations are provided for the Cray-X-MP/48, Cyber 205, IBM 3090/200, Amdahl 5840, Convex C-1, VAX 8600, VAX 11/785, VAX 11/780, SUN 3/50, and IBM RT-PC/125, and for the following benchmark programs or suites: Los Alamos (BMK8A1), Baskett, Linpack, Livermore Loops, Madelbrot Set, NAS Kernels, Shell Sort, Smith, Whetstone and Sieve of Erathostenes.

Sources and reactivities of marine-derived organic matter in coastal sediments as determined by alkaline CuO oxidation

NASA Astrophysics Data System (ADS)

Goñi, Miguel A.; Hedges, John I.

1995-07-01

Alkaline CuO oxidation of ubiquitous biochemicals such as proteins, polysaccharides, and lipids, yields specific products, including fatty acids, diacids, and carboxylated phenols. Oxidation of a variety of marine organisms, including macrophytes, phytoplankton, zooplankton, and bacteria, yields these CuO products in characteristic patterns that can often differentiate these biological sources. Sediments from Skan Bay (Unalaska Island, Alaska) display organic carbon and total nitrogen profiles which are consistent with three kinetically distinct pools of organic matter. The CuO fingerprints of these sediments distinguish these three pools at the molecular level, indicating a highly labile, fatty acid-rich surface organic layer of likely bacterial origin, intermediately reactive kelp debris and a background of phytoplankton remains that predominates at depth. The CuO method, which has been previously applied only to characterize cutin and lignin constituents of vascular land plants, also provides information on other types of abundant biochemicals, including those indicative of marine sources.

Double point source W-phase inversion: Real-time implementation and automated model selection

USGS Publications Warehouse

Nealy, Jennifer; Hayes, Gavin

2015-01-01

Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

Characterization of a high repetition-rate laser-driven short-pulsed neutron source

NASA Astrophysics Data System (ADS)

Hah, J.; Nees, J. A.; Hammig, M. D.; Krushelnick, K.; Thomas, A. G. R.

2018-05-01

We demonstrate a repetitive, high flux, short-pulsed laser-driven neutron source using a heavy-water jet target. We measure neutron generation at 1/2 kHz repetition rate using several-mJ pulse energies, yielding a time-averaged neutron flux of 2 × 105 neutrons s‑1 (into 4π steradians). Deuteron spectra are also measured in order to understand source characteristics. Analyses of time-of-flight neutron spectra indicate that two separate populations of neutrons, ‘prompt’ and ‘delayed’, are generated at different locations. Gamma-ray emission from neutron capture 1H(n,γ) is also measured to confirm the neutron flux.

Characterizing runoff and water yield for headwater catchments in the southern Sierra Nevada

Treesearch

Mohammad Safeeq; Carolyn T. Hunsaker

2016-01-01

In a Mediterranean climate where much of the precipitation falls during winter, snowpacks serve as the primary source of dry season runoff. Increased warming has led to significant changes in hydrology of the western United States. An important question in this context is how to best manage forested catchments for water and other ecosystem services? Answering this...

Tagged Neutron Source for API Inspection Systems with Greatly Enhanced Spatial Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2012-06-04

We recently developed induced fission and transmission imaging methods with time- and directionally-tagged neutrons offer new capabilities for characterization of fissile material configurations and enhanced detection of special nuclear materials (SNM). An Advanced Associated Particle Imaging (API) generator with higher angular resolution and neutron yield than existing systems is needed to fully exploit these methods.

Three-Dimensional Modeling of Low-Mode Asymmetries in OMEGA Cryogenic Implosions

NASA Astrophysics Data System (ADS)

Anderson, K. S.; McKenty, P. W.; Shvydky, A.; Collins, T. J. B.; Forrest, C. J.; Knauer, J. P.; Marozas, J. A.; Marshall, F. J.; Radha, P. B.; Sefkow, A. B.; Marinak, M. M.

2017-10-01

In direct-drive inertial confinement fusion implosions, long-wavelength asymmetries resulting from target offset, laser power imbalance, beam mispointing, etc. can be highly detrimental to target performance. Characterizing the effects of these asymmetry sources requires 3-D simulations performed in full-sphere geometry to accurately capture the evolution of shell perturbations and hot-spot flow. This paper will present 3-D HYDRA simulations characterizing the impact of these perturbation sources on yield and shell modulation. Various simulated observables are generated, and trends are analyzed and compared with experimental data. This material is based on work supported by the Department of Energy National Nuclear Security Administration under Award Numbers DE-NA0001944 and performed under the auspices of the LLNL under Contract No. DE-AC52-07NA27344.

Mesenchymal Stem Cell Levels of Human Spinal Tissues.

PubMed

Harris, Liam; Vangsness, C Thomas

2018-05-01

Systematic review. The aim of this study was to investigate, quantify, compare, and compile the various mesenchymal stem cell (MSC) tissue sources within human spinal tissues to act as a compendium for clinical and research application. Recent years have seen a dramatic increase in academic and clinical understanding of human MSCs. Previously limited to cells isolated from bone marrow, the past decade has illicited the characterization and isolation of human MSCs from adipose, bone marrow, synovium, muscle, periosteum, peripheral blood, umbilical cord, placenta, and numerous other tissues. As researchers explore practical applications of cells in these tissues, the absolute levels of MSCs in specific spinal tissue will be critical to guide future research. The PubMED, MEDLINE, EMBASE, and Cochrane databases were searched for articles relating to the harvest, characterization, isolation, and quantification of human MSCs from spinal tissues. Selected articles were examined for relevant data, categorized according to type of spinal tissue, and when possible, standardized to facilitate comparisons between sites. Human MSC levels varied widely between spinal tissues. Yields for intervertebral disc demonstrated roughly 5% of viable cells to be positive for MSC surface markers. Cartilage endplate cells yielded 18,500 to 61,875 cells/0.8 mm thick sample of cartilage end plate. Ligamentum flavum yielded 250,000 to 500,000 cells/g of tissue. Annulus fibrosus fluorescence activated cell sorting treatment found 29% of cells positive for MSC marker Stro-1. Nucleus pulposus yielded mean tissue samples of 40,584 to 234,137 MSCs per gram of tissue. Numerous tissues within and surrounding the spine represent a consistent and reliable source for the harvest and isolation of human MSCs. Among the tissues of the spine, the annulus fibrosus and ligamentum flavum each offer considerable levels of MSCs, and may prove comparable to that of bone marrow. 5.

DBP formation of aquatic humic substances

USGS Publications Warehouse

Pomes, M.L.; Green, W.R.; Thurman, E.M.; Orem, W.H.; Lerch, H.E.

1999-01-01

Aquatic humic substances (AHSs) in water generate potentially harmful disinfection by-products (DBPs) such as haloacetic acids (HAAs) and trihalomethanes (THMs) during chlorination. AHSs from two Arkansas reservoirs were characterized to define source, identify meta-dihydroxybenzene (m-DHB) structures as probable DBP precursors, and evaluate predicted HAA and THM formation potentials. Elemental nitrogen content 0.5 ??eq/mg, ??13C values of -27???, and low yields of syringyl phenols found by cupric oxide (CuO) oxidation suggest a pine tree source for the AHSs found in the Maumelle and Winona reservoirs in Little Rock, Ark. CuO oxidation yielded fewer m-DHB structures in Maumelle AHSs than in Winona AHSs. A higher 3,5-dihydroxybenzoic acid (3,5-DHBA) content correlated with increased HAA and THM formation potential. The 3,5-DHBA concentration in Winona AHSs was similar to the range found in AHSs extracted from deciduous leaf litter, twigs, and grass leachates.

Comparison of Protein Extracts from Various Unicellular Green Sources.

PubMed

Teuling, Emma; Wierenga, Peter A; Schrama, Johan W; Gruppen, Harry

2017-09-13

Photosynthetic unicellular organisms are considered as promising alternative protein sources. The aim of this study is to understand the extent to which these green sources differ with respect to their gross composition and how these differences affect the final protein isolate. Using mild isolation techniques, proteins were extracted and isolated from four different unicellular sources (Arthrospira (spirulina) maxima, Nannochloropsis gaditana, Tetraselmis impellucida, and Scenedesmus dimorphus). Despite differences in protein contents of the sources (27-62% w/w) and in protein extractability (17-74% w/w), final protein isolates were obtained that had similar protein contents (62-77% w/w) and protein yields (3-9% w/w). Protein solubility as a function of pH was different between the sources and in ionic strength dependency, especially at pH < 4.0. Overall, the characterization and extraction protocol used allows a relatively fast and well-described isolation of purified proteins from novel protein sources.

Comparison of Protein Extracts from Various Unicellular Green Sources

PubMed Central

2017-01-01

Photosynthetic unicellular organisms are considered as promising alternative protein sources. The aim of this study is to understand the extent to which these green sources differ with respect to their gross composition and how these differences affect the final protein isolate. Using mild isolation techniques, proteins were extracted and isolated from four different unicellular sources (Arthrospira (spirulina) maxima, Nannochloropsis gaditana, Tetraselmis impellucida, and Scenedesmus dimorphus). Despite differences in protein contents of the sources (27–62% w/w) and in protein extractability (17–74% w/w), final protein isolates were obtained that had similar protein contents (62–77% w/w) and protein yields (3–9% w/w). Protein solubility as a function of pH was different between the sources and in ionic strength dependency, especially at pH < 4.0. Overall, the characterization and extraction protocol used allows a relatively fast and well-described isolation of purified proteins from novel protein sources. PMID:28701042

Ronchi test for characterization of X-ray nanofocusing optics and beamlines.

PubMed

Uhlén, Fredrik; Rahomäki, Jussi; Nilsson, Daniel; Seiboth, Frank; Sanz, Claude; Wagner, Ulrich; Rau, Christoph; Schroer, Christian G; Vogt, Ulrich

2014-09-01

A Ronchi interferometer for hard X-rays is reported in order to characterize the performance of the nanofocusing optics as well as the beamline stability. Characteristic interference fringes yield qualitative data on present aberrations in the optics. Moreover, the visibility of the fringes on the detector gives information on the degree of spatial coherence in the beamline. This enables the possibility to detect sources of instabilities in the beamline like vibrations of components or temperature drift. Examples are shown for two different nanofocusing hard X-ray optics: a compound refractive lens and a zone plate.

Stable Extraction of Threshold Voltage Using Transconductance Change Method for CMOS Modeling, Simulation and Characterization

NASA Astrophysics Data System (ADS)

Choi, Woo Young; Woo, Dong-Soo; Choi, Byung Yong; Lee, Jong Duk; Park, Byung-Gook

2004-04-01

We proposed a stable extraction algorithm for threshold voltage using transconductance change method by optimizing node interval. With the algorithm, noise-free gm2 (=dgm/dVGS) profiles can be extracted within one-percent error, which leads to more physically-meaningful threshold voltage calculation by the transconductance change method. The extracted threshold voltage predicts the gate-to-source voltage at which the surface potential is within kT/q of φs=2φf+VSB. Our algorithm makes the transconductance change method more practical by overcoming noise problem. This threshold voltage extraction algorithm yields the threshold roll-off behavior of nanoscale metal oxide semiconductor field effect transistor (MOSFETs) accurately and makes it possible to calculate the surface potential φs at any other point on the drain-to-source current (IDS) versus gate-to-source voltage (VGS) curve. It will provide us with a useful analysis tool in the field of device modeling, simulation and characterization.

X-ray source characterization of aluminum X-pinch plasmas driven by the 0. 5 TW LION accelerator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, N.; Hammer, D.A.; Kalantar, D.H.

1989-12-01

Recent experiments at Cornell have been performed to investigate X-pinch plasmas as intense x-ray sources which might be used to pump resonant photoexcitation lasers. Crossed Al wires have been driven by up to 600 kA current for 40 ns. High density bright spots are observed at the crossing point(s). Various diagnostics were used to characterize the X-pinch plasmas as a function of initial mass loading for several specific wire configurations. The optimum mass loading for different ionization stages of Al, and the total x-ray energy yields, which are on the order of hundreds of Joules, were examined. Estimates of plasmamore » density, {similar to}10{sup 20} cm{sup {minus}3}, and temperature, about 400 eV, were obtained.« less

Regional W-Phase Source Inversion for Moderate to Large Earthquakes in China and Neighboring Areas

NASA Astrophysics Data System (ADS)

Zhao, Xu; Duputel, Zacharie; Yao, Zhenxing

2017-12-01

Earthquake source characterization has been significantly speeded up in the last decade with the development of rapid inversion techniques in seismology. Among these techniques, the W-phase source inversion method quickly provides point source parameters of large earthquakes using very long period seismic waves recorded at teleseismic distances. Although the W-phase method was initially developed to work at global scale (within 20 to 30 min after the origin time), faster results can be obtained when seismological data are available at regional distances (i.e., Δ ≤ 12°). In this study, we assess the use and reliability of regional W-phase source estimates in China and neighboring areas. Our implementation uses broadband records from the Chinese network supplemented by global seismological stations installed in the region. Using this data set and minor modifications to the W-phase algorithm, we show that reliable solutions can be retrieved automatically within 4 to 7 min after the earthquake origin time. Moreover, the method yields stable results down to Mw = 5.0 events, which is well below the size of earthquakes that are rapidly characterized using W-phase inversions at teleseismic distances.

Repeated-batch fermentations of xylose and glucose-xylose mixtures using a respiration-deficient Saccharomyces cerevisiae engineered for xylose metabolism.

PubMed

Kim, Soo Rin; Lee, Ki-Sung; Choi, Jin-Ho; Ha, Suk-Jin; Kweon, Dae-Hyuk; Seo, Jin-Ho; Jin, Yong-Su

2010-11-01

Xylose-fermenting Saccharomyces strains are needed for commercialization of ethanol production from lignocellulosic biomass. Engineered Saccharomyces cerevisiae strains expressing XYL1, XYL2 and XYL3 from Pichia stipitis, however, utilize xylose in an oxidative manner, which results in significantly lower ethanol yields from xylose as compared to glucose. As such, we hypothesized that reconfiguration of xylose metabolism from oxidative into fermentative manner might lead to efficient ethanol production from xylose. To this end, we generated a respiration-deficient (RD) mutant in order to enforce engineered S. cerevisiae to utilize xylose only through fermentative metabolic routes. Three different repeated-batch fermentations were performed to characterize characteristics of the respiration-deficient mutant. When fermenting glucose as a sole carbon source, the RD mutant exhibited near theoretical ethanol yields (0.46 g g(-1)) during repeated-batch fermentations by recycling the cells. As the repeated-batch fermentation progressed, the volumetric ethanol productivity increased (from 7.5 to 8.3 g L(-1)h(-1)) because of the increased biomass from previous cultures. On the contrary, the mutant showed decreasing volumetric ethanol productivities during the repeated-batch fermentations using xylose as sole carbon source (from 0.4 to 0.3 g L(-1)h(-1)). The mutant did not grow on xylose and lost fermenting ability gradually, indicating that the RD mutant cannot maintain a good fermenting ability on xylose as a sole carbon source. However, the RD mutant was capable of fermenting a mixture of glucose and xylose with stable yields (0.35 g g(-1)) and productivities (0.52 g L(-1)h(-1)) during the repeated-batch fermentation. In addition, ethanol yields from xylose during the mixed sugar fermentation (0.30 g g(-1)) were higher than ethanol yields from xylose as a sole carbon source (0.21 g g(-1)). These results suggest that a strategy for increasing ethanol yield through respiration-deficiency can be applied for the fermentation of lignocellulosic hydrolyzates containing glucose and xylose. Copyright © 2010 Elsevier B.V. All rights reserved.

Characterization of a new dosimeter for the development of a position-sensitive detector of radioactive sources in industrial NDT equipment

NASA Astrophysics Data System (ADS)

Kim, K. T.; Kim, J. H.; Han, M. J.; Heo, Y. J.; Park, S. K.

2018-02-01

Imaging technology based on gamma-ray sources has been extensively used in non-destructive testing (NDT) to detect any possible internal defects in products without changing their shapes or functions. However, such technology has been subject to increasingly stricter regulations, and an international radiation-safety management system has been recently established. Consequently, radiation source location in NDT systems has become an essential process, given that it can prevent radiation accidents. In this study, we focused on developing a monitoring system that can detect, in real time, the position of a radioactive source in the source guide tube of a projector. We fabricated a lead iodide (PbI2) dosimeter based on the particle-in-binder method, which has a high production yield and facilitates thickness and shape adjustment. Using a gamma-ray source, we then tested the reproducibility, linearity of the dosimeter response, and the dosimeter's percentage interval distance (PID). It was found that the fabricated PbI2 dosimeter yields highly accurate, reproducible, and linear dose measurements. The PID analysis—conducted to investigate the possibility of developing a monitoring system based on the proposed dosimeter—indicated that the valid detection distance was approximately 11.3 cm. The results of this study are expected to contribute to the development of an easily usable radiation monitoring system capable of significantly reducing the risk of radiation accidents.

Temporal Characterization of Aircraft Noise Sources

NASA Technical Reports Server (NTRS)

Grosveld, Ferdinand W.; Sullivan, Brenda M.; Rizzi, Stephen A.

2004-01-01

Current aircraft source noise prediction tools yield time-independent frequency spectra as functions of directivity angle. Realistic evaluation and human assessment of aircraft fly-over noise require the temporal characteristics of the noise signature. The purpose of the current study is to analyze empirical data from broadband jet and tonal fan noise sources and to provide the temporal information required for prediction-based synthesis. Noise sources included a one-tenth-scale engine exhaust nozzle and a one-fifth scale scale turbofan engine. A methodology was developed to characterize the low frequency fluctuations employing the Short Time Fourier Transform in a MATLAB computing environment. It was shown that a trade-off is necessary between frequency and time resolution in the acoustic spectrogram. The procedure requires careful evaluation and selection of the data analysis parameters, including the data sampling frequency, Fourier Transform window size, associated time period and frequency resolution, and time period window overlap. Low frequency fluctuations were applied to the synthesis of broadband noise with the resulting records sounding virtually indistinguishable from the measured data in initial subjective evaluations. Amplitude fluctuations of blade passage frequency (BPF) harmonics were successfully characterized for conditions equivalent to take-off and approach. Data demonstrated that the fifth harmonic of the BPF varied more in frequency than the BPF itself and exhibited larger amplitude fluctuations over the duration of the time record. Frequency fluctuations were found to be not perceptible in the current characterization of tonal components.

Coupling individual kernel-filling processes with source-sink interactions into GREENLAB-Maize.

PubMed

Ma, Yuntao; Chen, Youjia; Zhu, Jinyu; Meng, Lei; Guo, Yan; Li, Baoguo; Hoogenboom, Gerrit

2018-02-13

Failure to account for the variation of kernel growth in a cereal crop simulation model may cause serious deviations in the estimates of crop yield. The goal of this research was to revise the GREENLAB-Maize model to incorporate source- and sink-limited allocation approaches to simulate the dry matter accumulation of individual kernels of an ear (GREENLAB-Maize-Kernel). The model used potential individual kernel growth rates to characterize the individual potential sink demand. The remobilization of non-structural carbohydrates from reserve organs to kernels was also incorporated. Two years of field experiments were conducted to determine the model parameter values and to evaluate the model using two maize hybrids with different plant densities and pollination treatments. Detailed observations were made on the dimensions and dry weights of individual kernels and other above-ground plant organs throughout the seasons. Three basic traits characterizing an individual kernel were compared on simulated and measured individual kernels: (1) final kernel size; (2) kernel growth rate; and (3) duration of kernel filling. Simulations of individual kernel growth closely corresponded to experimental data. The model was able to reproduce the observed dry weight of plant organs well. Then, the source-sink dynamics and the remobilization of carbohydrates for kernel growth were quantified to show that remobilization processes accompanied source-sink dynamics during the kernel-filling process. We conclude that the model may be used to explore options for optimizing plant kernel yield by matching maize management to the environment, taking into account responses at the level of individual kernels. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The calibration of the intramolecular nitrogen isotope distribution in nitrous oxide measured by isotope ratio mass spectrometry.

PubMed

Westley, Marian B; Popp, Brian N; Rust, Terri M

2007-01-01

Two alternative approaches for the calibration of the intramolecular nitrogen isotope distribution in nitrous oxide using isotope ratio mass spectrometry have yielded a difference in the 15N site preference (defined as the difference between the delta15N of the central and end position nitrogen in NNO) of tropospheric N2O of almost 30 per thousand. One approach is based on adding small amounts of labeled 15N2O to the N2O reference gas and tracking the subsequent changes in m/z 30, 31, 44, 45 and 46, and this yields a 15N site preference of 46.3 +/- 1.4 per thousand for tropospheric N2O. The other involves the synthesis of N2O by thermal decomposition of isotopically characterized ammonium nitrate and yields a 15N site preference of 18.7 +/- 2.2 per thousand for tropospheric N2O. Both approaches neglect to fully account for isotope effects associated with the formation of NO+ fragment ions from the different isotopic species of N2O in the ion source of a mass spectrometer. These effects vary with conditions in the ion source and make it impossible to reproduce a calibration based on the addition of isotopically enriched N2O on mass spectrometers with different ion source configurations. These effects have a much smaller impact on the comparison of a laboratory reference gas with N2O synthesized from isotopically characterized ammonium nitrate. This second approach was successfully replicated and leads us to advocate the acceptance of the site preference value 18.7 +/- 2.2 per thousand for tropospheric N2O as the provisional community standard until further independent calibrations are developed and validated. We present a technique for evaluating the isotope effects associated with fragment ion formation and revised equations for converting ion signal ratios into isotopomer ratios. Copyright 2007 John Wiley & Sons, Ltd.

Characterization and use of the spent beam for serial operation of LCLS

DOE PAGES

Boutet, Sébastien; Foucar, Lutz; Barends, Thomas R. M.; ...

2015-04-11

X-ray free-electron laser sources such as the Linac Coherent Light Source offer very exciting possibilities for unique research. However, beam time at such facilities is very limited and in high demand. This has led to significant efforts towards beam multiplexing of various forms. One such effort involves re-using the so-called spent beam that passes through the hole in an area detector after a weak interaction with a primary sample. This beam can be refocused into a secondary interaction region and used for a second, independent experiment operating in series. The beam profile of this refocused beam was characterized for amore » particular experimental geometry at the Coherent X-ray Imaging instrument at LCLS. A demonstration of this multiplexing capability was performed with two simultaneous serial femtosecond crystallography experiments, both yielding interpretable data of sufficient quality to produce electron density maps.« less

Characterization and use of the spent beam for serial operation of LCLS

PubMed Central

Boutet, Sébastien; Foucar, Lutz; Barends, Thomas R. M.; Botha, Sabine; Doak, R. Bruce; Koglin, Jason E.; Messerschmidt, Marc; Nass, Karol; Schlichting, Ilme; Seibert, M. Marvin; Shoeman, Robert L.; Williams, Garth J.

2015-01-01

X-ray free-electron laser sources such as the Linac Coherent Light Source offer very exciting possibilities for unique research. However, beam time at such facilities is very limited and in high demand. This has led to significant efforts towards beam multiplexing of various forms. One such effort involves re-using the so-called spent beam that passes through the hole in an area detector after a weak interaction with a primary sample. This beam can be refocused into a secondary interaction region and used for a second, independent experiment operating in series. The beam profile of this refocused beam was characterized for a particular experimental geometry at the Coherent X-ray Imaging instrument at LCLS. A demonstration of this multiplexing capability was performed with two simultaneous serial femtosecond crystallography experiments, both yielding interpretable data of sufficient quality to produce electron density maps. PMID:25931079

Cosine beamforming

NASA Astrophysics Data System (ADS)

Ruigrok, Elmer; Wapenaar, Kees

2014-05-01

In various application areas, e.g., seismology, astronomy and geodesy, arrays of sensors are used to characterize incoming wavefields due to distant sources. Beamforming is a general term for phased-adjusted summations over the different array elements, for untangling the directionality and elevation angle of the incoming waves. For characterizing noise sources, beamforming is conventionally applied with a temporal Fourier and a 2D spatial Fourier transform, possibly with additional weights. These transforms become aliased for higher frequencies and sparser array-element distributions. As a partial remedy, we derive a kernel for beamforming crosscorrelated data and call it cosine beamforming (CBF). By applying beamforming not directly to the data, but to crosscorrelated data, the sampling is effectively increased. We show that CBF, due to this better sampling, suffers less from aliasing and yields higher resolution than conventional beamforming. As a flip-side of the coin, the CBF output shows more smearing for spherical waves than conventional beamforming.

X-ray resonant magnetic scattering ellipsometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Z.; Randall, K.J.; Gluskin, E.

1996-09-01

It is very difficult to characterize the polarization of a synchrotron radiation source in the soft and/or intermediate x-ray energy region particularly from 1 to 2 keV. Conventional multilayer mirror or single-crystal polarimeters do not work over this energy region because their throughput (the reflectivities combined with the phase shift) becomes insignificant. In this paper, we present a new ellipsometer scheme that is able to fully characterize the polarization of synchrotron radiation sources in this energy region. It is based on the dichroic x-ray resonant ferromagnetic scattering that yields information on both the polarization of the x-ray and the materialmore » (element specific) dielectric-constant tensor [C.-C. Kao {ital et} {ital al}., Phys. Rev. B {bold 50}, 9599 (1994)] due to the interband ferromagnetic Kerr effect [B.R. Cooper, Phys. Rev. A {bold 139}, 1504 (1965)]. {copyright} {ital 1996 American Institute of Physics.}« less

Flux growth and characterization of cuprorivaite: the influence of temperature, flux, and silica source

NASA Astrophysics Data System (ADS)

Bloise, A.; Abd El Salam, S.; De Luca, R.; Crisci, G. M.; Miriello, D.

2016-07-01

Single crystals of cuprorivaite (CaCuSi4O10), one of the oldest synthetic color pigments of Egyptian history, have been synthesized by slow-cooling flux method. Several runs were carried out at temperatures between 800 and 960 °C and with reaction times ranging from 10 to 72 h. The starting materials and run products were characterized by binocular microscope, X-ray powder diffraction, scanning electron microscopy with annexed energy-dispersive spectrometry, and μ-Raman spectroscopy. The effects of growth parameters (temperature, flux, silica source) on yield and size of crystals were studied. The growth of cuprorivaite depends greatly on the starting materials: they are observed as run products only using natron as flux. Furthermore, colorimetric analysis performed on the synthesizing pigment was compared with the archeological samples present in the literature in order to value similarities and differences.

Overexpression of OsGATA12 regulates chlorophyll content, delays plant senescence and improves rice yield under high density planting.

PubMed

Lu, Guangwen; Casaretto, José A; Ying, Shan; Mahmood, Kashif; Liu, Fang; Bi, Yong-Mei; Rothstein, Steven J

2017-05-01

Agronomic traits controlling the formation, architecture and physiology of source and sink organs are main determinants of rice productivity. Semi-dwarf rice varieties with low tiller formation but high seed production per panicle and dark green and thick leaves with prolonged source activity are among the desirable traits to further increase the yield potential of rice. Here, we report the functional characterization of a zinc finger transcription factor, OsGATA12, whose overexpression causes increased leaf greenness, reduction of leaf and tiller number, and affects yield parameters. Reduced tillering allowed testing the transgenic plants under high density which resulted in significantly increased yield per area and higher harvest index compared to wild-type. We show that delayed senescence of transgenic plants and the corresponding longer stay-green phenotype is mainly due to increased chlorophyll and chloroplast number. Further, our work postulates that the increased greenness observed in the transgenic plants is due to more chlorophyll synthesis but most significantly to decreased chlorophyll degradation, which is supported by the reduced expression of genes involved in the chlorophyll degradation pathway. In particular we show evidence for the down-regulation of the STAY GREEN RICE gene and in vivo repression of its promoter by OsGATA12, which suggests a transcriptional repression function for a GATA transcription factor for prolonging the onset of senescence in cereals.

Structure function monitor

DOEpatents

McGraw, John T [Placitas, NM; Zimmer, Peter C [Albuquerque, NM; Ackermann, Mark R [Albuquerque, NM

2012-01-24

Methods and apparatus for a structure function monitor provide for generation of parameters characterizing a refractive medium. In an embodiment, a structure function monitor acquires images of a pupil plane and an image plane and, from these images, retrieves the phase over an aperture, unwraps the retrieved phase, and analyzes the unwrapped retrieved phase. In an embodiment, analysis yields atmospheric parameters measured at spatial scales from zero to the diameter of a telescope used to collect light from a source.

Acute Blood Loss During Burn and Soft Tissue Excisions: An Observational Study of Blood Product Resuscitation Practices and Focused Review

DTIC Science & Technology

2015-06-24

centers have shifted to a damage-control resuscitation approach, focused on providing oxygen - carrying capacity while simultaneously mitigating...develop treatments for this widely recognized problem have yet to yield effective solutions. In both the ci- vilian and military settings, most deaths...characterizing the effects of significant intraoperative bleeding on coagulation may be an alternative source of data to guide ORIGINAL ARTICLE J

Calculations to support JET neutron yield calibration: Modelling of neutron emission from a compact DT neutron generator

NASA Astrophysics Data System (ADS)

Čufar, Aljaž; Batistoni, Paola; Conroy, Sean; Ghani, Zamir; Lengar, Igor; Milocco, Alberto; Packer, Lee; Pillon, Mario; Popovichev, Sergey; Snoj, Luka; JET Contributors

2017-03-01

At the Joint European Torus (JET) the ex-vessel fission chambers and in-vessel activation detectors are used as the neutron production rate and neutron yield monitors respectively. In order to ensure that these detectors produce accurate measurements they need to be experimentally calibrated. A new calibration of neutron detectors to 14 MeV neutrons, resulting from deuterium-tritium (DT) plasmas, is planned at JET using a compact accelerator based neutron generator (NG) in which a D/T beam impinges on a solid target containing T/D, producing neutrons by DT fusion reactions. This paper presents the analysis that was performed to model the neutron source characteristics in terms of energy spectrum, angle-energy distribution and the effect of the neutron generator geometry. Different codes capable of simulating the accelerator based DT neutron sources are compared and sensitivities to uncertainties in the generator's internal structure analysed. The analysis was performed to support preparation to the experimental measurements performed to characterize the NG as a calibration source. Further extensive neutronics analyses, performed with this model of the NG, will be needed to support the neutron calibration experiments and take into account various differences between the calibration experiment and experiments using the plasma as a source of neutrons.

Assessment of sewer source contamination of drinking water wells using tracers and human enteric viruses

USGS Publications Warehouse

Hunt, R.J.; Borchardt, M. A.; Richards, K.D.; Spencer, S. K.

2010-01-01

This study investigated the source, transport, and occurrence of human enteric viruses in municipal well water, focusing on sanitary sewer sources. A total of 33 wells from 14 communities were sampled once for wastewater tracers and viruses. Wastewater tracers were detected in four of these wells, and five wells were virus- positive by qRT-PCR. These results, along with exclusion of wells with surface water sources, were used to select three wells for additional investigation. Viruses and wastewater tracers were found in the groundwater at all sites. Some wastewater tracers, such as ionic detergents, flame retardants, and cholesterol, were considered unambiguous evidence of wastewater. Sampling at any given time may not show concurrent virus and tracer presence; however, given sufficient sampling over time, a relation between wastewater tracers and virus occurrence was identified. Presence of infectious viruses at the wellhead demonstrates that high-capacity pumping induced sufficiently short travel times for the transport of infectious viruses. Therefore, drinking-water wells are vulnerable to contaminants that travel along fast groundwater flowpaths even if they contribute a small amount of virus-laden water to the well. These results suggest that vulnerability assessments require characterization of "low yield-fast transport" in addition to traditional "high yield-slow transport", pathways. ?? 2010 American Chemical Society.

Co-production of biochar, bio-oil and syngas from halophyte grass (Achnatherum splendens L.) under three different pyrolysis temperatures.

PubMed

Irfan, Muhammad; Chen, Qun; Yue, Yan; Pang, Renzhong; Lin, Qimei; Zhao, Xiaorong; Chen, Hao

2016-07-01

In the present study, pyrolysis of Achnatherum splendens L. was performed under three different pyrolysis temperature (300, 500, and 700°C) to investigate the characteristics of biochar, bio-oil, and syngas. Biochar yield decreased from 48% to 24%, whereas syngas yield increased from 34% to 54% when pyrolysis temperature was increased from 300 to 700°C. Maximum bio-oil yield (27%) was obtained at 500°C. The biochar were characterized for elemental composition, surface, and adsorption properties. The results showed that obtained biochar could be used as a potential soil amendment. The bio-oil and syngas co-products will be evaluated in the future as bioenergy sources. Overall, our results suggests that A. splendens L. could be utilized as a potential feedstock for biochar and bioenergy production through pyrolytic route. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Nonlinear Optical Properties of Traditional and Novel Materials

NASA Astrophysics Data System (ADS)

Krupa, Sean J.

Nonlinear optical processes are an excellent candidate to provide the heralded, indistinguishable, or entangled photons necessary for development of quantum mechanics based technology which currently lack bright sources of these photons. In order to support these technologies, and others, two classes of materials: traditional and novel, were investigated via optical characterization methods with goal of gaining insight into which materials and experimental conditions yield the greatest nonlinear optical effects. Optical characterization of periodically poled lithium niobate (PPLN) helped support the development of a simple, efficient photon pair source that could be easily integrated into optical networks. Additionally, an in-situ measurement of the 2nd order nonlinear optical coefficient was developed to aid in the characterization of PPLN pair sources. Lastly, an undergraduate demonstration of quantum key distribution was constructed such that students could see the primary application for PPLN photon pair sources in an affordable, approachable demonstration. A class of novel optical materials known as 2D materials has been identified as potential replacements to the traditional nonlinear optical materials discussed in Part I. Through optical characterization of second harmonic generation (SHG) the ideal conditions for spontaneous parametric downconversion were established as well as signal thresholds for successful detection. Attempts to observe SPDC produces hints that weak generate SPDC may be present in WS2 samples however this is incredibly difficult to confirm. As growth techniques of 2D materials improve, a photonic device constructed from these materials may be possible, however it will need some mechanism e.g. stacking, a cavity, etc. to help enhance the SPDC signal.

Characterization of indoor aerosol temporal variations for the real-time management of indoor air quality

NASA Astrophysics Data System (ADS)

Ciuzas, Darius; Prasauskas, Tadas; Krugly, Edvinas; Sidaraviciute, Ruta; Jurelionis, Andrius; Seduikyte, Lina; Kauneliene, Violeta; Wierzbicka, Aneta; Martuzevicius, Dainius

2015-10-01

The study presents the characterization of dynamic patterns of indoor particulate matter (PM) during various pollution episodes for real-time IAQ management. The variation of PM concentrations was assessed for 20 indoor activities, including cooking related sources, other thermal sources, personal care and household products. The pollution episodes were modelled in full-scale test chamber representing a standard usual living room with the forced ventilation of 0.5 h-1. In most of the pollution episodes, the maximum concentration of particles in exhaust air was reached within a few minutes. The most rapid increase in particle concentration was during thermal source episodes such as candle, cigarette, incense stick burning and cooking related sources, while the slowest decay of concentrations was associated with sources, emitting ultrafine particle precursors, such as furniture polisher spraying, floor wet mopping with detergent etc. Placement of the particle sensors in the ventilation exhaust vs. in the centre of the ceiling yielded comparable results for both measured maximum concentrations and temporal variations, indicating that both locations were suitable for the placement of sensors for the management of IAQ. The obtained data provides information that may be utilized considering measurements of aerosol particles as indicators for the real-time management of IAQ.

A panorama of bacterial inulinases: Production, purification, characterization and industrial applications.

PubMed

Singh, Ram Sarup; Chauhan, Kanika; Kennedy, John F

2017-03-01

Inulinases are important hydrolysing enzymes which specifically act on β-2, 1 linkages of inulin to produce fructose or fructooligosaccharides. Fungi, yeasts and bacteria are the potent microbial sources of inulinases. The data on bacterial inulinases is scarce as compared to other microbial sources. Inulinases yield from bacteria is very less as compared to fungal and yeast sources of inulinases. Submerged fermentation (SmF) is the method of choice for the production of inulinases from bacterial sources. Moreover, inulin is a potent substrate for the production of inulinases in SmF. Many bacterial inulinases have been reported to display magnificent environment abiding features and variability in their biophysical and biochemical properties. These properties have attracted intention of many researchers towards exploring adverse ecological niches for more distinctive inulinase producing bacterial strains. Inulinases are substantially important in current biotechnological era due to their numerous industrial applications. High fructose syrup and fructooligosaccharides are two major industrial applications of inulinases. Additionally, there are many reports on the production of various metabolites like citric acid, lactic acid, ethanol, biofuels, butanediol etc. using mixed cultures of inulinase producing organisms with other microorganisms. The present review mainly envisages inulinase producing bacterial sources, inulinase production, purification, characterization and their applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization and fabrication of target materials for RIB generation

NASA Astrophysics Data System (ADS)

Welton, R. F.; Janney, M. A.; Mueller, P. E.; Ortman, W. K.; Rauniyar, R.; Stracener, D. W.; Williams, C. L.

2001-07-01

This report discusses two techniques developed at the Oak Ridge National Laboratory (ORNL) that are employed for the fabrication and characterization of targets used in the production of Radioactive Ion Beams (RIBs). First, our method of in-house fabrication of uranium carbide targets is discussed. We have found that remarkably uniform coatings of UC2 can be formed on the microstructure of porous C matrices. The technique has been used to form UC2 layers on highly thermally conductive graphitic foams. Targets fabricated in this fashion have been tested under low-intensity proton bombardment and yields of selected radioactive species are reported. This report also describes an off-line test stand for the investigation of effusive and diffusive transport in RIB target/ion sources. Permeation rates of gases and vapors passing through a high temperature membrane or through an effusive channel constructed from the material under investigation are recorded. Diffusion coefficients and adsorption enthalpies, which characterize the interaction of RIB species with materials of the target/ion source, are extracted from the time profile of the recorded data. Examples of diffusion, effusion, and conductance measurements are provided.

Characterize kinematic rupture history of large earthquakes with Multiple Haskell sources

NASA Astrophysics Data System (ADS)

Jia, Z.; Zhan, Z.

2017-12-01

Earthquakes are often regarded as continuous rupture along a single fault, but the occurrence of complex large events involving multiple faults and dynamic triggering challenges this view. Such rupture complexities cause difficulties in existing finite fault inversion algorithms, because they rely on specific parameterizations and regularizations to obtain physically meaningful solutions. Furthermore, it is difficult to assess reliability and uncertainty of obtained rupture models. Here we develop a Multi-Haskell Source (MHS) method to estimate rupture process of large earthquakes as a series of sub-events of varying location, timing and directivity. Each sub-event is characterized by a Haskell rupture model with uniform dislocation and constant unilateral rupture velocity. This flexible yet simple source parameterization allows us to constrain first-order rupture complexity of large earthquakes robustly. Additionally, relatively few parameters in the inverse problem yields improved uncertainty analysis based on Markov chain Monte Carlo sampling in a Bayesian framework. Synthetic tests and application of MHS method on real earthquakes show that our method can capture major features of large earthquake rupture process, and provide information for more detailed rupture history analysis.

Green separation and characterization of fatty acids from solid wastes of leather industry in supercritical fluid CO2.

PubMed

Onem, Ersin; Renner, Manfred; Prokein, Michael

2018-05-26

Considerable tannery waste is generated by leather industry around the world. Recovery of the value-added products as natural fats from the solid wastes gained interest of many researchers. In this study, supercritical fluid separation method was applied for the fatty acid isolation from leather industry solid wastes. Pre-fleshing wastes of the double-face lambskins were used as natural fat source. Only supercritical CO 2 was used as process media without any solvent additive in high-pressure view cell equipment. The effect of different conditions was investigated for the best separation influence. The parameters of pressure (100 to 200 bar), temperature (40 to 80 °C), and time (1 to 3 h) were considered. Extraction yields and fat yields of the parameters were statistically evaluated after the processes. Maximum 78.57 wt% fat yield was obtained from leather industry fleshings in supercritical fluid CO 2 at 200 bar, 80 °C, and 2 h. Morever, conventional Soxhlet and supercritical CO 2 extracted fatty acids were characterized by using gas chromatography (GC) coupled with mass spectrometry (MS) and flame ionization detector (FID). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) characterizations were also done. The results showed that supercritical fluid CO 2 extraction was highly effective for the fat separation as green solvent and leather industry tannery wastes could be used for the value-added products.

GT0 Explosion Sources for IMS Infrasound Calibration: Charge Design and Yield Estimation from Near-source Observations

NASA Astrophysics Data System (ADS)

Gitterman, Y.; Hofstetter, R.

2014-03-01

Three large-scale on-surface explosions were conducted by the Geophysical Institute of Israel (GII) at the Sayarim Military Range, Negev desert, Israel: about 82 tons of strong high explosives in August 2009, and two explosions of about 10 and 100 tons of ANFO explosives in January 2011. It was a collaborative effort between Israel, CTBTO, USA and several European countries, with the main goal to provide fully controlled ground truth (GT0) infrasound sources, monitored by extensive observations, for calibration of International Monitoring System (IMS) infrasound stations in Europe, Middle East and Asia. In all shots, the explosives were assembled like a pyramid/hemisphere on dry desert alluvium, with a complicated explosion design, different from the ideal homogenous hemisphere used in similar experiments in the past. Strong boosters and an upward charge detonation scheme were applied to provide more energy radiated to the atmosphere. Under these conditions the evaluation of the actual explosion yield, an important source parameter, is crucial for the GT0 calibration experiment. Audio-visual, air-shock and acoustic records were utilized for interpretation of observed unique blast effects, and for determination of blast wave parameters suited for yield estimation and the associated relationships. High-pressure gauges were deployed at 100-600 m to record air-blast properties, evaluate the efficiency of the charge design and energy generation, and provide a reliable estimation of the charge yield. The yield estimators, based on empirical scaled relations for well-known basic air-blast parameters—the peak pressure, impulse and positive phase duration, as well as on the crater dimensions and seismic magnitudes, were analyzed. A novel empirical scaled relationship for the little-known secondary shock delay was developed, consistent for broad ranges of ANFO charges and distances, which facilitates using this stable and reliable air-blast parameter as a new potential yield estimator. The delay data of the 2009 shot with IMI explosives, characterized by much higher detonation velocity, are clearly separated from ANFO data, thus indicating a dependence on explosive type. This unique dual Sayarim explosion experiment (August 2009/January 2011), with the strongest GT0 sources since the establishment of the IMS network, clearly demonstrated the most favorable westward/eastward infrasound propagation up to 3,400/6,250 km according to appropriate summer/winter weather pattern and stratospheric wind directions, respectively, and thus verified empirically common models of infrasound propagation in the atmosphere.

Critical Analyses of Data Differences Between FNMOC and AFGWC Spawned SSM/I Datasets

NASA Technical Reports Server (NTRS)

Ritchie, Adrian A., Jr.; Smith, Matthew R.; Goodman, H. Michael; Schudalla, Ronald L.; Conway, Dawn K.; LaFontaine, Frank J.; Moss, Don; Motta, Brian

1998-01-01

Antenna temperatures and the corresponding geolocation data from the five sources of the Special Sensor Microwave/Imager data from the Defense Meteorological Satellite Program F11 satellite have been characterized. Data from the Fleet Numerical Meteorology and Oceanography Center (FNMOC) have been compared with data from other sources to define and document the differences resulting from different processing systems. While all sources used similar methods to calculate antenna temperatures, different calibration averaging techniques and other processing methods yielded temperature differences. Analyses of the geolocation data identified perturbations in the FNMOC and National Environmental Satellite, Data and Information Service data. The effects of the temperature differences were examined by generating rain rates using the Goddard Scattering Algorithm. Differences in the geophysical precipitation products are directly attributable to antenna temperature differences.

Monochromatic body waves excited by great subduction zone earthquakes

NASA Astrophysics Data System (ADS)

Ihmlé, Pierre F.; Madariaga, Raúl

Large quasi-monochromatic body waves were excited by the 1995 Chile Mw=8.1 and by the 1994 Kurile Mw=8.3 events. They are observed on vertical/radial component seismograms following the direct P and Pdiff arrivals, at all azimuths. We devise a slant stack algorithm to characterize the source of the oscillations. This technique aims at locating near-source isotropic scatterers using broadband data from global networks. For both events, we find that the oscillations emanate from the trench. We show that these monochromatic waves are due to localized oscillations of the water column. Their period corresponds to the gravest ID mode of a water layer for vertically traveling compressional waves. We suggest that these monochromatic body waves may yield additional constraints on the source process of great subduction zone earthquakes.

Heat exchanger-ingot casting/slicing process, phase 1: Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

NASA Technical Reports Server (NTRS)

Schmid, F.; Khattak, C. P.

1977-01-01

A controlled growth, heat-flow and cool-down process is described that yielded silicon with a high degree of single crystallinity. Even when the seed melted out, very large grains formed. Solar cell samples made from cast material yielded conversion efficiency of over 9%. Representative characterizations of grown silicon demonstrated a dislocation density of less than 100/sq cm and a minority carrier diffusion length of 31 micron. The source of silicon carbide in silicon ingots was identified to be from graphite retainers in contact with silica crucibles. Higher growth rates were achieved with the use of a graphite plug at the bottom of the silica crucible.

An efficient laser vaporization source for chemically modified metal clusters characterized by thermodynamics and kinetics

NASA Astrophysics Data System (ADS)

Masubuchi, Tsugunosuke; Eckhard, Jan F.; Lange, Kathrin; Visser, Bradley; Tschurl, Martin; Heiz, Ulrich

2018-02-01

A laser vaporization cluster source that has a room for cluster aggregation and a reactor volume, each equipped with a pulsed valve, is presented for the efficient gas-phase production of chemically modified metal clusters. The performance of the cluster source is evaluated through the production of Ta and Ta oxide cluster cations, TaxOy+ (y ≥ 0). It is demonstrated that the cluster source produces TaxOy+ over a wide mass range, the metal-to-oxygen ratio of which can easily be controlled by changing the pulse duration that influences the amount of reactant O2 introduced into the cluster source. Reaction kinetic modeling shows that the generation of the oxides takes place under thermalized conditions at less than 300 K, whereas metal cluster cores are presumably created with excess heat. These characteristics are also advantageous to yield "reaction intermediates" of interest via reactions between clusters and reactive molecules in the cluster source, which may subsequently be mass selected for their reactivity measurements.

Endophytic Fungi—Alternative Sources of Cytotoxic Compounds: A Review

PubMed Central

Uzma, Fazilath; Mohan, Chakrabhavi D.; Hashem, Abeer; Konappa, Narasimha M.; Rangappa, Shobith; Kamath, Praveen V.; Singh, Bhim P.; Mudili, Venkataramana; Gupta, Vijai K.; Siddaiah, Chandra N.; Chowdappa, Srinivas; Alqarawi, Abdulaziz A.; Abd_Allah, Elsayed F.

2018-01-01

Cancer is a major cause of death worldwide, with an increasing number of cases being reported annually. The elevated rate of mortality necessitates a global challenge to explore newer sources of anticancer drugs. Recent advancements in cancer treatment involve the discovery and development of new and improved chemotherapeutics derived from natural or synthetic sources. Natural sources offer the potential of finding new structural classes with unique bioactivities for cancer therapy. Endophytic fungi represent a rich source of bioactive metabolites that can be manipulated to produce desirable novel analogs for chemotherapy. This review offers a current and integrative account of clinically used anticancer drugs such as taxol, podophyllotoxin, camptothecin, and vinca alkaloids in terms of their mechanism of action, isolation from endophytic fungi and their characterization, yield obtained, and fungal strain improvement strategies. It also covers recent literature on endophytic fungal metabolites from terrestrial, mangrove, and marine sources as potential anticancer agents and emphasizes the findings for cytotoxic bioactive compounds tested against specific cancer cell lines. PMID:29755344

Quantitative electron density characterization of soft tissue substitute plastic materials using grating-based x-ray phase-contrast imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarapata, A.; Chabior, M.; Zanette, I.

2014-10-15

Many scientific research areas rely on accurate electron density characterization of various materials. For instance in X-ray optics and radiation therapy, there is a need for a fast and reliable technique to quantitatively characterize samples for electron density. We present how a precise measurement of electron density can be performed using an X-ray phase-contrast grating interferometer in a radiographic mode of a homogenous sample in a controlled geometry. A batch of various plastic materials was characterized quantitatively and compared with calculated results. We found that the measured electron densities closely match theoretical values. The technique yields comparable results between amore » monochromatic and a polychromatic X-ray source. Measured electron densities can be further used to design dedicated X-ray phase contrast phantoms and the additional information on small angle scattering should be taken into account in order to exclude unsuitable materials.« less

Reconstruction of anthropogenic activities on the excavations of a fireplace sequence from the Krems-Wachtberg site (Austria) using molecular proxies

NASA Astrophysics Data System (ADS)

Wiesenberg, Guido; Hambach, Ulrich

2010-05-01

The well investigated Krems-Wachtberg excavation yielded a broad variety of anthropogenic artefacts and thus enables a proper reconstruction of an ancient settlement of Upper-Palaeolithic age. Despite these artefacts, some questions cannot be answered by sedimentologic and archaeologic approaches. Molecular fossils like lipids including aliphatic hydrocarbons are suitable to improve understanding of e.g. paleoclimatic, pedogenetic, and archaeologic contexts. Especially aliphatic hydrocarbons including straight-chain and branched alkanes yield potential to elucidate biogenic sources of soil and loess organic matter and to assess degradation conditions of primary organic matter. To improve understanding on the terms the fireplaces at the Krems-Wachtberg site are used, aliphatic hydrocarbons are investigated on a set of samples covering several horizons in the context of one fireplace, which was part of the excavation. Horizons above and below the fireplace as well as the fireplace itself were investigated for lipids. Additionally, reference loess samples from a similar age like the fireplace and a pit filling were investigated. Two replicates were available for most samples except for the pit filling. Two distinct fireplace series have been studies. All samples were extracted for lipids using Soxhlet extraction followed by column chromatography in order to separate the aliphatic hydrocarbon fraction from other lipids. Thereafter, aliphatic hydrocarbons were quantified using gas chromatography. The total amounts of extractable organic compounds in the whole sample set from the Krems-Wachtberg site were in the range of usual loess deposits and accounted for 30-80 mg kg-1 loess. The largest contents were observed in reference loess samples and decreased within the excavation from fireplaces > sediments covering fireplace > basement of fireplace > pit. The lower the extract yields, the stronger was the degradation of organic matter. In this context, the pit yielded either organic matter that was strongly degraded during rotting process of organic material after burial or incorporation of already strongly degraded organic matter like ash from fireplaces. The basement of the fireplace was exposed to high temperature for the whole usage of the place, resulting in a modification in the structure of the sediments and a degradation of organic matter within the sediments. The material from the fireplace itself probably was not completely burned and thus yielded comparatively large amounts of extractable components. The sediments covering the fireplace were potentially used to extinguish the fire and hence received a thermal alteration of the organic matter within the sediment under oxygen limiting conditions. Hence, the amount of extractable organic compounds can be used to reconstruct the firing process in the Krems-Wachtberg excavation. The amount of individual aliphatic hydrocarbons parallels the content of all extractable compounds and thus confirms the findings explained above. The aliphatic hydrocarbons reveal typical distribution patterns for grassland vegetation as indicated by a strong predomination of odd long chain alkanes and n-C31 as the most abundant homologue for most samples. Only sediments covering the fireplaces are dominated by n-C29 alkane. The different alkane distribution pattern for these sediments compared to all other samples including reference loess indicates a different biogenic source of the covering sediment than for all other samples. Probably, the covering sediments yield organic matter incorporated under forest or different grassland vegetation than the other sediments. In this study, several molecular markers have been tested for aliphatic hydrocarbons in order to elucidate their sources and to identify degradation effects responsible for the determined distribution patterns. The ratio of long chain vs. short chain alkanes enables the differentiation of plant-derived organic matter characterized by high ratios (>10) and organic matter derived from microbial biomass or degradation (<10). The reference loess samples were characterized by very high values (>50), which indicates plant biomass as the predominant source of loess organic matter. All other samples were characterized by low values (<10), which is due to degradation effects. Microbial alkanes as second potential source of short chain n-alkanes are not likely as odd homologues did not predominate over even homologues, which is typical for microbial alkanes. Furthermore even alkanes dominated in most samples, which can be related to thermal alteration of organic matter as common in fireplaces. Other degradation markers like n-alkanes vs. isoprenoid alkanes (n-C18/phytane) revealed values between 2-4.5. The fireplace samples were characterized by lowest values whereas the reference samples yielded highest values. Hence degradation increased from loess towards fireplace with an intermediate degradation of most other samples. Aliphatic hydrocarbon biomarkers like alkanes were found useful to reconstruct degradation intensity in ancient sediments and to elucidate anthropogenic activities like extinguishing of fire. Hence, organic geochemical investigations can be useful techniques to complement standard archaeological techniques.

Surface-plasmon resonance-enhanced multiphoton emission of high-brightness electron beams from a nanostructured copper cathode.

PubMed

Li, R K; To, H; Andonian, G; Feng, J; Polyakov, A; Scoby, C M; Thompson, K; Wan, W; Padmore, H A; Musumeci, P

2013-02-15

We experimentally investigate surface-plasmon assisted photoemission to enhance the efficiency of metallic photocathodes for high-brightness electron sources. A nanohole array-based copper surface was designed to exhibit a plasmonic response at 800 nm, fabricated using the focused ion beam milling technique, optically characterized and tested as a photocathode in a high power radio frequency photoinjector. Because of the larger absorption and localization of the optical field intensity, the charge yield observed under ultrashort laser pulse illumination is increased by more than 100 times compared to a flat surface. We also present the first beam characterization results (intrinsic emittance and bunch length) from a nanostructured photocathode.

Systems Level Regulation of Rhythmic Growth Rate and Biomass Accumulation in Grasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kay, Steve A.; Hazen, Samuel; Mullet, John

Critical to the development of renewable energy sources from biofuels is the improvement of biomass from energy feedstocks, such as sorghum and maize. The specific goals of this project include 1) characterize the growth and gene expression patterns under diurnal and circadian conditions, 2) select transcription factors associated with growth and build a cis-regulatory network in yeast, and 3) perturb these transcription factors in planta using transgenic Brachypodium and sorghum, and characterize the phenotypic outcomes as they relate to biomass accumulation. A better understanding of diurnally regulated growth behavior in grasses may lead to species-specific mechanisms highly relevant to futuremore » strategies to optimize energy crop biomass yield.« less

Method for silicon carbide production by reacting silica with hydrocarbon gas

DOEpatents

Glatzmaier, G.C.

1994-06-28

A method is described for producing silicon carbide particles using a silicon source material and a hydrocarbon. The method is efficient and is characterized by high yield. Finely divided silicon source material is contacted with hydrocarbon at a temperature of 400 C to 1000 C where the hydrocarbon pyrolyzes and coats the particles with carbon. The particles are then heated to 1100 C to 1600 C to cause a reaction between the ingredients to form silicon carbide of very small particle size. No grinding of silicon carbide is required to obtain small particles. The method may be carried out as a batch process or as a continuous process. 5 figures.

Method for silicon carbide production by reacting silica with hydrocarbon gas

DOEpatents

Glatzmaier, Gregory C.

1994-01-01

A method is described for producing silicon carbide particles using a silicon source material and a hydrocarbon. The method is efficient and is characterized by high yield. Finely divided silicon source material is contacted with hydrocarbon at a temperature of 400.degree. C. to 1000.degree. C. where the hydrocarbon pyrolyzes and coats the particles with carbon. The particles are then heated to 1100.degree. C. to 1600.degree. C. to cause a reaction between the ingredients to form silicon carbide of very small particle size. No grinding of silicon carbide is required to obtain small particles. The method may be carried out as a batch process or as a continuous process.

Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs

NASA Technical Reports Server (NTRS)

McGlynn, Thomas; Suchkov, A. A.; Winter, E. L.; Hanisch, R. J.; White, R. L.; Ochsenbein, F.; Derriere, S.; Voges, W.; Corcoran, M. F.

2004-01-01

We describe an on-line system for automated classification of X-ray sources, ClassX, and present preliminary results of classification of the three major catalogs of ROSAT sources, RASS BSC, RASS FSC, and WGACAT, into six class categories: stars, white dwarfs, X-ray binaries, galaxies, AGNs, and clusters of galaxies. ClassX is based on a machine learning technology. It represents a system of classifiers, each classifier consisting of a considerable number of oblique decision trees. These trees are built as the classifier is 'trained' to recognize various classes of objects using a training sample of sources of known object types. Each source is characterized by a preselected set of parameters, or attributes; the same set is then used as the classifier conducts classification of sources of unknown identity. The ClassX pipeline features an automatic search for X-ray source counterparts among heterogeneous data sets in on-line data archives using Virtual Observatory protocols; it retrieves from those archives all the attributes required by the selected classifier and inputs them to the classifier. The user input to ClassX is typically a file with target coordinates, optionally complemented with target IDs. The output contains the class name, attributes, and class probabilities for all classified targets. We discuss ways to characterize and assess the classifier quality and performance and present the respective validation procedures. Based on both internal and external validation, we conclude that the ClassX classifiers yield reasonable and reliable classifications for ROSAT sources and have the potential to broaden class representation significantly for rare object types.

Production of bacterial cellulose using different carbon sources and culture media.

PubMed

Mohammadkazemi, Faranak; Azin, Mehrdad; Ashori, Alireza

2015-03-06

In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) have been studied. BC nanofibers were synthesized using Gluconacetobacter xylinus strain PTCC 1734. Media used were Hestrin-Schramm (H), Yamanaka (Y), and Zhou (Z). Five different carbon sources, namely date syrup, glucose, mannitol, sucrose, and food-grade sucrose were used in these media. All the produced BC pellicles were characterized in terms of dry weight production, biomass yield, thermal stability, crystallinity and morphology by thermogravimetric analysis (TGA), x-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). The obtained results showed that mannitol lead to the highest yield, followed by sucrose. The highest production efficiency of mannitol might be due to the nitrogen source, which plays an important role. The maximum improvement on the thermal stability of the composites was achieved when mannitol was used in H medium. In addition, the crystallinity was higher in BC formed in H medium compared to other media. FE-SEM micrographs illustrated that the BC pellicles, synthesized in the culture media H and Z, were stable, unlike those in medium Y that were unstable. The micrographs of BC produced in media containing mannitol and sucrose provided evidence of the strong interfacial adhesion between the BC fibers without noticeable aggregates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Production and characterization of a novel antifungal chitinase identified by functional screening of a suppressive-soil metagenome.

PubMed

Berini, Francesca; Presti, Ilaria; Beltrametti, Fabrizio; Pedroli, Marco; Vårum, Kjell M; Pollegioni, Loredano; Sjöling, Sara; Marinelli, Flavia

2017-01-31

Through functional screening of a fosmid library, generated from a phytopathogen-suppressive soil metagenome, the novel antifungal chitinase-named Chi18H8 and belonging to family 18 glycosyl hydrolases-was previously discovered. The initial extremely low yield of Chi18H8 recombinant production and purification from Escherichia coli cells (21 μg/g cell) limited its characterization, thus preventing further investigation on its biotechnological potential. We report on how we succeeded in producing hundreds of milligrams of pure and biologically active Chi18H8 by developing and scaling up to a high-yielding, 30 L bioreactor process, based on a novel method of mild solubilization of E. coli inclusion bodies in lactic acid aqueous solution, coupled with a single step purification by hydrophobic interaction chromatography. Chi18H8 was characterized as a Ca 2+ -dependent mesophilic chitobiosidase, active on chitin substrates at acidic pHs and possessing interesting features, such as solvent tolerance, long-term stability in acidic environment and antifungal activity against the phytopathogens Fusarium graminearum and Rhizoctonia solani. Additionally, Chi18H8 was found to operate according to a non-processive endomode of action on a water-soluble chitin-like substrate. Expression screening of a metagenomic library may allow access to the functional diversity of uncultivable microbiota and to the discovery of novel enzymes useful for biotechnological applications. A persisting bottleneck, however, is the lack of methods for large scale production of metagenome-sourced enzymes from genes of unknown origin in the commonly used microbial hosts. To our knowledge, this is the first report on a novel metagenome-sourced enzyme produced in hundreds-of-milligram amount by recovering the protein in the biologically active form from recombinant E. coli inclusion bodies.

Using Adaptive Optics Follow-up to Characterize Microlensing Exoplanets

NASA Astrophysics Data System (ADS)

Henderson, Calen; Beichman, Charles; Shvartzvald, Yossi

2018-01-01

The mass and distance of a microlens are degenerate, thus requiring at least two relations to yield a unique solution. Measuring the finite-source effect from the light curve helps provide one mass-distance relation for the lens system. Currently, the primary avenue for establishing a second relation and thus uniquely solving for the mass and distance of the lens is by measuring the microlens parallax. One specific implementation is the satellite parallax technique, which involves taking observations simultaneously from two locations separated by a significant fraction of an AU, and which has been employed by Spitzer and K2's Campaign 9, transforming this methodology from a cottage industry to a booming economy. However, the majority of microlensing exoplanets to be discovered in the coming decades, up to and including the detections predicted for WFIRST, will not have a measurement of the satellite parallax, requiring another avenue for converting microlensing observables into physical parameters. Enter the lens flux characterization technique, through which a microlensing target is observed with a high-resolution facility, facilitating a constraint on the flux from the lens system. This yields a third mass-distance relation for the lens and can be combined with that from the detection of finite-source effects and/or the microlens parallax to determine the mass of the lens system as well as its distance from Earth. I will highlight recent programs using NIRC2 on Keck that are designed to make lens flux measurements for a myriad of exoplanetary lenses, including: (A) systems with high blend flux, which adaptive optics is perfectly suited to resolve; (B) systems with high relative lens-source proper motion; (C) free-floating planet candidates; and (D) bound exoplanets.

Characterizing Sorghum Panicles using 3D Point Clouds

NASA Astrophysics Data System (ADS)

Lonesome, M.; Popescu, S. C.; Horne, D. W.; Pugh, N. A.; Rooney, W.

2017-12-01

To address demands of population growth and impacts of global climate change, plant breeders must increase crop yield through genetic improvement. However, plant phenotyping, the characterization of a plant's physical attributes, remains a primary bottleneck in modern crop improvement programs. 3D point clouds generated from terrestrial laser scanning (TLS) and unmanned aerial systems (UAS) based structure from motion (SfM) are a promising data source to increase the efficiency of screening plant material in breeding programs. This study develops and evaluates methods for characterizing sorghum (Sorghum bicolor) panicles (heads) in field plots from both TLS and UAS-based SfM point clouds. The TLS point cloud over experimental sorghum field at Texas A&M farm in Burleston County TX were collected using a FARO Focus X330 3D laser scanner. SfM point cloud was generated from UAS imagery captured using a Phantom 3 Professional UAS at 10m altitude and 85% image overlap. The panicle detection method applies point cloud reflectance, height and point density attributes characteristic of sorghum panicles to detect them and estimate their dimensions (panicle length and width) through image classification and clustering procedures. We compare the derived panicle counts and panicle sizes with field-based and manually digitized measurements in selected plots and study the strengths and limitations of each data source for sorghum panicle characterization.

Analysis of commercial proanthocyanidins. Part 4: solid state (13)C NMR as a tool for in situ analysis of proanthocyanidin tannins, in heartwood and bark of quebracho and acacia, and related species.

PubMed

Reid, David G; Bonnet, Susan L; Kemp, Gabre; van der Westhuizen, Jan H

2013-10-01

(13)C NMR is an effective method of characterizing proanthocyanidin (PAC) tannins in quebracho (Schinopsis lorentzii) heartwood and black wattle (Acacia mearnsii) bark, before and after commercial extraction. The B-rings of the constituent flavan-3-ols, catechols (quebracho) or pyrogallols (wattle), are recognized in unprocessed source materials by "marker" signals at ca. 118 or 105ppm, respectively. NMR allows the minimum extraction efficiency to be calculated; ca. 30%, and ca. 80%, for quebracho heartwood and black wattle bark, respectively. NMR can also identify PAC tannin (predominantly robinetinidin), and compare tannin content, in bark from other acacia species; tannin content decreases in the order A. mearnsii, Acacia pycnantha (87% of A. mearnsii), Acacia dealbata and Acacia decurrens (each 74%) and Acacia karroo (30%). Heartwood from an underexploited PAC tannin source, Searsia lancea, taxonomically close to quebracho, shows abundant profisetinidin and catechin PACs. NMR offers the advantage of being applicable to source materials in their native state, and has potential applications in optimizing extraction processes, identification of tannin sources, and characterization of tannin content in cultivar yield improvement programmes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation and characterization of polymeric nanoparticles from Gadong starch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sisika, Regina; Ahmad, Wan Yaacob Wan; Lazim, Azwan Mat

Dioscorea hispida (Gadong tuber) was seldom used and forgotten as a food source due to their toxicity. In contrast to that, the Gadong tuber can be a source of polysaccharides which can be manipulated as an alternative source for industrial applications. This research reported on how to synthesize starch nanoparticles from Gadong tuber by using a simple acid hydrolysis process. The yield of starch nanoparticles obtained from seven days of acid hydrolysis was reduced to 13%. The X-ray diffraction measurements showed that the native Gadong starch particle is of the C-crystalline type, and that the synthesized nanoparticles showed an increasemore » in crystallinity compared to the native particles. Transmission electron microscopy results demonstrated that the starch particle morphologies were either round or irregular shape, with diameters ranging from 96-110 nm.« less

Deep UV emitting scintillators for alpha and beta particle detection

NASA Astrophysics Data System (ADS)

Zhou, Y.; Jia, D. D.; Lewis, L. A.; Feofilov, S. P.; Meltzer, R. S.

2011-03-01

Several deep UV emitting scintillators, whose emission falls in the solar blind region of the spectrum (200-280 nm), are described and their scintillator properties are characterized. They include LaPO 4:Pr, YPO 4:Pr, YAlO 3:Pr, Pr(PO 3) 3, YPO 4:Bi and ScPO 4. These materials would facilitate the detection of ionizing radiation in open areas, even during the daylight hours, and could be used to support large area surveys that monitor for the presence of ionization radiation due, for example, to system leaks or transfer contamination. These materials can be used in the form of powders, thin films or paints for radiation detection. They are characterized for both beta radiation using electron beams (2-35 keV) and 137Cs and alpha radiations using 241Am sources. Their absolute light yields are estimated and are compared to that of Y 2SiO 5:Ce. Their light yields decrease as a function of electron energy but at 10 keV they approach 8000 ph/MeV.

Electrodeposition of actinide compounds from an aqueous ammonium acetate matrix. Experimental development and optimization

DOE PAGES

Boll, Rose Ann; Matos, Milan; Torrico, Matthew N.

2015-03-27

Electrodeposition is a technique that is routinely employed in nuclear research for the preparation of thin solid films of actinide materials which can be used in accelerator beam bombardments, irradiation studies, or as radioactive sources. The present study investigates the deposition of both lanthanides and actinides from an aqueous ammonium acetate electrolyte matrix. Electrodepositions were performed primarily on stainless steel disks; with yield analysis evaluated using -spectroscopy. Experimental parameters were studied and modified in order to optimize the uniformity and adherence of the deposition while maximizing the yield. The initial development utilized samarium as the plating material, with and withoutmore » a radioactive tracer. As a result, surface characterization studies were performed by scanning electron microscopy, electron microprobe analysis, radiographic imaging, and x-ray diffraction.« less

Mechanical characterization of metallic nanowires by using a customized atomic microscope

NASA Astrophysics Data System (ADS)

Celik, Emrah

A new experimental method to characterize the mechanical properties of metallic nanowires is introduced. An accurate and fast mechanical characterization of nanowires requires simultaneous imaging and testing of nanowires. However, there exists no practical experimental procedure in the literature that provides a quantitative mechanical analysis and imaging of the nanowire specimens during mechanical testing. In this study, a customized atomic force microscope (AFM) is placed inside a scanning electron microscope (SEM) in order to locate the position of the nanowires. The tip of the atomic force microscope cantilever is utilized to bend and break the nanowires. The nanowires are prepared by electroplating of nickel ions into the nanoscale pores of the alumina membranes. Force versus bending displacement responses of these nanowires are measured experimentally and then compared against those of the finite element analysis and peridynamic simulations to extract their mechanical properties through an inverse approach. The average elastic modulus of nickel nanowires, which are extracted using finite element analysis and peridynamic simulations, varies between 220 GPa and 225 GPa. The elastic modulus of bulk nickel published in the literature is comparable to that of nickel nanowires. This observation agrees well with the previous findings on nanowires stating that the elastic modulus of nanowires with diameters over 100nm is similar to that of bulk counterparts. The average yield stress of nickel nanowires, which are extracted using finite element analysis and peridynamic simulations, is found to be between 3.6 GPa to 4.1 GPa. The average value of yield stress of nickel nanowires with 250nm diameter is significantly higher than that of bulk nickel. Higher yield stress of nickel nanowires observed in this study can be explained by the lower defect density of nickel nanowires when compared to their bulk counterparts. Deviation in the extracted mechanical properties is investigated by analyzing the major sources of uncertainty in the experimental procedure. The effects of the nanowire orientation, the loading position and the nanowire diameter on the mechanical test results are quantified using ANSYS simulations. Among all of these three sources of uncertainty investigated, the nanowire diameter has been found to have the most significant effect on the extracted mechanical properties.

Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration.

PubMed

Zhou, Jian; Rogers, Jason H; Lee, Scott H; Sun, DongMing; Yao, Hai; Mao, Jeremy J; Kong, Kimi Y

2017-01-15

Endothelial progenitor cells/endothelial cells (EPCs/ECs) have great potential to treat pathological conditions such as cardiac infarction, muscle ischemia, and bone fractures, but isolation of EPC/ECs from existing cell sources is challenging due to their low EC frequency. We have isolated endothelial progenitor (EP)-like cells from rat oral mucosa and characterized their yield, immunophenotype, growth, and in vivo angiogenic potential. The frequency of EP-like cells derived from oral mucosa is thousands of folds higher than EPCs derived from donor-match bone marrow samples. EP-like cells from oral mucosa were positive for EC markers CD31, VE-Cadherin, and VEGFR2. Oral mucosa-derived EP-like cells displayed robust uptake of acetylated low-density lipoprotein and formed stable capillary networks in Matrigel. Subcutaneously implanted oral mucosa-derived EP-like cells anastomosed with host blood vessels, implicating their ability to elicit angiogenesis. Similar to endothelial colony-forming cells, EP-like cells from oral mucosa have a significantly higher proliferative rate than human umbilical vein endothelial cells. These findings identify a putative EPC source that is easily accessible in the oral cavity, potentially from discarded tissue specimens, and yet with robust yield and potency for angiogenesis in tissue and organ regeneration.

Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration

PubMed Central

Zhou, Jian; Rogers, Jason H.; Lee, Scott H.; Sun, DongMing; Yao, Hai; Mao, Jeremy J.

2017-01-01

Endothelial progenitor cells/endothelial cells (EPCs/ECs) have great potential to treat pathological conditions such as cardiac infarction, muscle ischemia, and bone fractures, but isolation of EPC/ECs from existing cell sources is challenging due to their low EC frequency. We have isolated endothelial progenitor (EP)-like cells from rat oral mucosa and characterized their yield, immunophenotype, growth, and in vivo angiogenic potential. The frequency of EP-like cells derived from oral mucosa is thousands of folds higher than EPCs derived from donor-match bone marrow samples. EP-like cells from oral mucosa were positive for EC markers CD31, VE-Cadherin, and VEGFR2. Oral mucosa-derived EP-like cells displayed robust uptake of acetylated low-density lipoprotein and formed stable capillary networks in Matrigel. Subcutaneously implanted oral mucosa-derived EP-like cells anastomosed with host blood vessels, implicating their ability to elicit angiogenesis. Similar to endothelial colony-forming cells, EP-like cells from oral mucosa have a significantly higher proliferative rate than human umbilical vein endothelial cells. These findings identify a putative EPC source that is easily accessible in the oral cavity, potentially from discarded tissue specimens, and yet with robust yield and potency for angiogenesis in tissue and organ regeneration. PMID:27832737

Template-free solution approach to synthesize CdS dendrites with SCN based ionic liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Kangfeng; Li, Jiajia; Cheng, Xianyi

2011-07-15

Highlights: {yields} Template-free solution approach to synthesize CdS hierarchical dendrites. {yields} The 1-butyl-3-methlyimidazole thiocyanate ([BMIM][SCN]) plays doubly functional roles in the progress. {yields} The CdS hierarchical dendrites exhibit a more intense emission at 710 nm belongs to infrared band. -- Abstract: Cadmium sulfide dendrites were synthesized by a facile hydrothermal treatment from CdCl{sub 2} and ionic liquid 1-butyl-3-methlyimidazole thiocyanate acted both as sulfur source and surfactant. The product was characterized by means of X-ray powder diffraction and scanning electron microscopy. X-ray powder diffraction studies indicated that the product was well-crystallized hexagonal phase of CdS, and the scanning electron microscopy imagesmore » showed that the obtained powders consisted of a wealth of well-defined CdS dendritic microstructures with a pronounced trunk and highly ordered branches. The UV-Vis and photoluminescence spectroscopy measurements were taken as well. The possible formation mechanism of CdS dendrites was simply proposed in the end.« less

Simulation of fruit-set and trophic competition and optimization of yield advantages in six Capsicum cultivars using functional-structural plant modelling.

PubMed

Ma, Y T; Wubs, A M; Mathieu, A; Heuvelink, E; Zhu, J Y; Hu, B G; Cournède, P H; de Reffye, P

2011-04-01

Many indeterminate plants can have wide fluctuations in the pattern of fruit-set and harvest. Fruit-set in these types of plants depends largely on the balance between source (assimilate supply) and sink strength (assimilate demand) within the plant. This study aims to evaluate the ability of functional-structural plant models to simulate different fruit-set patterns among Capsicum cultivars through source-sink relationships. A greenhouse experiment of six Capsicum cultivars characterized with different fruit weight and fruit-set was conducted. Fruit-set patterns and potential fruit sink strength were determined through measurement. Source and sink strength of other organs were determined via the GREENLAB model, with a description of plant organ weight and dimensions according to plant topological structure established from the measured data as inputs. Parameter optimization was determined using a generalized least squares method for the entire growth cycle. Fruit sink strength differed among cultivars. Vegetative sink strength was generally lower for large-fruited cultivars than for small-fruited ones. The larger the size of the fruit, the larger variation there was in fruit-set and fruit yield. Large-fruited cultivars need a higher source-sink ratio for fruit-set, which means higher demand for assimilates. Temporal heterogeneity of fruit-set affected both number and yield of fruit. The simulation study showed that reducing heterogeneity of fruit-set was obtained by different approaches: for example, increasing source strength; decreasing vegetative sink strength, source-sink ratio for fruit-set and flower appearance rate; and harvesting individual fruits earlier before full ripeness. Simulation results showed that, when we increased source strength or decreased vegetative sink strength, fruit-set and fruit weight increased. However, no significant differences were found between large-fruited and small-fruited groups of cultivars regarding the effects of source and vegetative sink strength on fruit-set and fruit weight. When the source-sink ratio at fruit-set decreased, the number of fruit retained on the plant increased competition for assimilates with vegetative organs. Therefore, total plant and vegetative dry weights decreased, especially for large-fruited cultivars. Optimization study showed that temporal heterogeneity of fruit-set and ripening was predicted to be reduced when fruits were harvested earlier. Furthermore, there was a 20 % increase in the number of extra fruit set.

Omics approaches in food safety: fulfilling the promise?

PubMed Central

Bergholz, Teresa M.; Moreno Switt, Andrea I.; Wiedmann, Martin

2014-01-01

Genomics, transcriptomics, and proteomics are rapidly transforming our approaches to detection, prevention and treatment of foodborne pathogens. Microbial genome sequencing in particular has evolved from a research tool into an approach that can be used to characterize foodborne pathogen isolates as part of routine surveillance systems. Genome sequencing efforts will not only improve outbreak detection and source tracking, but will also create large amounts of foodborne pathogen genome sequence data, which will be available for data mining efforts that could facilitate better source attribution and provide new insights into foodborne pathogen biology and transmission. While practical uses and application of metagenomics, transcriptomics, and proteomics data and associated tools are less prominent, these tools are also starting to yield practical food safety solutions. PMID:24572764

Developing LED UV fluorescence sensors for online monitoring DOM and predicting DBPs formation potential during water treatment.

PubMed

Li, Wen-Tao; Jin, Jing; Li, Qiang; Wu, Chen-Fei; Lu, Hai; Zhou, Qing; Li, Ai-Min

2016-04-15

Online monitoring dissolved organic matter (DOM) is urgent for water treatment management. In this study, high performance size exclusion chromatography with multi-UV absorbance and multi-emission fluorescence scans were applied to spectrally characterize samples from 16 drinking water sources across Yangzi River and Huai River Watersheds. The UV absorbance indices at 254 nm and 280 nm referred to the same DOM components and concentration, and the 280 nm UV light could excite both protein-like and humic-like fluorescence. Hence a novel UV fluorescence sensor was developed out using only one UV280 light-emitting diode (LED) as light source. For all samples, enhanced coagulation was mainly effective for large molecular weight biopolymers; while anion exchange further substantially removed humic substances. During chlorination tests, UVA280 and UVA254 showed similar correlations with yields of disinfection byproducts (DBPs); the humic-like fluorescence obtained from LED sensors correlated well with both trihalomethanes and haloacetic acids yields, while the correlation between protein-like fluorescence and trihalomethanes was relatively poor. Anion exchange exhibited more reduction of DBPs yields as well as UV absorbance and fluorescence signals than enhanced coagulation. The results suggest that the LED UV fluorescence sensors are very promising for online monitoring DOM and predicting DBPs formation potential during water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Light yield and energy resolution studies for SoLid phase 1

NASA Astrophysics Data System (ADS)

Boursette, Delphine; SoLid Collaboration

2017-09-01

The SoLid experiment is searching for sterile neutrinos at a nuclear research reactor. It looks for inverse beta decays (producing a positron and a neutron in delayed coincidence) with a very segmented detector made of thousands of scintillating cubes. SoLid has a very innovative hybrid technology with two different scintillators which have different light emissions: polyvynil-toluene cubes (PVT) to detect the positrons and 6LiF:ZnS sheets on two faces of each PVT cube to detect the neutrons. It allows us to do an efficient pulse shape analysis to identify the signals from neutrons and positrons. The 288 kg detector prototype (SM1) took data in 2015. It demonstrated the detection principle and background rejection efficiency. The construction of SoLid phase I (˜ 1.5 t) has now started. To improve the energy resolution of SoLid phase I, we have tried to increase the light yield studying separately the two scintillators: PVT and ZnS. A test bench has been built to fully characterize and improve the neutron detection with the ZnS using an AmBe source. To study the positron light yield on the PVT, we have built another test bench with a 207Bi source. We have improved the design of the cubes, their wrapping or the type and the configuration of the fibers. We managed to increase the PVT light yield by about 66 % and improve the resolution of the positron energy on the test bench from 21 % to 16 % at 1 MeV.

Exploiting genetic diversity from landraces in wheat breeding for adaptation to climate change.

PubMed

Lopes, Marta S; El-Basyoni, Ibrahim; Baenziger, Peter S; Singh, Sukhwinder; Royo, Conxita; Ozbek, Kursad; Aktas, Husnu; Ozer, Emel; Ozdemir, Fatih; Manickavelu, Alagu; Ban, Tomohiro; Vikram, Prashant

2015-06-01

Climate change has generated unpredictability in the timing and amount of rain, as well as extreme heat and cold spells that have affected grain yields worldwide and threaten food security. Sources of specific adaptation related to drought and heat, as well as associated breeding of genetic traits, will contribute to maintaining grain yields in dry and warm years. Increased crop photosynthesis and biomass have been achieved particularly through disease resistance and healthy leaves. Similarly, sources of drought and heat adaptation through extended photosynthesis and increased biomass would also greatly benefit crop improvement. Wheat landraces have been cultivated for thousands of years under the most extreme environmental conditions. They have also been cultivated in lower input farming systems for which adaptation traits, particularly those that increase the duration of photosynthesis, have been conserved. Landraces are a valuable source of genetic diversity and specific adaptation to local environmental conditions according to their place of origin. Evidence supports the hypothesis that landraces can provide sources of increased biomass and thousand kernel weight, both important traits for adaptation to tolerate drought and heat. Evaluation of wheat landraces stored in gene banks with highly beneficial untapped diversity and sources of stress adaptation, once characterized, should also be used for wheat improvement. Unified development of databases and promotion of data sharing among physiologists, pathologists, wheat quality scientists, national programmes, and breeders will greatly benefit wheat improvement for adaptation to climate change worldwide. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Exoplanet Yield Estimation for Decadal Study Concepts using EXOSIMS

NASA Astrophysics Data System (ADS)

Morgan, Rhonda; Lowrance, Patrick; Savransky, Dmitry; Garrett, Daniel

2016-01-01

The anticipated upcoming large mission study concepts for the direct imaging of exo-earths present an exciting opportunity for exoplanet discovery and characterization. While these telescope concepts would also be capable of conducting a broad range of astrophysical investigations, the most difficult technology challenges are driven by the requirements for imaging exo-earths. The exoplanet science yield for these mission concepts will drive design trades and mission concept comparisons.To assist in these trade studies, the Exoplanet Exploration Program Office (ExEP) is developing a yield estimation tool that emphasizes transparency and consistent comparison of various design concepts. The tool will provide a parametric estimate of science yield of various mission concepts using contrast curves from physics-based model codes and Monte Carlo simulations of design reference missions using realistic constraints, such as solar avoidance angles, the observatory orbit, propulsion limitations of star shades, the accessibility of candidate targets, local and background zodiacal light levels, and background confusion by stars and galaxies. The python tool utilizes Dmitry Savransky's EXOSIMS (Exoplanet Open-Source Imaging Mission Simulator) design reference mission simulator that is being developed for the WFIRST Preliminary Science program. ExEP is extending and validating the tool for future mission concepts under consideration for the upcoming 2020 decadal review. We present a validation plan and preliminary yield results for a point design.

Mars Spark Source Prototype

NASA Technical Reports Server (NTRS)

Eichenberg, Dennis J.; Lindamood, Glenn R.; Weiland, Karen J.; VanderWal, Randall L.

1999-01-01

The Mars Spark Source Prototype (MSSP) hardware has been developed as part of a proof of concept system for the detection of trace metals such as lead, cadmium, and arsenic in Martian dusts and soils. A spark discharge produces plasma from a soil sample and detectors measure the optical emission from metals in the plasma that will allow their identification and quantification. Trace metal measurements are vital for the assessment of the potential toxicity of the Martian environment for human exploration. The current method of X-ray fluorescence can yield concentrations only of major species. Other instruments are incompatible with the volume, weight, and power constraints for a Mars mission. The instrument will be developed primarily for use in the Martian environment, but would be adaptable for terrestrial use in environmental monitoring. This paper describes the Mars Spark Source Prototype hardware, the results of the characterization tests, and future plans for hardware development.

Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source.

PubMed

Du, Yingchao; Yan, Lixin; Hua, Jianfei; Du, Qiang; Zhang, Zhen; Li, Renkai; Qian, Houjun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

2013-05-01

Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 × 10(6) per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented.

Source characteristics of the 3 September 2017, North Korean nuclear test (mb = 6.3) inferred from teleseismic forward modeling and regional waveform deconvolution of broadband P and Pn waves

NASA Astrophysics Data System (ADS)

Chaves, E. J.; Lay, T.; Voytan, D. P.

2017-12-01

On 3 September 2017, the Republic of North Korea conducted the sixth and largest declared underground nuclear test at the Punggye-ri test site. Estimates of yield (W) based on magnitude-yield calibrations for other test sites result in a wide range of yield estimates for the North Korean tests, due to uncertainty in the effects of site-specific coupling, likely overburial of the events, and poorly constrained crustal and mantle attenuation for the test site. The event produced good signal-to-noise broadband (BB) teleseismic P wave recordings at hundreds of stations along with high quality regional recordings. When using teleseismic data, robust estimation of W and depth of burial (DOB) must account for the biasing effects of laterally varying upper mantle attenuation (t*) on P waves, so we empirically determine a best choice of average t* by modeling remote observations. We assume a Mueller-Murphy source model for a granite medium to address the coupling issue. We compute synthetic Reduced Velocity Potential (RVP) seismograms for varying combinations of W and DOB for the 2017 event for a simple half-space case to account for possible overburial effects. RVPs are convolved with Futterman, constant operators, corrected for geometric spreading and receiver function, and then compared with teleseismic P wave displacement records from 435 BB seismic stations, pre-stacked in 26 azimuth and distance bins to suppress station effects. Our preliminary results for half-space modeling give high average cross-correlations and low waveform misfit errors between synthetic and observed waveforms for W of 110-130 kt with DOB 700-800 m and a preferred t* = 0.98 s. For the Mueller-Murphy model we find that frequency-dependent absorption band models are not preferred for this test site. Ongoing analysis is exploring effects of receiver crustal layering. Furthermore, we characterize the explosion source time function using the vertical component Pn-waves from regional BB recordings. We correct for attenuation, site and path effects using the lower yield nuclear tests carried out in 2016, 2013 and 2009 as empirical Green's functions. The deconvolved relative source functions exhibit a complex time sequence, with a second peak possibly related to a deviatoric source activated during the large explosion.

High duty cycle inverse Compton scattering X-ray source

DOE PAGES

Ovodenko, A.; Agustsson, R.; Babzien, M.; ...

2016-12-22

Inverse Compton Scattering (ICS) is an emerging compact X-ray source technology, where the small source size and high spectral brightness are of interest for multitude of applications. However, to satisfy the practical flux requirements, a high-repetition-rate ICS system needs to be developed. To this end, this article reports the experimental demonstration of a high peak brightness ICS source operating in a burst mode at 40 MHz. A pulse train interaction has been achieved by recirculating a picosecond CO 2 laser pulse inside an active optical cavity synchronized to the electron beam. The pulse train ICS performance has been characterized atmore » 5- and 15- pulses per train and compared to a single pulse operation under the same operating conditions. Lastly, with the observed near-linear X-ray photon yield gain due to recirculation, as well as noticeably higher operational reliability, the burst-mode ICS offers a great potential for practical scalability towards high duty cycles.« less

Wet-chemical synthesis of different bismuth telluride nanoparticles using metal organic precursors - single source vs. dual source approach.

PubMed

Bendt, Georg; Weber, Anna; Heimann, Stefan; Assenmacher, Wilfried; Prymak, Oleg; Schulz, Stephan

2015-08-28

Thermolysis of the single source precursor (Et2Bi)2Te in DIPB at 80 °C yielded phase-pure Bi4Te3 nanoparticles, while mixtures of Bi4Te3 and elemental Bi were formed at higher temperatures. In contrast, cubic Bi2Te particles were obtained by thermal decomposition of Et2BiTeEt in DIPB. Moreover, a dual source approach (hot injection method) using the reaction of Te(SiEt3)2 and Bi(NMe2)3 was applied for the synthesis of different pure Bi-Te phases including Bi2Te, Bi4Te3 and Bi2Te3, which were characterized by PXRD, REM, TEM and EDX. The influence of reaction temperature, precursor molar ratio and thermolysis conditions on the resulting material phase was verified. Moreover, reactions of alternate bismuth precursors such as Bi(NEt2)3, Bi(NMeEt)3 and BiCl3 with Te(SiEt3)2 were investigated.

A new compact, high sensitivity neutron imaging systema)

NASA Astrophysics Data System (ADS)

Caillaud, T.; Landoas, O.; Briat, M.; Rossé, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L.; Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C.; Park, H. S.; Robey, H. F.; Amendt, P.

2012-10-01

We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (109-1010 neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 × 1010. The resolution of this image was 54 μm and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a 60Co γ-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

Biophysical Variables Retrieval Over Russian Winter Wheat Fields Using Medium Resolution

NASA Astrophysics Data System (ADS)

d'Andrimont, Raphael; Waldner, Francois; Bartalev, Sergey; Plotnikov, Dmitry; Kleschenko, Alexander; Virchenko, Oleg; de Wit, Allard; Roerink, Gerbert; Defourny, Pierre

2013-12-01

Winter wheat production in the Russian Federation represents one of the sources of uncertainty for the international commodity market. In particular, adverse weather conditions may induce winter kill resulting in large yields' losses. Improving the monitoring of winter- wheat in Russia with a focus on winter-kill damage and its impacts on yield is thus a key challenge.This paper presents the methods and the results of the biophysical variables retrieval on a daily basis as an input for crop growth modeling at parcel level over a 10-years period (2003-2012) in the Russian context. The field campaigns carried out on 2 sites in the Tula region from 2010 to 2012 shows that it is possible to characterize the spatial and temporal variability at pixel, field and regional scale using medium resolution sensors (MODIS) over Russian fields.

Toward disentangling the effect of hydrologic and nitrogen source changes from 1992 to 2001 on incremental nitrogen yield in the contiguous United States

NASA Astrophysics Data System (ADS)

Alam, Md Jahangir; Goodall, Jonathan L.

2012-04-01

The goal of this research was to quantify the relative impact of hydrologic and nitrogen source changes on incremental nitrogen yield in the contiguous United States. Using nitrogen source estimates from various federal data bases, remotely sensed land use data from the National Land Cover Data program, and observed instream loadings from the United States Geological Survey National Stream Quality Accounting Network program, we calibrated and applied the spatially referenced regression model SPARROW to estimate incremental nitrogen yield for the contiguous United States. We ran different model scenarios to separate the effects of changes in source contributions from hydrologic changes for the years 1992 and 2001, assuming that only state conditions changed and that model coefficients describing the stream water-quality response to changes in state conditions remained constant between 1992 and 2001. Model results show a decrease of 8.2% in the median incremental nitrogen yield over the period of analysis with the vast majority of this decrease due to changes in hydrologic conditions rather than decreases in nitrogen sources. For example, when we changed the 1992 version of the model to have nitrogen source data from 2001, the model results showed only a small increase in median incremental nitrogen yield (0.12%). However, when we changed the 1992 version of the model to have hydrologic conditions from 2001, model results showed a decrease of approximately 8.7% in median incremental nitrogen yield. We did, however, find notable differences in incremental yield estimates for different sources of nitrogen after controlling for hydrologic changes, particularly for population related sources. For example, the median incremental yield for population related sources increased by 8.4% after controlling for hydrologic changes. This is in contrast to a 2.8% decrease in population related sources when hydrologic changes are included in the analysis. Likewise we found that median incremental yield from urban watersheds increased by 6.8% after controlling for hydrologic changes—in contrast to the median incremental nitrogen yield from cropland watersheds, which decreased by 2.1% over the same time period. These results suggest that, after accounting for hydrologic changes, population related sources became a more significant contributor of nitrogen yield to streams in the contiguous United States over the period of analysis. However, this study was not able to account for the influence of human management practices such as improvements in wastewater treatment plants or Best Management Practices that likely improved water quality, due to a lack of data for quantifying the impact of these practices for the study area.

Sugarcane for bioenergy production: an assessment of yield and regulation of sucrose content.

PubMed

Waclawovsky, Alessandro J; Sato, Paloma M; Lembke, Carolina G; Moore, Paul H; Souza, Glaucia M

2010-04-01

An increasing number of plant scientists, including breeders, agronomists, physiologists and molecular biologists, are working towards the development of new and improved energy crops. Research is increasingly focused on how to design crops specifically for bioenergy production and increased biomass generation for biofuel purposes. The most important biofuel to date is bioethanol produced from sugars (sucrose and starch). Second generation bioethanol is also being targeted for studies to allow the use of the cell wall (lignocellulose) as a source of carbon. If a crop is to be used for bioenergy production, the crop should be high yielding, fast growing, low lignin content and requiring relatively small energy inputs for its growth and harvest. Obtaining high yields in nonprime agricultural land is a key for energy crop development to allow sustainability and avoid competition with food production. Sugarcane is the most efficient bioenergy crop of tropical and subtropical regions, and biotechnological tools for the improvement of this crop are advancing rapidly. We focus this review on the studies of sugarcane genes associated with sucrose content, biomass and cell wall metabolism and the preliminary physiological characterization of cultivars that contrast for sugar and biomass yield.

Improved predictive modeling of white LEDs with accurate luminescence simulation and practical inputs with TracePro opto-mechanical design software

NASA Astrophysics Data System (ADS)

Tsao, Chao-hsi; Freniere, Edward R.; Smith, Linda

2009-02-01

The use of white LEDs for solid-state lighting to address applications in the automotive, architectural and general illumination markets is just emerging. LEDs promise greater energy efficiency and lower maintenance costs. However, there is a significant amount of design and cost optimization to be done while companies continue to improve semiconductor manufacturing processes and begin to apply more efficient and better color rendering luminescent materials such as phosphor and quantum dot nanomaterials. In the last decade, accurate and predictive opto-mechanical software modeling has enabled adherence to performance, consistency, cost, and aesthetic criteria without the cost and time associated with iterative hardware prototyping. More sophisticated models that include simulation of optical phenomenon, such as luminescence, promise to yield designs that are more predictive - giving design engineers and materials scientists more control over the design process to quickly reach optimum performance, manufacturability, and cost criteria. A design case study is presented where first, a phosphor formulation and excitation source are optimized for a white light. The phosphor formulation, the excitation source and other LED components are optically and mechanically modeled and ray traced. Finally, its performance is analyzed. A blue LED source is characterized by its relative spectral power distribution and angular intensity distribution. YAG:Ce phosphor is characterized by relative absorption, excitation and emission spectra, quantum efficiency and bulk absorption coefficient. Bulk scatter properties are characterized by wavelength dependent scatter coefficients, anisotropy and bulk absorption coefficient.

Impact of capillary rise and recirculation on simulated crop yields

NASA Astrophysics Data System (ADS)

Kroes, Joop; Supit, Iwan; van Dam, Jos; van Walsum, Paul; Mulder, Martin

2018-05-01

Upward soil water flow is a vital supply of water to crops. The purpose of this study is to determine if upward flow and recirculated percolation water can be quantified separately, and to determine the contribution of capillary rise and recirculated water to crop yield and groundwater recharge. Therefore, we performed impact analyses of various soil water flow regimes on grass, maize and potato yields in the Dutch delta. Flow regimes are characterized by soil composition and groundwater depth and derived from a national soil database. The intermittent occurrence of upward flow and its influence on crop growth are simulated with the combined SWAP-WOFOST model using various boundary conditions. Case studies and model experiments are used to illustrate the impact of upward flow on yield and crop growth. This impact is clearly present in situations with relatively shallow groundwater levels (85 % of the Netherlands), where capillary rise is a well-known source of upward flow; but also in free-draining situations the impact of upward flow is considerable. In the latter case recirculated percolation water is the flow source. To make this impact explicit we implemented a synthetic modelling option that stops upward flow from reaching the root zone, without inhibiting percolation. Such a hypothetically moisture-stressed situation compared to a natural one in the presence of shallow groundwater shows mean yield reductions for grassland, maize and potatoes of respectively 26, 3 and 14 % or respectively about 3.7, 0.3 and 1.5 t dry matter per hectare. About half of the withheld water behind these yield effects comes from recirculated percolation water as occurs in free-drainage conditions and the other half comes from increased upward capillary rise. Soil water and crop growth modelling should consider both capillary rise from groundwater and recirculation of percolation water as this improves the accuracy of yield simulations. This also improves the accuracy of the simulated groundwater recharge: neglecting these processes causes overestimates of 17 % for grassland and 46 % for potatoes, or 63 and 34 mm yr-1, respectively.

Preparation and Characterization of Cellulose and Nanocellulose from Agro-industrial Waste - Cassava Peel

NASA Astrophysics Data System (ADS)

Widiarto, S.; Yuwono, S. D.; Rochliadi, A.; Arcana, I. M.

2017-02-01

Cassava peel is an agro-industrial waste which is available in huge quantities in Lampung Province of Indonesia. This work was conducted to evaluate the potential of cassava peel as a source of cellulose and nanocellulose. Cellulose was extracted from cassava peel by using different chemical treatment, and the nanocellulose was prepared by hydrolysis with the use of sulfuric acid. The best methods of cellulose extraction from cassava peels are using alkali treatment followed by a bleaching process. The cellulose yield from this methods was 17.8% of dry base cassava peel, while the yield from nitric and sulfuric methods were about 10.78% and 10.32% of dry base cassava peel respectively. The hydrolysis was performed at the temperature of 50 °C for 2 hours. The intermediate reaction product obtained after each stage of the treatments was characterized. Fourier transform infrared spectroscopy showed the removal of non-cellulosic constituent. X-ray Diffraction (XRD) analysis revealed that the crystallinity of cellulose increased after hydrolysis. Morphological investigation was performed using Scanning Electron Microscopy (SEM). The size of particle was confirmed by Particle Size Analyzer (PSA) and Transmission Electron Microscopy (TEM).

Hemp ( Cannabis sativa L.) seed oil: analytical and phytochemical characterization of the unsaponifiable fraction.

PubMed

Montserrat-de la Paz, S; Marín-Aguilar, F; García-Giménez, M D; Fernández-Arche, M A

2014-02-05

Non-drug varieties of Cannabis sativa L., collectively namely as "hemp", have been an interesting source of food, fiber, and medicine for thousands of years. The ever-increasing demand for vegetables oils has made it essential to characterize additional vegetable oil through innovative uses of its components. The lipid profile showed that linoleic (55%), α-linolenic (16%), and oleic (11%) were the most abundant fatty acids. A yield (1.84-1.92%) of unsaponifiable matter was obtained, and the most interesting compounds were β-sitosterol (1905.00 ± 59.27 mg/kg of oil), campesterol (505.69 ± 32.04 mg/kg of oil), phytol (167.59 ± 1.81 mg/kg of oil), cycloartenol (90.55 ± 3.44 mg/kg of oil), and γ-tocopherol (73.38 ± 2.86 mg/100 g of oil). This study is an interesting contribution for C. sativa L. consideration as a source of bioactive compounds contributing to novel research applications for hemp seed oil in the pharmaceutical, cosmetic food, and other non-food industries.

Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my

Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations weremore » done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.« less

Machine learning reveals cyclic changes in seismic source spectra in Geysers geothermal field.

PubMed

Holtzman, Benjamin K; Paté, Arthur; Paisley, John; Waldhauser, Felix; Repetto, Douglas

2018-05-01

The earthquake rupture process comprises complex interactions of stress, fracture, and frictional properties. New machine learning methods demonstrate great potential to reveal patterns in time-dependent spectral properties of seismic signals and enable identification of changes in faulting processes. Clustering of 46,000 earthquakes of 0.3 < M L < 1.5 from the Geysers geothermal field (CA) yields groupings that have no reservoir-scale spatial patterns but clear temporal patterns. Events with similar spectral properties repeat on annual cycles within each cluster and track changes in the water injection rates into the Geysers reservoir, indicating that changes in acoustic properties and faulting processes accompany changes in thermomechanical state. The methods open new means to identify and characterize subtle changes in seismic source properties, with applications to tectonic and geothermal seismicity.

Simulations of Ground and Space-Based Oxygen Atom Experiments

NASA Technical Reports Server (NTRS)

Minton, T. K.; Cline, J. A.; Braunstein, M.

2002-01-01

Fast, pulsed atomic oxygen sources are a key tool in ground-based investigations of spacecraft contamination and surface erosion effects. These technically challenging ground-based studies provide a before and after picture of materials under low-earth-orbit (LEO) conditions. It would be of great interest to track in real time the pulsed flux from the source to the surface sample target and beyond in order to characterize the population of atoms and molecules that actually impact the surface and those that make it downstream to any coincident detectors. We have performed simulations in order to provide such detailed descriptions of these ground-based measurements and to provide an assessment of their correspondence to the actual LEO environment. Where possible we also make comparisons to measured fluxes and erosion yields. To perform the calculations we use a detailed description of a measurement beam and surface geometry based on the W, pulsed apparatus at Montana State University. In this system, a short pulse (on the order of 10 microseconds) of an O/O2 beam impacts a flat sample about 40 cm downstream and slightly displaced &om the beam s central axis. Past this target, at the end of the beam axis is a quadrupole mass spectrometer that measures the relative in situ flux of 0102 to give an overall normalized erosion yield. In our simulations we use the Direct Simulation Monte Carlo (DSMC) method, and track individual atoms within the atomic oxygen pulse. DSMC techniques are typically used to model rarefied (few collision) gas-flows which occur at altitudes above approximately 110 kilometers. These techniques are well suited for the conditions here, and multi-collision effects that can only be treated by this or a similar technique are included. This simulation includes collisions with the surface and among gas atoms that have scattered from the surface. The simulation also includes descriptions of the velocity spread and spatial profiles of the O/O2 beam obtained from separate measurements. These computations use basic engineering models for the gas-gas and gas-surface scattering and focus on the influence of multi-collision effects. These simulations characterize many important quantities of interest including the actual flux of atoms that reach the surface, the energy distribution of this flux, as well as the direction of the velocity of the flux that strikes the surface. These quantities are important in characterizing the conditions which give rise to measured surface erosion. The calculations also yield time- snapshots of the pulse as it impacts and flows around the surface. These snapshots reveal the local environment of gas near the surface for the duration of the pulse. We are also able to compute the flux of molecules that travel downstream and reach the spectrometer, and we characterize their velocity distribution. The number of atoms that reach the spectrometer can in fact be influenced by the presence of the surface due to gas-gas collisions from atoms scattered h m the surface, and it will generally be less than that with the surface absent. This amounts to an overall normalization factor in computing erosion yields. We discuss these quantities and their relationship to the gas-surf$ce interaction parameters. We have also performed similar calculations corresponding to conditions (number densities, temperatures, and velocities) of low-earth orbit. The steady-state nature and lower overall flux of the actual space environment give rise to differences in the nature of the gas-impacts on the surface from those of the ground-based measurements using a pulsed source.

Optimization, purification, and characterization of L-asparaginase from Actinomycetales bacterium BkSoiiA.

PubMed

Dash, Chitrangada; Mohapatra, Sukanti Bala; Maiti, Prasanta Kumar

2016-01-01

Actinobacteria are promising source of a wide range of important enzymes, some of which are produced in industrial scale, with others yet to be harnessed. L-Asparaginase is used as an antineoplastic agent. The present work deals with the production and optimization of L-asparaginase from Actinomycetales bacterium BkSoiiA using submerged fermentation in M9 medium. Production optimization resulted in a modified M9 medium with yeast extract and fructose as carbon and nitrogen sources, respectively, at pH 8.0, incubated for 120 hr at 30 ± 2 °C. The crude enzyme was purified to near homogeneity by ammonium sulfate precipitation following dialysis, ion-exchange column chromatography, and finally gel filtration. The sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) revealed an apparent molecular weight of 57 kD. The enzyme was purified 95.06-fold and showed a final specific activity of 204.37 U/mg with 3.49% yield. The purified enzyme showed maximum activity at a pH 10.0 and was stable at pH 7.0 to 9.0. The enzyme was activated by Mn(2+) and strongly inhibited by Ba(2+). All these preliminary characterization suggests that the L-asparaginase from the source may be a tool useful to pharmaceutical industries after further research.

Colloidal nickel/gallium nanoalloys obtained from organometallic precursors in conventional organic solvents and in ionic liquids: noble-metal-free alkyne semihydrogenation catalysts

NASA Astrophysics Data System (ADS)

Schütte, Kai; Doddi, Adinarayana; Kroll, Clarissa; Meyer, Hajo; Wiktor, Christian; Gemel, Christian; van Tendeloo, Gustaaf; Fischer, Roland A.; Janiak, Christoph

2014-04-01

Efforts to replace noble-metal catalysts by low-cost alternatives are of constant interest. The organometallic, non-aqueous wet-chemical synthesis of various hitherto unknown nanocrystalline Ni/Ga intermetallic materials and the use of NiGa for the selective semihydrogenation of alkynes to alkenes are reported. Thermal co-hydrogenolysis of the all-hydrocarbon precursors [Ni(COD)2] (COD = 1,5-cyclooctadiene) and GaCp* (Cp* = pentamethylcyclopentadienyl) in high-boiling organic solvents mesitylene and n-decane in molar ratios of 1 : 1, 2 : 3 and 3 : 1 yields the nano-crystalline powder materials of the over-all compositions NiGa, Ni2Ga3 and Ni3Ga, respectively. Microwave induced co-pyrolysis of the same precursors without additional hydrogen in the ionic liquid [BMIm][BF4] (BMIm = 1-butyl-3-methyl-imidazolium) selectively yields the intermetallic phases NiGa and Ni3Ga from the respective 1 : 1 and 3 : 1 molar ratios of the precursors. The obtained materials are characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), IR, powder X-ray diffraction (PXRD) and atomic absorption spectroscopy (AAS). The single-source precursor [Ni(GaCp*)(PMe3)3] with a fixed Ni : Ga stoichiometry of 1 : 1 was employed as well. In comparison with the co-hydrogenolytic dual precursor source approach it turned out to be less practical due to inefficient nickel incorporation caused by the parasitic formation of stable [Ni(PMe3)4]. The use of ionic liquid [BMIm][BF4] as a non-conventional solvent to control the reaction and stabilize the nanoparticles proved to be particularly advantageous and stable colloids of the nanoalloys NiGa and Ni3Ga were obtained. A phase-selective Ni/Ga colloid synthesis in conventional solvents and in the presence of surfactants such as hexadecylamine (HDA) was not feasible due to the undesired reactivity of HDA with GaCp* leading to inefficient gallium incorporation. Recyclable NiGa nanoparticles selectively semihydrogenate 1-octyne and diphenylacetylene (tolan) to 1-octene and diphenylethylene, respectively, with a yield of about 90% and selectivities of up to 94 and 87%. Ni-NPs yield alkanes with a selectivity of 97 or 78%, respectively, under the same conditions.Efforts to replace noble-metal catalysts by low-cost alternatives are of constant interest. The organometallic, non-aqueous wet-chemical synthesis of various hitherto unknown nanocrystalline Ni/Ga intermetallic materials and the use of NiGa for the selective semihydrogenation of alkynes to alkenes are reported. Thermal co-hydrogenolysis of the all-hydrocarbon precursors [Ni(COD)2] (COD = 1,5-cyclooctadiene) and GaCp* (Cp* = pentamethylcyclopentadienyl) in high-boiling organic solvents mesitylene and n-decane in molar ratios of 1 : 1, 2 : 3 and 3 : 1 yields the nano-crystalline powder materials of the over-all compositions NiGa, Ni2Ga3 and Ni3Ga, respectively. Microwave induced co-pyrolysis of the same precursors without additional hydrogen in the ionic liquid [BMIm][BF4] (BMIm = 1-butyl-3-methyl-imidazolium) selectively yields the intermetallic phases NiGa and Ni3Ga from the respective 1 : 1 and 3 : 1 molar ratios of the precursors. The obtained materials are characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), IR, powder X-ray diffraction (PXRD) and atomic absorption spectroscopy (AAS). The single-source precursor [Ni(GaCp*)(PMe3)3] with a fixed Ni : Ga stoichiometry of 1 : 1 was employed as well. In comparison with the co-hydrogenolytic dual precursor source approach it turned out to be less practical due to inefficient nickel incorporation caused by the parasitic formation of stable [Ni(PMe3)4]. The use of ionic liquid [BMIm][BF4] as a non-conventional solvent to control the reaction and stabilize the nanoparticles proved to be particularly advantageous and stable colloids of the nanoalloys NiGa and Ni3Ga were obtained. A phase-selective Ni/Ga colloid synthesis in conventional solvents and in the presence of surfactants such as hexadecylamine (HDA) was not feasible due to the undesired reactivity of HDA with GaCp* leading to inefficient gallium incorporation. Recyclable NiGa nanoparticles selectively semihydrogenate 1-octyne and diphenylacetylene (tolan) to 1-octene and diphenylethylene, respectively, with a yield of about 90% and selectivities of up to 94 and 87%. Ni-NPs yield alkanes with a selectivity of 97 or 78%, respectively, under the same conditions. Electronic supplementary information (ESI) available: Ni-Ga phase diagrams, EDX (XPS) of NP1-NP8, table of Ni : Ga ratios, TG of Ni-Ga SSPs, analysis of NP4, dec. of [Ni(GaCp*)3(PCy3)] with characterization, local resolution EDX of NP3-IL, Ni-NP characterization from Ni(COD)2 and details of (semi-)hydrogenation catalysis. See DOI: 10.1039/c4nr00111g

Perspectives on individual to ensembles of ambient fine and ultrafine particles and their sources

NASA Astrophysics Data System (ADS)

Bein, Keith James

By combining Rapid Single-ultrafine-particle Mass Spectrometry (RSMS) measurements during the Pittsburgh Supersite experiment with a large array of concurrent PM, gas and meteorological data, a synthesis of data and analyses is employed to characterize sources, emission trends and dynamics of ambient fine and ultrafine particles. Combinatorial analyses elicit individual to ensemble descriptions of particles, their sources, their changes in state from atmospheric processing and the scales of motion driving their transport and dynamics. Major results include (1) Particle size and composition are strong indicators of sources/source categories and real-time measurements allow source attribution at the single particle and point source level. (2) Single particle source attribution compares well to factor analysis of chemically-speciated bulk phase data and both resulted in similar conclusions but independently revealed new sources. (3) RSMS data can quantitatively estimate composition-resolved, number-based particle size distribution. Comparison to mass-based data yielded new information about physical and chemical properties of particles and instrument sensitivity. (4) Source-specific signatures and real-time monitoring allow passing plumes to be tracked and characterized. (5) The largest of three identified coal combustion sources emits ˜ 2.4 x 10 17 primary submicron particles per second. (6) Long-range transport has a significant impact on the eastern U.S. including specific influences of eight separate wildfire events. (7) Pollutant dynamics in the Pittsburgh summertime air shed, and Northeastern U.S., is characterized by alternating periods of stagnation and cleansing. The eight wildfire events were detected in between seven successive stagnation events. (8) Connections exist between boreal fire activity, southeast subsiding transport of the emissions, alternating periods of stagnation and cleansing at the receptor and the structure and propagation of extratropical waves. (9) Wildfire emissions can severely impact preexisting pollutant concentrations and physical and chemical processes at the receptor. (10) High-severity crown fires in boreal Canada emit ˜ 1.2 x 1015 particles/kg biomass burned. (11) In 1998, wildfire activity in the circumpolar boreal forest emitted ˜ 8 x 1026 particles, representing ˜ 14% of global wildland fire emissions. Results and conclusions address future scientific objectives in understanding effects of particles on human health and global climate change.

Characterizing the Degree of Fuel Magnetization for MagLIF Using Neutron Diagnostics

NASA Astrophysics Data System (ADS)

Hahn, K. D.; Chandler, G. A.; Schmit, P. F.; Knapp, P. F.; Hansen, S. B.; Harding, E.; Ruiz, C. L.; Jones, B.; Gomez, M. R.; Ampleford, D. J.; Torres, J. A.; Alberto, P. J.; Cooper, G. W.; Styron, J. D.

2017-10-01

We are studying Magnetized Liner Inertial Fusion sources which utilize deuterium fuel and produce up to 4e12 primary DD and 5e10 secondary DT neutrons. For this concept, magnetizing the fuel can relax the stagnation pressures and densities required for ignition by insulating the hot fuel and confining the charged fusion products. The degree of magnetization of the fuel at stagnation is quantified using secondary DT neutron spectral measurements in the axial and radial directions and is also related to the ratio of the secondary DT yield to the primary DD yield. Measurements have confirmed that charged fusion products are strongly magnetized, as indicated by the product of the magnetic field and the fuel radius, to 0.4 MG-cm. We present new results that compare the degree of fuel magnetization inferred from spectral and yield measurements. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.

Comparison of oil refining and biodiesel production process between screw press and n-hexane techniques from beauty leaf feedstock

NASA Astrophysics Data System (ADS)

Bhuiya, M. M. K.; Rasul, M. G.; Khan, M. M. K.; Ashwath, N.

2016-07-01

The Beauty Leaf Tree (Callophylum inophyllum) is regarded as an alternative source of energy to produce 2nd generation biodiesel due to its potentiality as well as high oil yield content in the seed kernels. The treating process is indispensable during the biodiesel production process because it can augment the yield as well as quality of the product. Oil extracted from both mechanical screw press and solvent extraction using n-hexane was refined. Five replications each of 25 gm of crude oil for screw press and five replications each of 25 gm of crude oil for n-hexane were selected for refining as well as biodiesel conversion processes. The oil refining processes consists of degumming, neutralization as well as dewaxing. The degumming, neutralization and dewaxing processes were performed to remove all the gums (phosphorous-based compounds), free fatty acids, and waxes from the fresh crude oil before the biodiesel conversion process carried out, respectively. The results indicated that up to 73% and 81% of mass conversion efficiency of the refined oil in the screw press and n-hexane refining processes were obtained, respectively. It was also found that up to 88% and 90% of biodiesel were yielded in terms of mass conversion efficiency in the transesterification process for the screw press and n-hexane techniques, respectively. While the entire processes (refining and transesterification) were considered, the conversion of beauty leaf tree (BLT) refined oil into biodiesel was yielded up to 65% and 73% of mass conversion efficiency for the screw press and n-hexane techniques, respectively. Physico-chemical properties of crude and refined oil, and biodiesel were characterized according to the ASTM standards. Overall, BLT has the potential to contribute as an alternative energy source because of high mass conversion efficiency.

Characterization of cellulolytic extract from Pycnoporus sanguineus PF-2 and its application in biomass saccharification.

PubMed

Falkoski, Daniel Luciano; Guimarães, Valéria Monteze; de Almeida, Maíra Nicolau; Alfenas, Acelino Couto; Colodette, Jorge Luiz; de Rezende, Sebastião Tavares

2012-03-01

The aim of this work was to evaluate the biochemical features of the white-rot fungi Pycnoporus sanguineus cellulolytic complex and its utilization to sugarcane bagasse hydrolysis. When cultivated under submerged fermentation using corn cobs as carbon source, P. sanguineus produced high FPase, endoglucanase, β-glucosidase, xylanase, mannanase, α-galactosidase, α-arabinofuranosidase, and polygalacturonase activities. Cellulase activities were characterized in relation to pH and temperature. β-Glucosidase and FPase activities were higher at 55 °C, pH 4.5, and endoglucanase activity was higher at 60 °C, in a pH range of 3.5-4.0. All cellulase activities were highly stable at 40 and 50 °C through 48 h of pre-incubation. Crude enzymatic extract from P. sanguineus was applied in a saccharification experiment using acid-treated and alkali-treated sugarcane bagasse as substrate, and the hydrolysis yields were compared to that obtained by a commercial cellulase preparation. Reducing sugar yields of 60.4% and 64.0% were reached when alkali-treated bagasse was hydrolyzed by P. sanguineus extract and commercial cellulase, respectively. Considering the glucose production, it was observed that P. sanguineus extract and commercial cellulase ensured yields of 22.6% and 36.5%, respectively. The saccharification of acid-treated bagasse was lower than that of alkali-treated bagasse regardless of the cellulolytic extract. The present work showed that P. sanguineus has a great potential as an enzyme producer for biomass saccharification.

Ion beam texturing

NASA Technical Reports Server (NTRS)

Hudson, W. R.

1976-01-01

A microscopic surface texture is created by sputter etching a surface while simultaneously sputter depositing a lower sputter yield material onto the surface. A xenon ion beam source has been used to perform this texturing process on samples as large as three centimeters in diameter. Ion beam textured surface structures have been characterized with SEM photomicrographs for a large number of materials including Cu, Al, Si, Ti, Ni, Fe, Stainless steel, Au, and Ag. Surfaces have been textured using a variety of low sputter yield materials - Ta, Mo, Nb, and Ti. The initial stages of the texture creation have been documented, and the technique of ion beam sputter removal of any remaining deposited material has been studied. A number of other texturing parameters have been studied such as the variation of the texture with ion beam power, surface temperature, and the rate of texture growth with sputter etching time.

Thermogravimetric characterization and gasification of pecan nut shells.

PubMed

Aldana, Hugo; Lozano, Francisco J; Acevedo, Joaquín; Mendoza, Alberto

2015-12-01

This study focuses on the evaluation of pecan nut shells as an alternative source of energy through pyrolysis and gasification. The physicochemical characteristics of the selected biomass that can influence the process efficiency, consumption rates, and the product yield, as well as create operational problems, were determined. In addition, the thermal decomposition kinetics necessary for prediction of consumption rates and yields were determined. Finally, the performance of a downdraft gasifier fed with pecan nut shells was analyzed in terms of process efficiency and exit gas characteristics. It was found that the pyrolytic decomposition of the nut shells can be modeled adequately using a single equation considering two independent parallel reactions. The performance of the gasification process can be influenced by the particle size and air flow rate, requiring a proper combination of these parameters for reliable operation and production of a valuable syngas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chromatographic Characterization and GC-MS Evaluation of the Bioactive Constituents with Antimicrobial Potential from the Pigmented Ink of Loligo duvauceli

PubMed Central

Girija, Smiline; Duraipandiyan, Veeramuthu; Kuppusamy, Pandi Suba; Gajendran, Hariprasad; Rajagopal, Raghuraman

2014-01-01

Chromatographic characterization and the GC-MS evaluation of the black pigmented ink of Loligo duvauceli in the present study have yielded an array of bioactive compounds with potent antimicrobial property. Facing an alarm of antimicrobial resistance globally, a need for elucidating antimicrobial agents from natural sources will be the need for the hour. In this view, this study is aimed at characterizing the black pigmented ink of the Indian squid L. duvauceli. The squid ink was subjected to crude solvent extraction and was fractionated by silica gel column chromatography. TLC and HPTLC profiles were recorded. Antimicrobial bioassay of the squid ink fractions was done by agar well diffusion method. The antimicrobial fraction was then characterized using GC-MS analysis. The results showed that the n-hexane extract upon column fractionation yielded a total of 8 fractions with the mobile phase of Hex/EtOAc in different gradients. TLC and HPTLC profiles showed a single spot with a retention factor of 0.76. Fraction 1 showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Lactobacillus acidophilus and a promising antifungal activity against Candida albicans. The antimicrobial fraction upon GC-MS analysis of bis(2-ethylhexyl) phthalate (BEHP) possesses the highest percentage of area normalisation (91%) with other few minor constituents. The study is concluded by stating that the antimicrobial efficacy of the squid ink might be due to the synergistic effects of the phthalate derivative and the other minor volatile compounds analysed in the squid ink. PMID:27437466

Chromatographic Characterization and GC-MS Evaluation of the Bioactive Constituents with Antimicrobial Potential from the Pigmented Ink of Loligo duvauceli.

PubMed

Girija, Smiline; Duraipandiyan, Veeramuthu; Kuppusamy, Pandi Suba; Gajendran, Hariprasad; Rajagopal, Raghuraman

2014-01-01

Chromatographic characterization and the GC-MS evaluation of the black pigmented ink of Loligo duvauceli in the present study have yielded an array of bioactive compounds with potent antimicrobial property. Facing an alarm of antimicrobial resistance globally, a need for elucidating antimicrobial agents from natural sources will be the need for the hour. In this view, this study is aimed at characterizing the black pigmented ink of the Indian squid L. duvauceli. The squid ink was subjected to crude solvent extraction and was fractionated by silica gel column chromatography. TLC and HPTLC profiles were recorded. Antimicrobial bioassay of the squid ink fractions was done by agar well diffusion method. The antimicrobial fraction was then characterized using GC-MS analysis. The results showed that the n-hexane extract upon column fractionation yielded a total of 8 fractions with the mobile phase of Hex/EtOAc in different gradients. TLC and HPTLC profiles showed a single spot with a retention factor of 0.76. Fraction 1 showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Lactobacillus acidophilus and a promising antifungal activity against Candida albicans. The antimicrobial fraction upon GC-MS analysis of bis(2-ethylhexyl) phthalate (BEHP) possesses the highest percentage of area normalisation (91%) with other few minor constituents. The study is concluded by stating that the antimicrobial efficacy of the squid ink might be due to the synergistic effects of the phthalate derivative and the other minor volatile compounds analysed in the squid ink.

Highly efficient mesophyll protoplast isolation and PEG-mediated transient gene expression for rapid and large-scale gene characterization in cassava (Manihot esculenta Crantz).

PubMed

Wu, Jun-Zheng; Liu, Qin; Geng, Xiao-Shan; Li, Kai-Mian; Luo, Li-Juan; Liu, Jin-Ping

2017-03-14

Cassava (Manihot esculenta Crantz) is a major crop extensively cultivated in the tropics as both an important source of calories and a promising source for biofuel production. Although stable gene expression have been used for transgenic breeding and gene function study, a quick, easy and large-scale transformation platform has been in urgent need for gene functional characterization, especially after the cassava full genome was sequenced. Fully expanded leaves from in vitro plantlets of Manihot esculenta were used to optimize the concentrations of cellulase R-10 and macerozyme R-10 for obtaining protoplasts with the highest yield and viability. Then, the optimum conditions (PEG4000 concentration and transfection time) were determined for cassava protoplast transient gene expression. In addition, the reliability of the established protocol was confirmed for subcellular protein localization. In this work we optimized the main influencing factors and developed an efficient mesophyll protoplast isolation and PEG-mediated transient gene expression in cassava. The suitable enzyme digestion system was established with the combination of 1.6% cellulase R-10 and 0.8% macerozyme R-10 for 16 h of digestion in the dark at 25 °C, resulting in the high yield (4.4 × 10 7 protoplasts/g FW) and vitality (92.6%) of mesophyll protoplasts. The maximum transfection efficiency (70.8%) was obtained with the incubation of the protoplasts/vector DNA mixture with 25% PEG4000 for 10 min. We validated the applicability of the system for studying the subcellular localization of MeSTP7 (an H + /monosaccharide cotransporter) with our transient expression protocol and a heterologous Arabidopsis transient gene expression system. We optimized the main influencing factors and developed an efficient mesophyll protoplast isolation and transient gene expression in cassava, which will facilitate large-scale characterization of genes and pathways in cassava.

DISENTANGLING CONFUSED STARS AT THE GALACTIC CENTER WITH LONG-BASELINE INFRARED INTERFEROMETRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stone, Jordan M.; Eisner, J. A.; Monnier, J. D.

2012-08-01

We present simulations of Keck Interferometer ASTRA and VLTI GRAVITY observations of mock star fields in orbit within {approx}50 mas of Sgr A*. Dual-field phase referencing techniques, as implemented on ASTRA and planned for GRAVITY, will provide the sensitivity to observe Sgr A* with long-baseline infrared interferometers. Our results show an improvement in the confusion noise limit over current astrometric surveys, opening a window to study stellar sources in the region. Since the Keck Interferometer has only a single baseline, the improvement in the confusion limit depends on source position angles. The GRAVITY instrument will yield a more compact andmore » symmetric point-spread function, providing an improvement in confusion noise which will not depend as strongly on position angle. Our Keck results show the ability to characterize the star field as containing zero, few, or many bright stellar sources. We are also able to detect and track a source down to m{sub K} {approx} 18 through the least confused regions of our field of view at a precision of {approx}200 {mu}as along the baseline direction. This level of precision improves with source brightness. Our GRAVITY results show the potential to detect and track multiple sources in the field. GRAVITY will perform {approx}10 {mu}as astrometry on an m{sub K} = 16.3 source and {approx}200 {mu}as astrometry on an m{sub K} = 18.8 source in 6 hr of monitoring a crowded field. Monitoring the orbits of several stars will provide the ability to distinguish between multiple post-Newtonian orbital effects, including those due to an extended mass distribution around Sgr A* and to low-order general relativistic effects. ASTRA and GRAVITY both have the potential to detect and monitor sources very close to Sgr A*. Early characterizations of the field by ASTRA, including the possibility of a precise source detection, could provide valuable information for future GRAVITY implementation and observation.« less

(E)-5-[2-(methoxycarbonyl)ethenyl]cytidine as a chemical actinometer for germicidal UV radiation.

PubMed

Shen, Chengyue; Fang, Shiyue; Bergstrom, Donald E; Blatchley, Ernest R

2005-05-15

(E)-5-[2-(Methoxycarbonyl)ethenyl]cytidine (S) was examined for use as a chemical actinometer for germicidal UV radiation. Its photoproduct, 3-beta-D-ribofuranosyl-2,7-dioxopyrido[2,3-d]pyrimidine (P), is strongly fluorescent with excitation and emission maxima at 330 and 385 nm, respectively. Experiments were conducted to characterize the dynamic behavior of aqueous solutions of S and P when subjected to UV radiation. UV sources used for these experiments included a low-pressure mercury lamp, a XeBr excimer lamp, and a KrCI excimer lamp; all three sources were mounted in collimating devices to provide incident beams that could be easily and accurately characterized by radiometry. These three sources each yielded essentially monochromatic outputwith characteristic wavelengths of 254, 282, and 222 nm, respectively. At practical concentrations, it was found that the absorbance of the actinometer solution was neither high enough to make the actinometer solutions optically opaque nor low enough to be optically transparent to UV. In addition, the photoproduct displayed a molar absorption coefficient that was similar in magnitude to that of the parent compound, thereby resulting in competitive absorption of UV energy between Sand Pduring irradiation. For purposes of evaluation of the results of irradiation, a mathematical model was developed to accountforthe nonideal optical characteristics of the system. The model is based on a description of local photochemical kinetics; predictions of overall reactor performance were developed by spatial and temporal integration of model results. The model was used to analyze the dynamic behavior of actinometer solutions during UV irradiation and to estimate the quantum yield for photoproduction of Pfrom S. This modeling approach is potentially applicable to other photochemical processes in which multiple compounds are present that absorb photoactive radiation; however, general application of this modeling approach to photochemical reactor systems will require inclusion of othertermsto describe relevanttransport behavior within the system.

Evaluating agricultural nonpoint-source pollution using integrated geographic information systems and hydrologic/water quality model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tim, U.S.; Jolly, R.

1994-01-01

Considerable progress has been made in developing physically based, distributed parameter, hydrologic/water quality (HIWQ) models for planning and control of nonpoint-source pollution. The widespread use of these models is often constrained by the excessive and time-consuming input data demands and the lack of computing efficiencies necessary for iterative simulation of alternative management strategies. Recent developments in geographic information systems (GIS) provide techniques for handling large amounts of spatial data for modeling nonpoint-source pollution problems. Because a GIS can be used to combine information from several sources to form an array of model input data and to examine any combinations ofmore » spatial input/output data, it represents a highly effective tool for HiWQ modeling. This paper describes the integration of a distributed-parameter model (AGNPS) with a GIS (ARC/INFO) to examine nonpoint sources of pollution in an agricultural watershed. The ARC/INFO GIS provided the tools to generate and spatially organize the disparate data to support modeling, while the AGNPS model was used to predict several water quality variables including soil erosion and sedimentation within a watershed. The integrated system was used to evaluate the effectiveness of several alternative management strategies in reducing sediment pollution in a 417-ha watershed located in southern Iowa. The implementation of vegetative filter strips and contour buffer (grass) strips resulted in a 41 and 47% reduction in sediment yield at the watershed outlet, respectively. In addition, when the integrated system was used, the combination of the above management strategies resulted in a 71% reduction in sediment yield. In general, the study demonstrated the utility of integrating a simulation model with GIS for nonpoini-source pollution control and planning. Such techniques can help characterize the diffuse sources of pollution at the landscape level. 52 refs., 6 figs., 1 tab.« less

Production of mycelial biomass by the Amazonian edible mushroom Pleurotus albidus.

PubMed

Kirsch, Larissa de Souza; de Macedo, Ana Júlia Porto; Teixeira, Maria Francisca Simas

2016-01-01

Edible mushroom species are considered as an adequate source of food in a healthy diet due to high content of protein, fiber, vitamins, and a variety of minerals. The representatives of Pleurotus genus are characterized by distinct gastronomic, nutritional, and medicinal properties among the edible mushrooms commercialized worldwide. In the present study, the growth of mycelial biomass of Pleurotus albidus cultivated in submerged fermentation was evaluated. Saccharose, fructose, and maltose were the three main carbon sources for mycelial biomass formation with corresponding yields of 7.28gL(-1), 7.07gL(-1), and 6.99gL(-1). Inorganic nitrogen sources did not stimulate growth and the optimal yield was significantly higher with yeast extract (7.98gL(-1)). The factorial design used to evaluate the influence of saccharose and yeast extract concentration, agitation speed, and initial pH indicated that all variables significantly influenced the production of biomass, especially the concentration of saccharose. The greater amount of saccharose resulted in the production of significantly more biomass. The highest mycelial biomass production (9.81gL(-1)) was reached in the medium formulated with 30.0gL(-1) saccharose, 2.5gL(-1) yeast extract, pH 7.0, and a speed of agitation at 180rpm. Furthermore, P. albidus manifested different aspects of morphology and physiology under the growth conditions employed. Media composition affected mycelial biomass production indicating that the diversification of carbon sources promoted its improvement and can be used as food or supplement. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

A Radium-223 Microgenerator from Cyclotron-Produced Trace Actinium-227

PubMed Central

Abou, Diane S.; Pickett, Juile; Mattson, John E.; Thorek, Daniel L. J.

2016-01-01

The alpha particle emitter Radium-223 dichloride (223RaCl2) has recently been approved for treatment of late-stage bone metastatic prostate cancer. There is considerable interest in studying this new agent outside of the clinical setting, however the supply of 223Ra is limited and expensive. We have engineered a 223Ra microgenerator using traces of 227Ac previously generated from cyclotron-produced 225Ac. Radiochemically pure 223RaCl2 was made, characterized, evaluated in vivo, and the source was recovered in high yield for regeneration of the microgenerator. PMID:27835737

Integrating remote sensing, geographic information system and modeling for estimating crop yield

NASA Astrophysics Data System (ADS)

Salazar, Luis Alonso

This thesis explores various aspects of the use of remote sensing, geographic information system and digital signal processing technologies for broad-scale estimation of crop yield in Kansas. Recent dry and drought years in the Great Plains have emphasized the need for new sources of timely, objective and quantitative information on crop conditions. Crop growth monitoring and yield estimation can provide important information for government agencies, commodity traders and producers in planning harvest, storage, transportation and marketing activities. The sooner this information is available the lower the economic risk translating into greater efficiency and increased return on investments. Weather data is normally used when crop yield is forecasted. Such information, to provide adequate detail for effective predictions, is typically feasible only on small research sites due to expensive and time-consuming collections. In order for crop assessment systems to be economical, more efficient methods for data collection and analysis are necessary. The purpose of this research is to use satellite data which provides 50 times more spatial information about the environment than the weather station network in a short amount of time at a relatively low cost. Specifically, we are going to use Advanced Very High Resolution Radiometer (AVHRR) based vegetation health (VH) indices as proxies for characterization of weather conditions.

Source characterization and modeling development for monoenergetic-proton radiography experiments on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manuel, M. J.-E.; Zylstra, A. B.; Rinderknecht, H. G.

2012-06-15

A monoenergetic proton source has been characterized and a modeling tool developed for proton radiography experiments at the OMEGA [T. R. Boehly et al., Opt. Comm. 133, 495 (1997)] laser facility. Multiple diagnostics were fielded to measure global isotropy levels in proton fluence and images of the proton source itself provided information on local uniformity relevant to proton radiography experiments. Global fluence uniformity was assessed by multiple yield diagnostics and deviations were calculated to be {approx}16% and {approx}26% of the mean for DD and D{sup 3}He fusion protons, respectively. From individual fluence images, it was found that the angular frequenciesmore » of Greater-Than-Or-Equivalent-To 50 rad{sup -1} contributed less than a few percent to local nonuniformity levels. A model was constructed using the Geant4 [S. Agostinelli et al., Nuc. Inst. Meth. A 506, 250 (2003)] framework to simulate proton radiography experiments. The simulation implements realistic source parameters and various target geometries. The model was benchmarked with the radiographs of cold-matter targets to within experimental accuracy. To validate the use of this code, the cold-matter approximation for the scattering of fusion protons in plasma is discussed using a typical laser-foil experiment as an example case. It is shown that an analytic cold-matter approximation is accurate to within Less-Than-Or-Equivalent-To 10% of the analytic plasma model in the example scenario.« less

Interference of avian guano in analyses of fuel-contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

James, D.E.; Johnson, T.E.; Kreamer, D.K.

1996-01-01

Site characterization on Johnston Island, Johnston Atoll, Pacific Ocean, has yielded preliminary data that seabird guano can be an interference in three common petroleum hydrocarbon quantification methods. Volatiles from seabird guano were measured on a hydrocarbon-specific handheld vapor meter (catalytic detector) in concentrations as high as 256 ppm by volume total hydrocarbon. Analysis of guano solids produced measurable concentrations of total petroleum hydrocarbon (TPH) as diesel using both an immunoassay test and the EPA 8015 Modified Method. The testing was conducted on one surface sample of guano collected from a seabird roosting and nesting area. Source species were not identified.more » Positive hydrocarbon test results for guano raise concerns regarding the effectiveness of standard methods of petroleum-contaminated site characterization for Johnston island, other Pacific islands, and coastal areas with historic or contemporary seabird populations.« less

Comparison of femtosecond laser and continuous wave UV sources for protein-nucleic acid crosslinking.

PubMed

Fecko, Christopher J; Munson, Katherine M; Saunders, Abbie; Sun, Guangxing; Begley, Tadhg P; Lis, John T; Webb, Watt W

2007-01-01

Crosslinking proteins to the nucleic acids they bind affords stable access to otherwise transient regulatory interactions. Photochemical crosslinking provides an attractive alternative to formaldehyde-based protocols, but irradiation with conventional UV sources typically yields inadequate product amounts. Crosslinking with pulsed UV lasers has been heralded as a revolutionary technique to increase photochemical yield, but this method had only been tested on a few protein-nucleic acid complexes. To test the generality of the yield enhancement, we have investigated the benefits of using approximately 150 fs UV pulses to crosslink TATA-binding protein, glucocorticoid receptor and heat shock factor to oligonucleotides in vitro. For these proteins, we find that the quantum yields (and saturating yields) for forming crosslinks using the high-peak intensity femtosecond laser do not improve on those obtained with low-intensity continuous wave (CW) UV sources. The photodamage to the oligonucleotides and proteins also has comparable quantum yields. Measurements of the photochemical reaction yields of several small molecules selected to model the crosslinking reactions also exhibit nearly linear dependences on UV intensity instead of the previously predicted quadratic dependence. Unfortunately, these results disprove earlier assertions that femtosecond pulsed laser sources provide significant advantages over CW radiation for protein-nucleic acid crosslinking.

An analysis of the sponge Acanthostrongylophora igens’ microbiome yields an actinomycete that produces the natural product manzamine A

PubMed Central

Waters, Amanda L.; Peraud, Olivier; Kasanah, Noer; Sims, James W.; Kothalawala, Nuwan; Anderson, Matthew A.; Abbas, Samuel H.; Rao, Karumanchi V.; Jupally, Vijay R.; Kelly, Michelle; Dass, Amala; Hill, Russell T.; Hamann, Mark T.

2016-01-01

Sponges have generated significant interest as a source of bioactive and elaborate secondary metabolites that hold promise for the development of novel therapeutics for the control of an array of human diseases. However, research and development of marine natural products can often be hampered by the difficulty associated with obtaining a stable and sustainable production source. Herein we report the first successful characterization and utilization of the microbiome of a marine invertebrate to identify a sustainable production source for an important natural product scaffold. Through molecular-microbial community analysis, optimization of fermentation conditions and MALDI-MS imaging, we provide the first report of a sponge-associated bacterium (Micromonospora sp.) that produces the manzamine class of antimalarials from the Indo-Pacific sponge Acanthostrongylophora ingens (Thiele, 1899) (Class Demospongiae, Order Haplosclerida, Family Petrosiidae). These findings suggest that a general strategy of analysis of the macroorganism’s microbiome could significantly transform the field of natural products drug discovery by gaining access to not only novel drug leads, but the potential for sustainable production sources and biosynthetic genes at the same time. PMID:27785452

Machine learning reveals cyclic changes in seismic source spectra in Geysers geothermal field

PubMed Central

Paisley, John

2018-01-01

The earthquake rupture process comprises complex interactions of stress, fracture, and frictional properties. New machine learning methods demonstrate great potential to reveal patterns in time-dependent spectral properties of seismic signals and enable identification of changes in faulting processes. Clustering of 46,000 earthquakes of 0.3 < ML < 1.5 from the Geysers geothermal field (CA) yields groupings that have no reservoir-scale spatial patterns but clear temporal patterns. Events with similar spectral properties repeat on annual cycles within each cluster and track changes in the water injection rates into the Geysers reservoir, indicating that changes in acoustic properties and faulting processes accompany changes in thermomechanical state. The methods open new means to identify and characterize subtle changes in seismic source properties, with applications to tectonic and geothermal seismicity. PMID:29806015

Enhanced-efficiency fertilizer effects on cotton yield and quality in the Coastal Plains

USDA-ARS?s Scientific Manuscript database

Interest in the use of enhanced-efficiency N fertilizer (EENFs) sources has increased in recent years due to the potential of these new EENF sources to increase crop yield, while at the same time decreasing N loss from agricultural fields. The efficacy of these fertilizer sources on cotton productio...

Pyrolysis of flax straw: Characterization of char, liquid, and gas as fuel

NASA Astrophysics Data System (ADS)

Tushar, Mohammad Shahed Hasan Khan

The demand for energy continues to outstrip its supply and necessitates the development of renewable energy options. Biomass has been recognized as a major renewable energy source to supplement the declining fossil fuel source of energy. It is the most popular form of renewable energy and, currently, biofuel production is becoming more promising. Being carbon neutral, readily available, and low in sulphur content makes biomass a very promising source of renewable energy. In the present research, both the isothermal and non-isothermal pressurized pyrolysis of flax straw is studied for the first time. In case of isothermal pyrolysis, the influence of pyrolysis temperature and reaction time on char yield and morphology was investigated. The applied pyrolysis temperature was varied between 300 and 500°C. The reaction time was varied from 15 to 60 min. The char yield was found to decrease as pyrolysis temperature and reaction time increased. The char structure and surface morphology were thoroughly investigated by means of x-ray diffraction (XRD), temperature-programmed oxidation (TPO), and scanning electron microscopy (SEM). The degree of porosity and graphitization increased as pyrolysis temperature and time increased. In fact, the experiment performed at 500°C for 1h duration did not yield any char; only residual ash could be obtained. The TPO studies on the char samples corroborated the XRD findings and showed the presence of two types of carbon, namely, amorphous filamentous carbon and graphitic carbon. A thermogravimetric analysis (TGA) of the char was performed to gain an understanding of combustion kinetics and reactivity. It implied that the reactivity of the char decreases as temperature increases, and this finding is well supported by the TPO, TGA, SEM, and XRD characterization data. Furthermore, an empirical global model was devised based on the power law to estimate activation energy and other kinetic parameters. For the non-isothermal pressurized pyrolysis of flax straw, the experiments were carried out at different pressures, ranging from 10 to 40 psig. The three types of products thus obtained (gas, liquid, char) were thoroughly quantified and analyzed. The yields of the products were found to be dependent on the experimental conditions. It was observed that 10 psig of pressure gave the maximum yield of bio-oil, while 20 psig pressure lead to maximum char yield. The gaseous products were analyzed using an online GC, while the bio-oils were characterized using an offline GC/MS. SEM studies were performed to study the char morphology and porosity. The main gaseous products observed were CO, H2, CO2, CH 4, and C3. The bio-oils were mainly composed of phenolic compounds, carboxylic acids, and furfural. The pH and density of the bio-oils was found to increase as pyrolysis pressure increased. SEM investigation gave insights into the porosity of chars; as pressure increased, an increase in the porosity of char was noted. XRD studies showed that amorphous hydrocarbon and graphitic carbons are the major constituents of char, which was supported by TPO experiments. A TGA study showed two reaction zones for char oxidation. The kinetic parameters of oxidation were estimated using a power law model, which was also used for isothermal pyrolysis and isothermal char oxidation kinetics. Based on the data generated, the pressure of 10 psig was found to be optimum for bio-oil production, while a pressure of 20 psig was optimum for char production. With the increase in pressure, the production of individual gas components increased within the pressure range studied. Finally, with the increase in reaction pressure, temperature and time, the produced chars became less reactive.

Hormonal and metabolic regulation of source-sink relations under salinity and drought: from plant survival to crop yield stability.

PubMed

Albacete, Alfonso A; Martínez-Andújar, Cristina; Pérez-Alfocea, Francisco

2014-01-01

Securing food production for the growing population will require closing the gap between potential crop productivity under optimal conditions and the yield captured by farmers under a changing environment, which is termed agronomical stability. Drought and salinity are major environmental factors contributing to the yield gap ultimately by inducing premature senescence in the photosynthetic source tissues of the plant and by reducing the number and growth of the harvestable sink organs by affecting the transport and use of assimilates between and within them. However, the changes in source-sink relations induced by stress also include adaptive changes in the reallocation of photoassimilates that influence crop productivity, ranging from plant survival to yield stability. While the massive utilization of -omic technologies in model plants is discovering hundreds of genes with potential impacts in alleviating short-term applied drought and salinity stress (usually measured as plant survival), only in relatively few cases has an effect on crop yield stability been proven. However, achieving the former does not necessarily imply the latter. Plant survival only requires water status conservation and delayed leaf senescence (thus maintaining source activity) that is usually accompanied by growth inhibition. However, yield stability will additionally require the maintenance or increase in sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves and to delayed stress-induced leaf senescence. This review emphasizes the role of several metabolic and hormonal factors influencing not only the source strength, but especially the sink activity and their inter-relations, and their potential to improve yield stability under drought and salinity stresses. © 2013.

Noise properties and task-based evaluation of diffraction-enhanced imaging

PubMed Central

Brankov, Jovan G.; Saiz-Herranz, Alejandro; Wernick, Miles N.

2014-01-01

Abstract. Diffraction-enhanced imaging (DEI) is an emerging x-ray imaging method that simultaneously yields x-ray attenuation and refraction images and holds great promise for soft-tissue imaging. The DEI has been mainly studied using synchrotron sources, but efforts have been made to transition the technology to more practical implementations using conventional x-ray sources. The main technical challenge of this transition lies in the relatively lower x-ray flux obtained from conventional sources, leading to photon-limited data contaminated by Poisson noise. Several issues that must be understood in order to design and optimize DEI imaging systems with respect to noise performance are addressed. Specifically, we: (a) develop equations describing the noise properties of DEI images, (b) derive the conditions under which the DEI algorithm is statistically optimal, (c) characterize the imaging performance that can be obtained as measured by task-based metrics, and (d) consider image-processing steps that may be employed to mitigate noise effects. PMID:26158056

Characterization of high-dose and high-energy implanted gate and source diode and analysis of lateral spreading of p gate profile in high voltage SiC static induction transistors

NASA Astrophysics Data System (ADS)

Onose, Hidekatsu; Kobayashi, Yutaka; Onuki, Jin

2017-03-01

The effect of the p gate dose on the characteristics of the gate-source diode in SiC static induction transistors (SIT) was investigated. It was found that a dose of 1.5 × 1014 cm-2 yields a pn junction breakdown voltage higher than 60 V and good forward characteristics. A normally on SiC SIT was fabricated and demonstrated. A blocking voltage higher than 2.0 kV at a gate-source voltage of -50 V and on-resistance of 70 mΩ cm2 were obtained. Device simulations were performed to investigate the effect of the lateral spreading. By comparing the measured I-V curves with simulation results, the lateral spreading factor was estimated to be about 0.5. The lateral spreading detrimentally affected the electrical properties of the SIT made using implantations at energies higher than 1 MeV.

Sediment sources in an urbanizing, mixed land-use watershed

NASA Astrophysics Data System (ADS)

Nelson, Erin J.; Booth, Derek B.

2002-07-01

The Issaquah Creek watershed is a rapidly urbanizing watershed of 144 km 2 in western Washington, where sediment aggradation of the main channel and delivery of fine sediment into a large downstream lake have raised increasingly frequent concerns over flooding, loss of fish habitat, and degraded water quality. A watershed-scale sediment budget was evaluated to determine the relative effects of land-use practices, including urbanization, on sediment supply and delivery, and to guide management responses towards the most effective source-reduction strategies. Human activity in the watershed, particularly urban development, has caused an increase of nearly 50% in the annual sediment yield, now estimated to be 44 tonnes km -2 yr -1. The main sources of sediment in the watershed are landslides (50%), channel-bank erosion (20%), and road-surface erosion (15%). This assessment characterizes the role of human activity in mixed-use watersheds such as this, and it demonstrates some of the key processes, particularly enhanced stream-channel erosion, by which urban development alters sediment loads.

A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis

PubMed Central

Goos, Sarah; Kämper, Jörg; Sauer, Norbert

2010-01-01

Plant pathogenic fungi cause massive yield losses and affect both quality and safety of food and feed produced from infected plants. The main objective of plant pathogenic fungi is to get access to the organic carbon sources of their carbon-autotrophic hosts. However, the chemical nature of the carbon source(s) and the mode of uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1) from the corn smut fungus Ustilago maydis and its characterization as a fungal virulence factor. Srt1 has an unusually high substrate affinity, is absolutely sucrose specific, and allows the direct utilization of sucrose at the plant/fungal interface without extracellular hydrolysis and, thus, without the production of extracellular monosaccharides known to elicit plant immune responses. srt1 is expressed exclusively during infection, and its deletion strongly reduces fungal virulence. This emphasizes the central role of this protein both for efficient carbon supply and for avoidance of apoplastic signals potentially recognized by the host. PMID:20161717

Selective enhancement and verification of woody biomass digestibility as a denitrification carbon source.

PubMed

Hu, Rongting; Zheng, Xilai; Xin, Jia; Sun, Zhaoyue; Zheng, Tianyuan

2017-11-01

The denitrification efficiency of woody biomass as carbon source is low because of its poor carbon availability. In this study, representative poplar sawdust was pretreated with lime and peracetic acid to enhance the biomass digestibility to different degrees; sawdust was then mixed with soil to investigate its denitrification efficiency. Under controllable conditions (25-95°C, 12-24h, varying dosages), sawdust digestibility (characterized by reducing sugar yield) was selectively enhanced 1.0-21.8 times over that of the raw sawdust (28.8mgeq.glucoseg -1 dry biomass). This increase was mainly attributed to the removal of lignin from the biomass. As a carbon source, the sawdust (digestibility enhanced by 5.4 times) increased the nitrate removal rate by 4.7 times, without N 2 O emission. However, the sawdust with high digestibility (12.6 or 18.0 times), despite releasing more dissolved organic carbon (DOC), did not exhibit further increase in denitrification efficiency, and emitted N 2 O. Copyright © 2017 Elsevier Ltd. All rights reserved.

Drop-in compatible entanglement for optical-fiber networks.

PubMed

Hall, Matthew A; Altepeter, Joseph B; Kumar, Prem

2009-08-17

A growing number of quantum communication protocols require entanglement distribution among remote parties, which is best accomplished by exploiting the mature technology and extensive infrastructure of low-loss optical fiber. For this reason, a practical source of entangled photons must be drop-in compatible with optical fiber networks. Here we demonstrate such a source for the first time, in which the nonlinearity of standard single-mode fiber is utilized to yield entangled photon pairs in the 1310-nm O-band. Using an ultra-stable design, we produce polarization entanglement with 98.0% +/- 0.5% fidelity to a maximally entangled state as characterized via coincidence-basis tomography. To demonstrate the source's drop-in capability, we transmit one photon from each entangled pair through a telecommunications-grade optical amplifier set to boost classical 1550-nm (C-band) communication signals. We verify that the photon pairs experience no measurable decoherence upon passing through the active amplifier (the output state's fidelity with a maximally entangled state is 98.4% +/- 1.4%). (c) 2009 Optical Society of America

Seismic Source Scaling and Characteristics of Six North Korean Underground Nuclear Explosions

NASA Astrophysics Data System (ADS)

Park, J.; Stump, B. W.; Che, I. Y.; Hayward, C.

2017-12-01

We estimate the range of yields and source depths for the six North Korean underground nuclear explosions in 2006, 2009, 2013, 2016 (January and September), and 2017, based on regional seismic observations in South Korea and China. Seismic data used in this study are from three seismo-acoustic stations, BRDAR, CHNAR, and KSGAR, cooperatively operated by SMU and KIGAM, the KSRS seismic array operated by the Comprehensive Nuclear Test Ban Treaty Organization, and MDJ, a station in the Global Seismographic Network. We calculate spectral ratios for event pairs using seismograms from the six explosions observed along the same paths and at the same receivers. These relative seismic source scaling spectra for Pn, Pg, Sn, and surface wave windows provide a basis for a grid search source solution that estimates source yield and depth for each event based on both the modified Mueller and Murphy (1971; MM71) and Denny and Johnson (1991; DJ91) source models. The grid search is used to identify the best-fit empirical spectral ratios subject to the source models by minimizing the goodness-of-fit (GOF) in the frequency range of 0.5-15 Hz. For all cases, the DJ91 model produces higher ratios of depth and yield than MM71. These initial results include significant trade-offs between depth and yield in all cases. In order to better take the effect of source depth into account, a modified grid search was implemented that includes the propagation effects for different source depths by including reflectivity Greens functions in the grid search procedure. This revision reduces the trade-offs between depth and yield, results in better model fits to frequencies as high as 15 Hz, and GOF values smaller than those where the depth effects on the Greens functions were ignored. The depth and yield estimates for all six explosions using this new procedure will be presented.

Sediment unmixing using detrital geochronology

USGS Publications Warehouse

Sharman, Glenn R.; Johnstone, Samuel

2017-01-01

Sediment mixing within sediment routing systems can exert a strong influence on the preservation of provenance signals that yield insight into the influence of environmental forcings (e.g., tectonism, climate) on the earth’s surface. Here we discuss two approaches to unmixing detrital geochronologic data in an effort to characterize complex changes in the sedimentary record. First we summarize ‘top-down’ mixing, which has been successfully employed in the past to characterize the different fractions of prescribed source distributions (‘parents’) that characterize a derived sample or set of samples (‘daughters’). Second we propose the use of ‘bottom-up’ methods, previously used primarily for grain size distributions, to model parent distributions and the abundances of these parents within a set of daughters. We demonstrate the utility of both top-down and bottom-up approaches to unmixing detrital geochronologic data within a well-constrained sediment routing system in central California. Use of a variety of goodness-of-fit metrics in top-down modeling reveals the importance of considering the range of allowable mixtures over any single best-fit mixture calculation. Bottom-up modeling of 12 daughter samples from beaches and submarine canyons yields modeled parent distributions that are remarkably similar to those expected from the geologic context of the sediment-routing system. In general, mixture modeling has potential to supplement more widely applied approaches in comparing detrital geochronologic data by casting differences between samples as differing proportions of geologically meaningful end-member provenance categories.

Sediment unmixing using detrital geochronology

NASA Astrophysics Data System (ADS)

Sharman, Glenn R.; Johnstone, Samuel A.

2017-11-01

Sediment mixing within sediment routing systems can exert a strong influence on the preservation of provenance signals that yield insight into the effect of environmental forcing (e.g., tectonism, climate) on the Earth's surface. Here, we discuss two approaches to unmixing detrital geochronologic data in an effort to characterize complex changes in the sedimentary record. First, we summarize 'top-down' mixing, which has been successfully employed in the past to characterize the different fractions of prescribed source distributions ('parents') that characterize a derived sample or set of samples ('daughters'). Second, we propose the use of 'bottom-up' methods, previously used primarily for grain size distributions, to model parent distributions and the abundances of these parents within a set of daughters. We demonstrate the utility of both top-down and bottom-up approaches to unmixing detrital geochronologic data within a well-constrained sediment routing system in central California. Use of a variety of goodness-of-fit metrics in top-down modeling reveals the importance of considering the range of allowable that is well mixed over any single best-fit mixture calculation. Bottom-up modeling of 12 daughter samples from beaches and submarine canyons yields modeled parent distributions that are remarkably similar to those expected from the geologic context of the sediment-routing system. In general, mixture modeling has the potential to supplement more widely applied approaches in comparing detrital geochronologic data by casting differences between samples as differing proportions of geologically meaningful end-member provenance categories.

Utilization of 2,6-diaminopurine by Salmonella typhimurium.

PubMed Central

Garber, B B; Gots, J S

1980-01-01

The pathway for the utilization of 2,6-diaminopurine (DAP) as an exogenous purine source in Salmonella typhimurium was examined. In strains able to use DAP as a purine source, mutant derivatives lacking either purine nucleoside phosphorylase or adenosine deaminase activity lost the ability to do so. The implied pathway of DAP utilization was via its conversion to DAP ribonucleoside by purine nucleoside phosphorylase, followed by deamination to guanosine by adenosine deaminase. Guanosine can then enter the established purine salvage pathways. In the course of defining this pathway, purine auxotrophs able to utilize DAP as sole purine source were isolated and partially characterized. These mutants fell into several classes, including (i) strains that only required an exogenous source of guanine nucleotides (e.g., guaA and guaB strains); (ii) strains that had a purF genetic lesion (i.e., were defective in alpha-5-phosphoribosyl 1-pyrophosphate amidotransferase activity); and (iii) strains that had constitutive levels of purine nucleoside phosphorylase. Selection among purine auxotrophs blocked in the de novo synthesis of inosine 5'-monophosphate, for efficient growth on DAP as sole source of purine nucleotides, readily yielded mutants which were defective in the regulation of their deoxyribonucleoside-catabolizing enzymes (e.g., deoR mutants). PMID:6782081

Multiscale Metabolic Modeling: Dynamic Flux Balance Analysis on a Whole-Plant Scale1[W][OPEN

PubMed Central

Grafahrend-Belau, Eva; Junker, Astrid; Eschenröder, André; Müller, Johannes; Schreiber, Falk; Junker, Björn H.

2013-01-01

Plant metabolism is characterized by a unique complexity on the cellular, tissue, and organ levels. On a whole-plant scale, changing source and sink relations accompanying plant development add another level of complexity to metabolism. With the aim of achieving a spatiotemporal resolution of source-sink interactions in crop plant metabolism, a multiscale metabolic modeling (MMM) approach was applied that integrates static organ-specific models with a whole-plant dynamic model. Allowing for a dynamic flux balance analysis on a whole-plant scale, the MMM approach was used to decipher the metabolic behavior of source and sink organs during the generative phase of the barley (Hordeum vulgare) plant. It reveals a sink-to-source shift of the barley stem caused by the senescence-related decrease in leaf source capacity, which is not sufficient to meet the nutrient requirements of sink organs such as the growing seed. The MMM platform represents a novel approach for the in silico analysis of metabolism on a whole-plant level, allowing for a systemic, spatiotemporally resolved understanding of metabolic processes involved in carbon partitioning, thus providing a novel tool for studying yield stability and crop improvement. PMID:23926077

Limitations of fluorescence spectroscopy to characterize organic matter in engineered systems

NASA Astrophysics Data System (ADS)

Korak, J.

2017-12-01

Fluorescence spectroscopy has been widely used to characterize dissolved organic matter (DOM) in engineered systems, such as drinking water, municipal wastewater and industrial water treatment. While fluorescence data collected in water treatment applications has led to the development of strong empirical relationships between fluorescence responses and process performance, the use of fluorescence to infer changes in the underlying organic matter chemistry is often oversimplified and applied out of context. Fluorescence only measures a small fraction of DOM as fluorescence quantum yields are less than 5% for many DOM sources. Relying on fluorescence as a surrogate for DOM presence, character or reactivity may not be appropriate for systems where small molecular weight, hydrophilic constituents unlikely to fluoresce are important. In addition, some methods rely on interpreting fluorescence signals at different excitation wavelengths as a surrogate for operationally-defined humic- and fulvic-acids in lieu of traditional XAD fractionation techniques, but these approaches cannot be supported by other lines of evidence considering natural abundance and fluorescence quantum yields of these fractions. These approaches also conflict with parallel factor analysis (PARAFAC), a statistical approach that routinely identifies fluorescence components with dual excitation behavior. Lastly, methods developed for natural systems are often applied out of context to engineered systems. Fluorescence signals characteristic of phenols or indoles are often interpreted as indicators for biological activity in natural systems due to fluorescent amino acids and peptides, but this interpretation is may not be appropriate in engineering applications where non-biological sources of phenolic functional groups may be present. This presentation explores common fluorescence interpretation approaches, discusses the limitations and provides recommendations related to engineered systems.

Sources of suspended-sediment loads in the lower Nueces River watershed, downstream from Lake Corpus Christi to the Nueces Estuary, south Texas, 1958–2010

USGS Publications Warehouse

Ockerman, Darwin J.; Heitmuller, Franklin T.; Wehmeyer, Loren L.

2013-01-01

During 2010, additional suspended-sediment data were collected during selected runoff events to provide new data for model testing and to help better understand the sources of suspended-sediment loads. The model was updated and used to estimate and compare sediment yields from each of 64 subwatersheds comprising the lower Nueces River watershed study area for three selected runoff events: November 20-21, 2009, September 7-8, 2010, and September 20-21, 2010. These three runoff events were characterized by heavy rainfall centered near the study area and during which minimal streamflow and suspended-sediment load entered the lower Nueces River upstream from Wesley E. Seale Dam. During all three runoff events, model simulations showed that the greatest sediment yields originated from the subwatersheds, which were largely cropland. In particular, the Bayou Creek subwatersheds were major contributors of suspended-sediment load to the lower Nueces River during the selected runoff events. During the November 2009 runoff event, high suspended-sediment concentrations in the Nueces River water withdrawn for the City of Corpus Christi public-water supply caused problems during the water-treatment process, resulting in failure to meet State water-treatment standards for turbidity in drinking water. Model simulations of the November 2009 runoff event showed that the Bayou Creek subwatersheds were the primary source of suspended-sediment loads during that runoff event.

Neutron Yield With a Pulsed Surface Flashover Deuterium Source

NASA Astrophysics Data System (ADS)

Guethlein, G.; Falabella, S.; Sampayan, S. E.; Meyer, G.; Tang, V.; Kerr, P.

2009-03-01

As a step towards developing an ultra compact D-D neutron source for various defense and homeland security applications, a compact, low average power ion source is needed. Towards that end, we are testing a high current, pulsed surface flashover ion source, with deuterated titanium as the spark contacts. Neutron yield and source lifetime data will be presented using a low voltage (<100 kV) deuterated target. With 20 ns spark drive pulses we have shown >106 neutrons/s with 1 kHz PRF

Production of Biodiesel from Jatropha Curcas using Nano Materials

NASA Astrophysics Data System (ADS)

Khan, M. Bilal; Bahadar, Ali; Anjum, Waqas

2009-09-01

Biodiesel is proving to be a viable clean energy resource for conventional fuel as well as more exotic, value added jet fuel applications. Various non edible agriculture based sources are exploited to produce biodiesel with varying degrees of conversion and properties. Systematic studies carried out to date reveal that the oil extracted from Jatropha Curcas gives best results on yield basis (2800 kg oil/Hectare max). However the research is marred by the production of often undesirable and cumbersome byproducts, which needs multifarious purification steps with associated cost. Sponification step is a main hurdle in the old technology. We have made a paradigm shift by introducing nanomaterials which not only eliminate the cited side reactions/byproducts, but also yield higher conversion and lower costs. Typically we have reduced the reaction time from 90 min at 70° C to a gainful 5 min at ambient temperatures. The nanomaterial has been characterized by SEM and EDS (Electron Dispersion Scanning Analysis) which clearly shows bimodal distribution of the nonmaterial employed. Further characterization study was carried out by FTIR and the results are compared with petrodiesel and standard biodiesel in the important region of 2000-4000 cm-1. Perfect matching/finger printing was achieved. In this work we also report detailed comparative elemental and flash point analysis of the Biodiesel produced via various established roots.

Evaluation of Long-term Performance of Enhanced Anaerobic Source Zone Bioremediation using mass flux

NASA Astrophysics Data System (ADS)

Haluska, A.; Cho, J.; Hatzinger, P.; Annable, M. D.

2017-12-01

Chlorinated ethene DNAPL source zones in groundwater act as potential long term sources of contamination as they dissolve yielding concentrations well above MCLs, posing an on-going public health risk. Enhanced bioremediation has been applied to treat many source zones with significant promise, but long-term sustainability of this technology has not been thoroughly assessed. This study evaluated the long-term effectiveness of enhanced anaerobic source zone bioremediation at chloroethene contaminated sites to determine if the treatment prevented contaminant rebound and removed NAPL from the source zone. Long-term performance was evaluated based on achieving MCL-based contaminant mass fluxes in parent compound concentrations during different monitoring periods. Groundwater concertation versus time data was compiled for 6-sites and post-remedial contaminant mass flux data was then measured using passive flux meters at wells both within and down-gradient of the source zone. Post-remedial mass flux data was then combined with pre-remedial water quality data to estimate pre-remedial mass flux. This information was used to characterize a DNAPL dissolution source strength function, such as the Power Law Model and the Equilibrium Stream tube model. The six-sites characterized for this study were (1) Former Charleston Air Force Base, Charleston, SC; (2) Dover Air Force Base, Dover, DE; (3) Treasure Island Naval Station, San Francisco, CA; (4) Former Raritan Arsenal, Edison, NJ; (5) Naval Air Station, Jacksonville, FL; and, (6) Former Naval Air Station, Alameda, CA. Contaminant mass fluxes decreased for all the sites by the end of the post-treatment monitoring period and rebound was limited within the source zone. Post remedial source strength function estimates suggest that decreases in contaminant mass flux will continue to occur at these sites, but a mass flux based on MCL levels may never be exceeded. Thus, site clean-up goals should be evaluated as order-of-magnitude reductions. Additionally, sites may require monitoring for a minimum of 5-years in order to sufficiently evaluate remedial performance. The study shows that enhanced anaerobic source zone bioremediation contributed to a modest reduction of source zone contaminant mass discharge and appears to have mitigated rebound of chlorinated ethenes.

Coprolites as a source of information on the genome and diet of the cave hyena

PubMed Central

Bon, Céline; Berthonaud, Véronique; Maksud, Frédéric; Labadie, Karine; Poulain, Julie; Artiguenave, François; Wincker, Patrick; Aury, Jean-Marc; Elalouf, Jean-Marc

2012-01-01

We performed high-throughput sequencing of DNA from fossilized faeces to evaluate this material as a source of information on the genome and diet of Pleistocene carnivores. We analysed coprolites derived from the extinct cave hyena (Crocuta crocuta spelaea), and sequenced 90 million DNA fragments from two specimens. The DNA reads enabled a reconstruction of the cave hyena mitochondrial genome with up to a 158-fold coverage. This genome, and those sequenced from extant spotted (Crocuta crocuta) and striped (Hyaena hyaena) hyena specimens, allows for the establishment of a robust phylogeny that supports a close relationship between the cave and the spotted hyena. We also demonstrate that high-throughput sequencing yields data for cave hyena multi-copy and single-copy nuclear genes, and that about 50 per cent of the coprolite DNA can be ascribed to this species. Analysing the data for additional species to indicate the cave hyena diet, we retrieved abundant sequences for the red deer (Cervus elaphus), and characterized its mitochondrial genome with up to a 3.8-fold coverage. In conclusion, we have demonstrated the presence of abundant ancient DNA in the coprolites surveyed. Shotgun sequencing of this material yielded a wealth of DNA sequences for a Pleistocene carnivore and allowed unbiased identification of diet. PMID:22456883

Characterization and optimization of schizophyllan production from date syrup.

PubMed

Jamshidian, Hajar; Shojaosadati, Seyed Abbas; Vilaplana, Francisco; Mousavi, Seyed Mohammad; Soudi, Mohammad Reza

2016-11-01

This study demonstrates the efficient utilization of low-cost agricultural substrates, particularly date syrup, by Schizophyllum commune ATCC 38548 for schizophyllan production. Initially, one factor-at-a-time method was used to find the best carbon and nitrogen sources for schizophyllan production. Subsequently, response surface methodology was employed to optimize the level of culture medium components to maximize substrate conversion yield and schizophyllan production in submerged culture. Maximum product yield (0.12g schizophyllan/g date syrup) and schizophyllan production (8.5g/l) were obtained at concentrations of date syrup and corn steep liquor, inoculum size and agitation rate at 7.02%w/v, 0.10%w/v, 7.68%v/v and 181rpm, respectively. Sugar composition analysis, FTIR, NMR and molar mass determination revealed the purity and molecular properties of recovered schizophyllan produced from date syrup as glycosidic linkage analysis showed three main schizophyllan characteristic peaks arising from the 3-linked, 3,6-linked and terminal glucose residues. Finally, process economic analysis suggested that use of date syrup and corn steep liquor as nutrients would result in approximately 6-fold reduction in cost of raw materials for schizophyllan production as compared to conventional carbon and nitrogen sources such as sucrose and malt extract. Copyright © 2016 Elsevier B.V. All rights reserved.

Design of angle-resolved illumination optics using nonimaging bi-telecentricity for 193 nm scatterfield microscopy.

PubMed

Sohn, Martin Y; Barnes, Bryan M; Silver, Richard M

2018-03-01

Accurate optics-based dimensional measurements of features sized well-below the diffraction limit require a thorough understanding of the illumination within the optical column and of the three-dimensional scattered fields that contain the information required for quantitative metrology. Scatterfield microscopy can pair simulations with angle-resolved tool characterization to improve agreement between the experiment and calculated libraries, yielding sub-nanometer parametric uncertainties. Optimized angle-resolved illumination requires bi-telecentric optics in which a telecentric sample plane defined by a Köhler illumination configuration and a telecentric conjugate back focal plane (CBFP) of the objective lens; scanning an aperture or an aperture source at the CBFP allows control of the illumination beam angle at the sample plane with minimal distortion. A bi-telecentric illumination optics have been designed enabling angle-resolved illumination for both aperture and source scanning modes while yielding low distortion and chief ray parallelism. The optimized design features a maximum chief ray angle at the CBFP of 0.002° and maximum wavefront deviations of less than 0.06 λ for angle-resolved illumination beams at the sample plane, holding promise for high quality angle-resolved illumination for improved measurements of deep-subwavelength structures using deep-ultraviolet light.

Characterization of cocoa production, income diversification and shade tree management along a climate gradient in Ghana.

PubMed

Abdulai, Issaka; Jassogne, Laurence; Graefe, Sophie; Asare, Richard; Van Asten, Piet; Läderach, Peter; Vaast, Philippe

2018-01-01

Reduced climatic suitability due to climate change in cocoa growing regions of Ghana is expected in the coming decades. This threatens farmers' livelihood and the cocoa sector. Climate change adaptation requires an improved understanding of existing cocoa production systems and farmers' coping strategies. This study characterized current cocoa production, income diversification and shade tree management along a climate gradient within the cocoa belt of Ghana. The objectives were to 1) compare existing production and income diversification between dry, mid and wet climatic regions, and 2) identify shade trees in cocoa agroforestry systems and their distribution along the climatic gradient. Our results showed that current mean cocoa yield level of 288kg ha-1yr-1 in the dry region was significantly lower than in the mid and wet regions with mean yields of 712 and 849 kg ha-1 yr-1, respectively. In the dry region, farmers diversified their income sources with non-cocoa crops and off-farm activities while farmers at the mid and wet regions mainly depended on cocoa (over 80% of annual income). Two shade systems classified as medium and low shade cocoa agroforestry systems were identified across the studied regions. The medium shade system was more abundant in the dry region and associated to adaptation to marginal climatic conditions. The low shade system showed significantly higher yield in the wet region but no difference was observed between the mid and dry regions. This study highlights the need for optimum shade level recommendation to be climatic region specific.

Characterization of cocoa production, income diversification and shade tree management along a climate gradient in Ghana

PubMed Central

Jassogne, Laurence; Graefe, Sophie; Asare, Richard; Van Asten, Piet; Läderach, Peter; Vaast, Philippe

2018-01-01

Reduced climatic suitability due to climate change in cocoa growing regions of Ghana is expected in the coming decades. This threatens farmers’ livelihood and the cocoa sector. Climate change adaptation requires an improved understanding of existing cocoa production systems and farmers’ coping strategies. This study characterized current cocoa production, income diversification and shade tree management along a climate gradient within the cocoa belt of Ghana. The objectives were to 1) compare existing production and income diversification between dry, mid and wet climatic regions, and 2) identify shade trees in cocoa agroforestry systems and their distribution along the climatic gradient. Our results showed that current mean cocoa yield level of 288kg ha-1yr-1 in the dry region was significantly lower than in the mid and wet regions with mean yields of 712 and 849 kg ha-1 yr-1, respectively. In the dry region, farmers diversified their income sources with non-cocoa crops and off-farm activities while farmers at the mid and wet regions mainly depended on cocoa (over 80% of annual income). Two shade systems classified as medium and low shade cocoa agroforestry systems were identified across the studied regions. The medium shade system was more abundant in the dry region and associated to adaptation to marginal climatic conditions. The low shade system showed significantly higher yield in the wet region but no difference was observed between the mid and dry regions. This study highlights the need for optimum shade level recommendation to be climatic region specific. PMID:29659629

Modification and characterization of a high-energy photon irradiation facility using nitrogen-16

NASA Astrophysics Data System (ADS)

Roy, Tapash Kumar

This work involves fabrication and characterization of a reactor source of high energy (˜7 MeV) nitrogen-16 photons for application in evaluation of dosimetric responses of personnel devices and portable instruments. The N-16 source has been established by continuously flowing coolant water from the core of a 1 MW research reactor through a cylindrical thin walled aluminium chamber. Dose measurements have been made at selected distances of interest along the depth axis both for with and without a near-air equilibrium wall of polymethyl methacrylate (PMMA) in place. Photon dose and exposure measurements were done using condenser-R ionization chambers with sufficiently thick walls to yield an approximate transient charged particle equilibrium (TCPE) condition. Field areal uniformity was defined using large area Kodak Readypack RP films along with lead foil radiators. Dosimetric quantities of interest include skin dose, eye (lens) dose, and 1 cm deep dose. Measurements were made at selected depths of 7, 300, and 1000 mg cm-2 for specific evaluation of these respective quantities. Photon spectral analysis was performed with a NaI(Tl) scintillation spectrometry system. Additionally, beta radiation measurements, and evaluation of neutron dose contributions to the radiation field were completed.

Verification of Plutonium Content in PuBe Sources Using MCNP® 6.2.0 Beta with TENDL 2012 Libraries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockhart, Madeline Louise; McMath, Garrett Earl

Although the production of PuBe neutron sources has discontinued, hundreds of sources with unknown or inaccurately declared plutonium content are in existence around the world. Institutions have undertaken the task of assaying these sources, measuring, and calculating the isotopic composition, plutonium content, and neutron yield. The nominal plutonium content, based off the neutron yield per gram of pure 239Pu, has shown to be highly inaccurate. New methods of measuring the plutonium content allow a more accurate estimate of the true Pu content, but these measurements need verification. Using the TENDL 2012 nuclear data libraries, MCNP6 has the capability to simulatemore » the (α, n) interactions in a PuBe source. Theoretically, if the source is modeled according to the plutonium content, isotopic composition, and other source characteristics, the calculated neutron yield in MCNP can be compared to the experimental yield, offering an indication of the accuracy of the declared plutonium content. In this study, three sets of PuBe sources from various backgrounds were modeled in MCNP6 1.2 Beta, according to the source specifications dictated by the individuals who assayed the source. Verification of the source parameters with MCNP6 also serves as a means to test the alpha transport capabilities of MCNP6 1.2 Beta with TENDL 2012 alpha transport libraries. Finally, good agreement in the comparison would indicate the accuracy of the source parameters in addition to demonstrating MCNP's capabilities in simulating (α, n) interactions.« less

Verification of Plutonium Content in PuBe Sources Using MCNP® 6.2.0 Beta with TENDL 2012 Libraries

DOE PAGES

Lockhart, Madeline Louise; McMath, Garrett Earl

2017-10-26

Although the production of PuBe neutron sources has discontinued, hundreds of sources with unknown or inaccurately declared plutonium content are in existence around the world. Institutions have undertaken the task of assaying these sources, measuring, and calculating the isotopic composition, plutonium content, and neutron yield. The nominal plutonium content, based off the neutron yield per gram of pure 239Pu, has shown to be highly inaccurate. New methods of measuring the plutonium content allow a more accurate estimate of the true Pu content, but these measurements need verification. Using the TENDL 2012 nuclear data libraries, MCNP6 has the capability to simulatemore » the (α, n) interactions in a PuBe source. Theoretically, if the source is modeled according to the plutonium content, isotopic composition, and other source characteristics, the calculated neutron yield in MCNP can be compared to the experimental yield, offering an indication of the accuracy of the declared plutonium content. In this study, three sets of PuBe sources from various backgrounds were modeled in MCNP6 1.2 Beta, according to the source specifications dictated by the individuals who assayed the source. Verification of the source parameters with MCNP6 also serves as a means to test the alpha transport capabilities of MCNP6 1.2 Beta with TENDL 2012 alpha transport libraries. Finally, good agreement in the comparison would indicate the accuracy of the source parameters in addition to demonstrating MCNP's capabilities in simulating (α, n) interactions.« less

Tracking historical increases in nitrogen-driven crop production possibilities

NASA Astrophysics Data System (ADS)

Mueller, N. D.; Lassaletta, L.; Billen, G.; Garnier, J.; Gerber, J. S.

2015-12-01

The environmental costs of nitrogen use have prompted a focus on improving the efficiency of nitrogen use in the global food system, the primary source of nitrogen pollution. Typical approaches to improving agricultural nitrogen use efficiency include more targeted field-level use (timing, placement, and rate) and modification of the crop mix. However, global efficiency gains can also be achieved by improving the spatial allocation of nitrogen between regions or countries, due to consistent diminishing returns at high nitrogen use. This concept is examined by constructing a tradeoff frontier (or production possibilities frontier) describing global crop protein yield as a function of applied nitrogen from all sources, given optimal spatial allocation. Yearly variation in country-level input-output nitrogen budgets are utilized to parameterize country-specific hyperbolic yield-response models. Response functions are further characterized for three ~15-year eras beginning in 1961, and series of calculations uses these curves to simulate optimal spatial allocation in each era and determine the frontier. The analyses reveal that excess nitrogen (in recent years) could be reduced by ~40% given optimal spatial allocation. Over time, we find that gains in yield potential and in-country nitrogen use efficiency have led to increases in the global nitrogen production possibilities frontier. However, this promising shift has been accompanied by an actual spatial distribution of nitrogen use that has become less optimal, in an absolute sense, relative to the frontier. We conclude that examination of global production possibilities is a promising approach to understanding production constraints and efficiency opportunities in the global food system.

Characterization of Edible Pork By-products by Means of Yield and Nutritional Composition

PubMed Central

Moon, Sung Sil

2014-01-01

Basic information regarding the yield and nutritional composition of edible pork by-products, namely heart, liver, lung, stomach, spleen, uterus, pancreas, and small and large intestines, was studied. Our results revealed that the yields varied widely among the pork by-products examined; in particular, liver had the highest yield (1.35%); whereas, spleen had the lowest yield (0.16%). The approximate composition range (minimum to maximum) of these by-products was found to be: moisture 71.59-82.48%; fat 0.28-19.54%; ash 0.155-1.34%, and protein 8.45-22.05%. The highest protein, vitamin A, B2, B6, and total essential amino acid (EAA) contents were found in liver. Large intestine had the highest fat content and lowest EAA content. Heart had the highest vitamin B1 content, whereas pancreas had the highest niacin and vitamin B3 contents. The concentrations of Fe and Zn were highest in liver and pancreas. Total saturated fatty acids (SFA) levels and polyunsaturated fatty acids (PUFA) levels between the by-products ranged from 43.15-50.48%, and 14.92-30.16%, respectively. Furthermore, with the exception of large intestine, all the by-products showed favorable PUFA/SFA ratios. The study indicated that almost all of the pork by-products examined were good sources of important nutrients, and that these data will be of great importance in the promotion of the consumption of edible pork by-products, as well as their utilization in meat processing. PMID:26761170

Synthesis of carbon nanotubes by arc discharge in open air.

PubMed

Paladugu, Mohan Chand; Maneesh, K; Nair, P Kesavan; Haridoss, Prathap

2005-05-01

In this work Carbon nanotubes have been synthesized by arc discharge in open air. A TIG welding ac/dc inverter was used as the power source for arc discharge. During each run of the arc discharge based synthesis, the anode was a low purity (approximately 85% C by weight) graphite rod. The effect of varying the atmosphere on the yield of soot of the carbon nanotube containing carbon soot has been studied. Various soots were produced, purified by oxidation and characterized to confirm formation of carbon nanotubes and their relative quality, using transmission electron microscopy, Raman spectroscopy, and XRD. It was found that the yield of soot formed on the cathode is higher when synthesis is carried out in open air than when carried out in a flowing argon atmosphere. When synthesized in open air, using a 7.2-mm-diameter graphite rod as anode, the yield of soot was around 50% by weight of the graphite consumed. Current and voltage for arcing were at identical starting values in all the experiments. This modified method does not require a controlled atmosphere as in the case of a conventional arc discharge method of synthesis and hence the cost of production may be reduced.

Characterization of poly-3-hydroxybutyrate (PHB) produced from Ralstonia eutropha using an alkali-pretreated biomass feedstock.

PubMed

Saratale, Ganesh D; Oh, Min-Kyu

2015-09-01

Alkaline pretreatment using NaOH, KOH, or NaOCl has been applied to various types of waste biomass to enhance enzymatic digestibility. Pretreatment (2% NaOH, 121 °C, 30 min) of rice paddy straw (PS) resulted in a maximum yield of 703 mg of reducing sugar per gram of PS with 84.19% hydrolysis yield after a two-step enzymatic hydrolysis process. Ralstonia eutropha ATCC 17699 was tested for its ability to synthesize poly-3-hydroxybutyrate (PHB) using PS hydrolysates as its sole carbon source. It is noteworthy that dry cell weight, polyhydroxyalkanoate (PHA) accumulation and PHB yield with the use of laboratory-grade sugars were similar to those achieved with PS-derived sugars. Under optimized conditions, we observed maximal PHA accumulation (75.45%) and PHB production (11.42 g/L) within 48 h of fermentation. After PHB recovery, the physicochemical properties of PHB were determined by various analytical techniques, showed the results were consistent with the characteristics of a standard polymer of PHB. Thus, the PS hydrolysate proved to be an excellent cheap carbon substrate for PHB production. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis of carbon nanostructures from high density polyethylene (HDPE) and polyethylene terephthalate (PET) waste by chemical vapour deposition

NASA Astrophysics Data System (ADS)

Hatta, M. N. M.; Hashim, M. S.; Hussin, R.; Aida, S.; Kamdi, Z.; Ainuddin, AR; Yunos, MZ

2017-10-01

In this study, carbon nanostructures were synthesized from High Density Polyethylene (HDPE) and Polyethylene terephthalate (PET) waste by single-stage chemical vapour deposition (CVD) method. In CVD, iron was used as catalyst and pyrolitic of carbon source was conducted at temperature 700, 800 and 900°C for 30 minutes. Argon gas was used as carrier gas with flow at 90 sccm. The synthesized carbon nanostructures were characterized by FESEM, EDS and calculation of carbon yield (%). FESEM micrograph shows that the carbon nanostructures were only grown as nanofilament when synthesized from PET waste. The synthesization of carbon nanostructure at 700°C was produced smooth and the smallest diameter nanofilament compared to others. The carbon yield of synthesized carbon nanostructures from PET was lower from HDPE. Furthermore, the carbon yield is recorded to increase with increasing of reaction temperature for all samples. Elemental study by EDS analysis were carried out and the formation of carbon nanostructures was confirmed after CVD process. Utilization of polymer waste to produce carbon nanostructures is beneficial to ensure that the carbon nanotechnology will be sustained in future.

Neutron spectroscopy by thermalization light yield measurement in a composite heterogeneous scintillator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, T.; Nattress, J.; Mayer, Michael F.

2016-12-11

An exothermic neutron capture reaction can be used to uniquely identify neutrons in particle detectors. With the use of a capture-gated coincidence technique, the sequence of scatter events that lead to neutron thermalization prior to the neutron capture can also be used to measure neutron energy. We report on the measurement of thermalization light yield via a time-of-flight technique in a polyvinyl toluene-based scintillator EJ-290 within a heterogeneous composite detector that also includes 6Li-doped glass scintillator. The thermalization light output exhibits a strong correlation with neutron energy because of the preference for near-complete energy deposition prior to the 6Li(n,t)4He neutronmore » capture reaction. The nonproportionality of the light yield from nuclear recoils contributes to the observed broadening of the distribution of thermalization light output. The nonproportional dependence of the scintillation light output in the EJ-290 scintillator as a function of proton recoil energy has been characterized in the range of 0.3–14.1 MeV via the Birks parametrization through a combination of time-of-flight measurement and previously conducted measurements with Monoenergetic neutron sources.« less

Improved yields for MOST’s using ion implantation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brockman, H. E.

1976-04-01

Conventionally diffused source and drain polysilicon gate MOST's commonly exhibit one type of fault, namely, that of polysilicon-to-diffusion short circuits. Investigations into the yields of large-area devices fabricated using ion-implanted sources and drains are compared with those of diffused structures. An improved technology for the chemical shaping of the polysilicon gates, which improves the yields for both types of devices, is also described. (AIP)

Ionic composition and nitrate in drainage water from fields fertilized with different nitrogen sources, middle swamp watershed, North Carolina, August 2000-August 2001

USGS Publications Warehouse

Harden, Stephen L.; Spruill, Timothy B.

2004-01-01

A study was conducted from August 2000 to August 2001 to characterize the influence of fertilizer use from different nitrogen sources on the quality of drainage water from 11 subsurface tile drains and 7 surface field ditches in a North Carolina Coastal Plain watershed. Agricultural fields receiving commercial fertilizer (conventional sites), swine lagoon effluent (spray sites), and wastewater-treatment plant sludge (sludge site) in the Middle Swamp watershed were investigated. The ionic composition of drainage water in tile drains and ditches varied depending on fertilizer source type. The dominant ions identified in water samples from tile drains and ditches include calcium, magnesium, sodium, chloride, nitrate, and sulfate, with tile drains generally having lower pH, low or no bicarbonates, and higher nitrate and chloride concentrations. Based on fertilizer source type, median nitrate-nitrogen concentrations were significantly higher at spray sites (32.0 milligrams per liter for tiles and 8.2 milligrams per liter for ditches) relative to conventional sites (6.8 milligrams per liter for tiles and 2.7 milligrams per liter for ditches). The median instantaneous nitrate-nitrogen yields also were significantly higher at spray sites (420 grams of nitrogen per hectare per day for tile drains and 15.6 grams of nitrogen per hectare per day for ditches) relative to conventional sites (25 grams of nitrogen per hectare per day for tile drains and 8.1 grams of nitrogen per hectare per day for ditches). The tile drain site where sludge is applied had a median nitrate-nitrogen concentration of 10.5 milligrams per liter and a median instantaneous nitrate-nitrogen yield of 93 grams of nitrogen per hectare per day, which were intermediate to those of the conventional and spray tile drain sites. Results from this study indicate that nitrogen loadings and subsequent edge-of-field nitrate-nitrogen yields through tile drains and ditches were significantly higher at sites receiving applications of swine lagoon effluent compared to sites receiving commercial fertilizer.

Influence of geologic setting on ground-water availability in the Lawrenceville area, Gwinnett County, Georgia

USGS Publications Warehouse

Williams, Lester J.; Kath, Randy L.; Crawford, Thomas J.; Chapman, Melinda J.

2005-01-01

Obtaining large quantities of ground water needed for municipal and industrial supply in the Piedmont and Blue Ridge physiographic provinces can be challenging because of the complex geology and the typically low primary permeability of igneous and metamorphic rocks. Areas of enhanced secondary permeability in the bedrock do occur, however, and 'high-yield' wells are not uncommon, particularly where careful site-selection techniques are used prior to test drilling. The U.S. Geological Survey - in cooperation with the City of Lawrenceville, Georgia - conducted this study from 2000 to 2002 to learn more about how different geologic settings influence the availability of ground water in igneous and metamorphic bedrock with the expectation that this knowledge could be used to help identify additional water resources in the area. In compositionally layered-rock settings, wells derive water almost exclusively from lithologically and structurally controlled water-bearing zones formed parallel to foliation and compositional layering. These high-permeability, water-bearing zones - termed foliation-parallel parting systems -combined with high-angle joint systems, are the primary control for the high-yield wells drilled in the Lawrenceville area; yields range from 100 to several hundred gallons per minute (gal/min). Near Lawrenceville, areas with high ground-water yield are present in sequences of amphibolite, biotite gneiss, and button schist where the structural attitude of the rocks is gently dipping, in areas characterized by abundant jointing, and in topographic settings with a continuous source of recharge along these structures. In massive-rock settings, wells derive water mostly from joint systems, although foliation-parallel parting systems also may be important. Wells deriving water primarily from steeply-dipping joint systems typically have low yields ranging from 1 to 5 gal/min. Joint systems in massive-rock settings can be identified and characterized by using many of the methods described in this report. Geologic mapping was the primary method used to determine the distribution, variability, and relative concentrations (intensity) of joint systems. In the subsurface, joints were characterized by taking orientation measurements in the open boreholes of wells using acoustic and/or optical televiewers. In this investigation, the only practical approach found for locating areas of high ground-water potential was first through detailed geologic mapping followed by test drilling, borehole geophysical logging, and aquifer testing. Geologic methods help characterize both large- and small-scale structures and other lithologic and stratigraphic features that influence development of increased secondary permeability in the bedrock. The rock types, discontinuities, depth of weathering, topographic position, and recharge potential - which were the principal factors assessed through detailed geologic mapping - must be evaluated carefully, in relation to one another, to assess the ground-water potential in a given area.

Nitriding of AISI 4140 steel by a low energy broad ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ochoa, E. A.; Figueroa, C. A.; Alvarez, F.

2006-11-15

A comprehensive study of the thermochemical nitriding process of steel AISI 4140 by low energy ion implantation (Kaufmann cell) is reported. Different times of implantation were employed and the studied samples were characterized by x-ray diffraction, in situ photoemission electron spectroscopy, scanning electron microscopy, and hardness (nanoindentation) measurements. The linear relationship between nitrogen content and hardness was verified. The structure of the nitrided layer was characterized yielding that the compound layer is formed by coarse precipitates, around small grains, constituted principally by {epsilon}-Fe{sub 2-3}N and {gamma}-Fe{sub 4}N phases and the diffusion zone is formed by fine precipitates, around big grainsmore » of the original martensitic phase, constituted principally by {gamma}-Fe{sub 4}N phase. Finally, a diffusion model for multiphase systems was applied to determine effective diffusion coefficients of nitrogen in the different phases.« less

Synthesis and x-ray characterization of sputtered bi-alkali antimonide photocathodes

DOE PAGES

Gaowei, M.; Ding, Z.; Schubert, S.; ...

2017-11-10

Advanced photoinjectors, which are critical to many next generation accelerators, open the door to new ways of material probing, both as injectors for free electron lasers and for ultra-fast electron diffraction. For these applications, the nonuniformity of the electric field near the cathode caused by surface roughness can be the dominant source of beam emittance. Therefore, improving the photocathode roughness while maintaining quantum efficiency is essential to the improvement of beam brightness. Here in this article, we report the demonstration of a bi-alkali antimonide photocathode with an order of magnitude improved roughness by sputter deposition from a K 2CsSb sputtermore » target, using in situ and operando X-ray characterizations. We found that a surface roughness of 0.5 nm for a sputtered photocathode with a final thickness of 42 nm can be achieved while still yielding a quantum efficiency of 3.3% at 530 nm wavelength.« less

Synthesis and x-ray characterization of sputtered bi-alkali antimonide photocathodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gaowei, M.; Ding, Z.; Schubert, S.

Advanced photoinjectors, which are critical to many next generation accelerators, open the door to new ways of material probing, both as injectors for free electron lasers and for ultra-fast electron diffraction. For these applications, the nonuniformity of the electric field near the cathode caused by surface roughness can be the dominant source of beam emittance. Therefore, improving the photocathode roughness while maintaining quantum efficiency is essential to the improvement of beam brightness. Here in this article, we report the demonstration of a bi-alkali antimonide photocathode with an order of magnitude improved roughness by sputter deposition from a K 2CsSb sputtermore » target, using in situ and operando X-ray characterizations. We found that a surface roughness of 0.5 nm for a sputtered photocathode with a final thickness of 42 nm can be achieved while still yielding a quantum efficiency of 3.3% at 530 nm wavelength.« less

An analysis of IGBP global land-cover characterization process

USGS Publications Warehouse

Loveland, Thomas R.; Zhu, Zhiliang; Ohlen, Donald O.; Brown, Jesslyn F.; Reed, Bradley C.; Yang, Limin

1999-01-01

The international Geosphere Biosphere Programme (IGBP) has called for the development of improved global land-cover data for use in increasingly sophisticated global environmental models. To meet this need, the staff of the U.S. Geological Survey and the University of Nebraska-Lincoln developed and applied a global land-cover characterization methodology using 1992-1993 1-km resolution Advanced Very High Resolution Radiometer (AVHRR) and other spatial data. The methodology, based on unsupervised classification with extensive postclassification refinement, yielded a multi-layer database consisting of eight land-cover data sets, descriptive attributes, and source data. An independent IGBP accuracy assessment reports a global accuracy of 73.5 percent, and continental results vary from 63 percent to 83 percent. Although data quality, methodology, interpreter performance, and logistics affected the results, significant problems were associated with the relationship between AVHRR data and fine-scale, spectrally similar land-cover patterns in complex natural or disturbed landscapes.

Characterization of UV fluorophores for application to luminescent solar concentrators

NASA Astrophysics Data System (ADS)

Hellier, Kaitlin; Carter, Sue

The implementation of solar as an alternative energy source faces many challenges, including the competition for space with agriculture and the environmental impacts of solar farms in deserts. As a solution to these problems, the Carter Lab has developed Luminescent Solar Concentrator (LSC) panels for applications to greenhouses. These panels utilize a luminescent dye compatible with the spectrum used in photosynthesis for the plants below and front-facing PV cells, achieving power enhancement of greater than 20% compared with the cells alone. To increase this enhancement, additional portions of the unused spectrum must be harvested. In this talk, we will discuss the characterization of UV absorbing fluorophores, including spectra, quantum yield, and the enhancement of light output and power generation. We will also address the combination of these UV dyes with the original LSC dye in low and high concentration, and the FRET efficiency and potential applications associated with high concentration films.

Real-time absorption and scattering characterization of slab-shaped turbid samples obtained by a combination of angular and spatially resolved measurements.

PubMed

Dam, Jan S; Yavari, Nazila; Sørensen, Søren; Andersson-Engels, Stefan

2005-07-10

We present a fast and accurate method for real-time determination of the absorption coefficient, the scattering coefficient, and the anisotropy factor of thin turbid samples by using simple continuous-wave noncoherent light sources. The three optical properties are extracted from recordings of angularly resolved transmittance in addition to spatially resolved diffuse reflectance and transmittance. The applied multivariate calibration and prediction techniques are based on multiple polynomial regression in combination with a Newton--Raphson algorithm. The numerical test results based on Monte Carlo simulations showed mean prediction errors of approximately 0.5% for all three optical properties within ranges typical for biological media. Preliminary experimental results are also presented yielding errors of approximately 5%. Thus the presented methods show a substantial potential for simultaneous absorption and scattering characterization of turbid media.

Laser waveform control of extreme ultraviolet high harmonics from solids.

PubMed

You, Yong Sing; Wu, Mengxi; Yin, Yanchun; Chew, Andrew; Ren, Xiaoming; Gholam-Mirzaei, Shima; Browne, Dana A; Chini, Michael; Chang, Zenghu; Schafer, Kenneth J; Gaarde, Mette B; Ghimire, Shambhu

2017-05-01

Solid-state high-harmonic sources offer the possibility of compact, high-repetition-rate attosecond light emitters. However, the time structure of high harmonics must be characterized at the sub-cycle level. We use strong two-cycle laser pulses to directly control the time-dependent nonlinear current in single-crystal MgO, leading to the generation of extreme ultraviolet harmonics. We find that harmonics are delayed with respect to each other, yielding an atto-chirp, the value of which depends on the laser field strength. Our results provide the foundation for attosecond pulse metrology based on solid-state harmonics and a new approach to studying sub-cycle dynamics in solids.

Spotting effect in microarray experiments

PubMed Central

Mary-Huard, Tristan; Daudin, Jean-Jacques; Robin, Stéphane; Bitton, Frédérique; Cabannes, Eric; Hilson, Pierre

2004-01-01

Background Microarray data must be normalized because they suffer from multiple biases. We have identified a source of spatial experimental variability that significantly affects data obtained with Cy3/Cy5 spotted glass arrays. It yields a periodic pattern altering both signal (Cy3/Cy5 ratio) and intensity across the array. Results Using the variogram, a geostatistical tool, we characterized the observed variability, called here the spotting effect because it most probably arises during steps in the array printing procedure. Conclusions The spotting effect is not appropriately corrected by current normalization methods, even by those addressing spatial variability. Importantly, the spotting effect may alter differential and clustering analysis. PMID:15151695

A facile approach towards increasing the nitrogen-content in nitrogen-doped carbon nanotubes via halogenated catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ombaka, L.M.; Ndungu, P.G.; Department of Applied Chemistry, Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028

Nitrogen-doped carbon nanotubes (N-CNTs) have been synthesized at 850 °C via a CVD deposition technique by use of three ferrocenyl derivative catalysts, i.e. para-CN, -CF{sub 3} and -Cl substituted-phenyl rings. The synthesized catalysts have been characterized by NMR, IR, HR-MS and XRD. The XRD analysis of the para-CF{sub 3} catalyst indicates that steric factors influence the X-ray structure of 1,1′-ferrocenylphenyldiacrylonitriles. Acetonitrile or pyridine was used as carbon and nitrogen sources to yield mixtures of N-CNTs and carbon spheres (CS). The N-CNTs obtained from the para-CF{sub 3} catalysts, in pyridine, have the highest nitrogen-doping level, show a helical morphology and aremore » less thermally stable compared with those synthesized by use of the para-CN and -Cl as catalyst. This suggests that fluorine heteroatoms enhance nitrogen-doping in N-CNTs and formation of helical-N-CNTs (H-N-CNTs). The para-CF{sub 3} and para-Cl catalysts in acetonitrile yielded iron-filled N-CNTs, indicating that halogens promote encapsulation of iron into the cavity of N-CNT. The use of acetonitrile, as carbon and nitrogen source, with the para-CN and -Cl as catalysts also yielded a mixture of N-CNTs and carbon nanofibres (CNFs), with less abundance of CNFs in the products obtained using para-Cl catalysts. However, para-CF{sub 3} catalyst in acetonitrile gave N-CNTs as the only shaped carbon nanomaterials. - Graphical abstract: Graphical abstract showing the synthesis of N-CNTs using halogenated-ferrocenyl derivatives as catalyst with pyridine or acetonitrile as nitrogen and carbon sources via the chemical vapour deposition technique. - Highlights: • N-CNTs were synthesized from halogenated ferrocenyl catalysts. • Halogenated catalysts promote nitrogen-doping and pyridinic nitrogen in N-CNTs. • Halogenated catalysts facilitate iron filling of N-CNTs.« less

Hot dry rock geothermal energy development program. Semiannual report, October 1, 1978-March 31, 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, M.C.; Nunz, G.J.; Cremer, G.M.

1979-09-01

The potential of energy extracted from hot dry rock (HDR) was investigated as a commercailly feasible alternate energy source. Run Segments 3 and 4 were completed in the prototype reservoir of the Phase I energy-extraction system at Fenton Hill, New Mexico. Results of these tests yielded significant data on the existing system and this information will be applicable to future HDR systems. Plans and operations initiating a Phase II system are underway at the Fenton Hill site. This system, a deeper, hotter commercial-size reservoir, is intended to demonstrate the longevity and economics of an HDR system. Major activity occurred inmore » evaluation of the national resource potential and in characterizing possible future HDR geothermal sites. Work has begun in the institutional and industrial support area to assess the economics and promote commercial interest in HDR systems as an alternate energy source.« less

Geometrical Properties of Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Cremades, Hebe; Bothmer, Volker

Based on the SOHO/LASCO dataset, a collection of "structured" coronal mass ejections (CMEs) has been compiled within the period 1996-2002, in order to analyze their three-dimensional configuration. These CME events exhibit white-light fine structures, likely indicative of their possible 3D topology. From a detailed investigation of the associated low coronal and photospheric source regions, a generic scheme has been deduced, which considers the white-light topology of a CME projected in the plane of the sky as being primarily dependent on the orientation and position of the source region's neutral line on the solar disk. The obtained results imply that structured CMEs are essentially organized along a symmetry axis, in a cylindrical manner. The measured dimensions of the cylinder's base and length yield a ratio of 1.6. These CMEs seem to be better approximated by elliptic cones, rather than by the classical ice cream cone, characterized by a circular cross section.

Audio Tracking in Noisy Environments by Acoustic Map and Spectral Signature.

PubMed

Crocco, Marco; Martelli, Samuele; Trucco, Andrea; Zunino, Andrea; Murino, Vittorio

2018-05-01

A novel method is proposed for generic target tracking by audio measurements from a microphone array. To cope with noisy environments characterized by persistent and high energy interfering sources, a classification map (CM) based on spectral signatures is calculated by means of a machine learning algorithm. Next, the CM is combined with the acoustic map, describing the spatial distribution of sound energy, in order to obtain a cleaned joint map in which contributions from the disturbing sources are removed. A likelihood function is derived from this map and fed to a particle filter yielding the target location estimation on the acoustic image. The method is tested on two real environments, addressing both speaker and vehicle tracking. The comparison with a couple of trackers, relying on the acoustic map only, shows a sharp improvement in performance, paving the way to the application of audio tracking in real challenging environments.

A Hydrothermal Route to the Synthesis of CaTiO3 Nanocuboids Using P25 as the Titanium Source

NASA Astrophysics Data System (ADS)

Yan, Yuxiang; Yang, Hua; Zhao, Xinxin; Zhang, Haimin; Jiang, Jinlong

2018-03-01

CaTiO3 nanocuboids (width 0.3-0.5 μm, length 0.8-1.1 μm) have been synthesized by a hydrothermal route using commercial P25 as the titanium source. The as-prepared sample was systematically characterized by means of x-ray powder diffraction, field-emission scanning electron microscopy, field-emission transmission electron microscopy, x-ray photoelectron spectroscopy, Brunauer-Emmett-Teller, ultraviolet-visible diffuse reflectance spectroscopy and electrochemical impedance spectroscopy. The photocatalytic activity of the sample was evaluated by degrading rhodamine B under simulated sunlight irradiation. It is demonstrated that CaTiO3 nanocuboids exhibit superior photocatalytic activity when compared with CaTiO3 nanoparticles. By investigating the effect of scavengers on the dye degradation and the yield of hydroxyl (·OH) radicals, it is concluded that ·OH is the dominant reactive species.

Deterministic implementation of a bright, on-demand single photon source with near-unity indistinguishability via quantum dot imaging.

PubMed

He, Yu-Ming; Liu, Jin; Maier, Sebastian; Emmerling, Monika; Gerhardt, Stefan; Davanço, Marcelo; Srinivasan, Kartik; Schneider, Christian; Höfling, Sven

2017-07-20

Deterministic techniques enabling the implementation and engineering of bright and coherent solid-state quantum light sources are key for the reliable realization of a next generation of quantum devices. Such a technology, at best, should allow one to significantly scale up the number of implemented devices within a given processing time. In this work, we discuss a possible technology platform for such a scaling procedure, relying on the application of nanoscale quantum dot imaging to the pillar microcavity architecture, which promises to combine very high photon extraction efficiency and indistinguishability. We discuss the alignment technology in detail, and present the optical characterization of a selected device which features a strongly Purcell-enhanced emission output. This device, which yields an extraction efficiency of η = (49 ± 4) %, facilitates the emission of photons with (94 ± 2.7) % indistinguishability.

Physiological-biochemical properties and the ability to synthesize polyhydroxyalkanoates of the glucose-utilizing strain of the hydrogen bacterium Ralstonia eutropha B8562.

PubMed

Volova, T G; Trusova, M Y; Kalacheva, G S; Kozhevnicov, I V

2006-11-01

Physiological-biochemical, genetic, and cultural properties of the glucose-utilizing mutant strain Ralstonia eutropha B8562 have been compared with those of its parent strain R. eutropha B5786. It has been shown that growth characteristics of the strain cultured on glucose as the sole carbon and energy source are comparable with those of the parent strain. Strain B8562 is characterized by high polyhydroxyalkanoate (PHA) yields on different carbon sources (CO(2), fructose, and glucose). PHA accumulation in the strain batch cultured on glucose under nitrogen deficiency reaches 90 %. The major monomer in the PHA is beta-hydroxybutyric acid (more than 99 mol %); the identified minor components are beta-hydroxyvaleric acid (0.25-0.72 mol %) and beta-hydroxyhexanoic acid (0.08-1.5 mol %). The strain is a promising PHA producer on available sugar-containing media with glucose.

Engineering Fluorometabolite Production: Fluorinase Expression in Salinispora tropica Yields Fluorosalinosporamide†

PubMed Central

Eustáquio, Alessandra S.; O'Hagan, David; Moore, Bradley S.

2010-01-01

Organofluorine compounds play an important role in medicinal chemistry where they are responsible for up to 15% of the pharmaceutical products on the market. While natural products are valuable sources of new chemical entities, natural fluorinated molecules are extremely rare and the pharmaceutical industry has not benefited from a microbial source of this class of compounds. Streptomyces cattleya is an unusual bacterium in that it elaborates fluoroacetate and the amino acid 4-fluorothreonine. The discovery in 2002 of the fluorination enzyme FlA responsible for C-F bond formation in S. cattleya, and its subsequent characterization, opened up for the first time the prospect of genetically engineering fluorometabolite production from fluoride ion in host organisms. As a proof of principle, we report here the induced production of fluorosalinosporamide by replacing the chlorinase gene salL from Salinispora tropica with the fluorinase gene flA. PMID:20085308

Aquifer-nomenclature guidelines

USGS Publications Warehouse

Laney, R.L.; Davidson, C.B.

1986-01-01

Guidelines and recommendations for naming aquifers are presented to assist authors of geohydrological reports in the United States Geological Survey, Water Resources Division. The hierarchy of terms that is used for water- yielding rocks from largest to smallest is aquifer system, aquifer, and zone. If aquifers are named, the names should be derived from lithologic terms, rock-stratigraphic units, or geographic names. The following items are not recommended as sources of aquifer names: time-stratigraphic names, relative position, alphanumeric designations, depositional environment, depth of occurrence, acronyms, and hydrologic conditions. Confining units should not be named unless doing so clearly promotes understanding of a particular aquifer system. Sources of names for confining units are similar to those for aquifer names, i.e. lithologic terms, rock-stratigraphic units or geographic names. Examples of comparison charts and tables that are used to define the geohydrologic framework are included. Aquifers are defined in 11 hypothetical examples that characterize geohydrologic settings throughout the country. (Author 's abstract)

Pristine Early Eocene wood buried deeply in kimberlite from northern Canada.

PubMed

Wolfe, Alexander P; Csank, Adam Z; Reyes, Alberto V; McKellar, Ryan C; Tappert, Ralf; Muehlenbachs, Karlis

2012-01-01

We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada's Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae). The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose δ(18)O and δ(2)H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12-17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information.

Pristine Early Eocene Wood Buried Deeply in Kimberlite from Northern Canada

PubMed Central

Wolfe, Alexander P.; Csank, Adam Z.; Reyes, Alberto V.; McKellar, Ryan C.; Tappert, Ralf; Muehlenbachs, Karlis

2012-01-01

We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada’s Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae). The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose δ18O and δ2H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12–17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information. PMID:23029080

Versatile Tri(pyrazolyl)phosphanes as Phosphorus Precursors for the Synthesis of Highly Emitting InP/ZnS Quantum Dots.

PubMed

Panzer, René; Guhrenz, Chris; Haubold, Danny; Hübner, René; Gaponik, Nikolai; Eychmüller, Alexander; Weigand, Jan J

2017-11-13

Tri(pyrazolyl)phosphanes (5 R1,R2 ) are utilized as an alternative, cheap and low-toxic phosphorus source for the convenient synthesis of InP/ZnS quantum dots (QDs). From these precursors, remarkably long-term stable stock solutions (>6 months) of P(OLA) 3 (OLAH=oleylamine) are generated from which the respective pyrazoles are conveniently recovered. P(OLA) 3 acts simultaneously as phosphorus source and reducing agent in the synthesis of highly emitting InP/ZnS core/shell QDs. These QDs are characterized by a spectral range between 530-620 nm and photoluminescence quantum yields (PL QYs) between 51-62 %. A proof-of-concept white light-emitting diode (LED) applying the InP/ZnS QDs as a color-conversion layer was built to demonstrate their applicability and processibility. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The genome and phenome of the green alga Chloroidium sp. UTEX 3007 reveal adaptive traits for desert acclimatization.

PubMed

Nelson, David R; Khraiwesh, Basel; Fu, Weiqi; Alseekh, Saleh; Jaiswal, Ashish; Chaiboonchoe, Amphun; Hazzouri, Khaled M; O'Connor, Matthew J; Butterfoss, Glenn L; Drou, Nizar; Rowe, Jillian D; Harb, Jamil; Fernie, Alisdair R; Gunsalus, Kristin C; Salehi-Ashtiani, Kourosh

2017-06-17

To investigate the phenomic and genomic traits that allow green algae to survive in deserts, we characterized a ubiquitous species, Chloroidium sp. UTEX 3007 , which we isolated from multiple locations in the United Arab Emirates (UAE). Metabolomic analyses of Chloroidium sp. UTEX 3007 indicated that the alga accumulates a broad range of carbon sources, including several desiccation tolerance-promoting sugars and unusually large stores of palmitate. Growth assays revealed capacities to grow in salinities from zero to 60 g/L and to grow heterotrophically on >40 distinct carbon sources. Assembly and annotation of genomic reads yielded a 52.5 Mbp genome with 8153 functionally annotated genes. Comparison with other sequenced green algae revealed unique protein families involved in osmotic stress tolerance and saccharide metabolism that support phenomic studies. Our results reveal the robust and flexible biology utilized by a green alga to successfully inhabit a desert coastline.

Pressure Flammability Thresholds in Oxygen of Selected Aerospace Materials

NASA Technical Reports Server (NTRS)

Hirsch, David; Williams, Jim; Harper, Susana; Beeson, Harold; Ruff, Gary; Pedley, Mike

2010-01-01

The experimental approach consisted of concentrating the testing in the flammability transition zone following the Bruceton Up-and-Down Method. For attribute data, the method has been shown to be very repeatable and most efficient. Other methods for characterization of critical levels (Karberand Probit) were also considered. The data yielded the upward limiting pressure index (ULPI), the pressure level where approx.50% of materials self-extinguish in a given environment.Parametric flammability thresholds other than oxygen concentration can be determined with the methodology proposed for evaluating the MOC when extinguishment occurs. In this case, a pressure threshold in 99.8% oxygen was determined with the methodology and found to be 0.4 to 0.9 psia for typical spacecraft materials. Correlation of flammability thresholds obtained with chemical, hot wire, and other ignition sources will be conducted to provide recommendations for using alternate ignition sources to evaluate flammability of aerospace materials.

Characterization of bean (Phaseolus vulgaris L.) ecotype "Fagiolo occhio nero di Oliveto Citra" using agronomic, biochemical and molecular approaches.

PubMed

Zaccardelli, Massimo; Pentangelo, Alfonso; Tripodi, Pasquale

2013-09-15

Common bean (Phaseolus vulgaris) is the most important grain legume and plays a significant role in human nutrition being a major source of dietary protein and representing a rich source of minerals and certain vitamins. Several large germplasm collections have been established, which contain large amounts of genetic diversity, including wild and domesticated species. In this study agronomic, biochemical and molecular characterization of landrace bean named "Fagiolo occhio nero di Oliveto Citra" (Phaseolus vulgaris L.), is described. Seeds were obtained by local farmers and field trials were carried out during years 2009-2010, in the typical cultivation site (Oliveto Citra, Salerno Province), using two different densities of investment. During 2011, in order to evaluate the performance in different environments, field trials were conducted in three localities (Battipaglia, Oliveto Citra and Controne). Data analysis shows good adaptability across locations and similar grain yield using two spacing's of seeds. Morphological characterization and molecular analysis, using AFLP and Minisatellite molecular markers, were performed on ten "biotypes" collected from local farmers. Seeds characterization showed variability on the violet area surrounding the hilum (named as eye) while markers have provided useful information on relationships between biotypes. Biochemical analysis, which includes the contents of protein, minerals and antioxidants, shows how the composition is consistent with respect to other landraces and commercial cultivars. The landrace under study revealed genetic stability and good adaptation to cultivated environment with best performance in the native area. In addition, the bio-agronomic characteristics are in accord with studies reported in literature.

Regulation Effects of Water and Nitrogen on the Source-Sink Relationship in Potato during the Tuber Bulking Stage

PubMed Central

Li, Wenting; Xiong, Binglin; Wang, Shiwen; Deng, Xiping; Yin, Lina; Li, Hongbing

2016-01-01

The source-sink relationship determines crop yield, and it is largely regulated by water and nutrients in agricultural production. This has been widely investigated in cereals, but fewer studies have been conducted in root and tuber crops such as potato (Solanum tuberosum L.). The objective of this study was to investigate the source-sink relationship in potato and the regulation of water and nitrogen on the source-sink relationship during the tuber bulking stage. A pot experiment using virus-free plantlets of the Atlantic potato cultivar was conducted, using three water levels (50%, 70% and 90% of field capacity) and three nitrogen levels (0, 0.2, 0.4 g N∙kg−1 soil). The results showed that, under all water and nitrogen levels, plant source capacity were small at the end of the experiment, since photosynthetic activity in leaves were low and non-structural reserves in underground stems were completely remobilized. While at this time, there were very big differences in maximum and minimum tuber number and tuber weight, indicating that the sink tuber still had a large potential capacity to take in assimilates. These results suggest that the source-supplied assimilates were not sufficient enough to meet the demands of sink growth. Thus, we concluded that, unlike cereals, potato yield is more likely to be source-limited than sink-limited during the tuber bulking stage. Water and nitrogen are two key factors in potato production management. Our results showed that water level, nitrogen level and the interaction between water and nitrogen influence potato yield mainly through affecting source capacity via the net photosynthetic rate, total leaf area and leaf life span. Well-watered, sufficient nitrogen and well-watered combined with sufficient nitrogen increased yield mainly by enhancing the source capacity. Therefore, this suggests that increasing source capacity is more crucial to improve potato yield. PMID:26752657

Coconut coir pith lignin: A physicochemical and thermal characterization.

PubMed

Asoka Panamgama, L; Peramune, P R U S K

2018-07-01

The structural and thermal features of coconut coir pith lignin, isolated by three different extraction protocols incorporating two different energy supply sources, were characterized by different analytical tools. The three different chemical extraction protocols were alkaline - 7.5% (w/v) NaOH, organosolv - 85% (v/v) formic and acetic acids at 7:3 (v/v) ratio and polyethylene glycol (PEG): water ratio at 80:20wt%. The two sources of energy were thermal or microwave. Raw lignins were modified by epichlorohydrin to enhance reactivity, and the characteristics of raw and modified lignins were comparatively analysed. Using the thermal energy source, the alkaline and organosolv processes obtained the highest and lowest lignin yields of 26.4±1.5wt% and 3.4±0.2wt%, respectively, as shown by wet chemical analysis. Specific functional group analysis by Fourier transform infrared spectra (FTIR) revealed that significantly different amounts of hydroxyl and carbonyl groups exist in alkaline, organosolv and PEG lignins. Thermogravimetric analysis (TGA) illustrated that the lowest degradation onset temperature was recorded for organosolv lignin, and the overall order was organosolv

A time-frequency analysis of the dynamics of cortical networks of sleep spindles from MEG-EEG recordings

PubMed Central

Zerouali, Younes; Lina, Jean-Marc; Sekerovic, Zoran; Godbout, Jonathan; Dube, Jonathan; Jolicoeur, Pierre; Carrier, Julie

2014-01-01

Sleep spindles are a hallmark of NREM sleep. They result from a widespread thalamo-cortical loop and involve synchronous cortical networks that are still poorly understood. We investigated whether brain activity during spindles can be characterized by specific patterns of functional connectivity among cortical generators. For that purpose, we developed a wavelet-based approach aimed at imaging the synchronous oscillatory cortical networks from simultaneous MEG-EEG recordings. First, we detected spindles on the EEG and extracted the corresponding frequency-locked MEG activity under the form of an analytic ridge signal in the time-frequency plane (Zerouali et al., 2013). Secondly, we performed source reconstruction of the ridge signal within the Maximum Entropy on the Mean framework (Amblard et al., 2004), yielding a robust estimate of the cortical sources producing observed oscillations. Lastly, we quantified functional connectivity among cortical sources using phase-locking values. The main innovations of this methodology are (1) to reveal the dynamic behavior of functional networks resolved in the time-frequency plane and (2) to characterize functional connectivity among MEG sources through phase interactions. We showed, for the first time, that the switch from fast to slow oscillatory mode during sleep spindles is required for the emergence of specific patterns of connectivity. Moreover, we show that earlier synchrony during spindles was associated with mainly intra-hemispheric connectivity whereas later synchrony was associated with global long-range connectivity. We propose that our methodology can be a valuable tool for studying the connectivity underlying neural processes involving sleep spindles, such as memory, plasticity or aging. PMID:25389381

What are the contemporary sources of sediment in the Mississippi River?

NASA Astrophysics Data System (ADS)

Hassan, M. A.; Roberge, L.; Church, M.; More, M.; Donner, S. D.; Leach, J.; Ali, K. F.

2017-09-01

Within the last two centuries, the Mississippi River basin has been transformed by changes in land use practices, dam construction, and training of the rivers for navigation. Here we analyze the contemporary patterns of fluvial sediment yield in the Mississippi River basin using all available data in order to assess the influence of regional land condition on the variation of sediment yield within the basin. We develop regional-scale relations between specific sediment yield (yield per unit area) and drainage area to reveal contemporary regional sediment yield patterns and source areas of riverine sediments. Extensive upland erosion before the development of soil conservation practices exported large amounts of sediment to the valleys and floodplains. We show that sediment today is sourced primarily along the river valleys from arable land, and from stream bank and channel erosion, with sediment yields from areas dominated by arable land 2 orders of magnitude greater than that of grassland dominated areas. Comparison with the "T factor," a commonly quoted measure of agricultural soil resilience suggests that the latter may not reflect contemporary soil loss from the landscape.

Characterization of PbWO4 crystals for high-energy physics experiments

NASA Astrophysics Data System (ADS)

Kim, M. J.; Park, H.; Kim, H. J.

2016-09-01

High-energy physics (HEP) experiments have employed many new types of scintillators. Specifically, bismuth germanate, thallium-doped cesium iodide, and lead tungstate (PbWO4, PWO) have been used for the L3 experiment; CLEO II, Belle and BES-III; and CMS, respectively. PWO has particularly beneficial properties, such as high density, fast decay time, short radiation length and radiation hardness. In this study, we tested the PWO crystals at low temperatures to determine their applicability in future calorimeters. Various crystals from the Proton Antiproton Annihilations at Darmstadt (PANDA) experiment in Giessen, the Bogoroditsk Techno-Chemical Plant (BTCP) in Russia and by Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS) in China were investigated. We studied the scintillation properties of PWO crystals, such as their X-ray luminescence, relative light yields, absolute light yields, energy resolutions, decay times and longitudinal uniformities of their light yields. In addition, we measured the temperature dependences of the light yields and decay times by using a 137Cs γ-ray source. The emission spectra of the PWO crystals consisted of a broad band from 350 nm to 700 nm, and the peak emission wavelength in each spectrum was 420 nm. The emission spectra of the PWO crystals from SICCAS were slightly shifted to longer wavelengths compared with those of the crystals from the other institutions.

Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

NASA Astrophysics Data System (ADS)

Veloce, L. M.; Kuźniak, M.; Di Stefano, P. C. F.; Noble, A. J.; Boulay, M. G.; Nadeau, P.; Pollmann, T.; Clark, M.; Piquemal, M.; Schreiner, K.

2016-06-01

Liquid noble based particle detectors often use the organic wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation light to the visible regime, facilitating its detection, but which also can scintillate on its own. Dark matter searches based on this type of detector commonly rely on pulse-shape discrimination (PSD) for background mitigation. Alpha-induced scintillation therefore represents a possible background source in dark matter searches. The timing characteristics of this scintillation determine whether this background can be mitigated through PSD. We have therefore characterized the pulse shape and light yield of alpha induced TPB scintillation at temperatures ranging from 300 K down to 4 K, with special attention given to liquid noble gas temperatures. We find that the pulse shapes and light yield depend strongly on temperature. In addition, the significant contribution of long time constants above ~50 K provides an avenue for discrimination between alpha decay events in TPB and nuclear-recoil events in noble liquid detectors.

White light photothermal lens spectrophotometer for the determination of absorption in scattering samples.

PubMed

Marcano, Aristides; Alvarado, Salvador; Meng, Junwei; Caballero, Daniel; Moares, Ernesto Marín; Edziah, Raymond

2014-01-01

We developed a pump-probe photothermal lens spectrophotometer that uses a broadband arc-lamp and a set of interference filters to provide tunable, nearly monochromatic radiation between 370 and 730 nm as the pump light source. This light is focused onto an absorbing sample, generating a photothermal lens of millimeter dimensions. A highly collimated monochromatic probe light from a low-power He-Ne laser interrogates the generated lens, yielding a photothermal signal proportional to the absorption of light. We measure the absorption spectra of scattering dye solutions using the device. We show that the spectra are not affected by the presence of scattering, confirming that the method only measures the absorption of light that results in generation of heat. By comparing the photothermal spectra with the usual absorption spectra determined using commercial transmission spectrophotometers, we estimate the quantum yield of scattering of the sample. We discuss applications of the device for spectroscopic characterization of samples such as blood and gold nanoparticles that exhibit a complex behavior upon interaction with light.

Physical factors controlling carbon cycling dynamics in blackwater river-dominated and particle dominated estuaries

NASA Astrophysics Data System (ADS)

Arellano, A. R.; Bianchi, T. S.; Osburn, C. L.; D'Sa, E. J.; Oviedo-Vargas, D.; Ward, N. D.; Joshi, I.

2017-12-01

While most blue carbon habitat (wetlands, seagrass beds and mangroves) research has focused on carbon burial/stocks and habitat fragmentation of these communities, few studies have examined physical factors that control exports and losses of blue carbon sources of organic matter (OM) to adjacent coastal waters. Here, we report on spatiotemporal changes in the composition and concentration of dissolved organic carbon (DOC), particulate organic carbon (POC), particulate nitrogen, pCO2, δ13C-DOC, δ13C-POC, δ13C-CO2, dissolved lignin-phenols (dΣ8), particulate lignin-phenols (pΣ8) and carbon normalized dissolved and particulate lignin phenol yields (dΛ8 and pΛ8) in surface waters of the Apalachicola and Barataria bays in the Gulf of Mexico. Discriminant analysis described spatial variability along canonical axis I (24.4%) while temporal variability was explained by canonical axis II (23.2%). Apalachicola Bay was low in POC concentration and characterized by high values for pCO2, DOC, C:N, dΣ8 and (Ad:Al)V. The latter three parameters indicated a clear terrestrial source of OM at Apalachicola Bay reflecting the importance of riverine DOM inputs in this system. In contrast, Barataria Bay was characterized by high values for POC, C:V, S:V, and δ13C-POC, indicating blue-carbon sources due to a lack of direct river inputs and high prevalence of wetlands, some recently submerged. Extreme weather, such as intense precipitation events in Apalachicola Bay and enhanced northerly winds in Barataria Bay were characterized by δ13C-CO2, dΛ8, C:V (Barataria), and C:N (Apalachicola). Results indicate that such physical factors can exert strong control on OM sources and sinks across the gradient of coastal wetlands and shelf waters and lead to enhanced transfer and degradation of wetland-derived blue carbon in coastal waters.

Dynamic evolution of the source volumes of gradual and impulsive solar flare emissions

NASA Technical Reports Server (NTRS)

Bruner, M. E.; Crannell, C. J.; Goetz, F.; Magun, A.; Mckenzie, D. L.

1987-01-01

This study compares flare source volumes inferred from impulsive hard X-rays and microwaves with those derived from density sensitive soft X-ray line ratios in the O VII spectrum. The data for this study were obtained with the SMM Hard X-Ray Burst Spectrometer, Earth-based radio observatories, and the SOLEX-B spectrometer on the P78-1 satellite. Data were available for the flares of 1980 April 8, 1980 May 9, and 1981 February 26. The hard X-ray/microwave source volume is determined under the assumption that the same electron temperature or power law index characterizes both the source of hard X-rays and the source of microwaves. The O VII line ratios yield the density and volume of the 2 X 10 to the 6th K plasma. For all three flares, the O VII source volume is found to be smallest at the beginning of the flare, near the time when the impulsive hard X-ray/microwave volume reaches its first maximum. At this time, the O VII volume is three to four orders of magnitude smaller than that inferred from the hard X-ray/microwave analysis. Subsequently, the O VII source volume increases by one or two orders of magnitude then remains almost constant until the end of the flare when it apparently increases again.

Sources and export of particle-borne organic matter during a monsoon flood in a catchment of northern Laos

NASA Astrophysics Data System (ADS)

Gourdin, E.; Huon, S.; Evrard, O.; Ribolzi, O.; Bariac, T.; Sengtaheuanghoung, O.; Ayrault, S.

2014-06-01

Tropical rivers of Southeast Asia are characterized by high specific carbon yields and supplies to the ocean. The origin and dynamics of particulate organic matter were studied in the Houay Xon River catchment located in northern Laos during the first erosive flood of the rainy season in May 2012. The partly cultivated catchment is equipped with three successive gauging stations draining areas ranging between 0.2 and 11.6 km2 on the main stem of the permanent stream, and two additional stations draining 0.6 ha hillslopes. In addition, the sequential monitoring of rainwater, overland flow and suspended organic matter compositions was realized at 1 m2 plot scale during a single storm. The composition of particulate organic matter (total organic carbon, total nitrogen, δ13C and δ15N) was determined for suspended sediment, soil surface and subsurface samples collected in the catchment (n = 57, 65 and 11 respectively). Hydrograph separation of event water was conducted using water electric conductivity and δ18O data measured for rainfall, overland flow and river water base flow (n = 9, 30 and 57, respectively). The composition of particulate organic matter indicates that upstream suspended sediments were mainly derived from cultivated soils labelled by their C3 vegetation cover (upland rice, fallow vegetation and teak plantations) but that collapsed riverbanks, characterized by C4 vegetation occurrence (Napier grass), significantly contributed to sediment yields during water level rise and at the downstream station. The highest runoff coefficient (11.7%), sediment specific yield (433 kg ha-1), total organic carbon specific yield (8.3 kg C ha-1) and overland flow contribution (78-100%) were found for the reforested areas covered by teak plantations. Total organic carbon specific yields were up to 2.6-fold higher (at downstream station) than the annual ones calculated 10 years earlier, before the expansion of teak plantations in the catchment. They may be attributed both to the sampling period at the onset of the rainy season (following field clearing by slash and burn) and to the impact of land use change during the past decade.

Contribution of Satellite Gravimetry to Understanding Seismic Source Processes of the 2011 Tohoku-Oki Earthquake

NASA Technical Reports Server (NTRS)

Han, Shin-Chan; Sauber, Jeanne; Riva, Riccardo

2011-01-01

The 2011 great Tohoku-Oki earthquake, apart from shaking the ground, perturbed the motions of satellites orbiting some hundreds km away above the ground, such as GRACE, due to coseismic change in the gravity field. Significant changes in inter-satellite distance were observed after the earthquake. These unconventional satellite measurements were inverted to examine the earthquake source processes from a radically different perspective that complements the analyses of seismic and geodetic ground recordings. We found the average slip located up-dip of the hypocenter but within the lower crust, as characterized by a limited range of bulk and shear moduli. The GRACE data constrained a group of earthquake source parameters that yield increasing dip (7-16 degrees plus or minus 2 degrees) and, simultaneously, decreasing moment magnitude (9.17-9.02 plus or minus 0.04) with increasing source depth (15-24 kilometers). The GRACE solution includes the cumulative moment released over a month and demonstrates a unique view of the long-wavelength gravimetric response to all mass redistribution processes associated with the dynamic rupture and short-term postseismic mechanisms to improve our understanding of the physics of megathrusts.

Source-sink interaction: a century old concept under the light of modern molecular systems biology.

PubMed

Chang, Tian-Gen; Zhu, Xin-Guang; Raines, Christine

2017-07-20

Many approaches to engineer source strength have been proposed to enhance crop yield potential. However, a well-co-ordinated source-sink relationship is required finally to realize the promised increase in crop yield potential in the farmer's field. Source-sink interaction has been intensively studied for decades, and a vast amount of knowledge about the interaction in different crops and under different environments has been accumulated. In this review, we first introduce the basic concepts of source, sink and their interactions, then summarize current understanding of how source and sink can be manipulated through both environmental control and genetic manipulations. We show that the source-sink interaction underlies the diverse responses of crops to the same perturbations and argue that development of a molecular systems model of source-sink interaction is required towards a rational manipulation of the source-sink relationship for increased yield. We finally discuss both bottom-up and top-down routes to develop such a model and emphasize that a community effort is needed for development of this model. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Large-N Over the Source Physics Experiment (SPE) Phase I and Phase II Test Beds

NASA Astrophysics Data System (ADS)

Snelson, C. M.; Carmichael, J. D.; Mellors, R. J.; Abbott, R. E.

2014-12-01

One of the current challenges in the field of monitoring and verification is source discrimination of low-yield nuclear explosions from background seismicity, both natural and anthropogenic. Work is underway at the Nevada National Security Site to conduct a series of chemical explosion experiments using a multi-institutional, multi-disciplinary approach. The goal of this series of experiments, called the Source Physics Experiments (SPE), is to refine the understanding of the effect of earth structures on source phenomenology and energy partitioning in the source region, the transition of seismic energy from the near field to the far field, and the development of S waves observed in the far field. To fully explore these problems, the SPE series includes tests in both hard and soft rock geologic environments. The project comprises a number of activities, which range from characterizing the shallow subsurface to acquiring new explosion data from both the near field (<100 m) and the far field (>100 m). SPE includes a series of planned explosions (with different yields and depths of burials), which are conducted in the same hole and monitored by a diverse set of sensors recording characteristics of the explosions, ground-shock, seismo-acoustic energy propagation. This presentation focuses on imaging the full 3D wavefield over hard rock and soft rock test beds using a large number of seismic sensors. This overview presents statistical analyses of optimal sensor layout required to estimate wavefield discriminants and the planned deployment for the upcoming experiments. This work was conducted under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Photodissociation of pernitric acid (HO2NO2) at 248 nm

NASA Technical Reports Server (NTRS)

Macleod, Helene; Smith, Gregory P.; Golden, David M.

1989-01-01

The photodissociation of pernitric acid (PNA) was studied at 248 nm. The quantum yield for production of OH radicals is 34 + or - 16 percent. The yield of OH from PNA was measured relative to that of H2O2. The translational and rotational energy content of the OH photofragment from PNA was characterized. A fluorescent emission was also observed and characterized. It is attributed to electronically excited NO2 produced in the PNA photodissociation. A maximum yield of 30 percent for NO2 production was determined. The intensity of this emission, and a mass spectrometric peak at m/e = 33, were found to be useful means of characterizing the purity of the PNA sample.

How to precisely measure the volume velocity transfer function of physical vocal tract models by external excitation

PubMed Central

Mainka, Alexander; Kürbis, Steffen; Birkholz, Peter

2018-01-01

Recently, 3D printing has been increasingly used to create physical models of the vocal tract with geometries obtained from magnetic resonance imaging. These printed models allow measuring the vocal tract transfer function, which is not reliably possible in vivo for the vocal tract of living humans. The transfer functions enable the detailed examination of the acoustic effects of specific articulatory strategies in speaking and singing, and the validation of acoustic plane-wave models for realistic vocal tract geometries in articulatory speech synthesis. To measure the acoustic transfer function of 3D-printed models, two techniques have been described: (1) excitation of the models with a broadband sound source at the glottis and measurement of the sound pressure radiated from the lips, and (2) excitation of the models with an external source in front of the lips and measurement of the sound pressure inside the models at the glottal end. The former method is more frequently used and more intuitive due to its similarity to speech production. However, the latter method avoids the intricate problem of constructing a suitable broadband glottal source and is therefore more effective. It has been shown to yield a transfer function similar, but not exactly equal to the volume velocity transfer function between the glottis and the lips, which is usually used to characterize vocal tract acoustics. Here, we revisit this method and show both, theoretically and experimentally, how it can be extended to yield the precise volume velocity transfer function of the vocal tract. PMID:29543829

Longitudinal study on the sources of Listeria monocytogenes contamination in cold-smoked salmon and its processing environment in Italy.

PubMed

Di Ciccio, Pierluigi; Meloni, Domenico; Festino, Anna Rita; Conter, Mauro; Zanardi, Emanuela; Ghidini, Sergio; Vergara, Alberto; Mazzette, Rina; Ianieri, Adriana

2012-08-01

The aim of the present study was to investigate the sources of Listeria monocytogenes contamination in a cold smoked salmon processing environment over a period of six years (2003-2008). A total of 170 samples of raw material, semi-processed, final product and processing surfaces at different production stages were tested for the presence of L. monocytogenes. The L. monocytogenes isolates were characterized by multiplex PCR for the analysis of virulence factors and for serogrouping. The routes of contamination over the six year period were traced by PFGE. L. monocytogenes was isolated from 24% of the raw salmon samples, 14% of the semi-processed products and 12% of the final products. Among the environmental samples, 16% were positive for L. monocytogenes. Serotyping yielded three serovars: 1/2a, 1/2b, 4b, with the majority belonging to serovars 1/2a (46%) and 1/2b (39%). PFGE yielded 14 profiles: two of them were repeatedly isolated in 2005-2006 and in 2007-2008 mainly from the processing environment and final products but also from raw materials. The results of this longitudinal study highlighted that contamination of smoked salmon occurs mainly during processing rather than originating from raw materials, even if raw fish can be a contamination source of the working environment. Molecular subtyping is critical for the identification of the contamination routes of L. monocytogenes and its niches into the production plant when control strategies must be implemented with the aim to reduce its prevalence during manufacturing. Copyright © 2012 Elsevier B.V. All rights reserved.

Exopolysaccharide-producing lactic acid bacteria strains from traditional Thai fermented foods: isolation, identification and exopolysaccharide characterization.

PubMed

Smitinont, T; Tansakul, C; Tanasupawat, S; Keeratipibul, S; Navarini, L; Bosco, M; Cescutti, P

1999-10-15

Lactic Acid Bacteria (LAB) isolated from various traditional Thai fermented foods were screened for exopolysaccharides (EPS) production. From 104 isolates, two rod-shaped and five coccal-shaped LAB were able to produce EPS from sucrose on solid media. However, only the cocci were capable of producing EPS in liquid media and these were identified as Pediococcus pentosaceus. Pediococcus pentosaceus strains AP-1 and AP-3 produced EPS in high yield. In liquid media containing sucrose as carbon source, the amount of EPS produced by AP-1 and AP-3 strains was 6.0 and 2.5 g/L, respectively. The isolated and purified EPSs were chemically characterized. On the basis of sugar composition, methylation analysis and nuclear magnetic resonance spectroscopy, both the EPSs were shown to belong to the same dextran class. In particular, both EPSs differed from linear dextran by branching through 3,6-di-Osubstituted alpha-D-glucopyranosyl residues. The EPS from P. pentosaceus AP-3 was characterized by a relatively higher degree of branching and by a higher molecular weight than that from P. pentosaceus AP-1.

Predicted Exoplanet Yields for the HabEx Mission Concept

NASA Astrophysics Data System (ADS)

Stark, Christopher; Mennesson, Bertrand; HabEx STDT

2018-01-01

The Habitable Exoplanet Imaging Mission (HabEx) is a concept for a flagship mission to directly image and characterize extrasolar planets around nearby stars and to enable a broad range of general astrophysics. The HabEx Science and Technology Definition Team (STDT) is currently studying two architectures for HabEx. Here we summarize the exoplanet science yield of Architecture A, a 4 m monolithic off-axis telescope that uses a vortex coronagraph and a 72m external starshade occulter. We summarize the instruments' capabilities, present science goals and observation strategies, and discuss astrophysical assumptions. Using a yield optimization code, we predict the yield of potentially Earth-like extrasolar planets that could be detected, characterized, and searched for signs of habitability and/or life by HabEx. We demonstrate that HabEx could also detect and characterize a wide variety of exoplanets while searching for potentially Earth-like planets.

Predicting Lg Coda Using Synthetic Seismograms and Media With Stochastic Heterogeneity

NASA Astrophysics Data System (ADS)

Tibuleac, I. M.; Stroujkova, A.; Bonner, J. L.; Mayeda, K.

2005-12-01

Recent examinations of the characteristics of coda-derived Sn and Lg spectra for yield estimation have shown that the spectral peak of Nevada Test Site (NTS) explosion spectra is depth-of-burial dependent, and that this peak is shifted to higher frequencies for Lop Nor explosions at the same depths. To confidently use coda-based yield formulas, we need to understand and predict coda spectral shape variations with depth, source media, velocity structure, topography, and geological heterogeneity. We present results of a coda modeling study to predict Lg coda. During the initial stages of this research, we have acquired and parameterized a deterministic 6 deg. x 6 deg. velocity and attenuation model centered on the Nevada Test Site. Near-source data are used to constrain density and attenuation profiles for the upper five km. The upper crust velocity profiles are quilted into a background velocity profile at depths greater than five km. The model is parameterized for use in a modified version of the Generalized Fourier Method in two dimensions (GFM2D). We modify this model to include stochastic heterogeneities of varying correlation lengths within the crust. Correlation length, Hurst number and fractional velocity perturbation of the heterogeneities are used to construct different realizations of the random media. We use nuclear explosion and earthquake cluster waveform analysis, as well as well log and geological information to constrain the stochastic parameters for a path between the NTS and the seismic stations near Mina, Nevada. Using multiple runs, we quantify the effects of variations in the stochastic parameters, of heterogeneity location in the crust and attenuation on coda amplitude and spectral characteristics. We calibrate these parameters by matching synthetic earthquake Lg coda envelopes to coda envelopes of local earthquakes with well-defined moments and mechanisms. We generate explosion synthetics for these calibrated deterministic and stochastic models. Secondary effects, including a compensated linear vector dipole source, are superposed on the synthetics in order to adequately characterize the Lg generation. We use this technique to characterize the effects of depth of burial on the coda spectral shapes.

Xiphoid Process-Derived Chondrocytes: A Novel Cell Source for Elastic Cartilage Regeneration

PubMed Central

Nam, Seungwoo; Cho, Wheemoon; Cho, Hyunji; Lee, Jungsun

2014-01-01

Reconstruction of elastic cartilage requires a source of chondrocytes that display a reliable differentiation tendency. Predetermined tissue progenitor cells are ideal candidates for meeting this need; however, it is difficult to obtain donor elastic cartilage tissue because most elastic cartilage serves important functions or forms external structures, making these tissues indispensable. We found vestigial cartilage tissue in xiphoid processes and characterized it as hyaline cartilage in the proximal region and elastic cartilage in the distal region. Xiphoid process-derived chondrocytes (XCs) showed superb in vitro expansion ability based on colony-forming unit fibroblast assays, cell yield, and cumulative cell growth. On induction of differentiation into mesenchymal lineages, XCs showed a strong tendency toward chondrogenic differentiation. An examination of the tissue-specific regeneration capacity of XCs in a subcutaneous-transplantation model and autologous chondrocyte implantation model confirmed reliable regeneration of elastic cartilage regardless of the implantation environment. On the basis of these observations, we conclude that xiphoid process cartilage, the only elastic cartilage tissue source that can be obtained without destroying external shape or function, is a source of elastic chondrocytes that show superb in vitro expansion and reliable differentiation capacity. These findings indicate that XCs could be a valuable cell source for reconstruction of elastic cartilage. PMID:25205841

Determining the source characteristics of explosions near the Earth's surface

DOE PAGES

Pasyanos, Michael E.; Ford, Sean R.

2015-04-09

We present a method to determine the source characteristics of explosions near the airearth interface. The technique is an extension of the regional amplitude envelope method and now accounts for the reduction of seismic amplitudes as the depth of the explosion approaches the free surface and less energy is coupled into the ground. We first apply the method to the Humming Roadrunner series of shallow explosions in New Mexico where the yields and depths are known. From these tests, we find an appreciation of knowing the material properties for both source coupling/excitation and the free surface effect. Although there ismore » the expected tradeoff between depth and yield due to coupling effects, the estimated yields are generally close to the known values when the depth is constrained to the free surface. We then apply the method to a regionally recorded explosion in Syria. We estimate an explosive yield less than the 60 tons claimed by sources in the open press. The modifications to the method allow us to apply the technique to new classes of events, but we will need a better understanding of explosion source models and properties of additional geologic materials.« less

Site Characterization of the Source Physics Experiment Phase II Location Using Seismic Reflection Data

NASA Astrophysics Data System (ADS)

Sexton, E. A.; Snelson, C. M.; Chipman, V.; Emer, D. F.; White, R. L.; Emmitt, R.; Wright, A. A.; Drellack, S.; Huckins-Gang, H.; Mercadante, J.; Floyd, M.; McGowin, C.; Cothrun, C.; Bonal, N.

2013-12-01

An objective of the Source Physics Experiment (SPE) is to identify low-yield nuclear explosions from a regional distance. Low-yield nuclear explosions can often be difficult to discriminate among the clutter of natural and man-made explosive events (e.g., earthquakes and mine blasts). The SPE is broken into three phases. Phase I has provided the first of the physics-based data to test the empirical models that have been used to discriminate nuclear events. The Phase I series of tests were placed within a highly fractured granite body. The evolution of the project has led to development of Phase II, to be placed within the opposite end member of geology, an alluvium environment, thereby increasing the database of waveforms to build upon in the discrimination models. Both the granite and alluvium sites have hosted nearby nuclear tests, which provide comparisons for the chemical test data. Phase III of the SPE is yet to be determined. For Phase II of the experiment, characterization of the location is required to develop the geologic/geophysical models for the execution of the experiment. Criteria for the location are alluvium thickness of approximately 170 m and a water table below 170 m; minimal fracturing would be ideal. A P-wave mini-vibroseis survey was conducted at a potential site in alluvium to map out the subsurface geology. The seismic reflection profile consisted of 168 geophone stations, spaced 5 m apart. The mini-vibe was a 7,000-lb peak-force source, starting 57.5 m off the north end of the profile and ending 57.5 m past the southern-most geophone. The length of the profile was 835 m. The source points were placed every 5 m, equally spaced between geophones to reduce clipping. The vibroseis sweep was from 20 Hz down to 180 Hz over 8 seconds, and four sweeps were stacked at each shot location. The shot gathers show high signal-to-noise ratios with clear first arrivals across the entire spread and the suggestion of some shallow reflectors. The data were processed using Seismic Processing Workshop in a standard reflection processing flow. The results from this vibroseis survey will contribute to the characterization of the location for Phase II of the SPE in order to appropriately execute the experiment. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1836. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Characterization of trace organic compounds associated with aged and diluted sidestream tobacco smoke in a controlled atmosphere—volatile organic compounds and polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Baek, Sung-Ok; Jenkins, Roger A.

In this study, a wide range of volatile organic constituents of aged and diluted sidestream tobacco smoke (ADSS) were determined in a controlled atmosphere, where ADSS is the sole source of target compounds. The ADSS was generated in a 30 m 3 environmental test chamber using a variety of cigarettes, including the Kentucky 1R4F reference cigarette and eight commercial brands, and a total of 24 experimental runs were conducted. Target analytes were divided into three groups, i.e. vapor and particulate phase markers for environmental tobacco smoke (ETS), volatile organic compounds (VOC) including carbonyls, and polycyclic aromatic hydrocarbons (PAH). The VOC samples were collected on triple sorbent traps, and then analyzed by thermal desorption coupled with gas chromatography/mass spectrometry (GC/MS), while the carbonyl compounds were sampled on DNPH cartridges, being analyzed by HPLC. ETS particles in the chamber were collected by high volume sampling, and then used for the determination of PAHs by GC/MS. Among more than 30 target VOCs, acetaldehyde appeared to be the most abundant compound, followed by 2-methyl-1,3-butadiene, and formaldehyde. The results from the chamber study were further used to generate characterized ratios of selected VOCs to 3-ethenyl pyridine (3-EP), a vapor phase ETS marker. The ratios appeared to be in generally good agreement with published values in the literature. This suggests that the characteristic ratios may be useful for quantifying the impact of ETS on the VOC concentrations in 'real world' indoor environments, which are affected by a complex mixture of components from multiple sources. The yields of ETS markers from this study are all slightly lower than those estimated by other studies, while VOC yields are in reasonable agreement in many cases with values in the literature. Among 16 target PAHs, chrysene appeared to be most abundant, followed by benzo(a)anthracene (BaA) and benzo(a)pyrene (BaP). The average contents of BaP and BaA in ADSS particles for the commercial brands were 12.8 and 21.5 μg g -1, respectively. These values are all approximately 1.5-3 times higher than those determined previously by other studies. The average yields of BaP per cigarette were estimated to be 209 and 215 ng for the reference and commercial cigarettes, respectively. Comparison of the PAH data from this study with literature values was complicated by a lack of consistency in cigarette smoke generating methodology among other studies. These data on the cigarette yields of ETS components may provide useful information to studies on the mathematical modeling of indoor air quality regarding tobacco smoke as a source of interest, or to studies on the assessment of human exposure to ETS.

Synthesis and adsorption properties of titanosilicates ETS-4 and ETS-10 from fly ash.

PubMed

Liu, Liying; Singh, Ranjeet; Li, Gang; Xiao, Penny; Webley, Paul; Zhai, Yuchun

2011-11-15

ETS-4 and ETS-10 titanosilicates were prepared from fly ash and anatase, as silica and titanium sources respectively, via a hydrothermal procedure for the first time. The fusion of fly ash by alkali was carried out at a relatively low temperature and the use potassium fluoride salt was avoided in the synthesis of ETS. The by-product of this process is mainly NaCl, which is a useful source material for industry. The energy efficiency and yield of the synthesis process was improved by directly recycling the final filtrate after recovering the product viz ETS-4. All the ETS materials were characterized in terms of structural morphology, thermal stability and surface/pore properties. The properties of ETS-4 prepared from fly ash by the filtrate recycling method were comparable to that from commercial sources. The results show that ETS type materials can be prepared from cheaper resources, with good purity, comparable physico-chemical properties as well as excellent adsorption properties with lower environmental impact. Copyright © 2011 Elsevier B.V. All rights reserved.

Growth of mono- and mixed cultures of Nannochloropsis salina and Phaeodactylum tricornutum on struvite as a nutrient source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davis, Ryan W.; Siccardi, Anthony J.; Huysman, Nathan D.

In this paper, the suitability of crude and purified struvite (MgNH 4PO 4), a major precipitate in wastewater streams, was investigated for renewable replacement of conventional nitrogen and phosphate resources for cultivation of microalgae. Bovine effluent wastewater stone, the source of crude struvite, was characterized for soluble N/P, trace metals, and biochemical components and compared to the purified mineral. Cultivation trials using struvite as a major nutrient source were conducted using two microalgae production strains, Nannochloropsis salina and Phaeodactylum tricornutum, in both lab and outdoor pilot-scale raceways in a variety of seasonal conditions. Both crude and purified struvite-based media weremore » found to result in biomass productivities at least as high as established media formulations (maximum outdoor co-culture yield ~20 ± 4 g AFDW/m 2/day). Finally, analysis of nutrient uptake by the alga suggest that struvite provides increased nutrient utilization efficiency, and that crude struvite satisfies the trace metals requirement and results in increased pigment productivity for both microalgae strains.« less

Constraints on Circumstellar Dust Grain Sizes from High Spatial Resolution Observations in the Thermal Infrared

NASA Technical Reports Server (NTRS)

Bloemhof, E. E.; Danen, R. M.; Gwinn, C. R.

1996-01-01

We describe how high spatial resolution imaging of circumstellar dust at a wavelength of about 10 micron, combined with knowledge of the source spectral energy distribution, can yield useful information about the sizes of the individual dust grains responsible for the infrared emission. Much can be learned even when only upper limits to source size are available. In parallel with high-resolution single-telescope imaging that may resolve the more extended mid-infrared sources, we plan to apply these less direct techniques to interpretation of future observations from two-element optical interferometers, where quite general arguments may be made despite only crude imaging capability. Results to date indicate a tendency for circumstellar grain sizes to be rather large compared to the Mathis-Rumpl-Nordsieck size distribution traditionally thought to characterize dust in the general interstellar medium. This may mean that processing of grains after their initial formation and ejection from circumstellar atmospheres adjusts their size distribution to the ISM curve; further mid-infrared observations of grains in various environments would help to confirm this conjecture.

Isolation and characterization of α-cellulose from blank bunches of palm oil and dry jackfruit leaves with alkaline process NaOH continued with bleaching process H2O2

NASA Astrophysics Data System (ADS)

Tristantini, Dewi; Dewanti, Dian Purwitasari; Sandra, Cindy

2017-11-01

Alpha cellulose is a pure form of cellulose. Cellulose is a natural polymer in the form of carbohydrates (polysaccharides) that has fiber which is white, insoluble in water, renewable, easily decomposes, and non-toxic. Cellulosic sources are abundant in nature even in untapped biomass wastes. In this study, cellulose was isolated from Empty Palm Oil Bunches (EPOB) of 45% and Dry Jackfruit Leaves (DJL) of 21.45%. This study aims to obtain optimum yield of cellulose at NaOH concentration and cellulose characterization with water content, FTIR, and SEM analysis. The optimum α-cellulose yield was determined by alkali process with 8, 10, 12 and 14% (w/v) NaOH variations at 90-100 °C for 3 hours to remove hemicellulose and lignin followed by bleaching process with H2O2 10% (w/v) at 80-90 °C for 1.5 h to obtain pure α-cellulose. The optimum yield of EPOB cellulose was 38,562% in 12% NaOH and DJL was 7.27% in 10% NaOH. The water content in OPB cellulose was 4.38% and DJL was 6.37%. A typical cellulose-forming functional group seen in FTIR (Fourier Transform Infra-Red) and morphological results appears in SEM (Scanning Electron Microscopy) analysis. From FTIR analysis result shows cellulose from EPOB and DJL contains O-H, C-H, and C-O. SEM analysis shows fibers from EPOB and DJL are uniform and have pores. However, DJL fibers have white patches, which suspected to be impurities.

Production and partial characterization of serine and metallo peptidases secreted by Aspergillus fumigatus Fresenius in submerged and solid state fermentation.

PubMed

da Silva, Ronivaldo Rodrigues; de Freitas Cabral, Tatiana Pereira; Rodrigues, André; Cabral, Hamilton

2013-01-01

Enzyme production varies in different fermentation systems. Enzyme expression in different fermentation systems yields important information for improving our understanding of enzymatic production induction. Comparative studies between solid-state fermentation (SSF) using agro-industrial waste wheat bran and submerged fermentation (SmF) using synthetic media were carried out to determinate the best parameters for peptidase production by the fungus Aspergillus fumigatus Fresen. Variables tested include: the concentration of carbon and protein nitrogen sources, the size of the inoculum, the pH of the media, temperature, and the length of the fermentation process. The best peptidase production during SSF was obtained after 96 hours using wheat bran at 30 °C with an inoculum of 1 × 10(6) spores and yielded 1500 active units (U/mL). The best peptidase production using SmF was obtained after periods of 72 and 96 hours of fermentation in media containing 0.5% and 0.25% of casein, respectively, at a pH of 6.0 and at 30 °C and yielded 40 U/mL. We also found examples of catabolite repression of peptidase production under SmF conditions. Biochemical characterization of the peptidases produced by both fermentative processes showed optimum activity at pH 8.0 and 50 °C, and also showed that their proteolytic activity is modulated by surfactants. The enzymatic inhibition profile using phenylmethylsulfonyl fluoride (PMSF) in SmF and SSF indicated that both fermentative processes produced a serine peptidase. Additionally, the inhibitory effect of the ethylene-diaminetetraacetic acid (EDTA) chelating agent on the peptidase produced by SmF indicated that this fermentative process also produced a metallopeptidase.

Regional Detection of Decoupled Explosions, Yield Estimation from Surface Waves, Two-Dimensional Source Effects, Three-Dimensional Earthquake Modeling and Automated Magnitude Measures

DTIC Science & Technology

1980-07-01

41 3.2 EXPERIMENTAL DETERMINATION OF THE DEPENDENCE OF RAYLEIGH WAVE AMPLITUDE ON PROPERTIES OF THE SOURCE MATERIAL ...Surface Wave Observations ...... ................ 48 3.3.3 Surface Wave Dependence on Source Material Properties ..... ................ .. 51 SYSTEMS...with various aspects of the problem of estimating yield from single station recordings of surface waves. The material in these four summaries has been

Metrology of variable-line-spacing x-ray gratings using the APS Long Trace Profiler

NASA Astrophysics Data System (ADS)

Sheung, Janet; Qian, Jun; Sullivan, Joseph; Thomasset, Muriel; Manton, Jonathan; Bean, Sunil; Takacs, Peter; Dvorak, Joseph; Assoufid, Lahsen

2017-09-01

As resolving power targets have increased with each generation of beamlines commissioned in synchrotron radiation facilities worldwide, diffraction gratings are quickly becoming crucial optical components for meeting performance targets. However, the metrology of variable-line-spacing (VLS) gratings for high resolution beamlines is not widespread; in particular, no metrology facility at any US DOE facility is currently equipped to fully characterize such gratings. To begin to address this issue, the Optics Group at the Advanced Photon Source at Argonne, in collaboration with SOLEIL and with support from Brookhaven National Laboratory (BNL), has developed an alternative beam path addition to the Long Trace Profiler (LTP) at Argonne's Advanced Photon Source. This significantly expands the functionality of the LTP not only to measure mirrors surface slope profile at normal incidence, but also to characterize the groove density of VLS diffraction gratings in the Littrow incidence up to 79°, which covers virtually all diffraction gratings used at synchrotrons in the first order. The LTP light source is a 20mW HeNe laser, which yields enough signal for diffraction measurements to be performed on low angle blazed gratings optimized for soft X-ray wavelengths. We will present the design of the beam path, technical requirements for the optomechanics, and our data analysis procedure. Finally, we discuss challenges still to be overcome and potential limitations with use of the LTP to perform metrology on diffraction gratings.

Potential applications of cutin-derived CuO reaction products for discriminating vascular plant sources in natural environments

NASA Astrophysics Data System (ADS)

Goñi, Miguel A.; Hedges, John I.

1990-11-01

An extensive suite of C 14-C 18 hydroxylated fatty acids of cutin origin was identified among the nonlignin CuO reaction products from tissues of 67 different plant species. These mid-chain and ω-hydroxylated cutin acids together accounted for 0.5 to 4% of the organic carbon (OC) in these nonwoody vascular plant tissues and were produced in characteristically different yields by the various plant types. Nonvascular plants, including bulk phytoplankton, kelps, mosses, and liverworts, did not yield measurable amounts of cutin acids, except for trace levels of ω-hydroxytetradecanoic acid detected in kelps. Most of the "lower" vascular plants, such as clubmosses and ferns, produced simple cutin acid suites composed mainly of ω-hydroxy C 14 and C 16 acids. Gymnosperm needles yielded cutin acid suites dominated by C 16 acids, in which 9,16- and 10,16-dihydroxyhexadecanoic acids were characteristically abundant. Relatively high yields of C 18 acids were obtained from angiosperm tissues, among which dicotyledons exhibited a predominance of 9,10,18-trihydroxyoctadecanoic acid over all the other C 18 acids. The Chromatographie peak corresponding to dihydroxyhexadecanoic acid was a mixture of the positional isomers 8,16-, 9, 16-, and 10,16-dihydroxyhexadecanoic acids, whose relative abundances uniquely characterized monocotyledon tissues and distinguished among different types of gymnosperm tissues. Based on the cutin acid yields obtained from the different plant types, several geochemical parameters were developed to distinguish up to six different cutin-bearing plant groups as possible components of sedimentary mixtures.

Characterization of newly isolated oleaginous yeasts - Cryptococcus podzolicus, Trichosporon porosum and Pichia segobiensis

PubMed Central

2014-01-01

The yeast strains Cryptococcus podzolicus, Trichosporon porosum and Pichia segobiensis were isolated from soil samples and identified as oleaginous yeast strains beneficial for the establishment of microbial production processes for sustainable lipid production suitable for several industrial applications. When cultured in bioreactors with glucose as the sole carbon source C. podzolicus yielded 31.8% lipid per dry biomass at 20°C, while T. porosum yielded 34.1% at 25°C and P. segobiensis 24.6% at 25°C. These amounts correspond to lipid concentrations of 17.97 g/L, 17.02 g/L and 12.7 g/L and volumetric productivities of 0.09 g/Lh, 0.1 g/Lh and 0.07 g/Lh, respectively. During the culture of C. podzolicus 30 g/l gluconic acid was detected as by-product in the culture broth and 12 g/L gluconic acid in T. porosum culture. The production of gluconic acid was eliminated for both strains when glucose was substituted by xylose as the carbon source. Using xylose lipid yields were 11.1 g/L and 13.9 g/L, corresponding to 26.8% and 33.4% lipid per dry biomass and a volumetric productivity of 0.07 g/Lh and 0.09 g/Lh, for C. podzolicus and T. porosum respectively. The fatty acid profile analysis showed that oleic acid was the main component (39.6 to 59.4%) in all three strains and could be applicable for biodiesel production. Palmitic acid (18.4 to 21.1%) and linolenic acid (7.5 to 18.7%) are valuable for cosmetic applications. P. segobiensis had a considerable amount of palmitoleic acid (16% content) and may be suitable for medical applications. PMID:24949259

Deconstructing the Effects of Flow on DOC, Nitrate, and Major Ion Interactions Using a High-Frequency Aquatic Sensor Network

NASA Astrophysics Data System (ADS)

Koenig, L. E.; Shattuck, M. D.; Snyder, L. E.; Potter, J. D.; McDowell, W. H.

2017-12-01

Streams provide a physical linkage between land and downstream river networks, delivering solutes derived from multiple catchment sources. We analyzed high-frequency time series of stream solutes to characterize the timing and magnitude of major ion, nutrient, and organic matter transport over event, seasonal, and annual timescales as well as to assess whether nitrate (NO3-) and dissolved organic carbon (DOC) transport are coupled in catchments, which would be expected if they are subject to similar biogeochemical controls throughout the watershed. Our data set includes in situ observations of NO3-, fluorescent dissolved organic matter (DOC proxy), and specific conductance spanning 2-4 years in 10 streams and rivers across New Hampshire, including observations of nearly 700 individual hydrologic events. We found a positive response of NO3- and DOC to flow in forested streams, but watershed development led to a negative relationship between NO3- and discharge, and thus a decoupling of the overall NO3- and DOC responses to flow. On event and seasonal timescales, NO3- and DOC consistently displayed different behaviors. For example, in several streams, FDOM yield was greatest during summer storms while NO3- yield was greatest during winter storms. Most streams had generalizable storm NO3- and DOC responses, but differences in the timing of NO3- and DOC transport suggest different catchment sources. Further, certain events, including rain-on-snow and summer storms following dry antecedent conditions, yielded disproportionate NO3- responses. High-frequency data allow for increased understanding of the processes controlling solute variability and will help reveal their responses to changing climatic regimes.

Characterization and source term assessments of radioactive particles from Marshall Islands using non-destructive analytical techniques

NASA Astrophysics Data System (ADS)

Jernström, J.; Eriksson, M.; Simon, R.; Tamborini, G.; Bildstein, O.; Marquez, R. Carlos; Kehl, S. R.; Hamilton, T. F.; Ranebo, Y.; Betti, M.

2006-08-01

Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized by non-destructive analytical and microanalytical methods. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector and with wavelength dispersive system as well as a secondary ion mass spectrometer were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups: particles with pure Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogenously distributed. All of the particles were identified as nuclear fuel fragments of exploded weapon components. As containing plutonium with low 240Pu/ 239Pu atomic ratio, less than 0.065, which corresponds to weapons-grade plutonium or a detonation with low fission yield, the particles were identified to originate from the safety test and low-yield tests conducted in the history of Runit Island. The Si/O-rich particles contained traces of 137Cs ( 239 + 240 Pu/ 137Cs activity ratio higher than 2500), which indicated that a minor fission process occurred during the explosion. The average 241Am/ 239Pu atomic ratio in the six particles was 3.7 × 10 - 3 ± 0.2 × 10 - 3 (February 2006), which indicated that plutonium in the different particles had similar age.

Characterization of Novel Materials with Very Low Secondary Electron Emission Yield for Use in High-Power Microwave Devices

NASA Astrophysics Data System (ADS)

Svimonishvili, Tengiz; Zameroski, Nathan; Gilmore, Mark; Schamiloglu, Edl; Gaudet, John; Yan, Lincan

2004-11-01

Secondary Electron Emission (SEE) results from bombarding materials with electrons, atoms, or ions. The amount of secondary emission depends on factors such as bulk and surface properties of materials, energy of incident particles, and their angle of incidence. Total secondary electron emission yield, defined as the number of secondary electrons ejected per primary electron, is an important material parameter. Materials with high yield find use, for instance, in photomultiplier tubes, whereas materials with low yield, such as graphite, are used for SEE suppression in high-power microwave devices. The lower the SEE yield, the better the performance of high-power microwave devices (for example, gyrotrons). Employing a low-energy electron gun (energy range from 5 eV to 2000 eV), our work aims at characterizing and eventually identifying novel materials (with the lowest possible SEE yield) that will enhance operation and efficiency of high-power microwave devices.

High-yield positron systems for linear colliders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clendenin, J.E.

1989-04-01

Linear colliders, such as the SLC, are among those accelerators for which a high-yield positron source operating at the repetition rate of the accelerator is desired. The SLC, having electron energies up to 50 GeV, presents the possibility of generating positron bunches with useful charge even exceeding that of the initial electron bunch. The exact positron yield to be obtained depends on the particular capture, transport and damping system employed. Using 31 GeV electrons impinging on a W-type converter phase-space at the target to the acceptance of the capture rf section, the SLC source is capable of producing, for everymore » electron, up to two positrons within the acceptance of the positron damping ring. The design of this source and the performance of the positron system as built are described. Also, future prospects and limitations for high-yield positron systems are discussed. 11 refs., 5 figs., 3 tabs.« less

Collagen extraction from mussel byssus: a new marine collagen source with physicochemical properties of industrial interest.

PubMed

Rodríguez, F; Morán, L; González, G; Troncoso, E; Zúñiga, R N

2017-04-01

Mussel byssus is a by-product of mussel production and is a potential source of collagen. The goal of this study was to extract collagen from the byssus of Chilean mussel using an enzymatic method and characterize it. A pepsin-aided extraction method was employed where first an enzymatic hydrolysis at two pepsin/substrate ratios (1:50 or 4:50) and times (4 or 24 h) was done. Extraction was conducted at 80 °C for 24 h, in a 0.5 N acetic acid solution. All samples were analyzed for collagen content, amino acid profile, turbidity, viscosity, solubility, denaturation temperature and surface tension. Hydrolysis time had significant effect on collagen content, hydroxyproline content and extraction yield. Hydrolysis with a pepsin/byssus ratio of 4:50 for 24 h gave the better extraction performance with values of 69 mg/g protein, 1.8 mg/g protein and 30%, for collagen content, hydroxyproline content and extraction yield, respectively. No differences were found for the viscosity and surface tension of collagen dispersions, suggesting that the enzymatic hydrolysis did not affect the integrity of the collagen molecule. Denaturation temperature of freeze-dried byssus collagen presented a high value (83-91 °C), making this kind of collagen a very interesting material for encapsulation of bioactive molecules and for biomedical applications.

Laser driven plasmas based incoherent x-ray sources at PALS and ELI Beamlines (Conference Presentation)

NASA Astrophysics Data System (ADS)

Kozlová, Michaela

2017-05-01

We will present data on a various X-ray production schemes from laser driven plasmas at the PALS Research Center and discuss the plan for the ELI Beamlines project. One of the approaches, how to generate ultrashort pulses of incoherent X-ray radiation, is based on interaction of femtosecond laser pulses with solid or liquid targets. So-called K-alpha source depending on used targets emits in hard X-ray region from micrometric source size. The source exhibits sufficient spatial coherence to observe phase contrast. Detailed characterization of various sources including the x-ray spectrum and the x-ray average yield along with phase contrast images of test objects will be presented. Other method, known as laser wakefield electron acceleration (LWFA), can produce up to GeV electron beams emitting radiation in collimated beam with a femtosecnond pulse duration. This approach was theoretically and experimentally examined at the PALS Center. The parameters of the PALS Ti:S laser interaction were studied by extensive particle-in-cell simulations with radiation post-processors in order to evaluate the capabilities of our system in this field. The extensions of those methods at the ELI Beamlines facility will enable to generate either higher X-ray energies or higher repetition rate. The architecture of such sources and their considered applications will be proposed.

Enhanced efficiency fertilizer’s effect on cotton yield and greenhouse gas emissions

USDA-ARS?s Scientific Manuscript database

Interest in the use of enhanced-efficiency nitrogen fertilizer (EENFs) sources has increased in recent years due to the potential of these new EENF sources to increase crop yield, while at the same time decreasing N loss from agricultural fields. Nitrogen is the most essential nutrient needed to op...

A probabilistic approach towards understanding how planet composition affects plate tectonics - through time and space.

NASA Astrophysics Data System (ADS)

Stamenkovic, V.

2017-12-01

We focus on the connections between plate tectonics and planet composition — by studying how plate yielding is affected by surface and mantle water, and by variable amounts of Fe, SiC, or radiogenic heat sources within the planet interior. We especially explore whether we can make any robust conclusions if we account for variable initial conditions, current uncertainties in model parameters and the pressure dependence of the viscosity, as well as uncertainties on how a variable composition affects mantle rheology, melting temperatures, and thermal conductivities. We use a 1D thermal evolution model to explore with more than 200,000 simulations the robustness of our results and use our previous results from 3D calculations to help determine the most likely scenario within the uncertainties we still face today. The results that are robust in spite of all uncertainties are that iron-rich mantle rock seems to reduce the efficiency of plate yielding occurring on silicate planets like the Earth if those planets formed along or above mantle solidus and that carbon planets do not seem to be ideal candidates for plate tectonics because of slower creep rates and generally higher thermal conductivities for SiC. All other conclusions depend on not yet sufficiently constrained parameters. For the most likely case based on our current understanding, we find that, within our range of varied planet conditions (1-10 Earth masses), planets with the greatest efficiency of plate yielding are silicate rocky planets of 1 Earth mass with large metallic cores (average density 5500-7000 kg m-3) with minimal mantle concentrations of iron (as little as 0% is preferred) and radiogenic isotopes at formation (up to 10 times less than Earth's initial abundance; less heat sources do not mean no heat sources). Based on current planet formation scenarios and observations of stellar abundances across the Galaxy as well as models of the evolution of the interstellar medium, such planets are suggested to be statistically more common around young stars in the outer disk of the Milky Way. Rocky super-Earths, undifferentiated planets, and still hypothetical carbon planets have the lowest plate yielding efficiencies found in our study. This work aids exoplanet characterization and helps explore the fundamental drivers of plate tectonics.

A subject with abnormally short stature from Imperial Rome.

PubMed

Ottini, L; Minozzi, S; Pantano, W B; Maucci, C; Gazzaniga, V; Angeletti, L R; Catalano, P; Mariani-Costantini, R

2001-01-01

In spite of the rich iconographic and literary documentation from ancient sources, the skeletal evidence concerning individuals of abnormally short stature in the Greco-Roman world is scarce. The necropolis of Viale della Serenissima/Via Basiliano in Rome, mostly referable to the II century AD, recently yielded the skeleton of an individual characterized by proportionate short stature, gracile features suggesting female gender, and delayed epiphysial closure, associated with full maturation of the permanent dentition. These characteristics could be compatible with the phenotype associated with female gonadal dysgenesis. The skeletal individual described here, although poorly preserved, represents the first evidence of a paleopathologic condition affecting skeletal growth documented for the population of ancient Rome.

New genes as drivers of phenotypic evolution

PubMed Central

Chen, Sidi; Krinsky, Benjamin H.; Long, Manyuan

2014-01-01

During the course of evolution, genomes acquire novel genetic elements as sources of functional and phenotypic diversity, including new genes that originated in recent evolution. In the past few years, substantial progress has been made in understanding the evolution and phenotypic effects of new genes. In particular, an emerging picture is that new genes, despite being present in the genomes of only a subset of species, can rapidly evolve indispensable roles in fundamental biological processes, including development, reproduction, brain function and behaviour. The molecular underpinnings of how new genes can develop these roles are starting to be characterized. These recent discoveries yield fresh insights into our broad understanding of biological diversity at refined resolution. PMID:23949544

New genes as drivers of phenotypic evolution.

PubMed

Chen, Sidi; Krinsky, Benjamin H; Long, Manyuan

2013-09-01

During the course of evolution, genomes acquire novel genetic elements as sources of functional and phenotypic diversity, including new genes that originated in recent evolution. In the past few years, substantial progress has been made in understanding the evolution and phenotypic effects of new genes. In particular, an emerging picture is that new genes, despite being present in the genomes of only a subset of species, can rapidly evolve indispensable roles in fundamental biological processes, including development, reproduction, brain function and behaviour. The molecular underpinnings of how new genes can develop these roles are starting to be characterized. These recent discoveries yield fresh insights into our broad understanding of biological diversity at refined resolution.

Strong terahertz field generation, detection, and application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ki-Yong

2016-05-22

This report describes the generation and detection of high-power, broadband terahertz (THz) radiation with using femtosecond terawatt (TW) laser systems. In particular, this focuses on two-color laser mixing in gases as a scalable THz source, addressing both microscopic and macroscopic effects governing its output THz yield and radiation profile. This also includes the characterization of extremely broad THz spectra extending from microwaves to infrared frequencies. Experimentally, my group has generated high-energy (tens of microjoule), intense (>8 MV/cm), and broadband (0.01~60 THz) THz radiation in two-color laser mixing in air. Such an intense THz field can be utilized to study THz-drivenmore » extremely nonlinear phenomena in a university laboratory.« less

Strong terahertz field generation, detection, and application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ki-Yong

2016-05-15

This report describes the generation and detection of high-power, broadband terahertz (THz) radiation with using femtosecond terawatt (TW) laser systems. In particular, this focuses on two-color laser mixing in gases as a scalable THz source, addressing both microscopic and macroscopic effects governing its output THz yield and radiation profile. This also includes the characterization of extremely broad THz spectra extending from microwaves to infrared frequencies. Experimentally, my group has generated high-energy (tens of microjoule), intense (>8 MV/cm), and broadband (0.01~60 THz) THz radiation in two-color laser mixing in air. Such an intense THz field can be utilized to study THz-drivenmore » extremely nonlinear phenomena in a university laboratory.« less

Orbital Debris Characterization via Laboratory Optical Measurements

NASA Technical Reports Server (NTRS)

Cowardin, Healther

2011-01-01

Optical observations of orbital debris offer insights that differ from radar measurements (specifically the size parameter,wavelength regime,and altitude range). For example, time-dependent photometric data yield lightcurves in multiple bandpasses that aid in material identification and possible periodic orientations. These data can also be used to help identify shapes and optical properties at multiple phase angles. Capitalizing on optical data products and applying them to generate a more complete understanding of orbital objects is a key objective of NASA's Optical Measurement Program, and the primary reason for the creation of the Optical Measurements Center(OMC). The OMC attempts to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations.

Diversity of Holocene life forms in fossil glacier ice

PubMed Central

Willerslev, Eske; Hansen, Anders J.; Christensen, Bent; Steffensen, Jørgen Peder; Arctander, Peter

1999-01-01

Studies of biotic remains of polar ice caps have been limited to morphological identification of plant pollen and spores. By using sensitive molecular techniques, we now demonstrate a much greater range of detectable organisms; from 2000- and 4000-year-old ice-core samples, we obtained and characterized 120 clones that represent at least 57 distinct taxa and reveal a diversity of fungi, plants, algae, and protists. The organisms derive from distant sources as well as from the local arctic environment. Our results suggest that additional taxa may soon be readily identified, providing a plank for future studies of deep ice cores and yielding valuable information about ancient communities and their change over time. PMID:10393940

Phenotypic characterization, genetic mapping and candidate gene analysis of a source conferring reduced plant height in sunflower.

PubMed

Ramos, María Laura; Altieri, Emiliano; Bulos, Mariano; Sala, Carlos A

2013-01-01

Reduced height germplasm has the potential to increase stem strength, standability, and also yields potential of the sunflower crop (Helianthus annuus L. var. macrocarpus Ckll.). In this study, we report on the inheritance, mapping, phenotypic and molecular characterization of a reduced plant height trait in inbred lines derived from the source DDR. This trait is controlled by a semidominant allele, Rht1, which maps on linkage group 12 of the sunflower public consensus map. Phenotypic effects of this allele include shorter height and internode length, insensibility to exogenous gibberellin application, normal skotomorphogenetic response, and reduced seed set under self-pollination conditions. This later effect presumably is related to the reduced pollen viability observed in all DDR-derived lines studied. Rht1 completely cosegregated with a haplotype of the HaDella1 gene sequence. This haplotype consists of a point mutation converting a leucine residue in a proline within the conserved DELLA domain. Taken together, the phenotypic, genetic, and molecular results reported here indicate that Rht1 in sunflower likely encodes an altered DELLA protein. If the DELPA motif of the HaDELLA1 sequence in the Rht1-encoded protein determines by itself the observed reduction in height is a matter that remains to be investigated.

Tunable optical coherence tomography in the infrared range using visible photons

NASA Astrophysics Data System (ADS)

Paterova, Anna V.; Yang, Hongzhi; An, Chengwu; Kalashnikov, Dmitry A.; Krivitsky, Leonid A.

2018-04-01

Optical coherence tomography (OCT) is an appealing technique for bio-imaging, medicine, and material analysis. For many applications, OCT in mid- and far-infrared (IR) leads to significantly more accurate results. Reported mid-IR OCT systems require light sources and photodetectors which operate in mid-IR range. These devices are expensive and need cryogenic cooling. Here, we report a proof-of-concept demonstration of a wavelength tunable IR OCT technique with detection of only visible range photons. Our method is based on the nonlinear interference of frequency correlated photon pairs. The nonlinear crystal, introduced in the Michelson-type interferometer, generates photon pairs with one photon in the visible and another in the IR range. The intensity of detected visible photons depends on the phase and loss of IR photons, which interact with the sample under study. This enables us to characterize sample properties and perform imaging in the IR range by detecting visible photons. The technique possesses broad wavelength tunability and yields a fair axial and lateral resolution, which can be tailored to the specific application. The work contributes to the development of versatile 3D imaging and material characterization systems working in a broad range of IR wavelengths, which do not require the use of IR-range light sources and photodetectors.

Biosuccinic Acid from Lignocellulosic-Based Hexoses and Pentoses by Actinobacillus succinogenes: Characterization of the Conversion Process.

PubMed

Ferone, Mariateresa; Raganati, Francesca; Olivieri, Giuseppe; Salatino, Piero; Marzocchella, Antonio

2017-12-01

Succinic acid (SA) is a well-established chemical building block. Actinobacillus succinogenes fermentation is by far the most investigated route due to very promising high SA yield and titer on several sugars. This study contributes to include the SA production within the concept of biorefinery of lignocellulose biomass. The study was focused on the SA production by A. succinogenes DSM 22257 using sugars representative from lignocellulose hydrolysis-glucose, mannose, arabinose, and xylose-as carbon source. Single sugar batch fermentation tests and mixture sugar fermentation tests were carried out. All the sugars investigated were converted in succinic acid by A. succinogenes. The best fermentation performances were measured in tests with glucose as carbon source. The bacterial growth kinetics was characterized by glucose inhibition. No inhibition phenomena were observed with the other sugar investigated. The sugar mixture fermentation tests highlighted the synergic effects of the co-presence of the four sugars. Under the operating conditions tested, the final concentration of succinic acid in the sugar mixture test was larger (27 g/L) than that expected (25.5 g/L) by combining the fermentation of the single sugar. Moreover, the concentration of acetic and formic acid was lower, consequently obtaining an increment in the succinic acid specificity.

Effects of Source RDP Models and Near-source Propagation: Implication for Seismic Yield Estimation

NASA Astrophysics Data System (ADS)

Saikia, C. K.; Helmberger, D. V.; Stead, R. J.; Woods, B. B.

- It has proven difficult to uniquely untangle the source and propagation effects on the observed seismic data from underground nuclear explosions, even when large quantities of near-source, broadband data are available for analysis. This leads to uncertainties in our ability to quantify the nuclear seismic source function and, consequently the accuracy of seismic yield estimates for underground explosions. Extensive deterministic modeling analyses of the seismic data recorded from underground explosions at a variety of test sites have been conducted over the years and the results of these studies suggest that variations in the seismic source characteristics between test sites may be contributing to the observed differences in the magnitude/yield relations applicable at those sites. This contributes to our uncertainty in the determination of seismic yield estimates for explosions at previously uncalibrated test sites. In this paper we review issues involving the relationship of Nevada Test Site (NTS) source scaling laws to those at other sites. The Joint Verification Experiment (JVE) indicates that a magnitude (mb) bias (δmb) exists between the Semipalatinsk test site (STS) in the former Soviet Union (FSU) and the Nevada test site (NTS) in the United States. Generally this δmb is attributed to differential attenuation in the upper-mantle beneath the two test sites. This assumption results in rather large estimates of yield for large mb tunnel shots at Novaya Zemlya. A re-examination of the US testing experiments suggests that this δmb bias can partly be explained by anomalous NTS (Pahute) source characteristics. This interpretation is based on the modeling of US events at a number of test sites. Using a modified Haskell source description, we investigated the influence of the source Reduced Displacement Potential (RDP) parameters ψ ∞ , K and B by fitting short- and long-period data simultaneously, including the near-field body and surface waves. In general, estimates of B and K are based on the initial P-wave pulse, which various numerical analyses show to be least affected by variations in near-source path effects. The corner-frequency parameter K is 20% lower at NTS (Pahute) than at other sites, implying larger effective source radii. The overshoot parameter B appears to be low at NTS (although variable) relative to other sites and is probably due to variations in source conditions. For a low B, the near-field data require a higher value of ψ ∞ to match the long-period MS and short-period mb observations. This flexibility in modeling proves useful in comparing released FSU yields against predictions based on mb and MS.

THE CELESTIAL REFERENCE FRAME AT 24 AND 43 GHz. II. IMAGING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charlot, P.; Boboltz, D. A.; Fey, A. L.

2010-05-15

We have measured the submilliarcsecond structure of 274 extragalactic sources at 24 and 43 GHz in order to assess their astrometric suitability for use in a high-frequency celestial reference frame (CRF). Ten sessions of observations with the Very Long Baseline Array have been conducted over the course of {approx}5 years, with a total of 1339 images produced for the 274 sources. There are several quantities that can be used to characterize the impact of intrinsic source structure on astrometric observations including the source flux density, the flux density variability, the source structure index, the source compactness, and the compactness variability.more » A detailed analysis of these imaging quantities shows that (1) our selection of compact sources from 8.4 GHz catalogs yielded sources with flux densities, averaged over the sessions in which each source was observed, of about 1 Jy at both 24 and 43 GHz, (2) on average the source flux densities at 24 GHz varied by 20%-25% relative to their mean values, with variations in the session-to-session flux density scale being less than 10%, (3) sources were found to be more compact with less intrinsic structure at higher frequencies, and (4) variations of the core radio emission relative to the total flux density of the source are less than 8% on average at 24 GHz. We conclude that the reduction in the effects due to source structure gained by observing at higher frequencies will result in an improved CRF and a pool of high-quality fiducial reference points for use in spacecraft navigation over the next decade.« less

A reassessment of ground water flow conditions and specific yield at Borden and Cape Cod

USGS Publications Warehouse

Grimestad, Garry

2002-01-01

Recent widely accepted findings respecting the origin and nature of specific yield in unconfined aquifers rely heavily on water level changes observed during two pumping tests, one conducted at Borden, Ontario, Canada, and the other at Cape Cod, Massachusetts. The drawdown patterns observed during those tests have been taken as proof that unconfined specific yield estimates obtained from long-duration pumping tests should approach the laboratory-estimated effective porosity of representative aquifer formation samples. However, both of the original test reports included direct or referential descriptions of potential supplemental sources of pumped water that would have introduced intractable complications and errors into straightforward interpretations of the drawdown observations if actually present. Searches for evidence of previously neglected sources were performed by screening the original drawdown observations from both locations for signs of diagnostic skewing that should be present only if some of the extracted water was derived from sources other than main aquifer storage. The data screening was performed using error-guided computer assisted fitting techniques, capable of accurately sensing and simulating the effects of a wide range of non-traditional and external sources. The drawdown curves from both tests proved to be inconsistent with traditional single-source pumped aquifer models but consistent with site-specific alternatives that included significant contributions of water from external sources. The corrected pumping responses shared several important features. Unsaturated drainage appears to have ceased effectively at both locations within the first day of pumping, and estimates of specific yield stabilized at levels considerably smaller than the corresponding laboratory-measured or probable effective porosity. Separate sequential analyses of progressively later field observations gave stable and nearly constant specific yield estimates for each location, with no evidence from either test that more prolonged pumping would have induced substantially greater levels of unconfined specific yield.

Effects of N Fertilizer Sources and Tillage Practices on NH3 Volatilization, Grain Yield, and N Use Efficiency of Rice Fields in Central China

PubMed Central

Liu, Tianqi; Huang, Jinfeng; Chai, Kaibin; Cao, Cougui; Li, Chengfang

2018-01-01

Tillage practices and nitrogen (N) sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH3 volatilization, nitrogen use efficiency (NUE), and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N fertilizer alone, organic N fertilizer plus inorganic N fertilizer, and slow-release N fertilizer plus inorganic N fertilizer) and tillage practices (no-tillage [NT] and conventional intensive tillage [CT]) on NH3 flux, grain yield, and NUE in the rice field of central China. N sources significantly affected NH3 volatilization, as the cumulative volatilization from the treatments of inorganic N fertilizer, organic N fertilizer, organic N fertilizer plus inorganic N fertilizer, slow-release N fertilizer plus inorganic N fertilizer was 4.19, 2.13, 3.42, and 2.23 folds in 2013, and 2.49, 1.68, 2.08, and 1.85 folds in 2014 compared with that under no N fertilizer treatment, respectively. The organic N fertilizer treatment had the lowest grain yield and NUE among all N fertilizer treatments, while slow-release N fertilizer plus inorganic N fertilizer treatment led to relatively higher grain yield and the greatest N use efficiency. Moreover, NT only markedly increased NH3 volatilization from basal fertilizer by 10–14% in average compared with CT, but had no obvious effects on total volatilization during the whole seasons. Tillage practices had no significant effects on grain yield and NUE. Our study suggested that the combination of slow-release N fertilizer plus inorganic N fertilizer and NT might be a sustainable method for mitigating greenhouse gas and NH3 emissions and improving grain yield and NUE in paddy fields of central China. PMID:29623086

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2012 CFR

2012-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2011 CFR

2011-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2013 CFR

2013-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2014 CFR

2014-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

Simultaneous Detection and Classification of Acoustic Emissions in Integrated Diagnostics with Yield in Aluminum

NASA Astrophysics Data System (ADS)

Parmar, Devendra

2006-04-01

Acoustic emission (AE) experiments were conducted on a strained aluminum (10 cm x 9 cm x 0.25 cm) specimen. Studies were conducted with the goal to characterize AE associated with material yield developed due to high loading and to correlate the course of the yield with AE signals. The American Association of State Highway and Transport Officials (AASHTO) listed aluminum as one of the structural components of highway brides^1 with unit weight of 2800 kg.m-3. The specimen, mounted on the load frame, was held on each end by the wedge grips and was electromechanically tested in a tension mode at rates of extension of 0.0333 mm/s and 0.0666 mm/s. Load was applied to the test frame via moving cross heads. A load transducer (load cell) mounted in series with the specimen measured the applied load by converting it into an electrical signal. Results are analyzed using defect zone model in which location of the defect is determined from the measurement of the arrival time of the signal at two different sensors placed at strategically around the source of emission from the test object. The sensor that detects the signal first is identified to be in the defect zone. ^1AASHTO LRFD Bridge Design Specifications, 1994.

Effects of Long-term Conservation Tillage on Soil Nutrients in Sloping Fields in Regions Characterized by Water and Wind Erosion

NASA Astrophysics Data System (ADS)

Tan, Chunjian; Cao, Xue; Yuan, Shuai; Wang, Weiyu; Feng, Yongzhong; Qiao, Bo

2015-12-01

Conservation tillage is commonly used in regions affected by water and wind erosion. To understand the effects of conservation tillage on soil nutrients and yield, a long-term experiment was set up in a region affected by water and wind erosion on the Loess Plateau. The treatments used were traditional tillage (CK), no tillage (NT), straw mulching (SM), plastic-film mulching (PM), ridging and plastic-film mulching (RPM) and intercropping (In). Our results demonstrate that the available nutrients in soils subjected to non-traditional tillage treatments decreased during the first several years and then remained stable over the last several years of the experiment. The soil organic matter and total nitrogen content increased gradually over 6 years in all treatments except CK. The nutrient content of soils subjected to conservative tillage methods, such as NT and SM, were significantly higher than those in soils under the CK treatment. Straw mulching and film mulching effectively reduced an observed decrease in soybean yield. Over the final 6 years of the experiment, soybean yields followed the trend RPM > PM > SM > NT > CK > In. This trend has implications for controlling soil erosion and preventing non-point source pollution in sloping fields by sacrificing some food production.

Production, characterization and applications for Toxoplasma gondii-specific polyclonal chicken egg yolk immunoglobulins.

PubMed

Ferreira Júnior, Álvaro; Santiago, Fernanda M; Silva, Murilo V; Ferreira, Flávia B; Macêdo Júnior, Arlindo G; Mota, Caroline M; Faria, Matheus S; Silva Filho, Hercílio H; Silva, Deise A O; Cunha-Júnior, Jair P; Mineo, José R; Mineo, Tiago W P

2012-01-01

Toxoplasma gondii may cause abortions, ocular and neurological disorders in warm-blood hosts. Immunized mammals are a wide source of hyperimmune sera used in different approaches, including diagnosis and the study of host-parasite interactions. Unfortunately, mammalian antibodies present limitations for its production, such as the necessity for animal bleeding, low yield, interference with rheumatoid factor, complement activation and affinity to Fc mammalian receptors. IgY antibodies avoid those limitations; therefore they could be an alternative to be applied in T. gondii model. In this study we immunized hens with soluble tachyzoite antigens of T. gondii (STAg) and purified egg yolk antibodies (IgY) by an inexpensive and simple method, with high yield and purity degree. IgY anti-STAg antibodies presented high avidity and were able to recognize a broad range of parasite antigens, although some marked differences were observed in reactivity profile between antibodies produced in immunized hens and mice. Interestingly, IgY antibodies against Neospora caninum and Eimeria spp. did not react to STAg. We also show that IgY antibodies were suitable to detect T. gondii forms in paraffin-embedded sections and culture cell monolayers. Due to its cost-effectiveness, high production yield and varied range of possible applications, polyclonal IgY antibodies are useful tools for studies involving T. gondii.

Sources of salmonellae in an uninfected commercially-processed broiler flock.

PubMed

Rigby, C E; Pettit, J R; Baker, M F; Bentley, A H; Salomons, M O; Lior, H

1980-07-01

Cultural monitoring was used to study the incidence and sources of salmonellae in a 4160 bird broiler flock during the growing period, transport and processing in a commercial plant. No salmonellae were isolated from any of 132 litter samples of 189 chickens cultured during the seven-week growing period, even though nest litter samples from four of the eight parent flocks yielded salmonellae and Salmonella worthington was isolated from the meat meal component of the grower ration. On arrival at the plant, 2/23 birds sampled carried S. infantis on their feathers, although intestinal cultures failed to yield salmonellae. Three of 18 processed carcasses samples yielded salmonellae (S. infantis, S. heidelberg, S. typhimurium var copenhagen). The most likely source of these salmonellae was the plastic transport crates, since 15/107 sampled before the birds were loaded yielded salmonellae (S. infantis, S. typhimurium). The crate washer at the plant did not reduce the incidence of Salmonella-contaminated crates, since 16/116 sampled after washing yielded salmonellae (S. infantis, S. typhimurium, S. heidelberg, S. schwarzengrund, S. albany).

Rg to Lg Scattering Observations and Modeling

NASA Astrophysics Data System (ADS)

Baker, G. E.; Stevens, J. L.; Xu, H.

2005-12-01

Lg is important to explosion yield estimation and earthquake/explosion discrimination, but the source of explosion generated Lg is still an area of active investigation. We investigate the contribution of Rg scattering to Lg. Common spectral nulls in vertical component Rg and Lg have been interpreted as evidence that scattered Rg is the dominant source of Lg in some areas. The nulls are assumed to result from non-spherical components of the explosion source, modeled as a CLVD located above the explosion. We compare Rg with 3-component Sg and Lg spectra in different source areas. Wavenumber synthetics and nonlinear source calculations constrain the predicted source spectra of Rg and directly generated Lg. Modal scattering calculations place bounds on the contribution of Rg to Lg relative to pS, S*, and directly generated S-waves. Rg recorded east and west of the Quartz 3 Deep Seismic Sounding explosion have persistent spectral nulls, but at different frequencies. The azimuthal dependence of the source spectra suggests that it may not be simply related to a CLVD source. The spectral nulls of Sg, Lg, and Lg coda do not correspond to the Rg spectral nulls, so for this overburied source, the spectral observations do not indicate that Rg scattering is a dominant contributor to Lg. Preliminary comparisons of Rg with Lg spectra for events from the Semipalatinsk Test Site yield a similar result. We compare Rg at 20-100 km with Lg at 650 km for Balapan and Degelen explosions with known yield and source depth. The events range from 130 to 50 percent of theoretical containment depth, so relative contributions from a CLVD are expected to vary significantly. For studied previously NTS and Kazakh depth of burial data, the use of 3-components provides further insight into scattering between components. In a complementary analysis, to assess whether S-wave generation is affected by source depth or scaled depth, we have examined regional phase amplitudes of 13 Degelen explosions with known yields and source depths. Initial Pn, the entire P wavetrain, Sn, Lg, and Lg coda have similar log amplitude vs. log yield curves. The slope of those curves varies with frequency, from approximately 0.84 at 0.6 Hz to 0.65 at 6 Hz. We will complement these results with similar observations of Balapan explosion records.

Analysis of atomic force microscopy data for surface characterization using fuzzy logic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Mousa, Amjed, E-mail: aalmousa@vt.edu; Niemann, Darrell L.; Niemann, Devin J.

2011-07-15

In this paper we present a methodology to characterize surface nanostructures of thin films. The methodology identifies and isolates nanostructures using Atomic Force Microscopy (AFM) data and extracts quantitative information, such as their size and shape. The fuzzy logic based methodology relies on a Fuzzy Inference Engine (FIE) to classify the data points as being top, bottom, uphill, or downhill. The resulting data sets are then further processed to extract quantitative information about the nanostructures. In the present work we introduce a mechanism which can consistently distinguish crowded surfaces from those with sparsely distributed structures and present an omni-directional searchmore » technique to improve the structural recognition accuracy. In order to demonstrate the effectiveness of our approach we present a case study which uses our approach to quantitatively identify particle sizes of two specimens each with a unique gold nanoparticle size distribution. - Research Highlights: {yields} A Fuzzy logic analysis technique capable of characterizing AFM images of thin films. {yields} The technique is applicable to different surfaces regardless of their densities. {yields} Fuzzy logic technique does not require manual adjustment of the algorithm parameters. {yields} The technique can quantitatively capture differences between surfaces. {yields} This technique yields more realistic structure boundaries compared to other methods.« less

EMBEDDED PROTOSTARS IN THE DUST, ICE, AND GAS IN TIME (DIGIT) HERSCHEL KEY PROGRAM: CONTINUUM SEDs, AND AN INVENTORY OF CHARACTERISTIC FAR-INFRARED LINES FROM PACS SPECTROSCOPY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, Joel D.; Evans, Neal J. II; Rascati, Michelle R.

2013-06-20

We present 50-210 {mu}m spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 {mu}m spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H{sub 2}O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rotational lines ranging from J = 14 {yields} 13 up to J = 40 {yields} 39. [O I] is detected in all but one source in the entire sample; among the sources with detectable [O I] are two very low luminosity objects. Themore » mean 63/145 {mu}m [O I] flux ratio is 17.2 {+-} 9.2. The [O I] 63 {mu}m line correlates with L{sub bol}, but not with the time-averaged outflow rate derived from low-J CO maps. [C II] emission is in general not local to the source. The sample L{sub bol} increased by 1.25 (1.06) and T{sub bol} decreased to 0.96 (0.96) of mean (median) values with the inclusion of the Herschel data. Most CO rotational diagrams are characterized by two optically thin components ( = (0.70 {+-} 1.12) x 10{sup 49} total particles). N{sub CO} correlates strongly with L{sub bol}, but neither T{sub rot} nor N{sub CO}(warm)/N{sub CO}(hot) correlates with L{sub bol}, suggesting that the total excited gas is related to the current source luminosity, but that the excitation is primarily determined by the physics of the interaction (e.g., UV-heating/shocks). Rotational temperatures for H{sub 2}O ( = 194 +/- 85 K) and OH ( = 183 +/- 117 K) are generally lower than for CO, and much of the scatter in the observations about the best fit is attributed to differences in excitation conditions and optical depths among the detected lines.« less

Enhancement of docosahexaenoic acid (DHA) production from Schizochytrium sp. S31 using different growth medium conditions.

PubMed

Sahin, Deniz; Tas, Ezgi; Altindag, Ulkü Hüma

2018-01-24

Schizochytrium species is one of the most studied microalgae for production of docosahexaenoic acid (DHA) which is an omega-3 fatty acid with positive effects for human health. However, high cost and low yield in production phase makes optimization of cultivation process inevitable. We focus on the optimization of DHA production using Schizochytrium sp. using different media supplements; glucose, fructose and glycerol as carbon variants, proteose peptone and tryptone as nitrogen variants. The highest biomass (5.61 g/L) and total fatty acid yield (1.74 g/L) were obtained in proteose peptone medium which was used as the alternative nitrogen source instead of yeast extract. The highest DHA yield (0.40 g/L) was achieved with glycerol as the carbon source although it had the second lowest biomass production after ethanol containing medium. Ethanol, as an alternative carbon source and a precursor for acetyl-CoA, increased DHA percentage in total lipid content from 29.94 to 40.04% but decreasing the biomass drastically. Considering different carbon and nitrogen sources during cultivation of Schizochytrium sp. will improve DHA production. Combination of proteose peptone and glycerol as nitrogen and carbon sources, respectively, and addition of ethanol with a proper timing will be useful to have higher DHA yield.

Culture medium pH influence on Gluconacetobacter physiology: Cellulose production rate and yield enhancement in presence of multiple carbon sources.

PubMed

Yassine, Fatima; Bassil, Nathalie; Flouty, Roula; Chokr, Ali; Samrani, Antoine El; Boiteux, Gisèle; Tahchi, Mario El

2016-08-01

Gluconacetobacter genera are valued for bacterial cellulose (BC) and acetic acid production. BC is produced at optimal yields in classical microbiological media that are expensive for a large scale of production. In addition, BC usage for industrial purposes is limited due to low conversion rate into cellulose and to long incubation duration. In this paper, Gluconacetobacter isolated from apple vinegar was kinetically studied to evaluate cellulose production in presence of different carbon sources. Acetic and citric acid effect on Gluconacetobacter metabolism is clarified. It was shown that Gluconacetobacter uses glucose as a primary carbon source for cells growth and products formation. Acetic acid employment as a co-carbon source in Hestrin Schramm medium showed an increase of 17% in BC yield with a moderate decrease in the crystallite size of the resulting polymer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimation of total nitrogen and total phosphorus in streams of the Middle Columbia River Basin (Oregon, Washington, and Idaho) using SPARROW models, with emphasis on the Yakima River Basin, Washington

USGS Publications Warehouse

Johnson, Henry M.; Black, Robert W.; Wise, Daniel R.

2013-01-01

The watershed model SPARROW (Spatially Related Regressions on Watershed attributes) was used to predict total nitrogen (TN) and total phosphorus (TP) loads and yields for the Middle Columbia River Basin in Idaho, Oregon, and Washington. The new models build on recently published models for the entire Pacific Northwest, and provide revised load predictions for the arid interior of the region by restricting the modeling domain and recalibrating the models. Results from the new TN and TP models are provided for the entire region, and discussed with special emphasis on the Yakima River Basin, Washington. In most catchments of the Yakima River Basin, the TN and TP in streams is from natural sources, specifically nitrogen fixation in forests (TN) and weathering and erosion of geologic materials (TP). The natural nutrient sources are overshadowed by anthropogenic sources of TN and TP in highly agricultural and urbanized catchments; downstream of the city of Yakima, most of the load in the Yakima River is derived from anthropogenic sources. Yields of TN and TP from catchments with nearly uniform land use were compared with other yield values and export coefficients published in the scientific literature, and generally were in agreement. The median yield of TN was greatest in catchments dominated by agricultural land and smallest in catchments dominated by grass and scrub land. The median yield of TP was greatest in catchments dominated by forest land, but the largest yields (90th percentile) of TP were from agricultural catchments. As with TN, the smallest TP yields were from catchments dominated by grass and scrub land.

Description and Yield of Current Quality and Safety Review in Selected US Academic Emergency Departments.

PubMed

Griffey, Richard Thomas; Schneider, Ryan M; Sharp, Brian R; Pothof, Jeffrey J; Hodkins, Sheridan; Capp, Roberta; Wiler, Jennifer L; Sreshta, Neil; Sather, John E; Sampson, Christopher S; Powell, Jonathan T; Groner, Kathryn Y; Adler, Lee M

2017-06-29

Quality and safety review for performance improvement is important for systems of care and is required for US academic emergency departments (EDs). Assessment of the impact of patient safety initiatives in the context of increasing burdens of quality measurement compels standardized, meaningful, high-yield approaches for performance review. Limited data describe how quality and safety reviews are currently conducted and how well they perform in detecting patient harm and areas for improvement. We hypothesized that decades-old approaches used in many academic EDs are inefficient and low yield for identifying patient harm. We conducted a prospective observational study to evaluate the efficiency and yield of current quality review processes at five academic EDs for a 12-month period. Sites provided descriptions of their current practice and collected summary data on the number and severity of events identified in their reviews and the referral sources that led to their capture. Categories of common referral sources were established at the beginning of the study. Sites used the Institute for Healthcare Improvement's definition in defining an adverse event and a modified National Coordinating Council for Medication Error Reporting and Prevention (MERP) Index for grading severity of events. Participating sites had similar processes for quality review, including a two-level review process, monthly reviews and conferences, similar screening criteria, and a grading system for evaluating cases. In 60 months of data collection, we reviewed a total of 4735 cases and identified 381 events. This included 287 near-misses, errors/events (MERP A-I) and 94 adverse events (AEs) (MERP E-I). The overall AE rate (event rate with harm) was 1.99 (95% confidence interval = 1.62%-2.43%), ranging from 1.24% to 3.47% across sites. The overall rate of quality concerns (events without harm) was 6.06% (5.42%-6.78%), ranging from 2.96% to 10.95% across sites. Seventy-two-hour returns were the most frequent referral source used, accounting for 47% of the cases reviewed but with a yield of only 0.81% in identifying harm. Other referral sources similarly had very low yields. External referrals were the highest yield referral source, with 14.34% (10.64%-19.03%) identifying AEs. As a percentage of the 94 AEs identified, external referrals also accounted for 41.49% of cases. With an overall adverse event rate of 1.99%, commonly used referral sources seem to be low yield and inefficient for detecting patient harm. Approximately 6% of the cases identified by these criteria yielded a near miss or quality concern. New approaches to quality and safety review in the ED are needed to optimize their yield and efficiency for identifying harm and areas for improvement.

Single-source precursors for ternary chalcopyrite materials, and methods of making and using the same

NASA Technical Reports Server (NTRS)

Banger, Kulbinder K. (Inventor); Hepp, Aloysius F. (Inventor); Harris, Jerry D. (Inventor); Jin, Michael Hyun-Chul (Inventor); Castro, Stephanie L. (Inventor)

2006-01-01

A single source precursor for depositing ternary I-III-VI.sub.2 chalcopyrite materials useful as semiconductors. The single source precursor has the I-III-VI.sub.2 stoichiometry built into a single precursor molecular structure which degrades on heating or pyrolysis to yield the desired I-III-VI.sub.2 ternary chalcopyrite. The single source precursors effectively degrade to yield the ternary chalcopyrite at low temperature, e.g. below 500.degree. C., and are useful to deposit thin film ternary chalcopyrite layers via a spray CVD technique. The ternary single source precursors according to the invention can be used to provide nanocrystallite structures useful as quantum dots. A method of making the ternary single source precursors is also provided.

Enhanced photoluminescence and characterization of multicolor carbon dots using plant soot as a carbon source.

PubMed

Tan, Mingqian; Zhang, Lingxin; Tang, Rong; Song, Xiaojie; Li, Yimin; Wu, Hao; Wang, Yanfang; Lv, Guojun; Liu, Wanfa; Ma, Xiaojun

2013-10-15

Carbon dots (C-dots) are a class of novel fluorescent nanomaterials, which have drawn great attention for their potential applications in bio-nanotechnology. Multicolor C-dots have been synthesized by chemical nitric acid oxidation using the reproducible plant soot as raw material. TEM analysis reveals that the prepared C-dots have an average size of 3.1 nm. The C-dots are well dispersed in aqueous solution and are strongly fluorescent under the irradiation of ultra-violet light. X-ray photoelectron spectroscopy characterization demonstrates that the O/C atomic ratio for C-dots change to from 0.207 to 0.436 due to the chemical oxidation process. The photo bleaching experiment reveals that the C-dots show excellent photostability as compared with the conventional organic dyes, fluorescein and rhodamine B. The fluorescence intensity of the C-dots did not change significantly in the pH range of 3-10. To further enhance the fluorescence quantum yield, the C-dots were surface modified with four types of passivation ligands, 4,7,10-trioxa-1,13-tridecanediamine (TTDDA), poly-L-lysine (PLL), cysteine and chitosan and the fluorescence quantum yields of the TTDDA, PLL, cysteine and chitosan passivated C-dots were improved 1.53-, 5.94-, 2.00- and 3.68-fold, respectively. Fourier-transform infrared (FTIR) spectra were employed to characterize the surface groups of the C-dots. The bio-application of the C-dots as fluorescent bio-probes was evaluated in cell imaging and ex vivo fish imaging, which suggests that the C-dots may have potential applications in biolabeling and bioimaging. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Characterization and Hygroscopicity Determination of Secondary Aerosol from D5 Cyclic Siloxane Oxidation

NASA Astrophysics Data System (ADS)

Stanier, C. O.; Janechek, N. J.; Bryngelson, N.; Marek, R. F.; Lersch, T.; Bunker, K.; Casuccio, G.; Brune, W. H.; Hornbuckle, K. C.

2017-12-01

Cyclic volatile methyl siloxanes are anthropogenic chemicals present in personal care products such as antiperspirants and lotions. These are volatile chemicals that are readily released into the atmosphere by product use. Due to their emission and relatively slow kinetics of their major transformation pathway, reaction with hydroxyl radicals (OH), these compounds are present in high concentrations in indoor environments and widespread in outdoor environments. Cyclic siloxane reaction with OH can lead to secondary organic aerosols, and due to the widespread prevalence of the parent compounds, may be an important source of ambient aerosols. Atmospheric aerosols have important influences to the climate by affecting the radiative balance and by serving as cloud condensation nuclei (CCN) which influence clouds. While the parent compounds have been well-studied, the oxidation products have received much less attention, with almost no ambient measurements or experimental physical property data. We report physical properties of aerosols generated by reacting the cyclic siloxane D5 with OH using a Potential Aerosol Mass (PAM) photochemical chamber. The particles were characterized by SMPS, imaging and elemental analysis using both Transmission Electron Microscopy and Scanning Transmission Electron Microscopy equipped with Energy Dispersive X-ray Spectroscopy systems (TEM-EDS and STEM-EDS), volatility measurements using Volatility Tandem Differential Mobility Analyzer (V-TDMA), and hygroscopicity measurements to determine CCN potential using a Droplet Measurement Technologies Cloud Condensation Nuclei Counter (DMT-CCN). Aerosol yield sensitivity to D5 and OH concentrations, residence time, and seed aerosols were analyzed. TEM-EDS and STEM-EDS analysis show spherical particle morphology with elemental composition consistent with aerosols derived from cyclic siloxane sources. Measured aerosol yields were 20-50% with typical aerosol concentrations 300,000 particles cm-3, up to 200 μg m-3, and diameters of 30-90 nm. Particles experienced little diameter change after heating up to 200°C suggesting low volatility, while particle activation was shifted to higher supersaturations compared to ammonium sulfate suggesting moderate hygroscopicity in line with other secondary organics.

Functional overexpression and characterization of lipogenesis-related genes in the oleaginous yeast Yarrowia lipolytica.

PubMed

Silverman, Andrew M; Qiao, Kangjian; Xu, Peng; Stephanopoulos, Gregory

2016-04-01

Single cell oil (SCO) is an attractive energy source due to scalability, utilization of low-cost renewable feedstocks, and type of product(s) made. Engineering strains capable of producing high lipid titers and yields is crucial to the economic viability of these processes. However, lipid synthesis in cells is a complex phenomenon subject to multiple layers of regulation, making gene target identification a challenging task. In this study, we aimed to identify genes in the oleaginous yeast Yarrowia lipolytica whose overexpression enhances lipid production by this organism. To this end, we examined the effect of the overexpression of a set of 44 native genes on lipid production in Y. lipolytica, including those involved in glycerolipid synthesis, fatty acid synthesis, central carbon metabolism, NADPH generation, regulation, and metabolite transport and characterized each resulting strain's ability to produce lipids growing on both glucose and acetate as a sole carbon source. Our results suggest that a diverse subset of genes was effective at individually influencing lipid production in Y. lipolytica, sometimes in a substrate-dependent manner. The most productive strain on glucose overexpressed the diacylglycerol acyltransferase DGA2 gene, increasing lipid titer, cellular content, and yield by 236, 165, and 246 %, respectively, over our control strain. On acetate, our most productive strain overexpressed the acylglycerol-phosphate acyltransferase SLC1 gene, with a lipid titer, cellular content, and yield increase of 99, 91, and 151 %, respectively, over the control strain. Aside from genes encoding enzymes that directly catalyze the reactions of lipid synthesis, other ways by which lipogenesis was increased in these cells include overexpressing the glycerol-3-phosphate dehydrogenase (GPD1) gene to increase production of glycerol head groups and overexpressing the 6-phosphogluconolactonase (SOL3) gene from the oxidative pentose phosphate pathway to increase NADPH availability for fatty acid synthesis. Taken together, our study demonstrates that the overall kinetics of microbial lipid synthesis is sensitive to a wide variety of factors. Fully optimizing a strain for single cell oil processes could involve manipulating and balancing many of these factors, and, due to mechanistic differences by which each gene product investigated here impacts lipid synthesis, there is a high likelihood that many of these genes will work synergistically to further increase lipid production when simultaneously overexpressed.

Production, characterization and operation of Ge enriched BEGe detectors in GERDA

NASA Astrophysics Data System (ADS)

Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Misiaszek, M.; Nemchenok, I.; Nisi, S.; O'Shaughnessy, C.; Palioselitis, D.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Ur, C. A.; Vanhoefer, L.; Vasenko, A. A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wilsenach, H.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

2015-02-01

The GERmanium Detector Array ( Gerda) at the Gran Sasso Underground Laboratory (LNGS) searches for the neutrinoless double beta decay () of Ge. Germanium detectors made of material with an enriched Ge fraction act simultaneously as sources and detectors for this decay. During Phase I of theexperiment mainly refurbished semi-coaxial Ge detectors from former experiments were used. For the upcoming Phase II, 30 new Ge enriched detectors of broad energy germanium (BEGe)-type were produced. A subgroup of these detectors has already been deployed in Gerda during Phase I. The present paper reviews the complete production chain of these BEGe detectors including isotopic enrichment, purification, crystal growth and diode production. The efforts in optimizing the mass yield and in minimizing the exposure of the Ge enriched germanium to cosmic radiation during processing are described. Furthermore, characterization measurements in vacuum cryostats of the first subgroup of seven BEGe detectors and their long-term behavior in liquid argon are discussed. The detector performance fulfills the requirements needed for the physics goals of Gerda Phase II.

Azomethine based nano-chemicals: Development, in vitro and in vivo fungicidal evaluation against Sclerotium rolfsii, Rhizoctonia bataticola and Rhizoctonia solani.

PubMed

Mondal, Prithusayak; Kumar, Rajesh; Gogoi, Robin

2017-02-01

Fungal diseases posing a severe threat to the production of pulses, a major protein source, necessitates the need of new highly efficient antifungal agents. The present study was aimed to develop azomethine based nano-fungicides for protecting the crop from fungal pathogens and subsequent yield losses. The protocol for the formation of nano-azomethines was generated and standardized. Technically pure azomethines were transformed into their nano-forms exploiting polyethylene glycol as the surface stabilizer. Characterization was performed by optical (imaging) probe (Zetasizer) and electron probe (TEM) characterization techniques. The mean particle sizes of all nano-fungicides were below 100nm. In vitro fungicidal potential of nano-chemicals was increased by 2 times in comparison to that of conventional sized azomethines against pathogenic fungi, namely, Rhizoctonia solani, Rhizoctonia bataticola and Sclerotium rolfsii. The performance of nano-chemicals in pot experiment study was also superior to conventional ones as antifungal agent. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of myrtle seed (Myrtus communis var. baetica) as a source of lipids, phenolics, and antioxidant activities.

PubMed

Wannes, Wissem Aidi; Marzouk, Brahim

2016-04-01

This study aimed to characterize the chemical composition and antioxidant activity of the oil and the methanolic extract of Myrtus communis var. baetica seed. The oil yield of myrtle seed was 8.90%, with the amount of neutral lipid, especially triacylglycerol, being the highest, followed by phospholipids and glycolipids. Total lipids and all lipid classes were rich in linoleic acid. The content of total phenols, flavonoids, tannins, and proanthocyanidins of the methanolic extract and the oil from myrtle seed was determined using spectrophotometric methods. Antioxidant activities of the oil and the methanolic extract from myrtle seed were evaluated using 1,1-diphenyl-2-picrylhydrazyl radical scavenging, β-carotene-linoleic acid bleaching, and reducing power and metal chelating activity assays. In all tests, the methanolic extract of myrtle seed showed better antioxidant activity than oil. This investigation could suggest the use of myrtle seed in food, industrial, and biomedical applications for its potential metabolites and antioxidant abilities. Copyright © 2015. Published by Elsevier B.V.

Chemical modeling of acid-base properties of soluble biopolymers derived from municipal waste treatment materials.

PubMed

Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Marinos, Janeth Alicia Tafur; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

2015-02-04

This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

Chemical Modeling of Acid-Base Properties of Soluble Biopolymers Derived from Municipal Waste Treatment Materials

PubMed Central

Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Tafur Marinos, Janeth Alicia; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

2015-01-01

This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials. PMID:25658795

Use of indicator chemicals to characterize the plastic fragments ingested by Laysan albatross.

PubMed

Nilsen, Frances; David Hyrenbach, K; Fang, Jiasong; Jensen, Brenda

2014-10-15

Laysan albatross (Phoebastria immutabilis) ingest plastic marine debris of a wide range of shape, sizes and sources. To better characterize this plastic and provide insights regarding its provenance and persistence in the environment, we developed a simple method to classify plastic fragments of unknown origin according to the resin codes used by the Society of Plastics Industry. Known plastics were analyzed by gas chromatography-mass spectroscopy (GC-MS) to identify indicator chemicals characteristic of each plastic resin. Application of this method to fragments of ingested plastic debris from boluses of Laysan albatross from Kure Atoll, Hawai'i, yielded proportions of 0.8% High Density Polyethylene, 6.8% Polystyrene, 8.5% Polyethylene Terephthalate, 20.5% Polyvinyl Chloride and 68.4% Polypropylene. Some fragments were composed of multiple resin types. These results suggest that infrequently recycled plastics are the dominant fragments ingested by albatross, and that these are the most prevalent and persistent resin types in the marine environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Simulation on Change Law of Runoff, Sediment and Non-point Source Nitrogen and Phosphorus Discharge under Different Land uses Based on SWAT Model: A Case Study of Er hai Lake Small Watershed

NASA Astrophysics Data System (ADS)

Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng

2018-05-01

The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.

A generalized method for characterization of 235U and 239Pu content using short-lived fission product gamma spectroscopy

DOE PAGES

Knowles, Justin R.; Skutnik, Steven E.; Glasgow, David C.; ...

2016-06-23

Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification,more » mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. Furthermore, it is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.« less

A generalized method for characterization of 235U and 239Pu content using short-lived fission product gamma spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knowles, Justin R.; Skutnik, Steven E.; Glasgow, David C.

Rapid non-destructive assay methods for trace fissile material analysis are needed in both nuclear forensics and safeguards communities. To address these needs, research at the High Flux Isotope Reactor Neutron Activation Analysis laboratory has developed a generalized non-destructive assay method to characterize materials containing fissile isotopes. This method relies on gamma-ray emissions from short-lived fission products and capitalizes off of differences in fission product yields to identify fissile compositions of trace material samples. Although prior work has explored the use of short-lived fission product gamma-ray measurements, the proposed method is the first to provide a holistic characterization of isotopic identification,more » mass ratios, and absolute mass determination. Successful single fissile isotope mass recoveries of less than 6% error have been conducted on standards of 235U and 239Pu as low as 12 nanograms in less than 10 minutes. Additionally, mixtures of fissile isotope standards containing 235U and 239Pu have been characterized as low as 229 nanograms of fissile mass with less than 12% error. The generalizability of this method is illustrated by evaluating different fissile isotopes, mixtures of fissile isotopes, and two different irradiation positions in the reactor. Furthermore, it is anticipated that this method will be expanded to characterize additional fissile nuclides, utilize various irradiation sources, and account for increasingly complex sample matrices.« less

Integrated arc suppression unit for defect reduction in PVD applications

NASA Astrophysics Data System (ADS)

Li, Jason; Narasimhan, Murali K.; Pavate, Vikram; Loo, David; Rosenblum, Steve; Trubell, Larry; Scholl, Richard; Seamons, Scott; Hagerty, Chris; Ramaswami, Sesh

1997-09-01

Arcing between the target and plasma during PVD deposition causes substantial damage to the target and splats and other contamination on the deposited films. Arc-related damages and defects are frequently encountered in microelectronics manufacturing and contributes largely to reduced wafer yields. Arcing is caused largely by the charge buildup at the contaminated sites on the target surface that contains either nonconducting inclusions or nodules. Arc suppression is a key issue for defect reduction, yield improvement and for reliable high quality metallization. An Integrated Arc Suppression Unit (IASU) has been designed for Endura HP PVDTM sputtering sources. The integrated design reduces cable length from unit to source and reduces electrical energy stored in the cable. Active arc handling mode, proactive arc prevention mode, and passive by-pass arc counting mode are incorporated into the same unit. The active mode is designed to quickly respond to chamber conditions, like a large chamber voltage drop, that signals a arc. The self run mode is designed to proactively prevent arc formation by pulsing and reversing target voltage at 50 kHz. The design of the IASU, also called mini small package arc repression circuit--low energy unit (mini Sparc-le), has been optimized for various DC magnetron sources, plasma stability, chamber impedance, power matching, CE MARK test, and power dissipation. Process characterization with Ti, TiN and Al sputtering indicates that the unit has little adverse impact on film properties. Mini Sparc-le unit has been shown here to significantly reduce splats occurrence in Al sputtering. Marathon test of the unit with Ti/TiN test demonstrated the unit's reliability and its ability to reduce sensitivity of defects to target characteristics.

Nonspinning numerical relativity waveform surrogates: assessing the model

NASA Astrophysics Data System (ADS)

Field, Scott; Blackman, Jonathan; Galley, Chad; Scheel, Mark; Szilagyi, Bela; Tiglio, Manuel

2015-04-01

Recently, multi-modal gravitational waveform surrogate models have been built directly from data numerically generated by the Spectral Einstein Code (SpEC). I will describe ways in which the surrogate model error can be quantified. This task, in turn, requires (i) characterizing differences between waveforms computed by SpEC with those predicted by the surrogate model and (ii) estimating errors associated with the SpEC waveforms from which the surrogate is built. Both pieces can have numerous sources of numerical and systematic errors. We make an attempt to study the most dominant error sources and, ultimately, the surrogate model's fidelity. These investigations yield information about the surrogate model's uncertainty as a function of time (or frequency) and parameter, and could be useful in parameter estimation studies which seek to incorporate model error. Finally, I will conclude by comparing the numerical relativity surrogate model to other inspiral-merger-ringdown models. A companion talk will cover the building of multi-modal surrogate models.

Growth and characterization of Na2Mo2O7 crystal scintillators for rare event searches

NASA Astrophysics Data System (ADS)

Pandey, Indra Raj; Kim, H. J.; Kim, Y. D.

2017-12-01

Disodium dimolybdate (Na2Mo2O7) crystals were grown using the Czochralski technique. The thermal characteristics of the compound were analyzed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements. The crystal structure of the grown sample was confirmed using X-ray diffraction (XRD). Luminescence properties were measured at room and low temperatures, using a light emitting diode (LED) source. Very weak luminescence was observed at room temperature; however, the luminescence intensity was enhanced at low temperatures. The crystal's transmittance spectrum was measured for estimating its optical quality and energy band gap. The grown crystal exhibited a luminescence light yield of 55% compared with CaMoO4 crystals at 10 K, when excited by a 280-nm-wavelength LED source, but does not have the drawbacks of radioactive Ca isotopes. These results suggest that at cryogenic temperatures, Na2Mo2O7 crystal scintillators are promising for the detection of dark matter and neutrinoless double beta decay of 100Mo.

Characterization of medium-chain-length polyhydroxyalkanoate biosynthesis by Pseudomonas mosselii TO7 using crude glycerol.

PubMed

Liu, Ming-Hsu; Chen, Yi-Jr; Lee, Chia-Yin

2018-03-01

Polyhydroxyalkanoates (PHAs) are biopolyesters produced by microorganisms that are environmentally friendly. PHAs can be used to replace traditional plastic to reduce environmental pollution in various fields. PHA production costs are high because PHA must be produced from a carbon substrate. The purpose of this study was to find the strain that can used the BDF by-product as the sole carbon source to produce high amounts of medium-chain-length PHA. Three isolates were evaluated for potential PHA production by using biodiesel-derived crude glycerol as the sole carbon source. Among them, Pseudomonas mosselii TO7 yielded high PHA content. The PHA produced from P. mosselii TO7 were medium-chain-length-PHAs. The PHA content of 48% cell dry weight in 48 h with a maximum PHA productivity of 13.16 mg PHAs L -1  h -1 . The narrow polydispersity index value of 1.3 reflected the homogeneity of the polymer chain, which was conducive to industrial applications.

Characterization of Fetal Keratinocytes, Showing Enhanced Stem Cell-Like Properties: A Potential Source of Cells for Skin Reconstruction

PubMed Central

Tan, Kenneth K.B.; Salgado, Giorgiana; Connolly, John E.; Chan, Jerry K.Y.; Lane, E. Birgitte

2014-01-01

Summary Epidermal stem cells have been in clinical application as a source of culture-generated grafts. Although applications for such cells are increasing due to aging populations and the greater incidence of diabetes, current keratinocyte grafting technology is limited by immunological barriers and the time needed for culture amplification. We studied the feasibility of using human fetal skin cells for allogeneic transplantation and showed that fetal keratinocytes have faster expansion times, longer telomeres, lower immunogenicity indicators, and greater clonogenicity with more stem cell indicators than adult keratinocytes. The fetal cells did not induce proliferation of T cells in coculture and were able to suppress the proliferation of stimulated T cells. Nevertheless, fetal keratinocytes could stratify normally in vitro. Experimental transplantation of fetal keratinocytes in vivo seeded on an engineered plasma scaffold yielded a well-stratified epidermal architecture and showed stable skin regeneration. These results support the possibility of using fetal skin cells for cell-based therapeutic grafting. PMID:25254345

CACTI: free, open-source software for the sequential coding of behavioral interactions.

PubMed

Glynn, Lisa H; Hallgren, Kevin A; Houck, Jon M; Moyers, Theresa B

2012-01-01

The sequential analysis of client and clinician speech in psychotherapy sessions can help to identify and characterize potential mechanisms of treatment and behavior change. Previous studies required coding systems that were time-consuming, expensive, and error-prone. Existing software can be expensive and inflexible, and furthermore, no single package allows for pre-parsing, sequential coding, and assignment of global ratings. We developed a free, open-source, and adaptable program to meet these needs: The CASAA Application for Coding Treatment Interactions (CACTI). Without transcripts, CACTI facilitates the real-time sequential coding of behavioral interactions using WAV-format audio files. Most elements of the interface are user-modifiable through a simple XML file, and can be further adapted using Java through the terms of the GNU Public License. Coding with this software yields interrater reliabilities comparable to previous methods, but at greatly reduced time and expense. CACTI is a flexible research tool that can simplify psychotherapy process research, and has the potential to contribute to the improvement of treatment content and delivery.

The genome and phenome of the green alga Chloroidium sp. UTEX 3007 reveal adaptive traits for desert acclimatization

PubMed Central

Nelson, David R; Khraiwesh, Basel; Fu, Weiqi; Alseekh, Saleh; Jaiswal, Ashish; Chaiboonchoe, Amphun; Hazzouri, Khaled M; O’Connor, Matthew J; Butterfoss, Glenn L; Drou, Nizar; Rowe, Jillian D; Harb, Jamil; Fernie, Alisdair R; Gunsalus, Kristin C; Salehi-Ashtiani, Kourosh

2017-01-01

To investigate the phenomic and genomic traits that allow green algae to survive in deserts, we characterized a ubiquitous species, Chloroidium sp. UTEX 3007, which we isolated from multiple locations in the United Arab Emirates (UAE). Metabolomic analyses of Chloroidium sp. UTEX 3007 indicated that the alga accumulates a broad range of carbon sources, including several desiccation tolerance-promoting sugars and unusually large stores of palmitate. Growth assays revealed capacities to grow in salinities from zero to 60 g/L and to grow heterotrophically on >40 distinct carbon sources. Assembly and annotation of genomic reads yielded a 52.5 Mbp genome with 8153 functionally annotated genes. Comparison with other sequenced green algae revealed unique protein families involved in osmotic stress tolerance and saccharide metabolism that support phenomic studies. Our results reveal the robust and flexible biology utilized by a green alga to successfully inhabit a desert coastline. DOI: http://dx.doi.org/10.7554/eLife.25783.001 PMID:28623667

Dust temperature distributions in star-forming condensations

NASA Technical Reports Server (NTRS)

Xie, Taoling; Goldsmith, Paul F.; Snell, Ronald L.; Zhou, Weimin

1993-01-01

The FIR spectra of the central IR condensations in the dense cores of molecular clouds AFGL 2591. B335, L1551, Mon R2, and Sgr B2 are reanalyzed here in terms of the distribution of dust mass as a function of temperature. FIR spectra of these objects can be characterized reasonably well by a given functional form. The general shapes of the dust temperature distributions of these objects are similar and closely resemble the theoretical computations of de Muizon and Rouan (1985) for a sample of 'hot centered' clouds with active star formation. Specifically, the model yields a 'cutoff' temperature below which essentially no dust is needed to interpret the dust emission spectra, and most of the dust mass is distributed in a broad temperature range of a few tens of degrees above the cutoff temperature. Mass, luminosity, average temperature, and column density are obtained, and it is found that the physical quantities differ considerably from source to source in a meaningful way.

Isolation of mesophilic solvent-producing clostridia from Colombian sources: physiological characterization, solvent production and polysaccharide hydrolysis.

PubMed

Montoya, D; Spitia, S; Silva, E; Schwarz, W H

2000-04-28

One hundred and seventy-eight new butanol-acetone producing bacteria related to saccharolytic clostridia were isolated from agricultural sources in Colombia and their fermentation potential was evaluated. Thirteen isolates produced more total solvents from glucose than Clostridium acetobutylicum ATCC 824. The isolates with the highest single solvent production were IBUN 125C and IBUN 18A with 0.46 mol butanol and 0.96 mol ethanol formed from 1 mol glucose, yielding 25. 2 and 29.1 g l(-1) total solvents, respectively, which is close to the maximum values described to date. Most of the new isolates produced exoenzymes for the hydrolysis of starch, carboxymethyl cellulose, xylan, polygalacturonic acid, inulin and chitosan. Together with the high efficiency of solvent production, these hydrolytic isolates may be useful for the direct fermentation of biomass. According to their physiological profile, the most solvent-productive isolates could be classified as strains of C. acetobutylicum, Clostridium beijerinckii, and Clostridium NCP262.

Contribution of X/Ka VLBI to Multi-Wavelength Celestial Frame Studies

NASA Technical Reports Server (NTRS)

Jacobs, C. S.; Clark, J. E.; Garcia-Miro, C.; Horiuchi, S.; Sotuela, I.

2011-01-01

This paper is an update of Sotuela et al. (2011) which improves their simulated Gaia frame tie precision by approximately 10% by adding three additional VLBI observing sessions. Astrometry at X/Ka-band (8.4/32 GHz) using NASAs Deep Space Network has detected 466 quasars with accuracies of 200-300 micro-arc seconds. A program is underway to reduce errors by a factor of 2-3. From our sample, 245 sources have optical magnitudes V less than 20 and should also be detectable by Gaia. A covariance study using existing X/Ka data and simulated Gaia uncertainties for the 345 objects yields a frame tie precision of 10-15 micro-arc seconds (1 - sigma). The characterization of wavelength dependent systematic from extended source morphology and core shift should benefit greatly from adding X/Ka-band measurements to S/X-band (2.3/8.4 GHz) measurements thus helping to constrain astrophysical models of the wavelength dependence of positions.

Charge coupled devices

NASA Technical Reports Server (NTRS)

Walker, J. W.; Hornbeck, L. J.; Stubbs, D. P.

1977-01-01

The results are presented of a program to design, fabricate, and test CCD arrays suitable for operation in an electron-bombarded mode. These intensified charge coupled devices have potential application to astronomy as photon-counting arrays. The objectives of this program were to deliver arrays of 250 lines of 400 pixels each and some associated electronics. Some arrays were delivered on tube-compatible headers and some were delivered after incorporation in vacuum tubes. Delivery of these devices required considerable improvements to be made in the processing associated with intensified operation. These improvements resulted in a high yield in the thinning process, reproducible results in the accumulation process, elimination of a dark current source in the accumulation process, solution of a number of header related problems, and the identification of a remaining major source of dark current. Two systematic failure modes were identified and protective measures established. The effects of tube processing on the arrays in the delivered ICCDs were determined and are reported along with the characterization data on the arrays.

Growth and yield of shortleaf pine

Treesearch

Paul A. Murphy

1986-01-01

A survey of available growth and yield information for shortleaf pine (Pinus echinata Mill.) is given. The kinds of studies and data sources that produce this information are also evaluated, and an example of how a growth and yield model can be used to answer management questions is illustrated. Guidelines are given for using growth and yield models, and needs for...

Intermediate pyrolysis of agro-industrial biomasses in bench-scale pyrolyser: Product yields and its characterization.

PubMed

Tinwala, Farha; Mohanty, Pravakar; Parmar, Snehal; Patel, Anant; Pant, Kamal K

2015-01-01

Pyrolysis of woody biomass, agro-residues and seed was carried out at 500 ± 10 °C in a fixed bed pyrolyser. Bio-oil yield was found varying from 20.5% to 47.5%, whereas the biochar and pyrolysis gas ranged from 27.5% to 40% and 24.5% to 40.5%, respectively. Pyrolysis gas was measured for flame temperature along with CO, CO2, H2, CH4 and other gases composition. HHV of biochar (29.4 MJ/kg) and pyrolitic gas (8.6 MJ/kg) of woody biomass was higher analogous to sub-bituminous coal and steam gasification based producer gas respectively, whereas HHV of bio-oil obtained from seed (25.6 MJ/kg) was significantly more than husks, shells and straws. TGA-DTG studies showed the husks as potential source for the pyrolysis. Bio-oils as a major by-product of intermediate pyrolysis have several applications like substitute of furnace oil, extraction of fine chemicals, whereas biochar as a soil amendment for enhancing soil fertility and gases for thermal application. Copyright © 2015 Elsevier Ltd. All rights reserved.

A portable neutron spectroscope (NSPECT) for detection, imaging and identification of nuclear material

NASA Astrophysics Data System (ADS)

Ryan, James M.; Bancroft, Christopher; Bloser, Peter; Bravar, Ulisse; Fourguette, Dominique; Frost, Colin; Larocque, Liane; McConnell, Mark L.; Legere, Jason; Pavlich, Jane; Ritter, Greg; Wassick, Greg; Wood, Joshua; Woolf, Richard

2010-08-01

We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252 source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification distances and times, and projected effective area for a fully populated instrument.

Impact of lead tolerant plant growth promoting rhizobacteria on growth, physiology, antioxidant activities, yield and lead content in sunflower in lead contaminated soil.

PubMed

Saleem, Muhammad; Asghar, Hafiz Naeem; Zahir, Zahir Ahmad; Shahid, Muhammad

2018-03-01

Present study was conducted to evaluate the effect of lead tolerant plant growth promoting rhizobacteria (LTPGPR) on growth, physiology, yield, antioxidant activities and lead uptake in sunflower in soil contaminated with lead under pot conditions. Three pre-characterized LTPGP strains (S2 (Pseudomonas gessardii strain BLP141), S5 (Pseudomonas fluorescens A506) and S10 (Pseudomonas fluorescens strain LMG 2189)) were used to inoculate sunflower growing in soil contaminated with different levels (300, 600 and 900 mg kg -1 ) of lead by using lead nitrate salt as source of lead. Treatments were arranged according to completely randomized design with factorial arrangements. At harvesting, data regarding growth attributes (root shoot length, root shoot fresh and dry weights), yield per plant, physiological attributes (Chlorophyll 'a', 'b' and carotenoids content), antioxidant activities (Ascorbate peroxidase, catalase, superoxide dismutase and glutathione reductase), proline and malanodialdehyde content, and lead content in root, shoot and achenes of sunflower were recorded. Data were analysed by standard statistical procedures. Results showed that lead contamination reduced the plants growth, physiology and yield at all levels of lead stress. But application of LTPGPR in soil contaminated with lead improved plant growth, physiology, yield, and antioxidant activities, proline, and reduced the malanodialdehyde content (that is reduced by the application of different strains in lead contamination) of sunflower as compared to plants grown in soil without inoculation. Inoculation also promoted the uptake of lead in root, shoots and reduced the uptake of lead in achenes of plants as compared to plants in lead contamination without inoculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sector-based VOCs emission factors and source profiles for the surface coating industry in the Pearl River Delta region of China.

PubMed

Zhong, Zhuangmin; Sha, Qing'e; Zheng, Junyu; Yuan, Zibing; Gao, Zongjiang; Ou, Jiamin; Zheng, Zhuoyun; Li, Cheng; Huang, Zhijiong

2017-04-01

Accurate depiction of VOCs emission characteristics is essential for the formulation of VOCs control strategies. As one of the continuous efforts in improving VOCs emission characterization in the Pearl River Delta (PRD) region, this study targeted on surface coating industry, the most important VOCs emission sources in the PRD. Sectors in analysis included shipbuilding coating, wood furniture coating, metal surface coating, plastic surface coating, automobile coating and fabric surface coating. Sector-based field measurement was conducted to characterize VOCs emission factors and source profiles in the PRD. It was found that the raw material-based VOCs emission factors for these six sectors ranged from 0.34 to 0.58kg VOCs per kg of raw materials (kg·kg -1 ) while the emission factors based on the production yield varied from 0.59kg to 13.72t VOCs for each production manufactured. VOCs emission factors of surface coating industry were therefore preferably calculated based on raw materials with low uncertainties. Source profiles differed greatly among different sectors. Aromatic was the largest group for shipbuilding coating, wood furniture coating, metal surface coating and automobile coating while the oxygenated VOCs (OVOCs) were the most abundant in the plastic and fabric surface coating sectors. The major species of aromatic VOCs in each of these six sectors were similar, mainly toluene and m/p-xylene, while the OVOCs varied among the different sectors. VOCs profiles in the three processes of auto industry, i.e., auto coating, auto drying and auto repairing, also showed large variations. The major species in these sectors in the PRD were similar with other places but the proportions of individual compounds were different. Some special components were also detected in the PRD region. This study highlighted the importance of updating local source profiles in a comprehensive and timely manner. Copyright © 2016 Elsevier B.V. All rights reserved.

Added-values of high spatiotemporal remote sensing data in crop yield estimation

NASA Astrophysics Data System (ADS)

Gao, F.; Anderson, M. C.

2017-12-01

Timely and accurate estimation of crop yield before harvest is critical for food market and administrative planning. Remote sensing derived parameters have been used for estimating crop yield by using either empirical or crop growth models. The uses of remote sensing vegetation index (VI) in crop yield modeling have been typically evaluated at regional and country scales using coarse spatial resolution (a few hundred to kilo-meters) data or assessed over a small region at field level using moderate resolution spatial resolution data (10-100m). Both data sources have shown great potential in capturing spatial and temporal variability in crop yield. However, the added value of data with both high spatial and temporal resolution data has not been evaluated due to the lack of such data source with routine, global coverage. In recent years, more moderate resolution data have become freely available and data fusion approaches that combine data acquired from different spatial and temporal resolutions have been developed. These make the monitoring crop condition and estimating crop yield at field scale become possible. Here we investigate the added value of the high spatial and temporal VI for describing variability of crop yield. The explanatory ability of crop yield based on high spatial and temporal resolution remote sensing data was evaluated in a rain-fed agricultural area in the U.S. Corn Belt. Results show that the fused Landsat-MODIS (high spatial and temporal) VI explains yield variability better than single data source (Landsat or MODIS alone), with EVI2 performing slightly better than NDVI. The maximum VI describes yield variability better than cumulative VI. Even though VI is effective in explaining yield variability within season, the inter-annual variability is more complex and need additional information (e.g. weather, water use and management). Our findings augment the importance of high spatiotemporal remote sensing data and supports new moderate resolution satellite missions for agricultural applications.

Production planning and backup sourcing strategy of a buyer-dominant supply chain with random yield and demand

NASA Astrophysics Data System (ADS)

Chen, Kebing; Xiao, Tiaojun

2015-11-01

This paper studies the backup sourcing strategy of the buyer and the production planning of the supplier in presence of both random yield and random demand. Since the production is susceptible to the randomness of yield beyond the control of the supplier, the buyer may access to a backup sourcing option for the finished items. We analyse the value of backup sourcing for both the decentralised and centralised channels. Backup sourcing strategy of the buyer may lower the supply chain's performance. We show that the order quantity of the buyer does not change the stocking factor of the supplier's input. Meanwhile, compared with the centralised operation, the decentralised operation is more dependent on the backup sourcing to reduce supply shortage of the contracting supplier. From the channel's perspective, an incentive scheme is developed to facilitate the coordination of both the buyer and the contracting supplier, we show that the proposed option contract can allow the supply chain members to share the respective risks involved in the production and selling processes. Finally, we also provide qualitative insights based on numerical examples of the centralised and decentralised solutions.

Experimental Characterization and Material Modelling of an AZ31 Magnesium Sheet Alloy at Elevated Temperatures under Consideration of the Tension-Compression Asymmetry

NASA Astrophysics Data System (ADS)

Behrens, B.-A.; Bouguecha, A.; Bonk, C.; Dykiert, M.

2017-09-01

Magnesium sheet alloys have a great potential as a construction material in the aerospace and automotive industry. However, the current state of research regarding temperature dependent material parameters for the description of the plastic behaviour of magnesium sheet alloys is scarce in literature and accurate statements concerning yield criteria and appropriate characterization tests to describe the plastic behaviour of a magnesium sheet alloy at elevated temperatures in deep drawing processes are to define. Hence, in this paper the plastic behaviour of the well-established magnesium sheet alloy AZ31 has been characterized by means of convenient mechanical tests (e. g. tension, compression and biaxial tests) at temperatures between 180 and 230 °C. In this manner, anisotropic and hardening behaviour as well as differences between the tension-compression asymmetry of the yield locus have been estimated. Furthermore, using the evaluated data from the above mentioned tests, two different yield criteria have been parametrized; the commonly used Hill’48 and an orthotropic yield criterion, CPB2006, which was developed especially for materials with hexagonal close packed lattice structure and is able to describe an asymmetrical yielding behaviour regarding tensile and compressive stress states. Numerical simulations have been finally carried out with both yield functions in order to assess the accuracy of the material models.

The Source Physics Experiments (SPE): A Physics-Based Approach to Discriminate Low-Yield Nuclear Events (Invited)

NASA Astrophysics Data System (ADS)

Snelson, C. M.; Chipman, V.; White, R. L.; Emmitt, R.; Townsend, M.

2013-12-01

Discriminating low-yield nuclear explosions is one of the current challenges in the field of monitoring and verification. Work is currently underway in Nevada to address this challenge by conducting a series of experiments using a physics-based approach. This has been accomplished by using a multifaceted, multi-disciplinary approach that includes a range of activities, from characterizing the shallow subsurface to acquiring new explosion data both in the near field (< 100 m from the source) to the far field (> 100 m to 10 s km from the source). The Source Physics Experiment (SPE) is a collaborative project between National Security Technologies, LLC, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Sandia National Laboratories, the Defense Threat Reduction Agency, and the Air Force Technical Applications Center. The goal of the SPE is to understand the transition of seismic energy from the near field to the far field; to understand the development of S-waves in explosives sources; and to understand how anisotropy controls seismic energy transmission and partitioning. To fully explore these problems, the SPE test series includes tests in both simple and complex geology cases. The current series is being conducted in a highly fractured granite body. This location was chosen, in part, because it was the location of previous nuclear tests in the same rock body and because generally the geology has been well characterized. In addition to historic data, high-resolution seismic reflection, cross-hole tomography, core samples, LIDAR, hyperspectral, and fracture mapping data have been acquired to further characterize and detect changes after each of the shot across the test bed. The complex geology series includes 7 planned shots using conventional explosives in the same shot hole surrounded by Continuous Reflectometry for Radius vs. Time Experiment (CORRTEX), Time of Arrival, Velocity of Detonation, down-hole accelerometers, surface accelerometers, infrasound, and a suite of seismic sensors of various frequency bands from the near field to the far field. This allows for the use of a single test bed in the granite instead of multiple test beds to obtain the same results. The shots are planned at various depths to obtain a Green's function, scaled depth-of-burial data, nominal depth-of-burial data and damage-zone data. Three shots have been executed to date and the fourth is planned for August 2013 as a 220 lb (100 kg) TNT equivalent shot at a depth of 315 ft (96 m). Over 400 data channels have been recorded on the first series of shots with high fidelity. Once the complex geology site data have been exploited, a new test bed will be developed in a simpler geology to test these physics-based models. Ultimately, the results from this project will provide the next advances in the science of monitoring to enable a physics-based predicative capability. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946--1835.

Polymer precursors for ceramic matrix composites

NASA Technical Reports Server (NTRS)

Litt, M. H.; Kumar, K.

1986-01-01

The synthesis and characterization of a polycyclohexasilane is reported. Because of its cyclic structure, it is anticipated that this polymer might serve as a precursor to SIC having a high char yield with little rearrangement to form small, volatile cyclic silanes, and, as such, would be of interest as a precursor to SiC composite matrices and fibers, or as a binder in ceramic processing. Several approaches to the synthesis of a bifunctional cyclic monomer were attempted; the most successful of these was metal coupling of PhMeSiCl2 and Me2SiCl2. The procedure gives six-membered ring compounds with all degrees of phenyl substitution, from none to hexaphenyl. The compounds with from 0-2 groups were isolated and characterized. The fraction with degree of phenyl substitution equal to 2, a mixture of cis and trans 1,2-; 1,3-; and 1,4 isomers, was isolated in 32 percent yield. Pure 1,4 diphenyldecamethylcyclohexasilane was isolated from the mixed diphenyl compounds and characterized. Diphenyldecamethylcyclohexasilanes were dephenylated to dichlorodecamethylcyclohexasilanes by treating with H2SO4.NH4Cl in benzene. The latter were purified and polymerized by reacting with sodium in toluene. The polymers were characterized by HPGPC, elemental analysis, proton NMR, and IR. Thermogravimetric analyses were carried out on the polymers. As the yield of residual SiC was low, polymers were heat treated to increase the residual char yield. As high as 51.52 percent residual char yield was obtained in one case.

Structural characterization of anion-calcium-humate complexes in phosphate-based fertilizers.

PubMed

Baigorri, Roberto; Urrutia, Oscar; Erro, Javier; Mandado, Marcos; Pérez-Juste, Ignacio; Garcia-Mina, José María

2013-07-01

Fertilizers based on phosphate-metal-humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid (31)P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the (31)P NMR peaks. Computational chemistry methods allowed the characterization of phosphate-calcium-humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate-calcium-humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate-metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental (31)P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the (31)P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate-calcium interactions within the crystals. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon spectrum utilization by an indigenous strain of Pseudomonas aeruginosa NCIM 5514: Production, characterization and surface active properties of biosurfactant.

PubMed

Varjani, Sunita J; Upasani, Vivek N

2016-12-01

The present research work was undertaken with a mandate to study carbon spectrum utilization and structural characterization of biosurfactant produced by indigenous Pseudomonas aeruginosa NCIM 5514, which showed unique properties to utilize a large number of carbon sources effectively for production of biosurfactant, although glucose was the best carbon substrate. In Bushnell-Hass medium supplemented with glucose (1%, w/v), 3.178±0.071g/l biosurfactant was produced by this isolate in 96h. The biosurfactant produced showed surface tension and emulsification activity values from 29.14±0.05 to 62.29±0.13mN/m and 88.50±1.96 to 15.40±0.91%, respectively. Toluene showed highest emulsification activity followed by kerosene. However, kerosene exhibited emulsion stability for 30days. Biosurfactant was characterized as a mixture of di-rhamnolipid (Rha-Rha-C 10 -C 14:1 ) and mono-rhamnolipid (Rha-C 8 -C 10 ) by FTIR, ESI-MS and LC-MS techniques. High biosurfactant yield opens up doors for the isolate to find utility in various industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Greater taxol yield of fungus Pestalotiopsis hainanensis from dermatitic scurf of the giant panda (Ailuropoda melanoleuca).

PubMed

Gu, Yu; Wang, Yanlin; Ma, Xiaoping; Wang, Chengdong; Yue, Guizhou; Zhang, Yuetian; Zhang, Yunyan; Li, Shanshan; Ling, Shanshan; Liu, Xiaomin; Wen, Xintian; Cao, Sanjie; Huang, Xiaobo; Deng, Junliang; Zuo, Zhicai; Yu, Shumin; Shen, Liuhong; Wu, Rui

2015-01-01

While taxol yields of fungi from non-animal sources are still low, whether Pestalotiopsis hainanensis isolated from the scurf of a dermatitic giant panda, Ailuropoda melanoleuca, provides a greater taxol yield remains unknown. The objective of the study was to determine the corresponding taxol yield. The structure of the taxol produced by the fungus was evaluated by thin layer chromatography (TLC), ultraviolet (UV) spectroscopy, high-performance liquid chromatography (HPLC), (1)H and (13)C nuclear magnetic resonance spectroscopy ((1)H-NMR and (13)C-NMR), and time-of-flight mass spectrometry (TOF-MS), with standard taxol as a control. The results demonstrated that the P. hainanensis fungus produced taxol, which had the same structure as the standard taxol and yield of 1,466.87 μg/L. This fungal taxol yield from the dermatitic giant panda was significantly greater than those of fungus from non-animal sources. The taxol-producing fungus may be a potential candidate for the production of taxol on an industrial scale.

Analysis and Simulations of Near-Field Ground Motion from Source Physics Experiments (spe)

NASA Astrophysics Data System (ADS)

Vorobiev, O.; Xu, H.; Lomov, I.; Herbold, E. B.; Glenn, L. A.; Antoun, T.

2012-12-01

This work is focused on analysis of near-field measurements (up to 50-70 m from the source) recorded during Source Physics Experiments SPE1, SPE2 and SPE3 in a granitic formation (the Climax Stock) at the Nevada National Security Site (NNSS). The explosive source used in these experiments is a sensitized heavy ANFO (SHANFO) with a well characterized equation of state. The first event, SPE1, had a yield of 0.1 ton, and was detonated at a 55 m depth of burial in a spherical cavity of about 0.3 m radius. SPE2 and SPE3 had an explosive yield of 1 ton, and they were both detonated in the same cavity at a depth of burial of 45 meters. One of the main goals of these experiments was to investigate the possible mechanisms of shear wave generation in the nonlinear source region. Another objective, relating specifically to the SPE2-SPE3 sequence, was to investigate the effect of damage from one explosion on the response of the medium to a second explosion of the same yield and at the same location as the first explosion. Comparison of the results from SPE2 and SPE3 show some interesting trends. . At the shot level, and at deeper locations, the data from SPE3 seem to agree quite well with SPE2 data, indicating that damage from SPE2 had little to no effect on the response of the medium at these locations. On the other hand, SPE3 data consistently show delay in arrival times as well as reduced wave amplitudes both at 50 ft (16 m) depth and at the ground surface, indicating that above the shot horizon damage from SPE2 had a perceptible effect on the SPE3 near field motions. The quality of the near field data at some gages from the SPE1 and SPE2 events is somewhat questionable, with orientation uncertainties making it difficult to ascertain with confidence the extent to which shear wave generation in the source region affected near field motions. New gages were strategically added to the SPE3 test bed to provide the data needed to address this issue and verify previous measurements. The new measurements for SPE 3 show significant tangential motion (up to 30 % of the radial) at many locations as well as azimuthal variations in radial velocities which cannot be predicted by continuum simulations using isotropic plasticity models. Both continuum and discrete 2D/3D simulations are currently being performed to better understand the experimental results, correlate observed motions with heterogeneities in the rock, and aid in assessing the origin of shear waves observed in the seismic frequency band.

Source spectral variation and yield estimation for small, near-source explosions

NASA Astrophysics Data System (ADS)

Yoo, S.; Mayeda, K. M.

2012-12-01

Significant S-wave generation is always observed from explosion sources which can lead to difficulty in discriminating explosions from natural earthquakes. While there are numerous S-wave generation mechanisms that are currently the topic of significant research, the mechanisms all remain controversial and appear to be dependent upon the near-source emplacement conditions of that particular explosion. To better understand the generation and partitioning of the P and S waves from explosion sources and to enhance the identification and discrimination capability of explosions, we investigate near-source explosion data sets from the 2008 New England Damage Experiment (NEDE), the Humble-Redwood (HR) series of explosions, and a Massachusetts quarry explosion experiment. We estimate source spectra and characteristic source parameters using moment tensor inversions, direct P and S waves multi-taper analysis, and improved coda spectral analysis using high quality waveform records from explosions from a variety of emplacement conditions (e.g., slow/fast burning explosive, fully tamped, partially tamped, single/ripple-fired, and below/above ground explosions). The results from direct and coda waves are compared to theoretical explosion source model predictions. These well-instrumented experiments provide us with excellent data from which to document the characteristic spectral shape, relative partitioning between P and S-waves, and amplitude/yield dependence as a function of HOB/DOB. The final goal of this study is to populate a comprehensive seismic source reference database for small yield explosions based on the results and to improve nuclear explosion monitoring capability.

Fragment emission from the mass-symmetric reactions 58Fe,58Ni +58Fe,58Ni at Ebeam=30 MeV/nucleon

NASA Astrophysics Data System (ADS)

Ramakrishnan, E.; Johnston, H.; Gimeno-Nogues, F.; Rowland, D. J.; Laforest, R.; Lui, Y.-W.; Ferro, S.; Vasal, S.; Yennello, S. J.

1998-04-01

The mass-symmetric reactions 58Fe,58Ni +58Fe,58Ni were studied at a beam energy of Ebeam=30 MeV/nucleon in order to investigate the isospin dependence of fragment emission. Ratios of inclusive yields of isotopic fragments from hydrogen through nitrogen were extracted as a function of laboratory angle. A moving source analysis of the data indicates that at laboratory angles around 40° the yield of intermediate mass fragments (IMF's) beyond Z=3 is predominantly from a midrapidity source. The angular dependence of the relative yields of isotopes beyond Z=3 indicates that the IMF's at more central angles originate from a source which is more neutron deficient than the source responsible for fragments emitted at forward angles. The charge distributions and kinetic energy spectra of the IMF's at various laboratory angles were well reproduced by calculations employing a quantum molecular-dynamics code followed by a statistical multifragmentation model for generating fragments. The calculations indicate that the measured IMF's originate mainly from a single source. The isotopic composition of the emitted fragments is, however, not reproduced by the same calculation. The measured isotopic and isobaric ratios indicate an emitting source that is more neutron rich in comparison to the source predicted by model calculations.

A Permanent-Magnet Microwave Ion Source For A Compact High-Yield Neutron Generator

NASA Astrophysics Data System (ADS)

Waldmann, O.; Ludewigt, B.

2011-06-01

We present recent work on the development of a microwave ion source that will be used in a high-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable of producing high neutron yields, 5×1011 n/s for D-T and ˜1×1010 n/s for D-D reactions, while remaining transportable. We constructed a microwave ion source (2.45 GHz) with permanent magnets to provide the magnetic field strength of 87.5 mT necessary for satisfying the electron cyclotron resonance (ECR) condition. Microwave ion sources can produce high extracted beam currents at the low gas pressures required for sealed tube operation and at lower power levels than previously used RF-driven ion sources. A 100 mA deuterium/tritium beam will be extracted through a large slit (60×6 mm2) to spread the beam power over a larger target area. This paper describes the design of the permanent-magnet microwave ion source and discusses the impact of the magnetic field design on the source performance. The required equivalent proton beam current density of 40 mA/cm2 was extracted at a moderate microwave power of 400 W with an optimized magnetic field.

Ozone Promotes Chloropicrin Formation by Oxidizing Amines to Nitro Compounds.

PubMed

McCurry, Daniel L; Quay, Amanda N; Mitch, William A

2016-02-02

Chloropicrin formation has been associated with ozonation followed by chlorination, but the reaction pathway and precursors have been poorly characterized. Experiments with methylamine demonstrated that ozonation converts methylamine to nitromethane at ∼100% yield. Subsequent chlorination converts nitromethane to chloropicrin at ∼50% yield under the conditions evaluated. Similarly high yields from other primary amines were limited to those with functional groups on the β-carbon (e.g., the carboxylic acid in glycine) that facilitate carbon-carbon bond cleavage to release nitromethyl anion. Secondary amines featuring these reactive primary amines as functional groups (e.g., secondary N-methylamines) formed chloropicrin at high yields, likely by facile dealkylation to release the primary nitro compound. Chloropicrin yields from tertiary amines were low. Natural water experiments, including derivatization to transform primary and secondary amines to less reactive carbamate functional groups, indicated that primary and secondary amines were the dominant chloropicrin precursors during ozonation/chlorination. Ozonation followed by chlorination of the primary amine side chain of lysine demonstrated low yields (∼0.2%) of chloropicrin, but high yields (∼17%) of dichloronitrolysine, a halonitroalkane structural analogue to chloropicrin. However, chloropicrin yields increased and dichloronitrolysine yields decreased in the absence of hydroxyl radical scavengers, suggesting that future research should characterize the potential occurrence of such halonitroalkane analogues relative to natural radical scavenger (e.g., carbonate) concentrations.

Metal loading assessment of a small mountainous sub-basin characterized by acid drainage -- Prospect Gulch, upper Animas River watershed, Colorado

USGS Publications Warehouse

Wirt, Laurie; Leib, Kenneth J.; Melick, Roger; Bove, Dana J.

2001-01-01

strongly affected by natural acidity from pyrite weathering. Metal content in the water column is a composite of multiple sources affected by hydrologic, geologic, climatic, and anthropogenic conditions. Identifying sources of metals from various drainage areas was determined using a tracer injection approach and synoptic sampling during low flow conditions on September 29, 1999 to determine loads. The tracer data was interpreted in conjunction with detailed geologic mapping, topographic profiling, geochemical characterization, and the occurrence and distribution of trace metals to identify sources of ground-water inflows. For this highly mineralized sub-basin, we demonstrate that SO4, Al, and Fe load contributions from drainage areas that have experienced historical mining?although substantial?are relatively insignificant in comparison with SO4, Al, and Fe loads from areas experiencing natural weathering of highlyaltered, pyritic rocks. Regional weathering of acid-sulfate mineral assemblages produces moderately low pH waters elevated in SO4, Al, and Fe; but generally lacking in Cu, Cd, Ni, and Pb. Samples impacted by mining are also characterized by low pH and large concentrations of SO4, Al, and Fe; but contained elevated dissolved metals from ore-bearing vein minerals such as Cu, Zn, Cd, Ni, and Pb. Occurrences of dissolved trace metals were helpful in identifying ground-water sources and flow paths. For example, cadmium was greatest in inflows associated with drainage from inactive mine sites and absent in inflows that were unaffected by past mining activities and thus served as an important indicator of mining contamination for this environmental setting. The most heavily mine-impacted reach (PG153 to PG800), contributed 8% of the discharge, and 11%, 9%, and 12% of the total SO4, Al, and Fe loads in Prospect Gulch. The same reach yielded 59% and 37% of the total Cu and Zn loads for the subbasin. In contrast, the naturally acidic inflows from the Red Chemotroph iron spring yielded 39% of the discharge and 54%, 73%, and 87% of the SO4, Al, and Fe loads; but only 4% of the total Cu and 30% of the total Zn loads in Prospect Gulch. Base flow from the Prospect Gulch sub-basin contributes about 4.8 percent of the total discharge at the mouth of Cement Creek; compared with sampled instream loads of 1.8%, 8.8%, 15.9%, 28%, and 8.6% for SO4, Al, Fe, Cu and Zn, respectively. Water-shed scale remediation efforts targeted at reducing loads of SO4, Al, and Fe at inactive mine sites are likely to fail because the major sources of these constituents in Prospect Gulch are predominantly discharged from natural sources. Remediation goals aimed at reducing acidity and loads of Cu and other base metals, may succeed, however, because changes in pH and loads are disproportionately greater than increases in discharge over the same reach, and a substantial fraction of the metal loading is from mining-impacted reaches. Whether remediation of abandoned mines in Prospect Gulch can be successful depends on how goals are defined?that is, whether the objective is to reduce loads of SO4, Al, and Fe; or whether loads of Cu and other base metals and pH are targeted.

Straight single-crystalline germanium nanowires and their patterns grown on sol gel prepared gold/silica substrates

NASA Astrophysics Data System (ADS)

Pan, Zheng Wei; Dai, Sheng; Lowndes, Douglas H.

2005-04-01

Straight single-crystalline Ge nanowires with a uniform diameter distribution of 50-80 nm and lengths up to tens of micrometers were grown in a high yield on sol-gel prepared gold/silica substrates by using Ge powder as the Ge source. Detailed electron microscopy analyses show that the nanowires grow through a vapor-liquid-solid growth mechanism with gold nanoparticles located at the nanowire tips. By using transmission electron microscope grids as the shadow mask, the sol-gel technique can be readily adapted to prepare patterned film-like gold/silica substrates, so that regular micropatterns of Ge nanowires were obtained, which could facilitate the integration of Ge nanowires for characterization and devices.

Initial Results from the Survey of Organizational Research Climates (SOuRCe) in the U.S. Department of Veterans Affairs Healthcare System.

PubMed

Martinson, Brian C; Nelson, David; Hagel-Campbell, Emily; Mohr, David; Charns, Martin P; Bangerter, Ann; Thrush, Carol R; Ghilardi, Joseph R; Bloomfield, Hanna; Owen, Richard; Wells, James A

2016-01-01

In service to its core mission of improving the health and well-being of veterans, Veterans Affairs (VA) leadership is committed to supporting research best practices in the VA. Recognizing that the behavior of researchers is influenced by the organizational climates in which they work, efforts to assess the integrity of research climates and share such information with research leadership in VA may be one way to support research best practices. The Survey of Organizational Research Climate (SOuRCe) is the first validated survey instrument specifically designed to assess the organizational climate of research integrity in academic research organizations. The current study reports on an initiative to use the SOuRCe in VA facilities to characterize the organizational research climates and pilot test the effectiveness of using SOuRCe data as a reporting and feedback intervention tool. We administered the SOuRCe using a cross-sectional, online survey, with mailed follow-up to non-responders, of research-engaged employees in the research services of a random selection of 42 VA facilities (e.g., Hospitals/Stations) believed to employ 20 or more research staff. We attained a 51% participation rate, yielding more than 5,200 usable surveys. We found a general consistency in organizational research climates across a variety of sub-groups in this random sample of research services in the VA. We also observed similar SOuRCe scale score means, relative rankings of these scales and their internal reliability, in this VA-based sample as we have previously documented in more traditional academic research settings. Results also showed more substantial variability in research climate scores within than between facilities in the VA research service as reflected in meaningful subgroup differences. These findings suggest that the SOuRCe is suitable as an instrument for assessing the research integrity climates in VA and that the tool has similar patterns of results that have been observed in more traditional academic research settings. The local and specific nature of organizational climates in VA research services, as reflected in variability across sub-groups within individual facilities, has important policy implications. Global, "one-size-fits-all" type initiatives are not likely to yield as much benefit as efforts targeted to specific organizational units or sub-groups and tailored to the specific strengths and weaknesses documented in those locations.

Sputtering yields of carbon based materials under high particle flux with low energy

NASA Astrophysics Data System (ADS)

Nakamura, K.; Nagase, A.; Dairaku, M.; Akiba, M.; Araki, M.; Okumura, Y.

1995-04-01

A new ion source which can produce high particle flux beams at low energies has been developed. This paper presents preliminary results on the sputtering yield of the carbon fiber reinforced composites (CFCs) measured with the new ion source. The sputtering yields of 1D and 2D CFCs, which are candidate materials for the divertor armour tiles, have been measured by the weight loss method under the hydrogen and deuterium particle fluxes of 2 ˜ 7 × 10 20/m 2 s at 50 ˜ 150 eV. Preferential sputtering of the matrix was observed on CFCs which included the matrix of 40 ˜ 60 w%. The energy dependence of the sputtering yields was weak. The sputtering yields of CFCs normally irradiated with deuterium beam were from 0.073 to 0.095, and were around three times larger than those with hydrogen beam.

Effects of nitrogen source and rate and method of fertilizer application on yield and fruit size in 'Bluecrop' highbush blueberry

USDA-ARS?s Scientific Manuscript database

A study was done to determine the effects of N source and rate and two common methods of fertilizer application on yield and fruit size in a maturing field of highbush blueberry. Plants were fertilized by drip fertigation or with granular fertilizer using urea or ammonium sulfate applied at a rate o...

An Experimental Investigation of Unsteady Thrust Augmentation Using a Speaker-Driven Jet

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Wernet, Mark P.; John, Wentworth T.

2004-01-01

An experimental investigation is described in which a simple speaker-driven jet was used as a pulsed thrust source (driver) for an ejector configuration. The objectives of the investigation were twofold: first, to add to the experimental body of evidence showing that an unsteady thrust source, combined with a properly sized ejector generally yields higher thrust augmentation values than a similarly sized, steady driver of equivalent thrust. Second, to identify characteristics of the unsteady driver that may be useful for sizing ejectors, and predicting what thrust augmentation values may be achieved. The speaker-driven jet provided a convenient source for the investigation because it is entirely unsteady (having no mean component) and because relevant parameters such as frequency, time-averaged thrust, and diameter are easily variable. The experimental setup will be described, as will the various measurements made. These include both thrust and Digital Particle Imaging Velocimetry of the driver. It will be shown that thrust augmentation values as high as 1.8 were obtained, that the diameter of the best ejector scaled with the dimensions of the emitted vortex, and that the so-called Formation Number serves as a useful dimensionless number by which to characterize the jet and predict performance.

Open-source three-dimensional printing of biodegradable polymer scaffolds for tissue engineering.

PubMed

Trachtenberg, Jordan E; Mountziaris, Paschalia M; Miller, Jordan S; Wettergreen, Matthew; Kasper, Fred K; Mikos, Antonios G

2014-12-01

The fabrication of scaffolds for tissue engineering requires elements of customization depending on the application and is often limited due to the flexibility of the processing technique. This investigation seeks to address this obstacle by utilizing an open-source three-dimensional printing (3DP) system that allows vast customizability and facilitates reproduction of experiments. The effects of processing parameters on printed poly(ε-caprolactone) scaffolds with uniform and gradient pore architectures have been characterized with respect to fiber and pore morphology and mechanical properties. The results demonstrate the ability to tailor the fiber diameter, pore size, and porosity through modification of pressure, printing speed, and programmed fiber spacing. A model was also used to predict the compressive mechanical properties of uniform and gradient scaffolds, and it was found that modulus and yield strength declined with increasing porosity. The use of open-source 3DP technologies for printing tissue-engineering scaffolds provides a flexible system that can be readily modified at a low cost and is supported by community documentation. In this manner, the 3DP system is more accessible to the scientific community, which further facilitates the translation of these technologies toward successful tissue-engineering strategies.

Vital Signs: Seismology of Icy Ocean Worlds

NASA Astrophysics Data System (ADS)

Vance, Steven D.; Kedar, Sharon; Panning, Mark P.; Stähler, Simon C.; Bills, Bruce G.; Lorenz, Ralph D.; Huang, Hsin-Hua; Pike, W. T.; Castillo, Julie C.; Lognonné, Philippe; Tsai, Victor C.; Rhoden, Alyssa R.

2018-01-01

Ice-covered ocean worlds possess diverse energy sources and associated mechanisms that are capable of driving significant seismic activity, but to date no measurements of their seismic activity have been obtained. Such investigations could reveal the transport properties and radial structures, with possibilities for locating and characterizing trapped liquids that may host life and yielding critical constraints on redox fluxes and thus on habitability. Modeling efforts have examined seismic sources from tectonic fracturing and impacts. Here, we describe other possible seismic sources, their associations with science questions constraining habitability, and the feasibility of implementing such investigations. We argue, by analogy with the Moon, that detectable seismic activity should occur frequently on tidally flexed ocean worlds. Their ices fracture more easily than rocks and dissipate more tidal energy than the <1 GW of the Moon and Mars. Icy ocean worlds also should create less thermal noise due to their greater distance and consequently smaller diurnal temperature variations. They also lack substantial atmospheres (except in the case of Titan) that would create additional noise. Thus, seismic experiments could be less complex and less susceptible to noise than prior or planned planetary seismology investigations of the Moon or Mars.

Online surveillance of media health event reporting in Nepal: digital disease detection from a One Health perspective.

PubMed

Schwind, Jessica S; Norman, Stephanie A; Karmacharya, Dibesh; Wolking, David J; Dixit, Sameer M; Rajbhandari, Rajesh M; Mekaru, Sumiko R; Brownstein, John S

2017-09-21

Traditional media and the internet are crucial sources of health information. Media can significantly shape public opinion, knowledge and understanding of emerging and endemic health threats. As digital communication rapidly progresses, local access and dissemination of health information contribute significantly to global disease detection and reporting. Health event reports in Nepal (October 2013-December 2014) were used to characterize Nepal's media environment from a One Health perspective using HealthMap - a global online disease surveillance and mapping tool. Event variables (location, media source type, disease or risk factor of interest, and affected species) were extracted from HealthMap. A total of 179 health reports were captured from various sources including newspapers, inter-government agency bulletins, individual reports, and trade websites, yielding 108 (60%) unique articles. Human health events were reported most often (n = 85; 79%), followed by animal health events (n = 23; 21%), with no reports focused solely on environmental health. By expanding event coverage across all of the health sectors, media in developing countries could play a crucial role in national risk communication efforts and could enhance early warning systems for disasters and disease outbreaks.

Microcosm assays and Taguchi experimental design for treatment of oil sludge containing high concentration of hydrocarbons.

PubMed

Castorena-Cortés, G; Roldán-Carrillo, T; Zapata-Peñasco, I; Reyes-Avila, J; Quej-Aké, L; Marín-Cruz, J; Olguín-Lora, P

2009-12-01

Microcosm assays and Taguchi experimental design was used to assess the biodegradation of an oil sludge produced by a gas processing unit. The study showed that the biodegradation of the sludge sample is feasible despite the high level of pollutants and complexity involved in the sludge. The physicochemical and microbiological characterization of the sludge revealed a high concentration of hydrocarbons (334,766+/-7001 mg kg(-1) dry matter, d.m.) containing a variety of compounds between 6 and 73 carbon atoms in their structure, whereas the concentration of Fe was 60,000 mg kg(-1) d.m. and 26,800 mg kg(-1) d.m. of sulfide. A Taguchi L(9) experimental design comprising 4 variables and 3 levels moisture, nitrogen source, surfactant concentration and oxidant agent was performed, proving that moisture and nitrogen source are the major variables that affect CO(2) production and total petroleum hydrocarbons (TPH) degradation. The best experimental treatment yielded a TPH removal of 56,092 mg kg(-1) d.m. The treatment was carried out under the following conditions: 70% moisture, no oxidant agent, 0.5% of surfactant and NH(4)Cl as nitrogen source.

Molecular Carbon in the Galaxy: Laboratory and Observational Studies

NASA Technical Reports Server (NTRS)

Saykally, Richard James

2003-01-01

In a collaboration with the Mats Larsson group from Stockholm, we carried out a new measurement of the rate of dissociative recombination of H(sup *, sub j), using a new pulsed supersonic beam source of rotationally cold H(sup *, sub j). This source was first designed and characterized in our lab by IR cavity ringdown spectroscopy, determining a rotationaYtranslationa1 temperature of 20-60K, depending on conditions. This new source was then taken to Stockholm for the recombination rate studies at the CRYRING storage ring. The recombination rate constant measured against temperature yields values consistent with the most recent calculations, whereas previous experimental measurements varied over a range of 10(exp 4) and were poor agreement with theory. This is a crucial achievement for understanding the ion chemistry of diffuse clouds. Moreover, this result in combination with recent observations implies a greatly enhanced (factor of 40) cosmic ray ionization rate in a diffuse cloud (zeta Persei) relative to previous studies. The implications of this are discussed in our recent Nature paper. An enhanced cosmic-ray flux towards zeta Persei inferred from a laboratory study of the H(sup *, sub j)-e(sup -) recombination rate.

Identification and genetic characterization of maize cell wall variation for improved biorefinery feedstock characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pauly, Markus; Hake, Sarah

2013-10-31

The objectives of this program are to 1) characterize novel maize mutants with altered cell walls for enhanced biorefinery characteristics and 2) find quantitative trait loci (QTLs) related to biorefinery characteristics by taking advantage of the genetic diversity of maize. As a result a novel non-transgenic maize plant (cal1) has been identified, whose stover (leaves and stalk) contain more glucan in their walls leading to a higher saccharification yield, when subjected to a standard enzymatic digestion cocktail. Stacking this trait with altered lignin mutants yielded evene higher saccharification yields. Cal-1 mutants do not show a loss of kernel and ormore » biomass yield when grown in the field . Hence, cal1 biomass provides an excellent feedstock for the biofuel industry.« less

Comparison of aquifer characterization approaches through steady state groundwater model validation: A controlled laboratory sandbox study

USGS Publications Warehouse

Illman, W.A.; Zhu, J.; Craig, A.J.; Yin, D.

2010-01-01

Groundwater modeling has become a vital component to water supply and contaminant transport investigations. An important component of groundwater modeling under steady state conditions is selecting a representative hydraulic conductivity (K) estimate or set of estimates which defines the K field of the studied region. Currently, there are a number of characterization approaches to obtain K at various scales and in varying degrees of detail, but there is a paucity of information in terms of which characterization approach best predicts flow through aquifers or drawdowns caused by some drawdown inducing events. The main objective of this paper is to assess K estimates obtained by various approaches by predicting drawdowns from independent cross-hole pumping tests and total flow rates through a synthetic heterogeneous aquifer from flow-through tests. Specifically, we (1) characterize a synthetic heterogeneous aquifer built in the sandbox through various techniques (permeameter analyses of core samples, single-hole, cross-hole, and flow-through testing), (2) obtain mean K fields through traditional analysis of test data by treating the medium to be homogeneous, (3) obtain heterogeneous K fields through kriging and steady state hydraulic tomography, and (4) conduct forward simulations of 16 independent pumping tests and six flowthrough tests using these homogeneous and heterogeneous K fields and comparing them to actual data. Results show that the mean K and heterogeneous K fields estimated through kriging of small-scale K data (core and single-hole tests) yield biased predictions of drawdowns and flow rates in this synthetic heterogeneous aquifer. In contrast, the heterogeneous K distribution or ?K tomogram? estimated via steady state hydraulic tomography yields excellent predictions of drawdowns of pumping tests not used in the construction of the tomogram and very good estimates of total flow rates from the flowthrough tests. These results suggest that steady state groundwater model validation is possible in this laboratory sandbox aquifer if the heterogeneous K distribution and forcing functions (boundary conditions and source/sink terms) are characterized sufficiently. ?? 2010 by the American Geophysical Union.

Acoustic emission monitoring of tensile testing of corroded and un-corroded clad aluminum 2024-T3 and characterization of effects of corrosion on AE source events and material tensile properties

NASA Astrophysics Data System (ADS)

Okafor, A. Chukwujekwu; Natarajan, Shridhar

2014-02-01

Corrosion damage affects structural integrity and deteriorates material properties of aluminum alloys in aircraft structures. Acoustic Emission (AE) is an effective nondestructive evaluation (NDE) technique for monitoring such damages and predicting failure in large structures of an aircraft. For successful interpretation of data from AE monitoring, sources of AE and factors affecting it need to be identified. This paper presents results of AE monitoring of tensile testing of corroded and un-corroded clad Aluminum 2024-T3 test specimens, and characterization of the effects of strain-rate and corrosion damage on material tensile properties and AE source events. Effect of corrosion was studied by inducing corrosion in the test specimens by accelerated corrosion testing in a Q-Fog accelerated corrosion chamber for 12 weeks. Eight (8) masked dog-bone shaped specimens were placed in the accelerated corrosion chamber at the beginning of the test. Two (2) dog-bone shaped specimens were removed from the corrosion chamber after exposure time of 3, 6, 9, and 12 weeks respectively, and subjected to tension testing till specimen failure along with AE monitoring, as well as two (2) reference samples not exposed to corrosion. Material tensile properties (yield strength, ultimate tensile strength, toughness, and elongation) obtained from tension test and AE parameters obtained from AE monitoring were analyzed and characterized. AE parameters increase with increase in exposure period of the specimens in the corrosive environment. Aluminum 2024-T3 is an acoustically silent material during tensile deformation without any damage. Acoustic emission events increase with increase of corrosion damage and with increase in strain rate above a certain value. Thus AE is suitable for structural health monitoring of corrosion damage. Ultimate tensile strength, toughness and elongation values decrease with increase of exposure period in corrosion chamber.

Production of an endoinulinase from Aspergillus niger AUMC 9375, by solid state fermentation of agricultural wastes, with purification and characterization of the free and immobilized enzyme.

PubMed

Housseiny, Manal M

2014-05-01

Two different substrates, sunflower (Helianthus annuus L.) tubers and lettuce (Lactuca sativa) roots, were tested. Using a mixture of both wastes resulted in higher production of endoinulinase than either waste alone. Also, ten fungal species grown on these substrates as inexpensive, carbon sources were screened for the best production of endoinulinase activities. Of these, Aspergillus niger AUMC 9375 was the most productive, when grown on the mixture using a 6:1 w/w ratio of sun flower: lettuce, and yielded the highest levels of inulinase at 50% moisture, 30°C, pH 5.0, with seven days of incubation, and with yeast extract as the best nitrogen source. Inulinase was purified to homogeneity by ion-exchange chromatography and gel-filtration giving a 51.11 fold purification. The mixture of sunflower tubers and lettuce roots has potential to be an effective and economical substrate for inulinase production. Inulinase was successfully immobilized with an immobilization yield of 71.28%. After incubation for 2 h at 60°C, the free enzyme activity decreased markedly to 10%, whereas that of the immobilized form decreased only to 87%. A reusability test demonstrated the durability of the immobilized inulinase for 10 cycles and in addition, that it could be stored for 32 days at 4°C. These results indicate that this inulinase, in the immobilized form, is a potential candidate for large-scale production of high purity fructose syrups.

A 10(9) neutrons/pulse transportable pulsed D-D neutron source based on flexible head plasma focus unit.

PubMed

Niranjan, Ram; Rout, R K; Srivastava, R; Kaushik, T C; Gupta, Satish C

2016-03-01

A 17 kJ transportable plasma focus (PF) device with flexible transmission lines is developed and is characterized. Six custom made capacitors are used for the capacitor bank (CB). The common high voltage plate of the CB is fixed to a centrally triggered spark gap switch. The output of the switch is coupled to the PF head through forty-eight 5 m long RG213 cables. The CB has a quarter time-period of 4 μs and an estimated current of 506 kA is delivered to the PF device at 17 kJ (60 μF, 24 kV) energy. The average neutron yield measured using silver activation detector in the radial direction is (7.1 ± 1.4) × 10(8) neutrons/shot over 4π sr at 5 mbar optimum D2 pressure. The average neutron yield is more in the axial direction with an anisotropy factor of 1.33 ± 0.18. The average neutron energies estimated in the axial as well as in the radial directions are (2.90 ± 0.20) MeV and (2.58 ± 0.20) MeV, respectively. The flexibility of the PF head makes it useful for many applications where the source orientation and the location are important factors. The influence of electromagnetic interferences from the CB as well as from the spark gap on applications area can be avoided by putting a suitable barrier between the bank and the PF head.

High cell density cultivation of a novel Aurantiochytrium sp. strain TC 20 in a fed-batch system using glycerol to produce feedstock for biodiesel and omega-3 oils.

PubMed

Lee Chang, Kim Jye; Dumsday, Geoff; Nichols, Peter D; Dunstan, Graeme A; Blackburn, Susan I; Koutoulis, Anthony

2013-08-01

A recently isolated Australian Aurantiochytrium sp. strain TC 20 was investigated using small-scale (2 L) bioreactors for the potential of co-producing biodiesel and high-value omega-3 long-chain polyunsaturated fatty acids. Higher initial glucose concentration (100 g/L compared to 40 g/L) did not result in markedly different biomass (48 g/L) or fatty acid (12-14 g/L) yields by 69 h. This comparison suggests factors other than carbon source were limiting biomass production. The effect of both glucose and glycerol as carbon sources for Aurantiochytrium sp. strain TC 20 was evaluated in a fed-batch process. Both glucose and glycerol resulted in similar biomass yields (57 and 56 g/L, respectively) by 69 h. The agro-industrial waste from biodiesel production-glycerol-is a suitable carbon source for Aurantiochytrium sp. strain TC 20. Approximately half the fatty acids from Aurantiochytrium sp. strain TC 20 are suitable for development of sustainable, low emission sources of transportation fuels and bioproducts. To further improve biomass and oil production, fortification of the feed with additional nutrients (nitrogen sources, trace metals and vitamins) improved the biomass yield from 56 g/L (34 % total fatty acids) to 71 g/L (52 % total fatty acids, cell dry weight) at 69 h; these yields are to our knowledge around 70 % of the biomass yields achieved, however, in less than half of the time by other researchers using glycerol and markedly greater than achieved using other industrial wastes. The fast growth and suitable fatty acid profile of this newly isolated Aurantiochytrium sp. strain TC 20 highlights the potential of co-producing the drop-in biodiesel and high value omega-3 oils.

[Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

NASA Technical Reports Server (NTRS)

1998-01-01

The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

Spallation as a dominant source of pusher-fuel and hot-spot mix in inertial confinement fusion capsules

DOE PAGES

Orth, Charles D.

2016-02-23

We suggest that a potentially dominant but previously neglected source of pusher-fuel and hot-spot “mix” may have been the main degradation mechanism for fusion energy yields of modern inertial confinement fusion (ICF) capsules designed and fielded to achieve high yields — not hydrodynamic instabilities. This potentially dominant mix source is the spallation of small chunks or “grains” of pusher material into the fuel regions whenever (1) the solid material adjacent to the fuel changes its phase by nucleation, and (2) this solid material spalls under shock loading and sudden decompression. Finally, we describe this mix mechanism, support it with simulationsmore » and experimental evidence, and explain how to eliminate it and thereby allow higher yields for ICF capsules and possibly ignition at the National Ignition Facility.« less

Characterization and standardization of tissue-simulating protoporphyrin IX optical phantoms

NASA Astrophysics Data System (ADS)

Marois, Mikael; Bravo, Jaime; Davis, Scott C.; Kanick, Stephen Chad

2016-03-01

Optical devices for measuring protoporphryin IX (PpIX) fluorescence in tissue are routinely validated by measurements in optical phantoms. Yet there exists limited data to form a consensus on the recipe for phantoms that both mimic the optical properties found in tissue and yield a reliable and stable relationship between PpIX concentration and the fluorescence remission intensity. This study characterizes the influence of multiple phantom components on PpIX fluorescence emission intensity, using Intralipid as the scattering source, bovine whole blood as the background absorber, and Tween as a surfactant to prevent PpIX aggregation. Optical measurements showed a linear proportionality (r>0.99) between fluorescence intensity and PpIX concentration (0.1 to 10 μg/mL) over a range of Intralipid (1 to 2%) and whole blood (0.5 to 3%) for phantoms containing low surfactant (≤0.1%), with fluorescence intensities and scattering and absorption properties stable for 5 h after mixing. The role of surfactant in PpIX phantoms was found to be complex, as aggregation was evident in aqueous nonturbid phantoms with no surfactant (0% Tween), and avoided in phantoms containing Intralipid as the scattering source with no additional or low amounts of added surfactant (≤0.1% Tween). Conversely, phantoms containing higher surfactant content (>0.1% Tween) and whole blood showed interactions that distorted the fluorescence emissions.

Characterizing the discoloration of methylene blue in Fe0/H2O systems.

PubMed

Noubactep, C

2009-07-15

Methylene blue (MB) was used as a model molecule to characterize the aqueous reactivity of metallic iron in Fe(0)/H(2)O systems. Likely discoloration mechanisms under used experimental conditions are: (i) adsorption onto Fe(0) and Fe(0) corrosion products (CP), (ii) co-precipitation with in situ generated iron CP, (iii) reduction to colorless leukomethylene blue (LMB). MB mineralization (oxidation to CO(2)) is not expected. The kinetics of MB discoloration by Fe(0), Fe(2)O(3), Fe(3)O(4), MnO(2), and granular activated carbon were investigated in assay tubes under mechanically non-disturbed conditions. The evolution of MB discoloration was monitored spectrophotometrically. The effect of availability of CP, Fe(0) source, shaking rate, initial pH value, and chemical properties of the solution were studied. The results present evidence supporting co-precipitation of MB with in situ generated iron CP as main discoloration mechanism. Under high shaking intensities (>150 min(-1)), increased CP generation yields a brownish solution which disturbed MB determination, showing that a too high shear stress induced the suspension of in situ generated corrosion products. The present study clearly demonstrates that comparing results from various sources is difficult even when the results are achieved under seemingly similar conditions. The appeal for an unified experimental procedure for the investigation of processes in Fe(0)/H(2)O systems is reiterated.

Characterization of novel pin-hole based plasma source for generation of discharge in liquids supplied by DC non-pulsing voltage

NASA Astrophysics Data System (ADS)

Krčma, F.; Kozáková, Z.; Mazánková, V.; Horák, J.; Dostál, L.; Obradović, B.; Nikiforov, A.; Belmonte, T.

2018-06-01

A recently presented novel plasma source generating discharge in liquids based on the pin-hole discharge configuration is characterized in detail. The system is supplied by DC non-pulsing high voltage of both polarities in NaCl water solutions at a conductivity range of 100–15 000 μS/cm. The discharge itself shows self-pulsing operation. The discharge ignition is observed in micro bubbles by transient discharge followed by a glow discharge in positive polarity at lower conductivities propagating inside the bubbles. At high conductivities, the glow regime is particularly replaced by a more energetic sequence of transient discharges followed by a shorter glow mode operation. The transient regime probability and its intensity are higher in the negative discharge polarity. The transient discharge produces acoustic waves and shock waves, which are observed at the moment of the bubble cavitation. The average gas temperature of 700–1500 K was calculated from the lowest OH (A-X) 0-0 band transitions. The average electron concentrations of 1020–1023 m‑3 were calculated from H α and H β line profiles. Finally, the production of a chemically active species is determined by hydrogen peroxide energy yields related to the energy consumption of the whole interelectrode system. All these quantities are dependent on the solution conductivity, the discharge polarity, and the applied power.

Nitrogen and sulfur co-doped carbon dots with strong blue luminescence

NASA Astrophysics Data System (ADS)

Ding, Hui; Wei, Ji-Shi; Xiong, Huan-Ming

2014-10-01

Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C&z.dbd;N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe3+ ions.Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C&z.dbd;N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe3+ ions. Electronic supplementary information (ESI) available: Experimental details and comparable characterization of three kinds of CDs. See DOI: 10.1039/c4nr04267k

Normal yield tables for red alder.

Treesearch

Norman P. Worthington; Floyd A. Johnson; George R. Staebler; William J. Lloyd

1960-01-01

Increasing interest in the management of red alder (Alnus rubra) has created a need for reliable yield information. Existing yield tables for red alder have been very useful as interim sources of information, but they are generally inadequate for current and prospective management needs. The advisory committee for the Station's Olympia...

Yield and depth Estimation of Selected NTS Nuclear and SPE Chemical Explosions Using Source Equalization by modeling Local and Regional Seismograms (Invited)

NASA Astrophysics Data System (ADS)

Saikia, C. K.; Roman-nieves, J. I.; Woods, M. T.

2013-12-01

Source parameters of nuclear and chemical explosions are often estimated by matching either the corner frequency and spectral level of a single event or the spectral ratio when spectra from two events are available with known source parameters for one. In this study, we propose an alternative method in which waveforms from two or more events can be simultaneously equalized by setting the differential of the processed seismograms at one station from any two individual events to zero. The method involves convolving the equivalent Mueller-Murphy displacement source time function (MMDSTF) of one event with the seismogram of the second event and vice-versa, and then computing their difference seismogram. MMDSTF is computed at the elastic radius including both near and far-field terms. For this method to yield accurate source parameters, an inherent assumption is that green's functions for the any paired events from the source to a receiver are same. In the frequency limit of the seismic data, this is a reasonable assumption and is concluded based on the comparison of green's functions computed for flat-earth models at various source depths ranging from 100m to 1Km. Frequency domain analysis of the initial P wave is, however, sensitive to the depth phase interaction, and if tracked meticulously can help estimating the event depth. We applied this method to the local waveforms recorded from the three SPE shots and precisely determined their yields. These high-frequency seismograms exhibit significant lateral path effects in spectrogram analysis and 3D numerical computations, but the source equalization technique is independent of any variation as long as their instrument characteristics are well preserved. We are currently estimating the uncertainty in the derived source parameters assuming the yields of the SPE shots as unknown. We also collected regional waveforms from 95 NTS explosions at regional stations ALQ, ANMO, CMB, COR, JAS LON, PAS, PFO and RSSD. We are currently employing a station based analysis using the equalization technique to estimate depth and yields of many relative to those of the announced explosions; and to develop their relationship with the Mw and Mo for the NTS explosions.

The neon gas field ion source—a first characterization of neon nanomachining properties

NASA Astrophysics Data System (ADS)

Livengood, Richard H.; Tan, Shida; Hallstein, Roy; Notte, John; McVey, Shawn; Faridur Rahman, F. H. M.

2011-07-01

At the Charged Particle Optics Conference (CPO7) in 2006, a novel trimer based helium gas field ion source (GFIS) was introduced for use in a new helium ion microscope (HIM), demonstrating the novel source performance attributes and unique imaging applications of the HIM (Hill et al., 2008 [1]; Livengood et al., 2008 [2]). Since that time there have been numerous enhancements to the HIM source and platform demonstrating resolution scaling into the sub 0.5 nm regime (Scipioni et al., 2009 [3]; Pickard et al., 2010 [4]). At this Charged Particle Optics Conference (CPO8) we will be introducing a neon version of the trimer-GFIS co-developed by Carl Zeiss SMT and Intel Corporation. The neon source was developed as a possible supplement to the gallium liquid metal ion source (LMIS) used today in most focused ion beam (FIB) systems (Abramo et al., 1994 [5]; Young et al.,1998 [6]). The neon GFIS source has low energy spread (∼1 eV) and a small virtual source size (sub-nanometer), similar to that of the helium GFIS. However neon does differ from the helium GFIS in two significant ways: neon ions have high sputtering yields (e.g. 1 Si atom per incident ion at 20 keV); and have relatively shallow implant depth (e.g. 46 nm in silicon at 20 keV). Both of these are limiting factors for helium in many nanomachining applications. In this paper we will present both simulation and experimental results of the neon GFIS used for imaging and nanomachining applications.

A previously unreported type of seismic source in the firn layer of the East Antarctic Ice Sheet

NASA Astrophysics Data System (ADS)

Lough, Amanda C.; Barcheck, C. Grace; Wiens, Douglas A.; Nyblade, Andrew; Anandakrishnan, Sridhar

2015-11-01

We identify a unique type of seismic source in the uppermost part of the East Antarctic Ice Sheet recorded by temporary broadband seismic arrays in East Antarctica. These sources, termed "firnquakes," are characterized by dispersed surface wave trains with frequencies of 1-10 Hz detectable at distances up to 1000 km. Events show strong dispersed Rayleigh wave trains and an absence of observable body wave arrivals; most events also show weaker Love waves. Initial events were discovered by standard detection schemes; additional events were then detected with a correlation scanner using the initial arrivals as templates. We locate sources by determining the L2 misfit for a grid of potential source locations using Rayleigh wave arrival times and polarization directions. We then perform a multiple-filter analysis to calculate the Rayleigh wave group velocity dispersion and invert the group velocity for shear velocity structure. The resulting velocity structure is used as an input model to calculate synthetic seismograms. Inverting the dispersion curves yields ice velocity structures consistent with a low-velocity firn layer ~100 m thick and show that velocity structure is laterally variable. The absence of observable body wave phases and the relative amplitudes of Rayleigh waves and noise constrain the source depth to be less than 20 m. The presence of Love waves for most events suggests the source is not isotropic. We propose the events are linked to the formation of small crevasses in the firn, and several events correlate with shallow crevasse fields mapped in satellite imagery.

From Observation to Information: Data-Driven Understanding of on Farm Yield Variation

PubMed Central

Jiménez, Daniel; Dorado, Hugo; Cock, James; Prager, Steven D.; Delerce, Sylvain; Grillon, Alexandre; Andrade Bejarano, Mercedes; Benavides, Hector; Jarvis, Andy

2016-01-01

Agriculture research uses “recommendation domains” to develop and transfer crop management practices adapted to specific contexts. The scale of recommendation domains is large when compared to individual production sites and often encompasses less environmental variation than farmers manage. Farmers constantly observe crop response to management practices at a field scale. These observations are of little use for other farms if the site and the weather are not described. The value of information obtained from farmers’ experiences and controlled experiments is enhanced when the circumstances under which it was generated are characterized within the conceptual framework of a recommendation domain, this latter defined by Non-Controllable Factors (NCFs). Controllable Factors (CFs) refer to those which farmers manage. Using a combination of expert guidance and a multi-stage analytic process, we evaluated the interplay of CFs and NCFs on plantain productivity in farmers’ fields. Data were obtained from multiple sources, including farmers. Experts identified candidate variables likely to influence yields. The influence of the candidate variables on yields was tested through conditional forests analysis. Factor analysis then clustered harvests produced under similar NCFs, into Homologous Events (HEs). The relationship between NCFs, CFs and productivity in intercropped plantain were analyzed with mixed models. Inclusion of HEs increased the explanatory power of models. Low median yields in monocropping coupled with the occasional high yields within most HEs indicated that most of these farmers were not using practices that exploited the yield potential of those HEs. Varieties grown by farmers were associated with particular HEs. This indicates that farmers do adapt their management to the particular conditions of their HEs. Our observations confirm that the definition of HEs as recommendation domains at a small-scale is valid, and that the effectiveness of distinct management practices for specific micro-recommendation domains can be identified with the methodologies developed. PMID:26930552

Reliable Exfoliation of Large-Area High-Quality Flakes of Graphene and Other Two-Dimensional Materials.

PubMed

Huang, Yuan; Sutter, Eli; Shi, Norman N; Zheng, Jiabao; Yang, Tianzhong; Englund, Dirk; Gao, Hong-Jun; Sutter, Peter

2015-11-24

Mechanical exfoliation has been a key enabler of the exploration of the properties of two-dimensional materials, such as graphene, by providing routine access to high-quality material. The original exfoliation method, which remained largely unchanged during the past decade, provides relatively small flakes with moderate yield. Here, we report a modified approach for exfoliating thin monolayer and few-layer flakes from layered crystals. Our method introduces two process steps that enhance and homogenize the adhesion force between the outermost sheet in contact with a substrate: Prior to exfoliation, ambient adsorbates are effectively removed from the substrate by oxygen plasma cleaning, and an additional heat treatment maximizes the uniform contact area at the interface between the source crystal and the substrate. For graphene exfoliation, these simple process steps increased the yield and the area of the transferred flakes by more than 50 times compared to the established exfoliation methods. Raman and AFM characterization shows that the graphene flakes are of similar high quality as those obtained in previous reports. Graphene field-effect devices were fabricated and measured with back-gating and solution top-gating, yielding mobilities of ∼4000 and 12,000 cm(2)/(V s), respectively, and thus demonstrating excellent electrical properties. Experiments with other layered crystals, e.g., a bismuth strontium calcium copper oxide (BSCCO) superconductor, show enhancements in exfoliation yield and flake area similar to those for graphene, suggesting that our modified exfoliation method provides an effective way for producing large area, high-quality flakes of a wide range of 2D materials.

Ranking the Potential Yield of Salinity and Selenium from Subbasins in the Lower Gunnison River Basin Using Seasonal, Multi-parameter Regression Models

NASA Astrophysics Data System (ADS)

Linard, J.; Leib, K.; Colorado Water Science Center

2010-12-01

Elevated levels of salinity and dissolved selenium can detrimentally effect the quality of water where anthropogenic and natural uses are concerned. In areas, such as the lower Gunnison Basin of western Colorado, salinity and selenium are such a concern that control projects are implemented to limit their mobilization. To prioritize the locations in which control projects are implemented, multi-parameter regression models were developed to identify subbasins in the lower Gunnison River Basin that were most likely to have elevated salinity and dissolved selenium levels. The drainage area is about 5,900 mi2 and is underlain by Cretaceous marine shale, which is the most common source of salinity and dissolved selenium. To characterize the complex hydrologic and chemical processes governing constituent mobilization, geospatial variables representing 70 different environmental characteristics were correlated to mean seasonal (irrigation and nonirrigation seasons) salinity and selenium yields estimated at 154 sampling sites. The variables generally represented characteristics of the physical basin, precipitation, soil, geology, land use, and irrigation water delivery systems. Irrigation and nonirrigation seasons were selected due to documented effects of irrigation on constituent mobilization. Following a stepwise approach, combinations of the geospatial variables were used to develop four multi-parameter regression models. These models predicted salinity and selenium yield, within a 95 percent confidence range, at individual points in the Lower Gunnison Basin for irrigation and non-irrigation seasons. The corresponding subbasins were ranked according to their potential to yield salinity and selenium and rankings were used to prioritize areas that would most benefit from control projects.

Refuse derived soluble bio-organics enhancing tomato plant growth and productivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sortino, Orazio; Dipasquale, Mauro; Montoneri, Enzo, E-mail: enzo.montoneri@unito.it

2012-10-15

Highlights: Black-Right-Pointing-Pointer Municipal bio-wastes are a sustainable source of bio-based products. Black-Right-Pointing-Pointer Refuse derived soluble bio-organics promote chlorophyll synthesis. Black-Right-Pointing-Pointer Refuse derived soluble bio-organics enhance plant growth and fruit ripening rate. Black-Right-Pointing-Pointer Sustainable chemistry exploiting urban refuse allows sustainable development. Black-Right-Pointing-Pointer Chemistry, agriculture and the environment benefit from biowaste technology. - Abstract: Municipal bio-refuse (CVD), containing kitchen wastes, home gardening residues and public park trimmings, was treated with alkali to yield a soluble bio-organic fraction (SBO) and an insoluble residue. These materials were characterized using elemental analysis, potentiometric titration, and 13C NMR spectroscopy, and then applied as organic fertilizers tomore » soil for tomato greenhouse cultivation. Their performance was compared with a commercial product obtained from animal residues. Plant growth, fruit yield and quality, and soil and leaf chemical composition were the selected performance indicators. The SBO exhibited the best performance by enhancing leaf chlorophyll content, improving plant growth and fruit ripening rate and yield. No product performance-chemical composition relationship could be assessed. Solubility could be one reason for the superior performance of SBO as a tomato growth promoter. The enhancement of leaf chlorophyll content is discussed to identify a possible link with the SBO photosensitizing properties that have been demonstrated in other work, and thus with photosynthetic performance.« less

Production, Characterization and Applications for Toxoplasma gondii-Specific Polyclonal Chicken Egg Yolk Immunoglobulins

PubMed Central

Ferreira Júnior, Álvaro; Santiago, Fernanda M.; Silva, Murilo V.; Ferreira, Flávia B.; Macêdo Júnior, Arlindo G.; Mota, Caroline M.; Faria, Matheus S.; Filho, Hercílio H. Silva; Silva, Deise A. O.; Cunha-Júnior, Jair P.; Mineo, José R.; Mineo, Tiago W. P.

2012-01-01

Background Toxoplasma gondii may cause abortions, ocular and neurological disorders in warm-blood hosts. Immunized mammals are a wide source of hyperimmune sera used in different approaches, including diagnosis and the study of host-parasite interactions. Unfortunately, mammalian antibodies present limitations for its production, such as the necessity for animal bleeding, low yield, interference with rheumatoid factor, complement activation and affinity to Fc mammalian receptors. IgY antibodies avoid those limitations; therefore they could be an alternative to be applied in T. gondii model. Methodology/Principal Findings In this study we immunized hens with soluble tachyzoite antigens of T. gondii (STAg) and purified egg yolk antibodies (IgY) by an inexpensive and simple method, with high yield and purity degree. IgY anti-STAg antibodies presented high avidity and were able to recognize a broad range of parasite antigens, although some marked differences were observed in reactivity profile between antibodies produced in immunized hens and mice. Interestingly, IgY antibodies against Neospora caninum and Eimeria spp. did not react to STAg. We also show that IgY antibodies were suitable to detect T. gondii forms in paraffin-embedded sections and culture cell monolayers. Conclusions/Significance Due to its cost-effectiveness, high production yield and varied range of possible applications, polyclonal IgY antibodies are useful tools for studies involving T. gondii. PMID:22808150

Nitrogen Sources Screening for Ethanol Production Using Carob Industrial Wastes.

PubMed

Raposo, S; Constantino, A; Rodrigues, F; Rodrigues, B; Lima-Costa, M E

2017-02-01

Nowadays, bioethanol production is one of the most important technologies by the necessity to identify alternative energy resources, principally when based on inexpensive renewable resources. However, the costs of 2nd-generation bioethanol production using current biotechnologies are still high compared to fossil fuels. The feasibility of bioethanol production, by obtaining high yields and concentrations of ethanol, using low-cost medium, is the primary goal, leading the research done today. Batch Saccharomyces cerevisiae fermentation of high-density sugar from carob residues with different organic (yeast extract, peptone, urea) and inorganic nitrogen sources (ammonium sulfate, ammonium nitrate) was performed for evaluating a cost-effective ethanol production, with high ethanol yield and productivity. In STR batch fermentation, urea has proved to be a very promising nitrogen source in large-scale production of bioethanol, reaching an ethanol yield of 44 % (w/w), close to theoretical maximum yield value and an ethanol production of 115 g/l. Urea at 3 g/l as nitrogen source could be an economical alternative with a great advantage in the sustainability of ethanol production from carbohydrates extracted from carob. Simulation studies, with experimental data using SuperPro Design software, have shown that the bioethanol production biorefinery from carob wastes could be a very promising way to the valorization of an endogenous resource, with a competitive cost.

In silico profiling of Escherichia coli and Saccharomyces cerevisiae as terpenoid factories

PubMed Central

2013-01-01

Background Heterologous microbial production of rare plant terpenoids of medicinal or industrial interest is attracting more and more attention but terpenoid yields are still low. Escherichia coli and Saccharomyces cerevisiae are the most widely used heterologous hosts; a direct comparison of both hosts based on experimental data is difficult though. Hence, the terpenoid pathways of E. coli (via 1-deoxy-D-xylulose 5-phosphate, DXP) and S. cerevisiae (via mevalonate, MVA), the impact of the respective hosts metabolism as well as the impact of different carbon sources were compared in silico by means of elementary mode analysis. The focus was set on the yield of isopentenyl diphosphate (IPP), the general terpenoid precursor, to identify new metabolic engineering strategies for an enhanced terpenoid yield. Results Starting from the respective precursor metabolites of the terpenoid pathways (pyruvate and glyceraldehyde-3-phosphate for the DXP pathway and acetyl-CoA for the MVA pathway) and considering only carbon stoichiometry, the two terpenoid pathways are identical with respect to carbon yield. However, with glucose as substrate, the MVA pathway has a lower potential to supply terpenoids in high yields than the DXP pathway if the formation of the required precursors is taken into account, due to the carbon loss in the formation of acetyl-CoA. This maximum yield is further reduced in both hosts when the required energy and reduction equivalents are considered. Moreover, the choice of carbon source (glucose, xylose, ethanol or glycerol) has an effect on terpenoid yield with non-fermentable carbon sources being more promising. Both hosts have deficiencies in energy and redox equivalents for high yield terpenoid production leading to new overexpression strategies (heterologous enzymes/pathways) for an enhanced terpenoid yield. Finally, several knockout strategies are identified using constrained minimal cut sets enforcing a coupling of growth to a terpenoid yield which is higher than any yield published in scientific literature so far. Conclusions This study provides for the first time a comprehensive and detailed in silico comparison of the most prominent heterologous hosts E. coli and S. cerevisiae as terpenoid factories giving an overview on several promising metabolic engineering strategies paving the way for an enhanced terpenoid yield. PMID:24059635

Catalytic action of β source on x-ray emission from plasma focus

NASA Astrophysics Data System (ADS)

Ahmad, S.; Sadiq, Mehboob; Hussain, S.; Shafiq, M.; Zakaullah, M.; Waheed, A.

2006-01-01

The influence of preionization around the insulator sleeve by a mesh-type β source (Ni6328) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4π geometry is measured as a function of argon and hydrogen gas filling pressures with and without β source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the β source. With argon, the CuKα emission is estimated to be 27.14 J with an efficiency of 0.7% for β source and 21.5 J with an efficiency of 0.55% without β source. The maximum x-ray yield in 4π geometry is found to be about 68.90 J with an efficiency of 1.8% for β source and 54.58 J with an efficiency of 1.4% without β source. With hydrogen, CuKα emission is 11.82 J with an efficiency of 0.32% for β source and 10.07 J with an efficiency of 0.27% without β source. The maximum x-ray yield in 4π geometry is found to be 30.20 J with an efficiency of 0.77% for β source and 25.58 J with an efficiency of 0.6% without β source. The x-ray emission with Pb insert at the anode tip without β source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4π geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without β source.

Exobiopolymer production of Ophiocordyceps dipterigena BCC 2073: optimization, production in bioreactor and characterization

PubMed Central

2010-01-01

Background Biopolymers have various applications in medicine, food and petroleum industries. The ascomycetous fungus Ophiocordyceps dipterigena BCC 2073 produces an exobiopolymer, a (1→3)-β-D-glucan, in low quantity under screening conditions. Optimization of O. dipterigena BCC 2073 exobiopolymer production using experimental designs, a scale-up in 5 liter bioreactor, analysis of molecular weight at different cultivation times, and levels of induction of interleukin-8 synthesis are described in this study. Results In order to improve and certify the productivity of this strain, a sequential approach of 4 steps was followed. The first step was the qualitative selection of the most appropriate carbon and nitrogen sources (general factorial design) and the second step was quantitative optimization of 5 physiological factors (fractional factorial design). The best carbon and nitrogen source was glucose and malt extract respectively. From an initial production of 2.53 g·L-1, over 13 g·L-1 could be obtained in flasks under the improved conditions (5-fold increase). The third step was cultivation in a 5 L bioreactor, which produced a specific growth rate, biomass yield, exobiopolymer yield and exobiopolymer production rate of 0.014 h-1, 0.32 g·g-1 glucose, 2.95 g·g biomass-1 (1.31 g·g-1 sugar), and 0.65 g.(L·d)-1, respectively. A maximum yield of 41.2 g·L-1 was obtained after 377 h, a dramatic improvement in comparison to the initial production. In the last step, the basic characteristics of the biopolymer were determined. The molecular weight of the polymer was in the range of 6.3 × 105 - 7.7 × 105 Da. The exobiopolymer, at 50 and 100. μg·mL-1, induced synthesis in normal dermal human fibroblasts of 2227 and 3363 pg·mL-1 interleukin-8 respectively. Conclusions High exobiopolymer yield produced by O. dipterigena BCC 2073 after optimization by qualitative and quantitative methods is attractive for various applications. It induced high IL-8 production by normal dermal fibroblasts, which makes it promising for application as wound healing material. However, there are still other possible applications for this biopolymer, such as an alternative source of biopolymer substitute for hyaluronic acid, which is costly, as a thickening agent in the cosmetic industry due to its high viscosity property, as a moisturizer, and in encapsulation. PMID:20624309

Neutron radiation characteristics of plutonium dioxide fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, (alpha, n) reactions with low Z impurities in the fuel, and (alpha, n) reactions with O-18. For spontaneous fission neutrons a value of (1.95 + or - 0.07) X 1,000 n/s/g PuO2 is obtained. The neutron yield from (alpha, n) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha-particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.14 + or - 0.26) X 10,000 n/s/g PuO2. The neutron yield from (alpha, n) reactions with low Z impurities in the fuel is presented in tabular form for one part part per million of each impurity. The total neutron yield due to the combined effects of all the impurities depends upon the fractional weight concentration of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

Yield Determination of Underground and Near Surface Explosions

NASA Astrophysics Data System (ADS)

Pasyanos, M.

2015-12-01

As seismic coverage of the earth's surface continues to improve, we are faced with signals from a wide variety of explosions from various sources ranging from oil train and ordnance explosions to military and terrorist attacks, as well as underground nuclear tests. We present on a method for determining the yield of underground and near surface explosions, which should be applicable for many of these. We first review the regional envelope method that was developed for underground explosions (Pasyanos et al., 2012) and more recently modified for near surface explosions (Pasyanos and Ford, 2015). The technique models the waveform envelope templates as a product of source, propagation (geometrical spreading and attenuation), and site terms, while near surface explosions include an additional surface effect. Yields and depths are determined by comparing the observed envelopes to the templates and minimizing the misfit. We then apply the method to nuclear and chemical explosions for a range of yields, depths, and distances. We will review some results from previous work, and show new examples from ordnance explosions in Scandinavia, nuclear explosions in Eurasia, and chemical explosions in Nevada associated with the Source Physics Experiments (SPE).

Numerical Simulation Of Cratering Effects In Adobe

DTIC Science & Technology

2013-07-01

DEVELOPMENT OF MATERIAL PARAMETERS .........................................................7 PROBLEM SETUP...37 PARAMETER ADJUSTMENTS ......................................................................................38 GLOSSARY...dependent yield surface with the Geological Yield Surface (GEO) modeled in CTH using well characterized adobe. By identifying key parameters that

Mechanical response of unidirectional boron/aluminum under combined loading

NASA Technical Reports Server (NTRS)

Becker, Wolfgang; Pindera, Marek-Jerzy; Herakovich, Carl T.

1987-01-01

Three test methods were employed to characterize the response of unidirectional Boron/Aluminum metal matrix composite material under monotonic and cyclic loading conditions, namely, losipescu shear, off-axis tension and compression. The characterization of the elastic and plastic response includes the elastic material properties, yielding and subsequent hardening of the unidirectional composite under different stress ratios in the material principal coordinate system. Yield loci generated for different stress ratios are compared for the three different test methods, taking into account residual stresses and specimen geometry. Subsequently, the yield locus for in-plane shear is compared with the prediction of an analytical, micromechanical model. The influence of the scatter in the experimental data on the predicted yield surface is also analyzed. Lastly, the experimental material strengths in tension and compression are correlated with the maximum stress and the Tsai-Wu failure criterion.

Synthesis and characterization of poly (dihydroxybiphenyl borate) with high char yield for high-performance thermosetting resins

NASA Astrophysics Data System (ADS)

Wang, Shujuan; Xing, Xiaolong; Li, Jian; Jing, Xinli

2018-01-01

The objective of the current work is to synthesize novel boron-containing polymers with excellent thermal resistance, and reveal the structure and the reason for the high char yield. Thus, poly (dihydroxybiphenyl borate) (PDDB) with a more rigid molecular chain, was successfully synthesized using 4,4‧-dihydroxybiphenyl and boric acid. Structural characterizations of the prepared PDDB were performed via NMR, FTIR, XPS, and XRD analyses. The results reveal that PDDB consists of aromatic, Phsbnd Osbnd B and Bsbnd Osbnd B structures as well as a small number of boron hydroxyl and phenolic hydroxyl groups. PDDB shows good solubility in strong polar solvents, which is of great importance for the modification of thermosetting resins. TGA combined with DSC were employed to evaluate the thermal properties of PDDB, and increases in the glass transition temperature (Tg) and char yield were observed with increased boron content. Tg and char yield of PDDB (800 °C, nitrogen atmosphere) reached up to 219 °C and 66.5%, respectively. PDDB was extensively characterized during pyrolysis to reveal the high char yield of PDDB. As briefly discussed, the boron oxide and boron carbide that formed during pyrolysis play a crucial role in the high char yield of PDDB, which reduces the release of volatile carbon dioxide and carbon. This research suggests that PDDB has great potential as a novel modified agent for the improvement of the comprehensive performance of thermosetting resins to broaden their applicability in the field of advanced composites.

Extracting DNA from 'jaws': high yield and quality from archived tiger shark (Galeocerdo cuvier) skeletal material.

PubMed

Nielsen, E E; Morgan, J A T; Maher, S L; Edson, J; Gauthier, M; Pepperell, J; Holmes, B J; Bennett, M B; Ovenden, J R

2017-05-01

Archived specimens are highly valuable sources of DNA for retrospective genetic/genomic analysis. However, often limited effort has been made to evaluate and optimize extraction methods, which may be crucial for downstream applications. Here, we assessed and optimized the usefulness of abundant archived skeletal material from sharks as a source of DNA for temporal genomic studies. Six different methods for DNA extraction, encompassing two different commercial kits and three different protocols, were applied to material, so-called bio-swarf, from contemporary and archived jaws and vertebrae of tiger sharks (Galeocerdo cuvier). Protocols were compared for DNA yield and quality using a qPCR approach. For jaw swarf, all methods provided relatively high DNA yield and quality, while large differences in yield between protocols were observed for vertebrae. Similar results were obtained from samples of white shark (Carcharodon carcharias). Application of the optimized methods to 38 museum and private angler trophy specimens dating back to 1912 yielded sufficient DNA for downstream genomic analysis for 68% of the samples. No clear relationships between age of samples, DNA quality and quantity were observed, likely reflecting different preparation and storage methods for the trophies. Trial sequencing of DNA capture genomic libraries using 20 000 baits revealed that a significant proportion of captured sequences were derived from tiger sharks. This study demonstrates that archived shark jaws and vertebrae are potential high-yield sources of DNA for genomic-scale analysis. It also highlights that even for similar tissue types, a careful evaluation of extraction protocols can vastly improve DNA yield. © 2016 John Wiley & Sons Ltd.

Non-structural carbohydrate partitioning in grass stems: a target to increase yield stability, stress tolerance, and biofuel production.

PubMed

Slewinski, Thomas L

2012-08-01

A dramatic change in agricultural crops is needed in order to keep pace with the demands of an increasing human population, exponential need for renewable fuels, and uncertain climatic changes. Grasses make up the vast majority of agricultural commodities. How these grasses capture, transport, and store carbohydrates underpins all aspects of crop productivity. Sink-source dynamics within the plant direct how much, where, and when carbohydrates are allocated, as well as determine the harvestable tissue. Carbohydrate partitioning can limit the yield capacity of these plants, thus offering a potential target for crop improvement. Grasses have the ability to buffer this sink-source interaction by transiently storing carbohydrates in stem tissue when production from the source is greater than whole-plant demand. These reserves improve yield stability in grain crops by providing an alternative source when photosynthetic capacity is reduced during the later phases of grain filling, or during periods of environmental and biotic stresses. Domesticated grasses such as sugarcane and sweet sorghum have undergone selection for high accumulation of stem carbohydrates, which serve as the primary sources of sugars for human and animal consumption, as well as ethanol production for fuel. With the enormous expectations placed on agricultural production in the near future, research into carbohydrate partitioning in grasses is essential for maintaining and increasing yields in grass crops. This review highlights the current knowledge of non-structural carbohydrate dynamics in grass stems and discusses the impacts of stem reserves in essential agronomic grasses.

Ammonium as sole N source improves grain quality in wheat.

PubMed

Fuertes-Mendizábal, Teresa; González-Torralba, Jon; Arregui, Luis M; González-Murua, Carmen; González-Moro, M Begoña; Estavillo, José M

2013-07-01

The skilful handling of N fertilizer, including N source type and its timing, is necessary to obtain maximum profitability in wheat crops in terms of production and quality. Studies on grain yield and quality with ammonium as sole N source have not yet been conducted. The aim of this study was to evaluate the effect of N source management (nitrate vs. ammonium), and splitting it into two or three amendments during the wheat life cycle, on grain yield and quality under irrigated conditions. This experiment demonstrates that Cezanne wheat plants growing with ammonium as exclusive N source are able to achieve the same yield as plants growing with nitrate and that individual wheat plants grown in irrigated pots can efficiently use late N applied in GS37. Ammonium nutrition increased both types of grain reserve proteins (gliadins and glutenins) and also increased the ratio gli/glu with respect to nitrate nutrition. The splitting of the N rate enhanced the ammonium effect on grain protein composition. The application of ammonium N source, especially when split into three amendments, has an analogous effect on grain protein content and composition to applications at a higher N rate, leading to higher N use efficiency. © 2012 Society of Chemical Industry.

Influence of calcium and silicon supplementation into Pleurotus ostreatus substrates on quality of fresh and canned mushrooms.

PubMed

Thongsook, T; Kongbangkerd, T

2011-08-01

Supplements of gypsum (calcium source), pumice (silicon source) and pumice sulfate (silicon and calcium source) into substrates for oyster mushrooms (Pleurotus ostreatus) were searched for their effects on production as well as qualities of fresh and canned mushrooms. The addition of pumice up to 30% had no effect on total yield, size distribution and cap diameters. The supplementation of gypsum at 10% decreased the total yield; and although gypsum at 5% did not affect total yield, the treatment increased the proportion of large-sized caps. High content (>10%) of pumice sulfate resulted in the lower yield. Calcium and silicon contents in the fruit bodies were not influenced by supplementations. The centrifugal drip loss values and solid content of fresh mushrooms, and the percentage of weight gained and firmness of canned mushrooms, cultivated in substrates supplemented with gypsum, pumice and pumice sulfate were significantly (p≤0.05) higher than those of the control. Scanning electron micrographs revealed the more compacted hyphae of mushroom stalks supplemented with silicon and/or calcium after heat treatment, compared to the control. Supplementation of P. ostreatus substrates with 20% pumice was the most practical treatment because it showed no effect on yield and the most cost-effective.

Transgressive variation for yield components and dynamic traits in Jefferson (Oryza sativa) x O. rufipogon introgression lines

USDA-ARS?s Scientific Manuscript database

Alleles from wild progenitors of crops can be a source of transgressive variation in modern cultivars. Introgressions from the Oryza rufipogon donor (IRGC104591) in an O. sativa tropical japonica cultivar (Jefferson) were shown to confer a yield advantage in multi-location field trials. Yield loci...

Development of a European Ensemble System for Seasonal Prediction: Application to crop yield

NASA Astrophysics Data System (ADS)

Terres, J. M.; Cantelaube, P.

2003-04-01

Western European agriculture is highly intensive and the weather is the main source of uncertainty for crop yield assessment and for crop management. In the current system, at the time when a crop yield forecast is issued, the weather conditions leading up to harvest time are unknown and are therefore a major source of uncertainty. The use of seasonal weather forecast would bring additional information for the remaining crop season and has valuable benefit for improving the management of agricultural markets and environmentally sustainable farm practices. An innovative method for supplying seasonal forecast information to crop simulation models has been developed in the frame of the EU funded research project DEMETER. It consists in running a crop model on each individual member of the seasonal hindcasts to derive a probability distribution of crop yield. Preliminary results of cumulative probability function of wheat yield provides information on both the yield anomaly and the reliability of the forecast. Based on the spread of the probability distribution, the end-user can directly quantify the benefits and risks of taking weather-sensitive decisions.

Spectroscopic measurements of soybeans used to parameterize physiological traits in the AgroIBIS ecosystem model

NASA Astrophysics Data System (ADS)

Singh, A.; Serbin, S.; Kucharik, C. J.; Townsend, P. A.

2014-12-01

Ecosystem models such AgroIBIS require detailed parameterizations of numerous vegetation traits related to leaf structure, biochemistry and photosynthetic capacity to properly assess plant carbon assimilation and yield response to environmental variability. In general, these traits are estimated from a limited number of field measurements or sourced from the literature, but rarely is the full observed range of variability in these traits utilized in modeling activities. In addition, pathogens and pests, such as the exotic soybean aphid (Aphis glycines), which affects photosynthetic pathways in soybean plants by feeding on phloem and sap, can potentially impact plant productivity and yields. Capturing plant responses to pest pressure in conjunction with environmental variability is of considerable interest to managers and the scientific community alike. In this research, we employed full-range (400-2500 nm) field and laboratory spectroscopy to rapidly characterize the leaf biochemical and physiological traits, namely foliar nitrogen, specific leaf area (SLA) and the maximum rate of RuBP carboxylation by the enzyme RuBisCo (Vcmax) in soybean plants, which experienced a broad range of environmental conditions and soybean aphid pressures. We utilized near-surface spectroscopic remote sensing measurements as a means to capture the spatial and temporal patterns of aphid impacts across broad aphid pressure levels. In addition, we used the spectroscopic data to generate a much larger dataset of key model parameters required by AgroIBIS than would be possible through traditional measurements of biochemistry and leaf-level gas exchange. The use of spectroscopic retrievals of soybean traits allowed us to better characterize the variability of plant responses associated with aphid pressure to more accurately model the likely impacts of soybean aphid on soybeans. Our next steps include the coupling of the information derived from our spectral measurements with the AgroIBIS model to project the impacts of increasing aphid pressures on yields expected with continued global change and altered environmental conditions.

Nano-Se: Cheap and easy-to-obtain novel material for all-dielectric nano-photonics

NASA Astrophysics Data System (ADS)

Ivanova, A. K.; Ionin, A. A.; Khmel'nitskii, R. A.; Klevkov, Yu. K.; Kudryashov, S. I.; Levchenko, A. O.; Mel'nik, N. N.; Nastulyavichus, A. A.; Rudenko, A. A.; Saraeva, I. N.; Smirnov, N. A.; Zayarny, D. A.; Gonchukov, S. A.; Tolordava, E. R.; Baranov, A. N.

2017-09-01

Milligram-per-second production of selenium nanoparticles in water sols was realized through few W, kHz-rate nanosecond laser ablation of a solid selenium pellet. High-yield particle formation mechanism and ultimate mass-removal yield were elucidated by optical profilometry and scanning electron microscopy characterization of crater depths and topographies. Deposited particles were inspected by scanning electron microscopy, while optical transmission Raman and dynamic light scattering spectroscopy characterized their hydrosols.

Molecular and immunological characterization of subtilisin like serine protease, a major allergen of Curvularia lunata.

PubMed

Tripathi, Prabhanshu; Nair, Smitha; Singh, B P; Arora, Naveen

2011-03-01

Serine protease from numerous sources have been identified and characterized as major allergens. The present study aimed to clone, express and characterize a serine protease from Curvularia lunata. cDNA library screening identified partial protease clones. A clone showed significant homology to subtilisin like serine proteases from Aspergillus and Penicillium species. Full length sequence was generated by RACE PCR, subcloned in pET vector, protein expressed in Escherichia coli and purified from inclusion bodies yielding 0.5 mg/L of culture. Bioinformatic analysis identified serine protease motifs of subtilase family, catalytic triad and N-glycosylation sites on the primary sequence. The protein resolved at 54-kDa on SDS-PAGE and was recognized as a major allergen on immunoblot with 13/16 C. lunata sensitive patients' sera in ELISA and immunoblot. Recombinant protein reacted with rabbit polyclonal antibodies against alkaline serine proteases from C. lunata. Recombinant protein required 50-56 ng of same protein for 50% inhibition of IgE binding in competitive ELISA. In addition, 13 of 16 patients' samples showed significant basophil histamine release upon stimulation with purified recombinant protein. In conclusion, a 54 kDa major allergen of C. lunata was cloned, expressed, characterized and showed biological activity. It has potential to be used in molecule based approach for allergy diagnosis and therapy. Copyright © 2010 Elsevier GmbH. All rights reserved.

Spatial and Temporal Patterns of Suspended Sediment Yields in Nested Urban Catchments

NASA Astrophysics Data System (ADS)

Kemper, J. T.; Miller, A. J.; Welty, C.

2017-12-01

In a highly regulated area such as the Chesapeake Bay watershed, suspended sediment is a matter of primary concern. Near real-time turbidity and discharge data have been collected continuously for more than four years at five stream gages representing three nested watershed scales (1-2 sq km, 5-6 sq km, 14 sq km) in the highly impervious Dead Run watershed, located in Baltimore County, MD. Using turbidity-concentration relationships based on sample analyses at the gage site, sediment yields for each station can be quantified for a variety of temporal scales. Sediment yields have been calculated for 60+ different storms across four years. Yields show significant spatial variation, both at equivalent sub-watershed scales and from headwaters to mouth. Yields are higher at the headwater station with older development and virtually no stormwater management (DR5) than at the station with more recent development and more extensive stormwater management (DR2). However, this pattern is reversed for the stations at the next larger scale: yields are lower at DR4, downstream of DR5, than at DR3, downstream of DR2. This suggests spatial variation in the dominant sediment sources within each subwatershed. Additionally, C-Q hysteresis curves display consistent counterclockwise behavior at the DR4 station, in contrast to the consistent clockwise behavior displayed at the DR3 station. This further suggests variation in dominant sediment sources (perhaps distal vs local, respectively). We observe consistent seasonal trends in the relative magnitudes of sediment yield for different subwatersheds (e.g. DR3>DR4 in summer, DR5>DR2 in spring). We also observe significant year-to-year variation in sediment yield at the headwater and intermediate scales, whereas yields at the 14 sq km scale are largely similar across the monitored years. This observation would be consistent with the possibility that internal storage and remobilization tend to modulate downstream yields even with spatial and temporal variation in upstream sources. The fine-scale design of this study represents a unique opportunity to compare and contrast sediment yields across a variety of spatial and temporal scales, and provide insight into sediment transport dynamics within an urbanized watershed.

A reassessment of the sources and importance of land-derived organic matter in surface sediments from the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Goñi, Miguel A.; Ruttenberg, Kathleen C.; Eglinton, Timothy I.

1998-09-01

Organic matter in surface sediments from two onshore-offshore transects in the northwestern Gulf of Mexico was characterized by a variety of techniques, including elemental, stable carbon, radiocarbon, and molecular-level analyses. In spite of the importance of the Mississippi River as a sediment source, there is little evidence for a significant terrigenous input based on the low carbon:nitrogen ratios (8-5) and the enriched δ 13C values of bulk sedimentary organic carbon (-19.7‰ to -21.7‰). Radiocarbon analyses, on the other hand, yield depleted Δ 14C values (-277‰ to -572‰) which indicate that a significant fraction of the sedimentary organic carbon (OC) in all these surface sediments must be relatively old and most likely of allochthonous origin. CuO oxidations yield relatively low quantities of lignin products (0.4-1.4 mg/100 mg OC) along with compounds derived from proteins, polysaccharides, and lipids. Syringyl:vanillyl and cinnamyl:vanillyl ratios (averaging 1.6 and 0.5, respectively) and acid:aldehyde ratios for both vanillyl and syringyl phenols (averaging 0.8 and 1.2, respectively) indicate that the lignin present in sediments originates from nonwoody angiosperm sources and is highly degraded. The δ 13C values of lignin phenols in shelf sediments are relatively depleted in 13C (averaging -26.3‰) but are increasingly enriched in 13C at the slope sites (averaging -17.5‰ for the two deepest stations). We interpret these molecular and isotopic compositions to indicate that a significant fraction (≥50%) of the lignin and, by inference, the land-derived organic carbon in northwestern Gulf of Mexico sediments ultimately originated from C 4 plants. The source of this material is likely to be soil organic matter eroded from the extensive grasslands of the Mississippi River drainage basin. Notably, the mixed C 4 and C 3 source and the highly degraded state of this material hampers its recognition and quantification in shelf and slope sediments. Our data are consistent with higher than previously estimated inputs of land-derived organic carbon to regions of the ocean, such as the Gulf of Mexico, with significant sources of terrigenous C 4-derived organic matter.

Detrital K-feldspar thermochronology of the Nanaimo Group: Characterization of Basement and Extraregional Basin Contributions

NASA Astrophysics Data System (ADS)

Isava, V.; Grove, M.; Mahoney, J. B.; Kimbrough, D. L.

2016-12-01

The Late Cretaceous-Early Paleogene Nanaimo Group covers the contact between Triassic basement Wrangellia terrane and the Jurassic-Cretaceous Coast Plutonic Complex (CPC) in southern British Columbia. Prior detrital zircon U-Pb and Hf studies indicate a change in sediment source for the Nanaimo basin, from the primitive CPC in Santonian-Early Campanian time to an isotopically evolved continental extraregional source during the late Campanian/Maastrictian. Two notably different areas have been proposed as potential source regions: (1) the Idaho/Boulder batholith and Belt Supergroup, and (2) the Mojave/Salinia segment of structurally disrupted late Cretaceous southern California margin. Single crystal 40Ar/39Ar laser fusion of ca. 100-200 grains apiece from seven detrital K-feldspar samples from Santonian-Maastrichtian strata of the northern Nanaimo Group constrain the history of the sediments' source regions. The two oldest samples, from the K-feldspar poor Comox and Extension Fms., display a monotonic increasing distribution of cooling ages 80-125 Ma that reflects shallow erosion of the CPC. In contrast, Late Campanian strata of the Cedar District and De Courcy Fms. exhibit a more pronounced cluster of cooling ages 80-95 Ma as well as a greater proportion of Jurassic ages that represent progressively deeper erosion of the CPC. Evidence for an extraregional sediment source appears abruptly in the Geoffrey Fm. by 72 Ma, matching the time of local-to-extraregional shift indicated in detrital zircon U-Pb studies. Over 90% of the detrital K-feldspars from these arkosic sandstones yield cooling ages of 70-80 Ma, with sparse older ages associated with the CPC. Samples from the successively younger Spray and Gabriola Fms. also yield >90% K-feldspar ages younger than 80 Ma and exhibit age maxima of 68 Ma and 65 Ma, respectively. These results are distinct from detrital zircon U-Pb and K-feldspar 40Ar/39Ar ages of the southern Sierra Nevada, Mojave/Salina, and northern Peninsular Ranges of southern California. Resemblance with the Idaho/Boulder batholith indicates the latter as a more likely source of extraregional detritus. Measurements are underway to couple detrital K-feldspar 40Ar/39Ar thermochronology with U-Pb isotopes on the same grains to further distinguish between these two possibilities.

Evaluating the effectiveness of various biochars as porous media for biodiesel synthesis via pseudo-catalytic transesterification.

PubMed

Lee, Jechan; Jung, Jong-Min; Oh, Jeong-Ik; Ok, Yong Sik; Lee, Sang-Ryong; Kwon, Eilhann E

2017-05-01

This study focuses on investigating the optimized chemical composition of biochar used as porous material for biodiesel synthesis via pseudo-catalytic transesterification. To this end, six biochars from different sources were prepared and biodiesel yield obtained from pseudo-catalytic transesterification of waste cooking oil using six biochars were measured. Biodiesel yield and optimal reaction temperature for pseudo-catalytic transesterification were strongly dependent on the raw material of biochar. For example, biochar generated from maize residue exhibited the best performance, which yield was reached ∼90% at 300°C; however, the maximum biodiesel yield with pine cone biochar was 43% at 380°C. The maximum achievable yield of biodiesel was sensitive to the lignin content of biomass source of biochar but not sensitive to the cellulose and hemicellulose content. This study provides an insight for screening the most effective biochar as pseudo-catalytic porous material, thereby helping develop more sustainable and economically viable biodiesel synthesis process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Switching predominance of organic versus inorganic carbon exports from an intermediate-size subarctic watershed

USGS Publications Warehouse

Dornblaser, Mark M.; Striegl, Robert G.

2015-01-01

Hydrologic exports of dissolved inorganic and organic carbon (DIC, DOC) reflect permafrost conditions in arctic and subarctic river basins. DIC yields in particular, increase with decreased permafrost extent. We investigated the influence of permafrost extent on DIC and DOC yield in a tributary of the Yukon River, where the upper watershed has continuous permafrost and the lower watershed has discontinuous permafrost. Our results indicate that DIC versus DOC predominance switches with interannual changes in water availability and flow routing in intermediate-size watersheds having mixed permafrost coverage. Large water yield and small concentrations from mountainous headwaters and small water yield and high concentrations from lowlands produced similar upstream and downstream carbon yields. However, DOC export exceeded DIC export during high-flow 2011 while DIC predominated during low-flow 2010. The majority of exported carbon derived from near-surface organic sources when landscapes were wet or frozen and from mineralized subsurface sources when infiltration increased.

Thiourea, a ROS scavenger, regulates source-to-sink relationship to enhance crop yield and oil content in Brassica juncea (L.).

PubMed

Pandey, Manish; Srivastava, Ashish Kumar; D'Souza, Stanislaus Francis; Penna, Suprasanna

2013-01-01

In the present agricultural scenario, the major thrust is to increase crop productivity so as to ensure sustainability. In an earlier study, foliar application of thiourea (TU; a non physiological thiol based ROS scavenger) has been demonstrated to enhance the stress tolerance and yield of different crops under field condition. Towards this endeavor, present work deals with the effect of TU on photosynthetic efficiency and source-to-sink relationship of Indian mustard (Brassica juncea) for understanding its mode of action. The application of TU increased the efficiency of both PSI and PSII photosystems and vegetative growth of plant. The comparative analysis of sucrose to starch ratio and expression level of sugar transporters confirmed the higher source and sink strength in response to TU treatment. The biochemical evidence in support of this was derived from higher activities of sucrose phosphate synthase and fructose-1,6-bis-phosphatase at source; and sucrose synthase and different classes of invertases at both source and sink. This indicated an overall increase in photoassimilate level at sink. An additional contribution through pod photosynthesis was confirmed through the analysis of phosphoenol pyruvate carboxylase enzyme activity and level of organic acids. The increased photoassimilate level was also co-ordinated with acetyl coA carboxylase mediated oil biosynthesis. All these changes were ultimately reflected in the form of 10 and 20% increase in total yield and oil content, respectively under TU treatment as compared to control. Additionally, no change was observed in oil composition of seeds derived from TU treated plants. The study thus signifies the co-ordinated regulation of key steps of photosynthesis and source-to-sink relationship through the external application of TU resulting in increased crop yield and oil content.

Characterization of Brachypodium distachyon as a nonhost model against switchgrass rust pathogen Puccinia emaculata.

PubMed

Gill, Upinder S; Uppalapati, Srinivasa R; Nakashima, Jin; Mysore, Kirankumar S

2015-05-08

Switchgrass rust, caused by Puccinia emaculata, is an important disease of switchgrass, a potential biofuel crop in the United States. In severe cases, switchgrass rust has the potential to significantly affect biomass yield. In an effort to identify novel sources of resistance against switchgrass rust, we explored nonhost resistance against P. emaculata by characterizing its interactions with six monocot nonhost plant species. We also studied the genetic variations for resistance among Brachypodium inbred accessions and the involvement of various defense pathways in nonhost resistance of Brachypodium. We characterized P. emaculata interactions with six monocot nonhost species and identified Brachypodium distachyon (Bd21) as a suitable nonhost model to study switchgrass rust. Interestingly, screening of Brachypodium accessions identified natural variations in resistance to switchgrass rust. Brachypodium inbred accessions Bd3-1 and Bd30-1 were identified as most and least resistant to switchgrass rust, respectively, when compared to tested accessions. Transcript profiling of defense-related genes indicated that the genes which were induced in Bd21after P. emaculata inoculation also had higher basal transcript abundance in Bd3-1 when compared to Bd30-1 and Bd21 indicating their potential involvement in nonhost resistance against switchgrass rust. In the present study, we identified Brachypodium as a suitable nonhost model to study switchgrass rust which exhibit type I nonhost resistance. Variations in resistance response were also observed among tested Brachypodium accessions. Brachypodium nonhost resistance against P. emaculata may involve various defense pathways as indicated by transcript profiling of defense related genes. Overall, this study provides a new avenue to utilize novel sources of nonhost resistance in Brachypodium against switchgrass rust.

The contribution of thermally labile sugar lesions to DNA double-strand break formation in cells grown in the presence of BrdU.

PubMed

Li, Fanghua; Cheng, Yanlei; Iliakis, George

2015-04-01

Radiosensitization by bromodeoxyuridine (BrdU) is commonly attributed to an increase in the yield of double-strand breaks (DSB) in the DNA and an associated decrease in the reparability of these lesions. Radiation chemistry provides a mechanism for the increased yield of DSB through the generation, after bromine loss, of a highly reactive uracilyl radical that attacks the sugar moiety of the nucleotide to produce a single-strand break (SSB). The effects underpinning DSB repair inhibition remain, in contrast, incompletely characterized. A possible source of reduced reparability is a change in the nature or complexity of the DSB in BrdU-substituted DNA. Recent studies show that DSB-complexity or DSB-nature may also be affected by the presence within the cluster of thermally labile sugar lesions (TLSL) that break the DNA backbone only if they chemically evolve to SSB, a process thought to occur within the first hour post-irradiation. Since BrdU radiosensitization might be associated with increased yields and reduced reparability of DSB, we investigated whether BrdU underpins these effects by shifting the balance in the generation of TLSL. We employed asymmetric-field-inversion gel electrophoresis (AFIGE), a pulsed-field gel electrophoresis (PFGE) method to quantitate DSB in a battery of five cells lines grown in the presence of different concentrations of BrdU. We measured specifically the yields of promptly forming DSB (prDSB) using low temperature lysis protocols, and the yields of total DSB (tDSB = prDSB + tlDSB; tlDSB form after evolution to SSB of TLSL) using high temperature lysis protocols. We report that incorporation of BrdU generates similar increases in the formation of tlDSB and prDSB, but variations are noted among the different cell lines tested. The similar increase in the yields of tlDSB and prDSB in BrdU substituted DNA showed that shifts in the yields of these forms of lesions could not be invoked to explain BrdU radiosensitization.

Structural characterization of phospholipids by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry.

PubMed

Marto, J A; White, F M; Seldomridge, S; Marshall, A G

1995-11-01

Matrix-assisted laser desorption/ionization (MALDI) Fourier transform ion cyclotron resonance mass spectrometry provides for structural analysis of the principal biological phospholipids: glycerophosphatidylcholine, -ethanolamine, -serine, and -inositol. Both positive and negative molecular or quasimolecular ions are generated in high abundance. Isolated molecular ions may be collisionally activated in the source side of a dual trap mass analyzer, yielding fragments serving to identify the polar head group (positive ion mode) and fatty acid side chains (negative ion mode). Azimuthal quadrupolar excitation following collisionally activated dissociation refocuses productions close to the solenoid axis; subsequent transfer of product ions to the analyzer ion trap allows for high-resolution mass analysis. Cyro-cooling of the sample probe with liquid nitrogen greatly reduces matrix adduction encountered in the negative ion mode.

Chitosan/chondroitin sulfate hydrogels prepared in [Hmim][HSO4] ionic liquid.

PubMed

Nunes, Cátia S; Rufato, Kessily B; Souza, Paulo R; de Almeida, Elizângela A M S; da Silva, Michael J V; Scariot, Débora B; Nakamura, Celso V; Rosa, Fernanda A; Martins, Alessandro F; Muniz, Edvani C

2017-08-15

[Hmim][HSO 4 ] ionic liquid (IL) and bio-renewable sources as chitosan (CHT) and chondroitin sulfate (CS) were used to yield hydrogel-based materials (CHT/CS). The use of IL to solubilize both polysaccharides was considered an innovative way based on "green chemistry" principle, aiming the production of CHT/CS blended systems. CHT/CS hydrogels were carried out in homogeneous medium from short dissolution times. The hydrogels were characterized and achieved with excellent stabilities (in the 1.2-10pH range), larger swelling capacities, as well as devoid of cytotoxicity towards the normal VERO and diseased HT29 cells. The CHT/CS hydrogels carried out in [Hmim][HSO 4 ] could be applied in many technological purposes, like medical, pharmaceutical, and environmental fields. Copyright © 2017 Elsevier Ltd. All rights reserved.

Manganese oxide nanoparticle-assisted laser desorption/ionization mass spectrometry for medical applications

NASA Astrophysics Data System (ADS)

Taira, Shu; Kitajima, Kenji; Katayanagi, Hikaru; Ichiishi, Eiichiro; Ichiyanagi, Yuko

2009-06-01

We prepared and characterized manganese oxide magnetic nanoparticles (d =5.6 nm) and developed nanoparticle-assited laser desorption/ionization (nano-PALDI) mass spectrometry. The nanoparticles had MnO2 and Mn2O3 cores conjugated with hydroxyl and amino groups, and showed paramagnetism at room temperature. The nanoparticles worked as an ionization assisting reagent in mass spectroscopy. The mass spectra showed no background in the low m/z. The nanoparticles could ionize samples of peptide, drug and proteins (approx. 5000 Da) without using matrix, i.e., 2,5-dihydroxybenzoic acid (DHB), 4-hydroxy-α-cinnamic acid (CHCA) and liquid matrix, as conventional ionization assisting reagents. Post source decay spectra by nano-PALDI mass spectrometry will yield information of the chemical structure of analytes.

LPE grown LSO:Tb scintillator films for high-resolution X-ray imaging applications at synchrotron light sources

NASA Astrophysics Data System (ADS)

Cecilia, A.; Rack, A.; Douissard, P.-A.; Martin, T.; Dos Santos Rolo, T.; Vagovič, P.; Hamann, E.; van de Kamp, T.; Riedel, A.; Fiederle, M.; Baumbach, T.

2011-08-01

Within the project ScinTAX of the 6th framework program (FP6) of the European Commission (SCINTAX—STRP 033 427) we have developed a new thin single crystal scintillator for high-resolution X-ray imaging. The scintillator is based on a Tb-doped Lu2SiO5 (LSO) film epitaxially grown on an adapted substrate. The high density, effective atomic number and light yield of the scintillating LSO significantly improves the efficiency of the X-ray imaging detectors currently used in synchrotron micro-imaging applications. In this work we present the characterization of the scintillating LSO films in terms of their spatial resolution performance and we provide two examples of high spatial and high temporal resolution applications.

Chlorxanthomycin, a Fluorescent, Chlorinated, Pentacyclic Pyrene from a Bacillus sp.†

PubMed Central

Magyarosy, Andrew; Ho, Jonathan Z.; Rapoport, Henry; Dawson, Scott; Hancock, Joe; Keasling, Jay D.

2002-01-01

A gram-positive Bacillus sp. that fluoresces yellow under long-wavelength UV light on several common culture media was isolated from soil samples. On the basis of carbon source utilization studies, fatty acid methyl ester analysis, and 16S ribosomal DNA analysis, this bacterium was most similar to Bacillus megaterium. Chemical extraction yielded a yellow-orange fluorescent pigment, which was characterized by X-ray crystallography, mass spectrometry, and nuclear magnetic resonance spectroscopy. The fluorescent compound, chlorxanthomycin, is a pentacyclic, chlorinated molecule with the molecular formula C22H15O6Cl and a molecular weight of 409.7865. Chlorxanthomycin appears to be located in the cytoplasm, does not diffuse out of the cells into the culture medium, and has selective antibiotic activity. PMID:12147512

Characterizing Materials Sources and Sinks; Current Approaches: Part II. Chemical and Physical Characterization

EPA Science Inventory

The paper discusses methods for characterizing chemical emissions from material sources, including laboratory, dynamic chamber, and full-scale studies. Indoor sources and their interaction with sinks play a major role in determining indoor air quality (IAQ). Techniques for evalua...

Materials Characterization at Utah State University: Facilities and Knowledge-base of Electronic Properties of Materials Applicable to Spacecraft Charging

NASA Technical Reports Server (NTRS)

Dennison, J. R.; Thomson, C. D.; Kite, J.; Zavyalov, V.; Corbridge, Jodie

2004-01-01

In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledge-base as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further details of the instrumentation used for insulator measurements and representative measurements of insulating spacecraft materials are provided in other Spacecraft Charging Conference presentations. The NASA Space Environments and Effects Program, the Air Force Office of Scientific Research, the Boeing Corporation, NASA Graduate Research Fellowships, and the NASA Rocky Mountain Space Grant Consortium have provided support.

Water resources of part of Canyonlands National Park, southeastern Utah

USGS Publications Warehouse

Sumsion, C.T.; Bloke, E.L.

1972-01-01

Canyonlands National Park is in about the center of the Canyon Lands section of the Colorado Plateaus physiographic province in southeastern Utah. The part of the park discussed embraces an area of about 400 square miles comprising isolated mesas, precipitous canyons, and dissected broad benches near the confluence of the Green and Colorado Rivers, the only perennial streams in the area. The climate is arid to semiarid; normal annual precipitation ranges from less than 8 to about 10 inches. Potential evapotranspiration is about 41 inches annually.Geology of the park is characterized by nearly horizontal strata that dip gently northward. Exposed rock formations and deposits range in age from Middle Pennsylvanian to Holocene. Owing to the elevated and deeply dissected topography, only parts of the Cedar Mesa and White Rim Sandstone Members of the Cutler Formation of Permian age have potential for development of wells. Strata above and below them support only small springs, are dry, or contain brine.In the northwest part of the park, the Green River at Taylor Canyon is a potential source of surface water for public supplies for the Island In The Sky area and a small part of the northwest White Rim area. It will require filtration and treatment before use. In the same area, two unused wells in Taylor Canyon will supply enough water for present requirements from the White Rim Sandstone Member of the Cutler Formation, about 140 gallons per minute combined, but yield mineralized water that will require treatment before use. Springs yielding good water at the Island In The Sky and White Rim are mostly intermittent and too small for public-water supply. Most of the White Rim area is dry, having no usable ground water. In The Needles area, wells provide water of good quality from the Cedar Mesa Sandstone Member of the Cutler Formation. Springs yielding good water in the same area are available for supplementary supplies. West of The Needles, The Grabens area is without springs or potential aquifers bearing usable water.During 1970 about 510,000 gallons of water was used in Canyonlands National Park. Of this amount, 110,000 gallons was supplied to Island In The Sky by tank truck from a source outside the park, and about 400,000 gallons was withdrawn from the well in use at The Needles. Estimated total annual requirements in 10 years (1980) may be as much as 6 million gallons. Sources of water supplies within the park now in use and potential sources of surface water or ground water outlined by this investigation will meet the estimated requirements. Development of rainfall-collection and cistern-storage systems could furnish small emergency sources of water for waterless areas on the White Rim and in The Grabens.

Simulation Study of Near-Surface Coupling of Nuclear Devices vs. Equivalent High-Explosive Charges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fournier, Kevin B; Walton, Otis R; Benjamin, Russ

2014-09-29

A computational study was performed to examine the differences in near-surface ground-waves and air-blast waves generated by high-explosive energy sources and those generated by much higher energy - density low - yield nuclear sources. The study examined the effect of explosive-source emplacement (i.e., height-of-burst, HOB, or depth-of-burial, DOB) over a range from depths of -35m to heights of 20m, for explosions with an explosive yield of 1-kt . The chemical explosive was modeled by a JWL equation-of-state model for a ~14m diameter sphere of ANFO (~1,200,000kg – 1 k t equivalent yield ), and the high-energy-density source was modeled asmore » a one tonne (1000 kg) plasma of ‘Iron-gas’ (utilizing LLNL’s tabular equation-of-state database, LEOS) in a 2m diameter sphere, with a total internal-energy content equivalent to 1 k t . A consistent equivalent-yield coupling-factor approach was developed to compare the behavior of the two sources. The results indicate that the equivalent-yield coupling-factor for air-blasts from 1 k t ANFO explosions varies monotonically and continuously from a nearly perfec t reflected wave off of the ground surface for a HOB ≈ 20m, to a coupling factor of nearly zero at DOB ≈ -25m. The nuclear air - blast coupling curve, on the other hand, remained nearly equal to a perfectly reflected wave all the way down to HOB’s very near zero, and then quickly dropped to a value near zero for explosions with a DOB ≈ -10m. The near - surface ground - wave traveling horizontally out from the explosive source region to distances of 100’s of meters exhibited equivalent - yield coupling - factors t hat varied nearly linearly with HOB/DOB for the simulated ANFO explosive source, going from a value near zero at HOB ≈ 5m to nearly one at DOB ≈ -25m. The nuclear-source generated near-surface ground wave coupling-factor remained near zero for almost all HOB’s greater than zero, and then appeared to vary nearly - linearly with depth-of-burial until it reached a value of one at a DOB between 15m and 20m. These simulations confirm the expected result that the variation of coupling to the ground, or the air, change s much more rapidly with emplacement location for a high-energy-density (i.e., nuclear-like) explosive source than it does for relatively low - energy - density chemical explosive sources. The Energy Partitioning, Energy Coupling (EPEC) platform at LLNL utilizes laser energy from one quad (i.e. 4-laser beams) of the 192 - beam NIF Laser bank to deliver ~10kJ of energy to 1mg of silver in a hohlraum creating an effective small-explosive ‘source’ with an energy density comparable to those in low-yield nuclear devices. Such experiments have the potential to provide direct experimental confirmation of the simulation results obtained in this study, at a physical scale (and time-scale) which is a factor of 1000 smaller than the spatial- or temporal-scales typically encountered when dealing with nuclear explosions.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, William Scott

This seminar presentation describes amplitude models and yield estimations that look at the data in order to inform legislation. The following points were brought forth in the summary: global models that will predict three-component amplitudes (R-T-Z) were produced; Q models match regional geology; corrected source spectra can be used for discrimination and yield estimation; three-component data increase coverage and reduce scatter in source spectral estimates; three-component efforts must include distance-dependent effects; a community effort on instrument calibration is needed.

High yield production of long branched Au nanoparticles characterized by atomic resolution transmission electron microscopy

PubMed Central

Mayoral, Alvaro; Magen, Cesar; Jose-Yacaman, Miguel

2011-01-01

Long multi-branched gold nanoparticles have been synthesized in a very high yield through a facile synthesis combining two different capping agents. The stability of these materials with the time has been tested and their characterization have been performed by diverse advanced electron microscopy techniques, paying special attention to aberration corrected transmission electron microscopy in order to unambiguously analyze the surface structure of the branches and provide insights for the formation of stellated gold nanoparticles. PMID:22125420

Glassy carbon/multi walled carbon nanotube/cadmium sulphide photoanode for light energy storage in vanadium photoelectrochemical cell

NASA Astrophysics Data System (ADS)

Peimanifard, Zahra; Rashid-Nadimi, Sahar

2015-12-01

The aim of this study is utilizing the artificial photosynthesis, which is an attractive and challenging theme in the photoelectrocatalytic water splitting, to charge the vanadium redox flow battery (VRFB). In this work multi walled carbon nanotube/cadmium sulphide hybrid is employed as a photoanode material to oxidize VO2+ toVO2+ for charging the positive vanadium redox flow battery's half-cell. Characterization studies are also described using the scanning electron microscopic-energy-dispersive X-ray spectroscopy (SEM-EDS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and UV-Visible methods. The phtoelectrochemical performance is characterized by cyclic voltammetry and chronoamperometry. Applied bias photon-to-current efficiency (ABPE) is achieved for both two and three-electrode configurations. The glassy carbon/multi walled carbon nanotube/cadmium sulphide yields high maximum ABPE of 2.6% and 2.12% in three and two-electrode setups, respectively. These results provide a useful guideline in designing photoelectrochemical cells for charging the vanadium redox flow batteries by sunlight as a low cost, free and abundant energy source, which does not rely on an external power input.

Characterization of a tin-loaded liquid scintillator for gamma spectroscopy and neutron detection

NASA Astrophysics Data System (ADS)

Wen, Xianfei; Harvey, Taylor; Weinmann-Smith, Robert; Walker, James; Noh, Young; Farley, Richard; Enqvist, Andreas

2018-07-01

A tin-loaded liquid scintillator has been developed for gamma spectroscopy and neutron detection. The scintillator was characterized in regard to energy resolution, pulse shape discrimination, neutron light output function, and timing resolution. The loading of tin into scintillators with low effective atomic number was demonstrated to provide photopeaks with acceptable energy resolution. The scintillator was shown to have reasonable neutron/gamma discrimination capability based on the charge comparison method. The effect on the discrimination quality of the total charge integration time and the initial delay time for tail charge integration was studied. To obtain the neutron light output function, the time-of-flight technique was utilized with a 252Cf source. The light output function was validated with the MCNPX-PoliMi code by comparing the measured and simulated pule height spectra. The timing resolution of the developed scintillator was also evaluated. The tin-loading was found to have negligible impact on the scintillation decay times. However, a relatively large degradation of timing resolution was observed due to the reduced light yield.

Lipase-catalyzed acylation of microbial mannosylerythritol lipids (biosurfactants) and their characterization.

PubMed

Recke, Verena K; Beyrle, Catharina; Gerlitzki, Melanie; Hausmann, Rudolf; Syldatk, Christoph; Wray, Victor; Tokuda, Harukuni; Suzuki, Nobutaka; Lang, Siegmund

2013-05-24

Culturing Pseudozyma aphidis on glucose as main carbon source and soybean oil as co-substrate the mannosylerythritol lipids MEL-A and MEL-B were produced. Based on their excellent surface/interfacial active behavior they possess a high potential among all known biosurfactants. The components of a microbial MEL mixture were purified by medium pressure liquid chromatography (MPLC) and were used as substrates for in vitro enzymatic modifications. Lipase-catalyzed acylations of MEL-A and MEL-B with uncommon fatty acids from other microbial glycolipids-3-hydroxydecanoic acid from rhamnolipids and 17-hydroxyoctadecanoic acid from classical sophorolipids-yielded functionalized products at the C-1 position of the erythritol. The novel products were purified by MPLC and their structures elucidated by (1)H and (13)C nuclear magnetic resonance spectroscopy and mass spectrometry. In physicochemical characterization experiments two of the three new glycoconjugates lowered the surface tension of water from 72 mN m(-1) to 27-38 mN m(-1). Moreover the novel compounds inhibited the growth of gram-positive bacteria and showed a potential for anti-tumor-promoting activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization and energy potential of food waste from catering service in Hangzhou, China.

PubMed

Guo, Xiao-Hui; Sun, Fa-Qian; Sun, Ying-Jun; Lu, Hao-Hao; Wu, Wei-Xiang

2014-08-01

Safe disposal of food waste is becoming an impending issue in China with the rapid increase of its production and the promotion of environmental awareness. Food waste from catering services in Hangzhou, China, was surveyed and characterized in this study. A questionnaire survey involving 632 units across the urban districts showed that 83.5% of the food waste was not properly treated. Daily food waste production from catering units was estimated to be 1184.5 tonnes. The ratio of volatile solid to total solid, easily biodegradable matter (including crude fat, crude protein and total starch) content in total solid and the ratio of total organic carbon to nitrogen varied in ranges of 90.1%-93.9%, 60.9%-72.1%, and 11.9-19.9, respectively. Based on the methane yield of 350 mL g VS(-1) in anaerobic batch tests, annual biogas energy of 1.0 × 10(9) MJ was estimated to be recovered from the food waste. Food waste from catering services was suggested to be an attractive clean energy source by anaerobic digestion. © The Author(s) 2014.

Evaluation of Flinders Technology Associates cards for storage and molecular detection of avian metapneumoviruses.

PubMed

Awad, Faez; Baylis, Matthew; Jones, Richard C; Ganapathy, Kannan

2014-01-01

The feasibility of using Flinders Technology Associates (FTA) cards for the molecular detection of avian metapneumovirus (aMPV) by reverse transcriptase-polymerase chain reaction (RT-PCR) was investigated. Findings showed that no virus isolation was possible from aMPV-inoculated FTA cards, confirming viral inactivation upon contact with the cards. The detection limits of aMPV from the FTA card and tracheal organ culture medium were 10(1.5) median ciliostatic doses/ml and 10(0.75) median ciliostatic doses/ml respectively. It was possible to perform molecular characterization of both subtypes A and B aMPV using inoculated FTA cards stored for up to 60 days at 4 to 6°C. Tissues of the turbinate, trachea and lung of aMPV-infected chicks sampled either by direct impression smears or by inoculation of the tissue homogenate supernatants onto the FTA cards were positive by RT-PCR. However, the latter yielded more detections. FTA cards are suitable for collecting and transporting aMPV-positive samples, providing a reliable and hazard-free source of RNA for molecular characterization.

Transport of sugars.

PubMed

Chen, Li-Qing; Cheung, Lily S; Feng, Liang; Tanner, Widmar; Frommer, Wolf B

2015-01-01

Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.

Production and characterization of poly-3-hydroxybutyrate from Bacillus cereus PS 10.

PubMed

Sharma, Priyanka; Bajaj, Bijender Kumar

2015-11-01

Usage of renewable raw materials for production of fully degradable bioplastics (bacterial poly-3-hydroxybutyrate, PHB) has gained immense research impetus considering recalcitrant nature of petroleum based plastics, dwindling fossil fuel feed stocks, and associated green house gas emissions. However, high production cost of PHB is the major bottleneck for its wide range industrial applications. In current study, Bacillus cereus PS 10, a recent isolate, efficiently utilized molasses, an abundantly available by-product from sugar industries as sole carbon source for growth and PHB production. Most influential bioprocess variables i.e. molasses, pH and NH4Cl were identified based on Plackett-Burman-designed experiments. Design of experiment approach (response surface methodology) was further employed for optimization of these bioprocess variables, and an enhanced PHB yield (57.5%) was obtained. PHB produced by Bacillus cereus PS 10 was investigated using various physico-chemical approaches viz. thermogravimetric analysis, proton and carbon NMR ((1)H and (13)C) spectroscopy, melting point, elemental analysis and polarimetry for its detail characterization, and assessment for industrial application potential. Copyright © 2015 Elsevier B.V. All rights reserved.

The effects of climate change on instream nitrogen transport in the contiguous United States

NASA Astrophysics Data System (ADS)

Alam, M. J.; Goodall, J. L.

2011-12-01

Excessive nitrogen loading has caused significant environmental impacts such as eutrophication and hypoxia in waterbodies around the world. Nitrogen loading is largely dependent on nonpoint source pollution and nitrogen transport from nonpoint source pollution is greatly impacted by climate conditions. For example, increased precipitation leads to more runoff and a higher nitrogen yield. However, higher temperatures also impact nitrogen transport in that higher temperatures increase denitrification and therefore reduce nitrogen yield. The purpose of this research is to quantify potential changes in nitrogen yield for the contiguous United States under predicted climate change scenarios, specifically changes in precipitation and air temperature. The analysis was performed for high (A2) and low (B1) emission scenarios and for the year 2030, 2050 and 2090. We used 11 different IPCC (The Intergovernmental Panel on Climate Change) models predicted precipitation and temperature estimates to capture uncertainty. The SPARROW model was calibrated using historical nitrogen loading data and used to predict nitrogen yields for future climate conditions. We held nitrogen source data constant in order to isolate the impact of predicted precipitation and temperature changes for each model scenario. Preliminary results suggest an overall decrease in nitrogen yield if climate change impacts are considered in isolation. For the A2 scenario, the model results indicated an overall incremental nitrogen yield decrease of 2-17% by the year 2030, 4-26% by the year 2050, and 11-45% by the year 2090. The B1 emission scenario also indicated an incremental yield decrease, but at lesser amounts of 2-18%, 5-21% and 10-38% by the years 2030, 2050, and 2090, respectively. This decrease is mainly due to higher predicted temperatures that result in increased denitrification rates.

RESEARCH AREA -- MOBILE SOURCE EMISSIONS (EMISSIONS CHARACTERIZATION AND PREVENTION BRANCH, APPCD, NRMRL)

EPA Science Inventory

The objective of this program is to characterize mobile source emissions which are one of the largest sources of tropospheric ozone precursor emissions (CO, NOx, and volotile organic compounds) in the U.S. The research objective of the Emissions Characterization and Prevention Br...

Source Characterization of Microseismic Events using Empirical Green's Functions at the Basel EGS Project

NASA Astrophysics Data System (ADS)

Folesky, Jonas; Kummerow, Jörn

2015-04-01

The Empirical Green's Function (EGF) method uses pairs of events of high wave form similarity and adjacent hypocenters to decompose the influences of source time function, ray path, instrument site, and instrument response. The seismogram of the smaller event is considered as the Green's function which then can be deconvolved from the other seismogram. The result provides a reconstructed relative source time function (RSTF) of the larger event of that event pair. The comparison of the RSTFs at all stations of the observation systems produces information on the rupture process of the event based on an apparent directivity effect and possible changes in the RSTFs complexities. The Basel EGS dataset of 2006-2007 consists of about 2800 localized events of magnitudes between 0.0 < ML < 3.5 with event pairs of adequate magnitude difference for EGF analysis. The data has sufficient quality to analyse events with magnitudes down to ML = 0.0 for an apparent directivity effect although the approximate rupture duration for those events is of only a few milliseconds. The dataset shows a number of multiplets where fault plane solutions are known from earlier studies. Using the EGF method we compute rupture orientations for about 190 event pairs and compare them to the fault plane solutions of the multiplets. For the majority of events we observe a good consistency between the rupture direction found there and one of the previously determined nodal planes from fault plane solutions. In combination this resolves the fault plane ambiguity. Furthermore the rupture direction fitting yields estimates for projections of the rupture velocity on the horizontal plane. They seem to vary between the multiplets in the reservoir from 0.3 to 0.7 times the S-wave velocity. To our knowledge source characterization by EGF analysis has not yet been introduced to microseismic reservoirs with the data quality found in Basel. Our results show that EGF analysis can provide valuable additional insights on the distribution of rupture properties within the reservoir.

Detrital fingerprints of fossil continental-subduction zones (Axial Belt Provenance, European Alps)

NASA Astrophysics Data System (ADS)

Resentini, Alberto; Garzanti, Eduardo; Vezzoli, Giovanni; Andò, Sergio; Malusà, Marco G.; Padoan, Marta; Paparella, Paolo

2010-05-01

Alpine-type collision orogens are generated by attempted subduction of thinned continental margins. Because of complex tectonic structure, orogenic detritus is characterized by a range of detrital signatures, making its recognition an arduous task (Dickinson and Suczek, 1979). Among the various orogenic sub-provenances, Axial Belt Provenance, derived from the erosion of the neometamorphic axial pile, can be regarded as the most typifying signature of collision orogens (Garzanti et al., 2007). In the Austroalpine Cretaceous and Penninic Eocene axial belts of the Alps, we ideally distinguish three structural levels, each characterized by diagnostic detrital fingerprints. The shallow level chiefly consists of offscraped remnant-ocean turbidites and unmetamorphosed continental-margin sediments, and mostly produces lithic to lithoquartzose sedimentaclastic sands yielding very-poor heavy-mineral suites including ultrastable minerals. The intermediate level includes low-grade metasediments and polymetamorphic basements, and sheds lithoquartzose to quartzolithofeldspathic metamorphiclastic sands yielding moderately-rich epidote- amphibole suites with chloritoid or garnet. The deep level contains eclogitic remnants of continent- ocean transitions, and supplies quartzofeldspathic to quartzolithic high-rank metamorphiclastic to lithic ultramaficlastic sands yielding rich to extremely-rich suites dominated by garnet, hornblende, or epidote depending on protoliths (continental vs. oceanic) and pressure/temperature paths followed during exhumation. Although widely overprinted under greenschist-facies or amphibolite-facies conditions, occurrence of ultradense eclogite in source areas is readily revealed by the Heavy Mineral Concentration (HMC) index, which mirrors the average density of source rocks in the absence of hydraulic-sorting effects (Garzanti and Andò 2007). The Metamorphic Index (MI, Garzanti and Vezzoli, 2003) and Hornblende Colour Index (HCI) reflect peak temperatures reached at later stages, when subduction is throttled by arrival of thicker continental crust and geothermal gradients increase. Experience gained from modern sediments provides fundamental help to decrypt the innumerable pieces of information stored in the sedimentary record, and thus to identify and reconstruct subduction events of the past. Dickinson, W., R., Suczek, C.A., 1979.Plate tectonics and sandstone compositions. AAPG Bull. 63, 2164-2182. Garzanti, E. and Andò, S. 2007. Heavy-mineral concentration in modern sands: implications for provenance interpretation. In Mange, M., and Wright, D., eds. Heavy Minerals in Use. Developments in Sedimentology Series 58. Amsterdam, Elsevier, p. 517-545. Garzanti, E., and Vezzoli, G. 2003. A classification of metamorphic grains in sands based on their composition and grade. J. Sediment. Res. 73:830-837. Garzanti, E., Doglioni, C., Vezzoli, G., Andò, S., 2007. Orogenic belts and orogenic sediment provenante. J. Geology, 115:315-334.

A quantitative approach to combine sources in stable isotope mixing models

EPA Science Inventory

Stable isotope mixing models, used to estimate source contributions to a mixture, typically yield highly uncertain estimates when there are many sources and relatively few isotope elements. Previously, ecologists have either accepted the uncertain contribution estimates for indiv...

The Study of High-Speed Surface Dynamics Using a Pulsed Proton Beam

NASA Astrophysics Data System (ADS)

Buttler, William; Stone, Benjamin; Oro, David; Dimonte, Guy; Preston, Dean; Cherne, Frank; Germann, Timothy; Terrones, Guillermo; Tupa, Dale

2011-06-01

Los Alamos National Laboratory is presently engaged in development and implementation of ejecta source term and transport models for integration into LANL hydrodynamic computer codes. Experimental support for the effort spans a broad array of activities, including ejecta source term measurements from machine roughened Sn surfaces shocked by HE or flyer plates. Because the underlying postulate for ejecta formation is that ejecta are characterized by Richtmyer-Meshkov instability (RMI) phenomena, a key element of the theory and modeling effort centers on validation and verification RMI experiments at the LANSCE Proton Radiography Facility (pRad) to compare with modeled ejecta measurements. Here we present experimental results used to define and validate a physics based ejecta model together with remarkable, unexpected results of Sn instability growth in vacuum and gasses, and Sn and Cu RM growth that reveals the sensitivity of the RM instability to the yield strength of the material, Cu. The motivation of this last subject, RM growth linked to material strength, is to probe the shock pressure regions over which ejecta begins to form. Presenter

Evaluation of potential surface rupture and review of current seismic hazards program at the Los Alamos National Laboratory. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-12-09

This report summarizes the authors review and evaluation of the existing seismic hazards program at Los Alamos National Laboratory (LANL). The report recommends that the original program be augmented with a probabilistic analysis of seismic hazards involving assignment of weighted probabilities of occurrence to all potential sources. This approach yields a more realistic evaluation of the likelihood of large earthquake occurrence particularly in regions where seismic sources may have recurrent intervals of several thousand years or more. The report reviews the locations and geomorphic expressions of identified fault lines along with the known displacements of these faults and last knowmore » occurrence of seismic activity. Faults are mapped and categorized into by their potential for actual movement. Based on geologic site characterization, recommendations are made for increased seismic monitoring; age-dating studies of faults and geomorphic features; increased use of remote sensing and aerial photography for surface mapping of faults; the development of a landslide susceptibility map; and to develop seismic design standards for all existing and proposed facilities at LANL.« less

Generation of a U.S. national urban land use product

USGS Publications Warehouse

Falcone, James A.; Homer, Collin G.

2012-01-01

Characterization of urban land uses is essential for many applications. However, differentiating among thematically-detailed urban land uses (residential, commercial, industrial, institutional, recreational, etc.) over broad areas is challenging, in part because image-based solutions are not ideal for establishing the contextual basis for identifying economic function and use. At present no current United States national-scale mapping exists for urban land uses similar to the classical Anderson Level II classification. This paper describes a product that maps urban land uses, and is linked to and corresponds with the National Land Cover Database (NLCD) 2006. In this product, NLCD urban pixels, in addition to their current imperviousness intensity classification, are assigned one of nine urban use classes based on information drawn from multiple data sources. These sources include detailed infrastructure information, population characteristics, and historical land use. The result is a method for creating a 30 m national-scale grid providing thematically-detailed urban land use information which complements the NLCD. Initial results for 10 major metropolitan areas are provided as an on-line link. Accuracy assessment of initial products yielded an overall accuracy of 81.6 percent.

Physiological characterization of strain DCB-1, a unique dehalogenating sulfidogenic bacterium.

PubMed Central

Stevens, T O; Linkfield, T G; Tiedje, J M

1988-01-01

Strain DCB-1 is an obligately anaerobic bacterium which carries out the reductive dehalogenation of halobenzoates and was previously known to grow only on pyruvate plus 20% ruminal fluid. When various electron acceptors were supplied, thiosulfate and sulfite were found to stimulate growth. Sulfide was produced from thiosulfate. Cytochrome c and desulfoviridin were detected. The mol% G+C was 49 (at the thermal denaturation temperature). Of 55 carbon sources tested, only pyruvate supported growth as the sole carbon source in mineral medium. Lactate, acetate, L- and D-malate, glycerol, and L- and D-arabinose stimulated growth when supplemented with 10% ruminal fluid and 20 mM thiosulfate. In mineral medium, pyruvate was converted to acetate and lactate, with small amounts of succinate and fumarate accumulating transiently. During growth with thiosulfate, all of these products accumulated transiently. Addition of excess hydrogen to pyruvate-grown cultures resulted in diversion of carbon to formate, lactate, and butyrate, which caused a decrease in cell yield. We conclude that strain DCB-1 is a new type of sulfidogenic bacterium. PMID:3223760

Plate mode velocities in graphite/epoxy plates

NASA Technical Reports Server (NTRS)

Prosser, W. H.; Gorman, M. R.

1994-01-01

Measurements of the velocities of the extensional and flexural plate modes were made along three directions of propagation in four graphite/epoxy composite plates. The acoustic signals were generated by simulated acoustic emission events (pencil lead breaks or Hsu-Neilson sources) and detected by by broadband ultrasonic transducers. The first arrival of the extensional plate mode, which is nondispersive at low frequencies, was measured at a number of different distances from the source along the propagation direction of interest. The velocity was determined by plotting the distance versus arrival time and computing its slope. Because of the large dispersion of the flexural mode, a Fourier phase velocity technique was used to characterize this mode. The velocity was measured up to a frequency of 160 kHz. Theoretical predictions of the velocities of these modes were also made and compared with experimental observations. Classical plate theory yields good agreement with the measured extensional velocities. For predictions of the dispersion of the flexural mode, Mindlin plates theory, which includes the effects of shear deformation and rotatory inertia was shown to give better agreement with the experimental measurements.

The 27.3 meter neutron time-of-flight system for the National Ignition Facility

NASA Astrophysics Data System (ADS)

Grim, G. P.; Morgan, G. L.; Aragonez, R.; Archuleta, T. N.; Bower, D. E.; Danly, C. R.; Drury, O. B.; Dzenitis, J. M.; Fatherley, V. E.; Felker, B.; Fittinghoff, D. N.; Guler, N.; Merrill, F. E.; Oertel, J. A.; Wilde, C. H.; Wilke, M. D.

2013-09-01

One of the scientific goals of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, Livermore CA, is to obtain thermonuclear ignition by compressing 2.2 mm diameter capsules filed with deuterium and tritium to densities approaching 1000 g/cm3 and temperatures in excess of 4 keV. Thefusion reaction d + t --> n + a results in a 14.03 MeV neutron providing a source of diagnostic particles to characterize the implosion. The spectrum of neutrons emanating from the assembly may be used to infer the fusion yield, plasma ion temperature, and fuel areal density, all key diagnostic quantities of implosion quality. The neutron time-of-flight (nToF) system co-located along the Neutron Imaging System line-of-site, (NIToF), is a set of 4 scintillation detectors located approximately 27.3 m from the implosion source. Neutron spectral information is inferred using arrival time at the detector. The NIToF system is described below, including the hardware elements, calibration data, analysis methods, and an example of its basic performance characteristics.

Effects of climatic seasonality on the isotopic composition of evaporating soil waters

NASA Astrophysics Data System (ADS)

Benettin, Paolo; Volkmann, Till H. M.; von Freyberg, Jana; Frentress, Jay; Penna, Daniele; Dawson, Todd E.; Kirchner, James W.

2018-05-01

Stable water isotopes are widely used in ecohydrology to trace the transport, storage, and mixing of water on its journey through landscapes and ecosystems. Evaporation leaves a characteristic signature on the isotopic composition of the water that is left behind, such that in dual-isotope space, evaporated waters plot below the local meteoric water line (LMWL) that characterizes precipitation. Soil and xylem water samples can often plot below the LMWL as well, suggesting that they have also been influenced by evaporation. These soil and xylem water samples frequently plot along linear trends in dual-isotope space. These trend lines are often termed "evaporation lines" and their intersection with the LMWL is often interpreted as the isotopic composition of the precipitation source water. Here we use numerical experiments based on established isotope fractionation theory to show that these trend lines are often by-products of the seasonality in evaporative fractionation and in the isotopic composition of precipitation. Thus, they are often not true evaporation lines, and, if interpreted as such, can yield highly biased estimates of the isotopic composition of the source water.

Synthesis of polyhydroxyalkanoate from palm oil and some new applications.

PubMed

Sudesh, Kumar; Bhubalan, Kesaven; Chuah, Jo-Ann; Kek, Yik-Kang; Kamilah, Hanisah; Sridewi, Nanthini; Lee, Yan-Fen

2011-03-01

Polyhydroxyalkanoate (PHA) is a potential substitute for some petrochemical-based plastics. This biodegradable plastic is derived from microbial fermentation using various carbon substrates. Since carbon source has been identified as one of the major cost-absorbing factors in PHA production, cheap and renewable substrates are currently being investigated as substitutes for existing sugar-based feedstock. Plant oils have been found to result in high-yield PHA production. Malaysia, being the world's second largest producer of palm oil, is able to ensure continuous supply of palm oil products for sustainable PHA production. The biosynthesis and characterization of various types of PHA using palm oil products have been described in detail in this review. Besides, by-products and waste stream from palm oil industry have also demonstrated promising results as carbon sources for PHA biosynthesis. Some new applications in cosmetic and wastewater treatment show the diversity of PHA usage. With proper management practices and efficient milling processes, it may be possible to supply enough palm oil-based raw materials for human consumption and other biotechnological applications such as production of PHA in a sustainable manner.

Production of recombinant albumin by a herd of cloned transgenic cattle.

PubMed

Echelard, Yann; Williams, Jennifer L; Destrempes, Margaret M; Koster, Julie A; Overton, Susan A; Pollock, Daniel P; Rapiejko, Karen T; Behboodi, Esmail; Masiello, Nicholas C; Gavin, William G; Pommer, Jerry; Van Patten, Scott M; Faber, David C; Cibelli, Jose B; Meade, Harry M

2009-06-01

Purified plasma derived human albumin has been available as a therapeutic product since World War II. However, cost effective recombinant production of albumin has been challenging due to the amount needed and the complex folding pattern of the protein. In an effort to provide an abundant source of recombinant albumin, a herd of transgenic cows expressing high levels of rhA in their milk was generated. Expression cassettes efficiently targeting the secretion of human albumin to the lactating mammary gland were obtained and tested in transgenic mice. A high expressing transgene was transfected in primary bovine cell lines to produce karyoplasts for use in a somatic cell nuclear transfer program. Founder transgenic cows were produced from four independent cell lines. Expression levels varying from 1-2 g/l to more than 40 g/l of correctly folded albumin were observed. The animals expressing the highest levels of rhA exhibited shortened lactation whereas cows yielding 1-2 g/l had normal milk production. This herd of transgenic cattle is an easily scalable and well characterized source of rhA for biomedical uses.

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].

PubMed

Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

2005-01-01

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.

CACTI: Free, Open-Source Software for the Sequential Coding of Behavioral Interactions

PubMed Central

Glynn, Lisa H.; Hallgren, Kevin A.; Houck, Jon M.; Moyers, Theresa B.

2012-01-01

The sequential analysis of client and clinician speech in psychotherapy sessions can help to identify and characterize potential mechanisms of treatment and behavior change. Previous studies required coding systems that were time-consuming, expensive, and error-prone. Existing software can be expensive and inflexible, and furthermore, no single package allows for pre-parsing, sequential coding, and assignment of global ratings. We developed a free, open-source, and adaptable program to meet these needs: The CASAA Application for Coding Treatment Interactions (CACTI). Without transcripts, CACTI facilitates the real-time sequential coding of behavioral interactions using WAV-format audio files. Most elements of the interface are user-modifiable through a simple XML file, and can be further adapted using Java through the terms of the GNU Public License. Coding with this software yields interrater reliabilities comparable to previous methods, but at greatly reduced time and expense. CACTI is a flexible research tool that can simplify psychotherapy process research, and has the potential to contribute to the improvement of treatment content and delivery. PMID:22815713

A series of inorganic solid nitrogen sources for the synthesis of metal nitride clusterfullerenes: the dependence of production yield on the oxidation state of nitrogen and counter ion.

PubMed

Liu, Fupin; Guan, Jian; Wei, Tao; Wang, Song; Jiao, Mingzhi; Yang, Shangfeng

2013-04-01

A series of nitrogen-containing inorganic solid compounds with variable oxidation states of nitrogen and counter ions have been successfully applied as new inorganic solid nitrogen sources toward the synthesis of Sc-based metal nitride clusterfullerenes (Sc-NCFs), including ammonium salts [(NH4)xH(3-x)PO4 (x = 0-2), (NH4)2SO4, (NH4)2CO3, NH4X (X = F, Cl), NH4SCN], thiocyanate (KSCN), nitrates (Cu(NO3)2, NaNO3), and nitrite (NaNO2). Among them, ammonium phosphates ((NH4)xH(3-x)PO4, x = 1-3) and ammonium thiocyanate (NH4SCN) are revealed to behave as better nitrogen sources than others, and the highest yield of Sc-NCFs is achieved when NH4SCN was used as a nitrogen source. The optimum molar ratio of Sc2O3:(NH4)3PO4·3H2O:C and Sc2O3:NH4SCN:C has been determined to be 1:2:15 and 1:3:15, respectively. The thermal decomposition products of these 12 inorganic compounds have been discussed in order to understand their different performances toward the synthesis of Sc-NCFs, and accordingly the dependence of the production yield of Sc-NCFs on the oxidation state of nitrogen and counter ion is interpreted. The yield of Sc3N@C80 (I(h) + D(5h)) per gram Sc2O3 by using the N2-based group of nitrogen sources (thiocyanate, nitrates, and nitrite) is overall much lower than those by using gaseous N2 and NH4SCN, indicating the strong dependence of the yield of Sc-NCFs on the oxidation state of nitrogen, which is attributed to the "in-situ" redox reaction taking place for the N2-based group of nitrogen sources during discharging. For NH3-based group of nitrogen sources (ammonium salts) which exhibits a (-3) oxidation states of nitrogen, their performance as nitrogen sources is found to be sensitively dependent on the anion, and this is understood by considering their difference on the thermal stability and/or decomposition rate. Contrarily, for the N2-based group of nitrogen sources, the formation of Sc-NCFs is independent to both the oxidation state of nitrogen (+3 or +5) and the cation.

Production and optimization of polyhydroxyalkanoates from non-edible Calophyllum inophyllum oil using Cupriavidus necator.

PubMed

Arumugam, A; Senthamizhan, S G; Ponnusami, V; Sudalai, S

2018-06-01

Polyhydroxyalkanoates (PHA) are biodegradable polymers found in the cellular masses of a wide range of bacterial species and the demand for PHA is steadily growing. In this work we have produced PHA from a low-cost substrate, Calophyllum inophyllum oil, using Cupriavidus necator. Effects of various process parameters such as Oil concentration, Nitrogen source and inoculum size on the production of PHA were studied using Response Surface Methodology. A quadratic equation was used in the model to fit the experimental data. It was found that the model could satisfactorily predict the PHA yield (R 2 =99.17%). Linear, quadratic and interaction terms used in the model were found to be statistically significant. Maximum PHA yield of 10.6gL -1 was obtained under the optimized conditions of oil concentration - 17.5%, inoculum concentration - 50mL/L and nitrogen content - 1.125gL -1 , respectively. The product obtained was characterized using FTIR and NMR to confirm that it was PHA. The results demonstrate that C. inophyllum oil, a non-edible oil, can be potentially used as a low-cost substrate for the production of PHA. Copyright © 2018 Elsevier B.V. All rights reserved.

Laser-driven strong magnetostatic fields with applications to charged beam transport and magnetized high energy-density physics

NASA Astrophysics Data System (ADS)

Santos, J. J.; Bailly-Grandvaux, M.; Ehret, M.; Arefiev, A. V.; Batani, D.; Beg, F. N.; Calisti, A.; Ferri, S.; Florido, R.; Forestier-Colleoni, P.; Fujioka, S.; Gigosos, M. A.; Giuffrida, L.; Gremillet, L.; Honrubia, J. J.; Kojima, S.; Korneev, Ph.; Law, K. F. F.; Marquès, J.-R.; Morace, A.; Mossé, C.; Peyrusse, O.; Rose, S.; Roth, M.; Sakata, S.; Schaumann, G.; Suzuki-Vidal, F.; Tikhonchuk, V. T.; Toncian, T.; Woolsey, N.; Zhang, Z.

2018-05-01

Powerful nanosecond laser-plasma processes are explored to generate discharge currents of a few 100 kA in coil targets, yielding magnetostatic fields (B-fields) in excess of 0.5 kT. The quasi-static currents are provided from hot electron ejection from the laser-irradiated surface. According to our model, which describes the evolution of the discharge current, the major control parameter is the laser irradiance Ilasλlas2 . The space-time evolution of the B-fields is experimentally characterized by high-frequency bandwidth B-dot probes and proton-deflectometry measurements. The magnetic pulses, of ns-scale, are long enough to magnetize secondary targets through resistive diffusion. We applied it in experiments of laser-generated relativistic electron transport through solid dielectric targets, yielding an unprecedented 5-fold enhancement of the energy-density flux at 60 μm depth, compared to unmagnetized transport conditions. These studies pave the ground for magnetized high-energy density physics investigations, related to laser-generated secondary sources of radiation and/or high-energy particles and their transport, to high-gain fusion energy schemes, and to laboratory astrophysics.

Detection of bio-signature by microscopy and mass spectrometry

NASA Astrophysics Data System (ADS)

Tulej, M.; Wiesendanger, R.; Neuland, M., B.; Meyer, S.; Wurz, P.; Neubeck, A.; Ivarsson, M.; Riedo, V.; Moreno-Garcia, P.; Riedo, A.; Knopp, G.

2017-09-01

We demonstrate detection of micro-sized fossilized bacteria by means of microscopy and mass spectrometry. The characteristic structures of lifelike forms are visualized with a micrometre spatial resolution and mass spectrometric analyses deliver elemental and isotope composition of host and fossilized materials. Our studies show that high selectivity in isolation of fossilized material from host phase can be achieved while applying a microscope visualization (location), a laser ablation ion source with sufficiently small laser spot size and applying depth profiling method. Our investigations shows that fossilized features can be well isolated from host phase. The mass spectrometric measurements can be conducted with sufficiently high accuracy and precision yielding quantitative elemental and isotope composition of micro-sized objects. The current performance of the instrument allows the measurement of the isotope fractionation in per mill level and yield exclusively definition of the origin of the investigated species by combining optical visualization of investigated samples (morphology and texture), chemical characterization of host and embedded in the host micro-sized structure. Our isotope analyses involved bio-relevant B, C, S, and Ni isotopes which could be measured with sufficiently accuracy to conclude about the nature of the micro-sized objects.

Mechanical properties of ion-beam-textured surgical implant alloys

NASA Technical Reports Server (NTRS)

Weigand, A. J.

1977-01-01

An electron-bombardment Hg ion thruster was used as an ion source to texture surfaces of materials used to make orthopedic and/or dental prostheses or implants. The materials textured include 316 stainless steel, titanium-6% aluminum, 4% vanadium, and cobalt-20% chromium, 15% tungsten. To determine the effect of ion texturing on the ultimate strength and yield strength, stainless steel and Co-Cr-W alloy samples were tensile tested to failure. Three types of samples of both materials were tested. One type was ion-textured (the process also heats each sample to 300 C), another type was simply heated to 300 C in an oven, and the third type was untreated. Stress-strain diagrams, 0.2% offset yield strength data, total elongation data, and area reduction data are presented. Fatigue specimens of ion textured and untextured 316 stainless steel and Ti-6% Al-4% V were tested. Included as an ion textured sample is a Ti-6% Al-4% V sample which was ion machined by means of Ni screen mask so as to produce an array of 140 mu m x 140 mu m x 60 mu m deep pits. Scanning electron microscopy was used to characterize the ion textured surfaces.

Quantitative Comparison of Tandem Mass Spectra Obtained on Various Instruments

NASA Astrophysics Data System (ADS)

Bazsó, Fanni Laura; Ozohanics, Oliver; Schlosser, Gitta; Ludányi, Krisztina; Vékey, Károly; Drahos, László

2016-08-01

The similarity between two tandem mass spectra, which were measured on different instruments, was compared quantitatively using the similarity index (SI), defined as the dot product of the square root of peak intensities in the respective spectra. This function was found to be useful for comparing energy-dependent tandem mass spectra obtained on various instruments. Spectral comparisons show the similarity index in a 2D "heat map", indicating which collision energy combinations result in similar spectra, and how good this agreement is. The results and methodology can be used in the pharma industry to design experiments and equipment well suited for good reproducibility. We suggest that to get good long-term reproducibility, it is best to adjust the collision energy to yield a spectrum very similar to a reference spectrum. It is likely to yield better results than using the same tuning file, which, for example, does not take into account that contamination of the ion source due to extended use may influence instrument tuning. The methodology may be used to characterize energy dependence on various instrument types, to optimize instrumentation, and to study the influence or correlation between various experimental parameters.

Production of a Lipopeptide Biosurfactant by a Novel Bacillus sp. and Its Applicability to Enhanced Oil Recovery.

PubMed

Varadavenkatesan, Thivaharan; Murty, Vytla Ramachandra

2013-01-01

Biosurfactants are surface-active compounds derived from varied microbial sources including bacteria and fungi. They are secreted extracellularly and have a wide range of exciting properties for bioremediation purposes. They also have vast applications in the food and medicine industry. With an objective of isolating microorganisms for enhanced oil recovery (EOR) operations, the study involved screening of organisms from an oil-contaminated site. Morphological, biochemical, and 16S rRNA analysis of the most promising candidate revealed it to be Bacillus siamensis, which has been associated with biosurfactant production, for the first time. Initial fermentation studies using mineral salt medium supplemented with crude oil resulted in a maximum biosurfactant yield of 0.64 g/L and reduction of surface tension to 36.1 mN/m at 96 h. Characterization studies were done using thin layer chromatography and Fourier transform infrared spectroscopy. FTIR spectra indicated the presence of carbonyl groups, alkyl bonds, and C-H and N-H stretching vibrations, typical of peptides. The extracted biosurfactant was stable at extreme temperatures, pH, and salinity. Its applicability to EOR was further verified by conducting sand pack column studies that yielded up to 60% oil recovery.

Reanalysis of Water, Land Use, and Production Data for Assessing China's Agricultural Resources

NASA Astrophysics Data System (ADS)

Smith, T.; Pan, J.; McLaughlin, D.

2016-12-01

Quantitative data about water availability, crop evapotranspiration (ET), agricultural land use, and production are needed at high temporal and spatial resolutions to develop sustainable water and agricultural plan and policies. However, large-scale high-resolution measured data can be susceptible to errors, physically inconsistent, or incomplete. Reanalysis provides a way to develop improved physically consistent estimates of both measured and hidden variables. The reanalysis approach described here uses a least-squares technique constrained by water balances and crop water requirements to assimilate many possibly redundant data sources to yield estimates of water, land use, and food production variables that are physically consistent while minimizing differences from measured data. As an example, this methodology is applied in China, where food demand is expected to increase but land and water resources could constrain further increases in food production. Hydrologic fluxes, crop ET, agricultural land use, yields, and food production are characterized at 0.5o by 0.5o resolution for a nominal year around the year 2000 for 22 different crop groups. The reanalysis approach provides useful information for resource management and policy, both in China and around the world.

A Statistical approach to optimize the production of Polyhydroxyalkanoates from Wickerhamomyces anomalus VIT-NN01 using Response Surface Methodology.

PubMed

Ojha, Nupur; Das, Nilanjana

2018-02-01

Polyhydroxyalkanoates (PHAs) are three-level group of biodegradable polymers and attractive substitutes over conventional plastics to avoid the pollution problems. The yeast strain isolated from sugarcane juice, identified as Wickerhamomyces anomalus VIT-NN01, was used for the production of polyhydroxyalkanoates (PHA). Response surface methodology (RSM), three-level six variables Box-Behnken design (BBD), was employed to optimize the factors such as pH 8.0, temperature 37°C, sugarcane molasses (35g/L) supplemented with co-substrate palm oil (0.5%),corn steep liquor (2%) after a period of 96h of incubation for the maximum yield (19.50±0.3g/L) of PHA. It was well in close agreement with the predicted value obtained by RSM model yield (19.55±0.1g/L).Characterization of the extracted polymer was done using FTIR, GC-MS, XRD, TGA and AFM analysis. NMR spectroscopic analysis revealed that the biopolymer was poly (3-hydroxybutyrate-co-3-hydroxyvalerate), copolymer of PHA. This is the first report on optimization of PHA production using yeast strain isolated from natural sources. Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.

PubMed

Zheng, Ya-Di; Luo, Qing-Lin; Zhou, Mei-Liang; Wang, De-Zhou; Zhang, Ye-Dong; Shao, Ji-Rong; Zhu, Xue-Mei; Tang, Yu

2013-02-01

The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60 kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40 °C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30 °C after 5 days fermentation, the quercetin production raised up to 1.78 mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sulfates as chromophores for multiwavelength photoacoustic imaging phantoms

NASA Astrophysics Data System (ADS)

Fonseca, Martina; An, Lu; Beard, Paul; Cox, Ben

2017-12-01

As multiwavelength photoacoustic imaging becomes increasingly widely used to obtain quantitative estimates, the need for validation studies conducted on well-characterized experimental phantoms becomes ever more pressing. One challenge that such studies face is the design of stable, well-characterized phantoms and absorbers with properties in a physiologically realistic range. This paper performs a full experimental characterization of aqueous solutions of copper and nickel sulfate, whose properties make them close to ideal as chromophores in multiwavelength photoacoustic imaging phantoms. Their absorption varies linearly with concentration, and they mix linearly. The concentrations needed to yield absorption values within the physiological range are below the saturation limit. The shape of their absorption spectra makes them useful analogs for oxy- and deoxyhemoglobin. They display long-term photostability (no indication of bleaching) as well as resistance to transient effects (no saturable absorption phenomena), and are therefore suitable for exposure to typical pulsed photoacoustic light sources, even when exposed to the high number of pulses required in scanning photoacoustic imaging systems. In addition, solutions with tissue-realistic, predictable, and stable scattering can be prepared by mixing sulfates and Intralipid, as long as an appropriate emulsifier is used. Finally, the Grüneisen parameter of the sulfates was found to be larger than that of water and increased linearly with concentration.

Colorization and Automated Segmentation of Human T2 MR Brain Images for Characterization of Soft Tissues

PubMed Central

Attique, Muhammad; Gilanie, Ghulam; Hafeez-Ullah; Mehmood, Malik S.; Naweed, Muhammad S.; Ikram, Masroor; Kamran, Javed A.; Vitkin, Alex

2012-01-01

Characterization of tissues like brain by using magnetic resonance (MR) images and colorization of the gray scale image has been reported in the literature, along with the advantages and drawbacks. Here, we present two independent methods; (i) a novel colorization method to underscore the variability in brain MR images, indicative of the underlying physical density of bio tissue, (ii) a segmentation method (both hard and soft segmentation) to characterize gray brain MR images. The segmented images are then transformed into color using the above-mentioned colorization method, yielding promising results for manual tracing. Our color transformation incorporates the voxel classification by matching the luminance of voxels of the source MR image and provided color image by measuring the distance between them. The segmentation method is based on single-phase clustering for 2D and 3D image segmentation with a new auto centroid selection method, which divides the image into three distinct regions (gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) using prior anatomical knowledge). Results have been successfully validated on human T2-weighted (T2) brain MR images. The proposed method can be potentially applied to gray-scale images from other imaging modalities, in bringing out additional diagnostic tissue information contained in the colorized image processing approach as described. PMID:22479421

Fusion of multi-source remote sensing data for agriculture monitoring tasks

NASA Astrophysics Data System (ADS)

Skakun, S.; Franch, B.; Vermote, E.; Roger, J. C.; Becker Reshef, I.; Justice, C. O.; Masek, J. G.; Murphy, E.

2016-12-01

Remote sensing data is essential source of information for enabling monitoring and quantification of crop state at global and regional scales. Crop mapping, state assessment, area estimation and yield forecasting are the main tasks that are being addressed within GEO-GLAM. Efficiency of agriculture monitoring can be improved when heterogeneous multi-source remote sensing datasets are integrated. Here, we present several case studies of utilizing MODIS, Landsat-8 and Sentinel-2 data along with meteorological data (growing degree days - GDD) for winter wheat yield forecasting, mapping and area estimation. Archived coarse spatial resolution data, such as MODIS, VIIRS and AVHRR, can provide daily global observations that coupled with statistical data on crop yield can enable the development of empirical models for timely yield forecasting at national level. With the availability of high-temporal and high spatial resolution Landsat-8 and Sentinel-2A imagery, course resolution empirical yield models can be downscaled to provide yield estimates at regional and field scale. In particular, we present the case study of downscaling the MODIS CMG based generalized winter wheat yield forecasting model to high spatial resolution data sets, namely harmonized Landsat-8 - Sentinel-2A surface reflectance product (HLS). Since the yield model requires corresponding in season crop masks, we propose an automatic approach to extract winter crop maps from MODIS NDVI and MERRA2 derived GDD using Gaussian mixture model (GMM). Validation for the state of Kansas (US) and Ukraine showed that the approach can yield accuracies > 90% without using reference (ground truth) data sets. Another application of yearly derived winter crop maps is their use for stratification purposes within area frame sampling for crop area estimation. In particular, one can simulate the dependence of error (coefficient of variation) on the number of samples and strata size. This approach was used for estimating the area of winter crops in Ukraine for 2013-2016. The GMM-GDD approach is further extended for HLS data to provide automatic winter crop mapping at 30 m resolution for crop yield model and area estimation. In case of persistent cloudiness, addition of Sentinel-1A synthetic aperture radar (SAR) images is explored for automatic winter crop mapping.

Maximization of DRAM yield by control of surface charge and particle addition during high dose implantation

NASA Astrophysics Data System (ADS)

Horvath, J.; Moffatt, S.

1991-04-01

Ion implantation processing exposes semiconductor devices to an energetic ion beam in order to deposit dopant ions in shallow layers. In addition to this primary process, foreign materials are deposited as particles and surface films. The deposition of particles is a major cause of IC yield loss and becomes even more significant as device dimensions are decreased. Control of particle addition in a high-volume production environment requires procedures to limit beamline and endstation sources, control of particle transport, cleaning procedures and a well grounded preventative maintenance philosophy. Control of surface charge by optimization of the ion beam and electron shower conditions and measurement with a real-time charge sensor has been effective in improving the yield of NMOS and CMOS DRAMs. Control of surface voltages to a range between 0 and -20 V was correlated with good implant yield with PI9200 implanters for p + and n + source-drain implants.

Functional genomics of bio-energy plants and related patent activities.

PubMed

Jiang, Shu-Ye; Ramachandran, Srinivasan

2013-04-01

With dwindling fossil oil resources and increased economic growth of many developing countries due to globalization, energy driven from an alternative source such as bio-energy in a sustainable fashion is the need of the hour. However, production of energy from biological source is relatively expensive due to low starch and sugar contents of bioenergy plants leading to lower oil yield and reduced quality along with lower conversion efficiency of feedstock. In this context genetic improvement of bio-energy plants offers a viable solution. In this manuscript, we reviewed the current status of functional genomics studies and related patent activities in bio-energy plants. Currently, genomes of considerable bio-energy plants have been sequenced or are in progress and also large amount of expression sequence tags (EST) or cDNA sequences are available from them. These studies provide fundamental data for more reliable genome annotation and as a result, several genomes have been annotated in a genome-wide level. In addition to this effort, various mutagenesis tools have also been employed to develop mutant populations for characterization of genes that are involved in bioenergy quantitative traits. With the progress made on functional genomics of important bio-energy plants, more patents were filed with a significant number of them focusing on genes and DNA sequences which may involve in improvement of bio-energy traits including higher yield and quality of starch, sugar and oil. We also believe that these studies will lead to the generation of genetically altered plants with improved tolerance to various abiotic and biotic stresses.

Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production.

PubMed

Geipel, Katja; Song, Xue; Socher, Maria Lisa; Kümmritz, Sibylle; Püschel, Joachim; Bley, Thomas; Ludwig-Müller, Jutta; Steingroewer, Juliane

2014-03-01

Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l(-1) sucrose, 0.5 mg l(-1) of the auxin 1-naphthalene acetic acid, and 0.5 mg l(-1) of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230%) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.

A highly functional synthetic phage display library containing over 40 billion human antibody clones.

PubMed

Weber, Marcel; Bujak, Emil; Putelli, Alessia; Villa, Alessandra; Matasci, Mattia; Gualandi, Laura; Hemmerle, Teresa; Wulhfard, Sarah; Neri, Dario

2014-01-01

Several synthetic antibody phage display libraries have been created and used for the isolation of human monoclonal antibodies. The performance of antibody libraries, which is usually measured in terms of their ability to yield high-affinity binding specificities against target proteins of interest, depends both on technical aspects (such as library size and quality of cloning) and on design features (which influence the percentage of functional clones in the library and their ability to be used for practical applications). Here, we describe the design, construction and characterization of a combinatorial phage display library, comprising over 40 billion human antibody clones in single-chain fragment variable (scFv) format. The library was designed with the aim to obtain highly stable antibody clones, which can be affinity-purified on protein A supports, even when used in scFv format. The library was found to be highly functional, as >90% of randomly selected clones expressed the corresponding antibody. When selected against more than 15 antigens from various sources, the library always yielded specific and potent binders, at a higher frequency compared to previous antibody libraries. To demonstrate library performance in practical biomedical research projects, we isolated the human antibody G5, which reacts both against human and murine forms of the alternatively spliced BCD segment of tenascin-C, an extracellular matrix component frequently over-expressed in cancer and in chronic inflammation. The new library represents a useful source of binding specificities, both for academic research and for the development of antibody-based therapeutics.

Development of a Quasi-monoenergetic 6 MeV Gamma Facility at NASA Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Nowicki, Suzanne F.; Hunter, Stanley D.; Parsons, Ann M.

2012-01-01

The 6 MeV Gamma Facility has been developed at NASA Goddard Space Flight Center (GSFC) to allow in-house characterization and testing of a wide range of gamma-ray instruments such as pixelated CdZnTe detectors for planetary science and Compton and pair-production imaging telescopes for astrophysics. The 6 MeV Gamma Facility utilizes a circulating flow of water irradiated by 14 MeV neutrons to produce gamma rays via neutron capture on oxygen (O-16(n,p)N-16 yields O-16* yields O-16 + gamma). The facility provides a low cost, in-house source of 2.742, 6.129 and 7.117 MeV gamma rays, near the lower energy range of most accelerators and well above the 2.614 MeV line from the Th-228 decay chain, the highest energy gamma ray available from a natural radionuclide. The 7.13 s half-life of the N-16 decay allows the water to be irradiated on one side of a large granite block and pumped to the opposite side to decay. Separating the irradiation and decay regions allows for shielding material, the granite block, to be placed between them, thus reducing the low-energy gamma-ray continuum. Comparison between high purity germanium (HPGe) spectra from the facility and a manufactured source, Pu-238/C-13, shows that the low-energy continuum from the facility is reduced by a factor approx. 30 and the gamma-ray rate is approx.100 times higher at 6.129 MeV.

A Highly Functional Synthetic Phage Display Library Containing over 40 Billion Human Antibody Clones

PubMed Central

Weber, Marcel; Bujak, Emil; Putelli, Alessia; Villa, Alessandra; Matasci, Mattia; Gualandi, Laura; Hemmerle, Teresa; Wulhfard, Sarah; Neri, Dario

2014-01-01

Several synthetic antibody phage display libraries have been created and used for the isolation of human monoclonal antibodies. The performance of antibody libraries, which is usually measured in terms of their ability to yield high-affinity binding specificities against target proteins of interest, depends both on technical aspects (such as library size and quality of cloning) and on design features (which influence the percentage of functional clones in the library and their ability to be used for practical applications). Here, we describe the design, construction and characterization of a combinatorial phage display library, comprising over 40 billion human antibody clones in single-chain fragment variable (scFv) format. The library was designed with the aim to obtain highly stable antibody clones, which can be affinity-purified on protein A supports, even when used in scFv format. The library was found to be highly functional, as >90% of randomly selected clones expressed the corresponding antibody. When selected against more than 15 antigens from various sources, the library always yielded specific and potent binders, at a higher frequency compared to previous antibody libraries. To demonstrate library performance in practical biomedical research projects, we isolated the human antibody G5, which reacts both against human and murine forms of the alternatively spliced BCD segment of tenascin-C, an extracellular matrix component frequently over-expressed in cancer and in chronic inflammation. The new library represents a useful source of binding specificities, both for academic research and for the development of antibody-based therapeutics. PMID:24950200

Optimization of rhamnolipid production from Pseudomonas aeruginosa PBS towards application for microbial enhanced oil recovery.

PubMed

Sharma, Rajni; Singh, Jagdish; Verma, Neelam

2018-01-01

The present work reveals the potential of biosurfactant producing P. aeruginosa PBS for microbial enhanced oil recovery (MEOR). The biosurfactant production medium and culture conditions were optimized using response surface methodology. The optimization of media components and process parameters was consecutively executed in two sets of experimental runs designed by central composite rotatable design (CCRD). The maximum biosurfactant yield was attained with 2% fresh inoculum of P. aeruginosa PBS in minimal salt medium (pH 7), possessing 2.17% sodium citrate as C-source and 0.5% yeast extract as N-source, after 48 h upon incubation at 30 °C/150 rpm. Under optimum conditions, biosurfactant yield was increased more than threefold and turned out to be 2.65 g/L as compared to 0.82 g/L under previous conditions. The biosurfactant was characterized as a glycolipid comprising of four rhamnolipid homologs (RhaRhaC 10 C 10 , RhaRhaC 8 C 10 , RhaRhaC 12 C 10 /RhaRhaC 10 C 12 , RhaC 10 C 10 ) by thin layer chromatography, fourier transform infrared spectroscopy, nuclear magnetic resonance and mass spectrometry. The produced biosurfactant was highly efficient for oil recovery application showing extreme reduction in surface tension of medium (71.80 to 23.76 mN/m), immense hydrocarbons emulsification capacity (50-60%) and greater stability at wide range of temperature (4-100 °C) and pH (4-10) along with an excellent (56.18 ± 1.59%) additional oil recovery in sand-pack column lab test.

A 10{sup 9} neutrons/pulse transportable pulsed D-D neutron source based on flexible head plasma focus unit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niranjan, Ram, E-mail: niranjan@barc.gov.in; Rout, R. K.; Srivastava, R.

2016-03-15

A 17 kJ transportable plasma focus (PF) device with flexible transmission lines is developed and is characterized. Six custom made capacitors are used for the capacitor bank (CB). The common high voltage plate of the CB is fixed to a centrally triggered spark gap switch. The output of the switch is coupled to the PF head through forty-eight 5 m long RG213 cables. The CB has a quarter time-period of 4 μs and an estimated current of 506 kA is delivered to the PF device at 17 kJ (60 μF, 24 kV) energy. The average neutron yield measured using silvermore » activation detector in the radial direction is (7.1 ± 1.4) × 10{sup 8} neutrons/shot over 4π sr at 5 mbar optimum D{sub 2} pressure. The average neutron yield is more in the axial direction with an anisotropy factor of 1.33 ± 0.18. The average neutron energies estimated in the axial as well as in the radial directions are (2.90 ± 0.20) MeV and (2.58 ± 0.20) MeV, respectively. The flexibility of the PF head makes it useful for many applications where the source orientation and the location are important factors. The influence of electromagnetic interferences from the CB as well as from the spark gap on applications area can be avoided by putting a suitable barrier between the bank and the PF head.« less

Endopolysaccharides from Ganoderma resinaceum, Phlebia rufa, and Trametes versicolor affect differently the proliferation rate of HepG2 cells.

PubMed

Silva, Amélia M; Miranda, Andreia; Fernandes, Elisabete; Santos, Susana; Fraga, Irene; Santos, Dario L; Dias, Albino A; Bezerra, Rui M

2013-03-01

Fungi have been used for medicinal purposes for long time by Asian countries, being a putative source of powerful new phytopharmaceuticals such as polysaccharides. The aim of this study was to extract endopolysaccharides (IPS) from Ganoderma resinaceum, Phlebia rufa, and Trametes versicolor, grown under submerged culture, to compare crude IPS production, total carbohydrate, and protein yield, and to study the effect of these IPS on HepG2 cells proliferation rate. Total biomass produced by G. resinaceum, P. rufa, and T. versicolor was (in gram per liter) 3.32 ± 0.80, 5.42 ± 0.58, and 4.2 ± 1.29 and the IPS yield (as the biomass percent) was 9.9 ± 0.05, 29.0 ± 6.3, and 9.1 ± 3.1 %, respectively. Characterization of IPS has shown different proportion between total sugar and protein being, on average 6.04, 10.74, and 22.62, for G. resinaceum, T. versicolor, and P. rufa, respectively. The IPS effect, at 50, 100, and 200 μg mL(-1) on HepG2 cell growth and viability was negligible for G. resinaceum and P. rufa but, in the case of T. versicolor, 200 μg mL(-1) of IPS evoked 40 % reduction on cell growth. The results suggest that the intracellular polysaccharides from T. versicolor are a potential source for bioactive molecules with anti-proliferative properties.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano

Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has mademore » piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.« less

Utility of Capture-Recapture Methodology to Estimate Prevalence of Congenital Heart Defects Among Adolescents in 11 New York State Counties: 2008 to 2010.

PubMed

Akkaya-Hocagil, Tugba; Hsu, Wan-Hsiang; Sommerhalter, Kristin; McGarry, Claire; Van Zutphen, Alissa

2017-11-01

Congenital heart defects (CHDs) are the most common birth defects in the United States, and the population of individuals living with CHDs is growing. Though CHD prevalence in infancy has been well characterized, better prevalence estimates among children and adolescents in the United States are still needed. We used capture-recapture methods to estimate CHD prevalence among adolescents residing in 11 New York counties. The three data sources used for analysis included Statewide Planning and Research Cooperative System (SPARCS) hospital inpatient records, SPARCS outpatient records, and medical records provided by seven pediatric congenital cardiac clinics from 2008 to 2010. Bayesian log-linear models were fit using the R package Conting to account for dataset dependencies and heterogeneous catchability. A total of 2537 adolescent CHD cases were captured in our three data sources. Forty-four cases were identified in all data sources, 283 cases were identified in two of three data sources, and 2210 cases were identified in a single data source. The final model yielded an estimated total adolescent CHD population of 3845, indicating that 66% of the cases in the catchment area were identified in the case-identifying data sources. Based on 2010 Census estimates, we estimated adolescent CHD prevalence as 6.4 CHD cases per 1000 adolescents (95% confidence interval: 6.2-6.6). We used capture-recapture methodology with a population-based surveillance system in New York to estimate CHD prevalence among adolescents. Future research incorporating additional data sources may improve prevalence estimates in this population. Birth Defects Research 109:1423-1429, 2017.© 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

A comparative study on the analytical utility of atmospheric and low-pressure MALDI sources for the mass spectrometric characterization of peptides.

PubMed

Moskovets, Eugene; Misharin, Alexander; Laiko, Viktor; Doroshenko, Vladimir

2016-07-15

A comparative MS study was conducted on the analytical performance of two matrix-assisted laser desorption/ionization (MALDI) sources that operated at either low pressure (∼1Torr) or at atmospheric pressure. In both cases, the MALDI sources were attached to a linear ion trap mass spectrometer equipped with a two-stage ion funnel. The obtained results indicate that the limits of detection, in the analysis of identical peptide samples, were much lower with the source that was operated slightly below the 1-Torr pressure. In the low-pressure (LP) MALDI source, ion signals were observed at a laser fluence that was considerably lower than the one determining the appearance of ion signals in the atmospheric pressure (AP) MALDI source. When the near-threshold laser fluences were used to record MALDI MS spectra at 1-Torr and 750-Torr pressures, the level of chemical noise at the 1-Torr pressure was much lower compared to that at AP. The dependency of the analyte ion signals on the accelerating field which dragged the ions from the MALDI plate to the MS analyzer are presented for the LP and AP MALDI sources. The study indicates that the laser fluence, background gas pressure, and field accelerating the ions away from a MALDI plate were the main parameters which determined the ion yield, signal-to-noise (S/N) ratios, the fragmentation of the analyte ions, and adduct formation in the LP and AP MALDI MS methods. The presented results can be helpful for a deeper insight into the mechanisms responsible for the ion formation in MALDI. Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical investigation of three plutonium–beryllium neutron sources

DOE PAGES

Byerly, Benjamin; Kuhn, Kevin; Colletti, Lisa; ...

2017-02-03

Thorough physical and chemical characterization of plutonium–beryllium (PuBe) neutron sources is an important capability with applications ranging from material accountancy to nuclear forensics. Furthermore, characterization of PuBe sources is not trivial owing to range of existing source designs and the need for adequate infrastructure to deal with radiation and protect the analyst. Our study demonstrates a method for characterization of three PuBe sources that includes physical inspection and imaging followed by controlled disassembly and destructive analysis.

Chemical investigation of three plutonium–beryllium neutron sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byerly, Benjamin; Kuhn, Kevin; Colletti, Lisa

Thorough physical and chemical characterization of plutonium–beryllium (PuBe) neutron sources is an important capability with applications ranging from material accountancy to nuclear forensics. Furthermore, characterization of PuBe sources is not trivial owing to range of existing source designs and the need for adequate infrastructure to deal with radiation and protect the analyst. Our study demonstrates a method for characterization of three PuBe sources that includes physical inspection and imaging followed by controlled disassembly and destructive analysis.

Pyrolysis-high resolution gas chromatography and pyrolysis gas chromatography-mass spectrometry of kerogens and kerogen precursors

NASA Technical Reports Server (NTRS)

Van De Meent, D.; Brown, S. C.; Philp, R. P.; Simoneit, B. R. T.

1980-01-01

A series of kerogens and kerogen precursors isolated from DSDP samples, oil shales and recent algal mats have been examined by Curie point pyrolysis-high resolution gas chromatography and gas chromatography-mass spectrometry. This study has shown that the three main types of kerogens (marine, terrestrial and mixtures of both) can be characterized using these techniques. The marine (algal) kerogens yield principally aliphatic products and the terrestrial kerogens yield more aromatic and phenolic products with some n-alkanes and n-alkenes. The yields of n-alkanes and n-alkenes increase and phenols decrease with increasing geologic age, however, pyrolysis-GC cannot be used to characterize the influence of short term diagenesis on the kerogen structure.

Measurement of fluorophore concentrations and fluorescence quantum yield in tissue-simulating phantoms using three diffusion models of steady-state spatially resolved fluorescence.

PubMed

Diamond, Kevin R; Farrell, Thomas J; Patterson, Michael S

2003-12-21

Steady-state diffusion theory models of fluorescence in tissue have been investigated for recovering fluorophore concentrations and fluorescence quantum yield. Spatially resolved fluorescence, excitation and emission reflectance Carlo simulations, and measured using a multi-fibre probe on tissue-simulating phantoms containing either aluminium phthalocyanine tetrasulfonate (AlPcS4), Photofrin meso-tetra-(4-sulfonatophenyl)-porphine dihydrochloride The accuracy of the fluorophore concentration and fluorescence quantum yield recovered by three different models of spatially resolved fluorescence were compared. The models were based on: (a) weighted difference of the excitation and emission reflectance, (b) fluorescence due to a point excitation source or (c) fluorescence due to a pencil beam excitation source. When literature values for the fluorescence quantum yield were used for each of the fluorophores, the fluorophore absorption coefficient (and hence concentration) at the excitation wavelength (mu(a,x,f)) was recovered with a root-mean-square accuracy of 11.4% using the point source model of fluorescence and 8.0% using the more complicated pencil beam excitation model. The accuracy was calculated over a broad range of optical properties and fluorophore concentrations. The weighted difference of reflectance model performed poorly, with a root-mean-square error in concentration of about 50%. Monte Carlo simulations suggest that there are some situations where the weighted difference of reflectance is as accurate as the other two models, although this was not confirmed experimentally. Estimates of the fluorescence quantum yield in multiple scattering media were also made by determining mu(a,x,f) independently from the fitted absorption spectrum and applying the various diffusion theory models. The fluorescence quantum yields for AlPcS4 and TPPS4 were calculated to be 0.59 +/- 0.03 and 0.121 +/- 0.001 respectively using the point source model, and 0.63 +/- 0.03 and 0.129 +/- 0.002 using the pencil beam excitation model. These results are consistent with published values.

Characterization of atomic oxygen from an ECR plasma source

NASA Astrophysics Data System (ADS)

Naddaf, M.; Bhoraskar, V. N.; Mandale, A. B.; Sainkar, S. R.; Bhoraskar, S. V.

2002-11-01

A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from ~1×1020 to ~10×1020 atom m-3 as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe.

The New York Brain Bank of Columbia University: practical highlights of 35 years of experience.

PubMed

Ramirez, Etty Paola Cortes; Keller, Christian Ernst; Vonsattel, Jean Paul

2018-01-01

The New York Brain Bank processes brains and organs of clinically well-characterized patients with age-related neurodegenerative diseases, and for comparison, from individuals without neurologic or psychiatric impairments. The donors, either patients or individuals, were evaluated at healthcare facilities of the Columbia University of New York. Each source brain yields four categories of samples: fresh frozen blocks and crushed parenchyma, and formalin-fixed wet blocks and histology sections. A source brain is thoroughly evaluated to determine qualitatively and quantitatively any changes it might harbor using conventional neuropathologic techniques. The clinical and pathologic diagnoses are integrated to determine the distributive diagnosis assigned to the samples obtained from a source brain. The gradual standardization of the protocol was developed in 1981 in response to the evolving requirements of basic investigations on neurodegeneration. The methods assimilate long-standing experience from multiple centers. The resulting and current protocol includes a constant central core applied to all brains with conditional flexibility around it. The New York Brain Bank is an integral part of the department of pathology, where the expertise, teaching duties, and hardware are shared. Since details of the protocols are available online, this chapter focuses on practical issues in professionalizing brain banking. Copyright © 2018 Elsevier B.V. All rights reserved.

Euphorbia tirucalli L.-comprehensive characterization of a drought tolerant plant with a potential as biofuel source.

PubMed

Hastilestari, Bernadetta Rina; Mudersbach, Marina; Tomala, Filip; Vogt, Hartmut; Biskupek-Korell, Bettina; Van Damme, Patrick; Guretzki, Sebastian; Papenbrock, Jutta

2013-01-01

Of late, decrease in mineral oil supplies has stimulated research on use of biomass as an alternative energy source. Climate change has brought problems such as increased drought and erratic rains. This, together with a rise in land degeneration problems with concomitant loss in soil fertility has inspired the scientific world to look for alternative bio-energy species. Euphorbia tirucalli L., a tree with C3/CAM metabolism in leaves/stem, can be cultivated on marginal, arid land and could be a good alternative source of biofuel. We analyzed a broad variety of E. tirucalli plants collected from different countries for their genetic diversity using AFLP. Physiological responses to induced drought stress were determined in a number of genotypes by monitoring growth parameters and influence on photosynthesis. For future breeding of economically interesting genotypes, rubber content and biogas production were quantified. Cluster analysis shows that the studied genotypes are divided into two groups, African and mostly non-African genotypes. Different genotypes respond significantly different to various levels of water. Malate measurement indicates that there is induction of CAM in leaves following drought stress. Rubber content varies strongly between genotypes. An investigation of the biogas production capacities of six E. tirucalli genotypes reveals biogas yields higher than from rapeseed but lower than maize silage.

Experimental Investigation of Unsteady Thrust Augmentation Using a Speaker-Driven Jet

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.; Wernet, Mark P.; John, Wentworth T.

2007-01-01

An experimental investigation is described in which a simple speaker-driven jet was used as a pulsed thrust source (driver) for an ejector configuration. The objectives of the investigation were twofold. The first was to expand the experimental body of evidence showing that an unsteady thrust source, combined with a properly sized ejector generally yields higher thrust augmentation values than a similarly sized, steady driver of equivalent thrust. The second objective was to identify characteristics of the unsteady driver that may be useful for sizing ejectors, and for predicting the thrust augmentation levels that may be achieved. The speaker-driven jet provided a convenient source for the investigation because it is entirely unsteady (i.e., it has no mean velocity component) and because relevant parameters such as frequency, time-averaged thrust, and diameter are easily variable. The experimental setup will be described, as will the two main measurements techniques employed. These are thrust and digital particle imaging velocimetry of the driver. It will be shown that thrust augmentation values as high as 1.8 were obtained, that the diameter of the best ejector scaled with the dimensions of the emitted vortex, and that the so-called formation time serves as a useful dimensionless parameter by which to characterize the jet and predict performance.

Real-Time Microscopic Monitoring of Flow, Voltage and Current in the Proton Exchange Membrane Water Electrolyzer.

PubMed

Lee, Chi-Yuan; Li, Shih-Chun; Chen, Chia-Hung; Huang, Yen-Ting; Wang, Yu-Syuan

2018-03-15

Looking for alternative energy sources has been an inevitable trend since the oil crisis, and close attentioned has been paid to hydrogen energy. The proton exchange membrane (PEM) water electrolyzer is characterized by high energy efficiency, high yield, simple system and low operating temperature. The electrolyzer generates hydrogen from water free of any carbon sources (provided the electrons come from renewable sources such as solar and wind), so it is very clean and completely satisfies the environmental requirement. However, in long-term operation of the PEM water electrolyzer, the membrane material durability, catalyst corrosion and nonuniformity of local flow, voltage and current in the electrolyzer can influence the overall performance. It is difficult to measure the internal physical parameters of the PEM water electrolyzer, and the physical parameters are interrelated. Therefore, this study uses micro-electro-mechanical systems (MEMS) technology to develop a flexible integrated microsensor; internal multiple physical information is extracted to determine the optimal working parameters for the PEM water electrolyzer. The real operational data of local flow, voltage and current in the PEM water electrolyzer are measured simultaneously by the flexible integrated microsensor, so as to enhance the performance of the PEM water electrolyzer and to prolong the service life.

Real-Time Microscopic Monitoring of Flow, Voltage and Current in the Proton Exchange Membrane Water Electrolyzer

PubMed Central

Lee, Chi-Yuan; Li, Shih-Chun; Chen, Chia-Hung; Huang, Yen-Ting; Wang, Yu-Syuan

2018-01-01

Looking for alternative energy sources has been an inevitable trend since the oil crisis, and close attentioned has been paid to hydrogen energy. The proton exchange membrane (PEM) water electrolyzer is characterized by high energy efficiency, high yield, simple system and low operating temperature. The electrolyzer generates hydrogen from water free of any carbon sources (provided the electrons come from renewable sources such as solar and wind), so it is very clean and completely satisfies the environmental requirement. However, in long-term operation of the PEM water electrolyzer, the membrane material durability, catalyst corrosion and nonuniformity of local flow, voltage and current in the electrolyzer can influence the overall performance. It is difficult to measure the internal physical parameters of the PEM water electrolyzer, and the physical parameters are interrelated. Therefore, this study uses micro-electro-mechanical systems (MEMS) technology to develop a flexible integrated microsensor; internal multiple physical information is extracted to determine the optimal working parameters for the PEM water electrolyzer. The real operational data of local flow, voltage and current in the PEM water electrolyzer are measured simultaneously by the flexible integrated microsensor, so as to enhance the performance of the PEM water electrolyzer and to prolong the service life. PMID:29543734

Sorbitol Can Fuel Mouse Sperm Motility and Protein Tyrosine Phosphorylation via Sorbitol Dehydrogenase1

PubMed Central

Cao, Wenlei; Aghajanian, Haig K.; Haig-Ladewig, Lisa A.; Gerton, George L.

2008-01-01

Energy sources that can be metabolized to yield ATP are essential for normal sperm functions such as motility. Two major monosaccharides, sorbitol and fructose, are present in semen. Furthermore, sorbitol dehydrogenase (SORD) can convert sorbitol to fructose, which can then be metabolized via the glycolytic pathway in sperm to make ATP. Here we characterize Sord mRNA and SORD expression during mouse spermatogenesis and examine the ability of sorbitol to support epididymal sperm motility and tyrosine phosphorylation. Sord mRNA levels increased during the course of spermatogenic differentiation. SORD protein, however, was first detected at the condensing spermatid stage. By indirect immunofluorescence, SORD was present along the length of the flagella of caudal epididymal sperm. Furthermore, immunoelectron microscopy showed that SORD was associated with mitochondria and the plasma membranes of sperm. Sperm incubated with sorbitol maintained motility, indicating that sorbitol was utilized as an energy source. Sorbitol, as well as glucose and fructose, were not essential to induce hyperactive motility. Protein tyrosine phosphorylation increased in a similar manner when sorbitol was substituted for glucose in the incubation medium used for sperm capacitation. These results indicate that sorbitol can serve as an alternative energy source for sperm motility and protein tyrosine phosphorylation. PMID:18799757

Isolation and characterization of (15Z)-lycopene thermally generated from a natural source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takehara, Munenori, E-mail: takehara@mat.usp.ac.jp; Kuwa, Takahiro; Inoue, Yoshinori

(15Z)-Lycopene was prepared by thermal isomerization of (all-E)-lycopene derived from tomatoes, and isolated by using a series of chromatographies. The fine red crystalline powder of (15Z)-lycopene was obtained from 556 mg of (all-E)-lycopene with a yield of 0.6 mg (purity: reversed-phase HPLC, 97.2%; normal-phase HPLC, ≥99.9%), and {sup 1}H and {sup 13}C NMR spectra of the isomer were fully assigned. More refined computational analyses that considered differences in the energy levels of the conformers involved in isomerization have also determined the stabilities of (15Z)-lycopene and other geometric isomers, along with the activation energies during isomerization from the all-E form. The fine controlmore » of conditions for HPLC separation and an advanced theoretical insight into geometric isomerization have led to the discovery of the 15Z-isomer generated from a natural source. - Highlights: • (15Z)-lycopene, isomerized from the all-E form of a natural source, was purified. • The obtained (15Z)-lycopene was structurally identified by an NMR analysis. • A modified theoretical study accounted for the generation of the 15Z-isomer. • This study demonstrated the occurrence of the isomer from a natural origin.« less

How Big Was It? Getting at Yield

NASA Astrophysics Data System (ADS)

Pasyanos, M.; Walter, W. R.; Ford, S. R.

2013-12-01

One of the most coveted pieces of information in the wake of a nuclear test is the explosive yield. Determining the yield from remote observations, however, is not necessarily a trivial thing. For instance, recorded observations of seismic amplitudes, used to estimate the yield, are significantly modified by the intervening media, which varies widely, and needs to be properly accounted for. Even after correcting for propagation effects such as geometrical spreading, attenuation, and station site terms, getting from the resulting source term to a yield depends on the specifics of the explosion source model, including material properties, and depth. Some formulas are based on assumptions of the explosion having a standard depth-of-burial and observed amplitudes can vary if the actual test is either significantly overburied or underburied. We will consider the complications and challenges of making these determinations using a number of standard, more traditional methods and a more recent method that we have developed using regional waveform envelopes. We will do this comparison for recent declared nuclear tests from the DPRK. We will also compare the methods using older explosions at the Nevada Test Site with announced yields, material and depths, so that actual performance can be measured. In all cases, we also strive to quantify realistic uncertainties on the yield estimation.

Cf-252 Characterization Documents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, Alexander

2014-03-14

Six documents were written by Vance and Associates under contract to the Off-Site Source Recovery Project of Los Alamos National Laboratory. These Six documents provided the basis for characterization of Californium-252 sealed sources and for the packaging and manifesting of this material for disposal at the Waste Isolation Pilot Project. The Six documents are: 1. VA-OSR-10, Development of radionuclide distributions for Cf-252 sealed sources. 2. VA-OSR-11, Uncertainty analysis for Cf-252 sealed sources. 3. VA-OSR-12, To determine the radionuclides in the waste drums containing Cf-252 sealed source waste that are required to be reported under the requirements of the WIPP WACmore » and the TRAMPAC. 4. VA-OSR-13, Development of the spreadsheet for the radiological calculations for the characterization of Cf-252 sources. 5. VA-OSR-14, Relative importance of neutron-induced fission in Cf-252 sources. 6. VA-OSR-15, Determine upper bound of decay product inventories from a drum of Cf-252 sources. These six documents provide the technical basis for the characterization of Cf-252 sources and will be part of the AK documentation required for submittal to the Central Characterization Project (CCP) of WIPP.« less

Projecting Future Land Use Changes in West Africa Driven by Climate and Socioeconomic Factors: Uncertainties and Implications for Adaptation

NASA Astrophysics Data System (ADS)

Wang, G.; Ahmed, K. F.; You, L.

2015-12-01

Land use changes constitute an important regional climate change forcing in West Africa, a region of strong land-atmosphere coupling. At the same time, climate change can be an important driver for land use, although its importance relative to the impact of socio-economic factors may vary significant from region to region. This study compares the contributions of climate change and socioeconomic development to potential future changes of agricultural land use in West Africa and examines various sources of uncertainty using a land use projection model (LandPro) that accounts for the impact of socioeconomic drivers on the demand side and the impact of climate-induced crop yield changes on the supply side. Future crop yield changes were simulated by a process-based crop model driven with future climate projections from a regional climate model, and future changes of food demand is projected using a model for policy analysis of agricultural commodities and trade. The impact of human decision-making on land use was explicitly considered through multiple "what-if" scenarios to examine the range of uncertainties in projecting future land use. Without agricultural intensification, the climate-induced decrease of crop yield together with increase of food demand are found to cause a significant increase in agricultural land use at the expense of forest and grassland by the mid-century, and the resulting land use land cover changes are found to feed back to the regional climate in a way that exacerbates the negative impact of climate on crop yield. Analysis of results from multiple decision-making scenarios suggests that human adaptation characterized by science-informed decision making to minimize land use could be very effective in many parts of the region.

Purification of human erythropoietin by affinity chromatography using cyclic peptide ligands.

PubMed

Kish, William S; Roach, Matthew K; Sachi, Hiroyuki; Naik, Amith D; Menegatti, Stefano; Carbonell, Ruben G

2018-05-15

Prior work described the identification and characterization of erythropoietin-binding cyclic peptides SLFFLH, VVFFVH, FSLLHH and FSLLSH (all of the form cyclo[(N α -Ac)Dap(A)-X 1 -X 6 -AE], wherein X 1 -X 6 is the listed sequences). In this work, the peptide ligands were synthesized on Toyopearl chromatographic resins and utilized for purifying recombinant human erythropoietin (rHuEPO) from complex sources. Elution buffer pH and composition were optimized to maximize the recovery of standard rHuEPO from the peptide resins. The peptide-based adsorbents were employed for separating rHuEPO from a mixture of albumin, myoglobin, and IgG to examine their selectivity. When using FSLLHH, the inclusion of low amounts of surfactants in the wash and elution buffers facilitated the recovery of rHuEPO with high yield and purity. Specifically, FSLLSH and VVFFVH afforded the most efficient separation of rHuEPO, with yield and purity of 85% and 95-97%, respectively. The affinity resins were also utilized to purify rHuEPO from spiked CHO cell culture fluid. In particular, FSLLSH provided the most successful separation from CHO, with yield and purity above 90%, and 1.0 log 10 reduction of host cell proteins. The influence of conductivity and pH in the CHO-rHuEPO load was investigated. Finally, FSLLSH-based resins were used to purify rHuEPO spiked into a Pichia pastoris cell culture fluid, resulting in product yield and purity of 96% and 84%, respectively, and 1.3 log 10 reduction of host DNA. These results compare well with values obtained using wheat germ agglutinin agarose and clearly indicate the potential of the cyclic peptide resins as a viable tool for rHuEPO purification. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization of Stormflows and Wastewater Treatment-Plant Effluent Discharges on Water Quality, Suspended Sediment, and Stream Morphology for Fountain and Monument Creek Watersheds, Colorado, 1981-2006

USGS Publications Warehouse

Mau, David P.; Stogner, Sr., Robert W.; Edelmann, Patrick

2007-01-01

In 1998, the U.S. Geological Survey, in cooperation with Colorado Springs City Engineering, began a study of the Fountain and Monument Creek watersheds to characterize water quality and suspended-sediment conditions in the watershed for different flow regimes, with an emphasis on characterizing water quality during storm runoff. Water-quality and suspended-sediment samples were collected in the Fountain and Monument Creek watersheds from 1981 through 2006 to evaluate the effects of stormflows and wastewater-treatment effluent on Fountain and Monument Creeks in the Colorado Springs, Colorado, area. Water-quality data were collected at 11 sites between 1981 and 2001, and 14 tributary sites were added in 2003 to increase spatial coverage and characterize water quality throughout the watersheds. Suspended-sediment samples collected daily at 7 sites from 1998 through 2001, 6 sites daily from 2003 through 2006, and 13 tributary sites intermittently from 2003 through 2006 were used to evaluate the effects of stormflow on suspended-sediment concentrations, discharges, and yields. Data were separated into three flow regimes: base flow, normal flow, and stormflow. Stormflow concentrations from 1998 through 2006 were compared to Colorado acute instream standards and, with the exception of a few isolated cases, did not exceed water-quality standards for inorganic constituents that were analyzed. However, stormflow concentrations of both fecal coliform and Escherichia coli (E. coli) frequently exceeded water-quality standards during 1998 through 2006 on main-stem and tributary sites by more than an order of magnitude. There were two sites on Cottonwood Creek, a tributary to Monument Creek, with elevated concentrations of dissolved nitrite plus nitrate: site 07103985 (TbCr), a tributary to Cottonwood Creek and site 07103990 (lower_CoCr), downstream from site 07103985 (TbCr), and near the confluence with Monument Creek. During base-flow and normal-flow conditions, the median concentrations of dissolved nitrite plus nitrate ranged from 5.1 to 6.1 mg/L and were 4 to 7 times larger than concentrations at the nearest upstream site on Monument Creek, site 07103970 (MoCr_Woodmen). The source of these larger dissolved nitrite plus nitrate concentrations has not been identified, but the fact that all measurements had elevated dissolved nitrite plus nitrate concentrations indicates a relatively constant source. Most stormflow concentrations of dissolved trace elements were smaller than concentrations from base-flow or normal-flow samples. However, median concentrations of total arsenic, copper, lead, manganese, nickel, and zinc generally were much larger during periods of stormflow than during base flow or normal flow. Concentrations of dissolved and total copper, total manganese, total nickel, dissolved and total selenium, and dissolved and total zinc ranged from 3 to 27 times larger at site 07103707 (FoCr_8th) than site 07103700 (FoCr_Manitou) during base flow, indicating a large source of trace elements between these two sites. Both of these sites are located on Fountain Creek, upstream from the confluence with Monument Creek. The likely source area is Gold Hill Mesa, a former tailings pile for a gold refinery located just upstream from the confluence with Monument Creek, and upstream from site 07103707 (FoCr_8th). Farther downstream in Fountain Creek, stormflow samples for total copper, manganese, lead, nickel, and zinc were larger at the downstream site near the city of Security, site 07105800 (FoCr_Security), than at the upstream site near Janitell Road, site 07105530 (FoCr_Janitell), compared with other main-stem sites and indicated a relatively large source of these metals between the two sites. Nitrogen, phosphorus, and trace-element loads substantially increased during stormflow. Suspended-sediment concentrations, discharges, and yields associated with stormflow were significantly larger than those associated with normal flow. The Apr

Convenient determination of luminescence quantum yield using a combined electronic absorption and emission spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prakash, John; Mishra, Ashok Kumar

2016-01-15

It is possible to measure luminescence quantum yield in a facile way, by designing an optical spectrometer capable of obtaining electronic absorption as well as luminescence spectra, with a setup that uses the same light source and detector for both the spectral measurements. Employment of a single light source and single detector enables use of the same correction factor profile for spectral corrections. A suitable instrumental scaling factor is used for adjusting spectral losses.

Rapid Characterization of Microalgae and Microalgae Mixtures Using Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS)

PubMed Central

Barbano, Duane; Diaz, Regina; Zhang, Lin; Sandrin, Todd; Gerken, Henri; Dempster, Thomas

2015-01-01

Current molecular methods to characterize microalgae are time-intensive and expensive. Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) may represent a rapid and economical alternative approach. The objectives of this study were to determine whether MALDI-TOF MS can be used to: 1) differentiate microalgae at the species and strain levels and 2) characterize simple microalgal mixtures. A common protein extraction sample preparation method was used to facilitate rapid mass spectrometry-based analysis of 31 microalgae. Each yielded spectra containing between 6 and 56 peaks in the m/z 2,000 to 20,000 range. The taxonomic resolution of this approach appeared higher than that of 18S rDNA sequence analysis. For example, two strains of Scenedesmus acutus differed only by two 18S rDNA nucleotides, but yielded distinct MALDI-TOF mass spectra. Mixtures of two and three microalgae yielded relatively complex spectra that contained peaks associated with members of each mixture. Interestingly, though, mixture-specific peaks were observed at m/z 11,048 and 11,230. Our results suggest that MALDI-TOF MS affords rapid characterization of individual microalgae and simple microalgal mixtures. PMID:26271045

A Survey of Xenon Ion Sputter Yield Data and Fits Relevant to Electric Propulsion Spacecraft Integration

NASA Technical Reports Server (NTRS)

Yim, John T.

2017-01-01

A survey of low energy xenon ion impact sputter yields was conducted to provide a more coherent baseline set of sputter yield data and accompanying fits for electric propulsion integration. Data uncertainties are discussed and different available curve fit formulas are assessed for their general suitability. A Bayesian parameter fitting approach is used with a Markov chain Monte Carlo method to provide estimates for the fitting parameters while characterizing the uncertainties for the resulting yield curves.

The influence of different cultivation conditions on the metabolome of Fusarium oxysporum.

PubMed

Panagiotou, Gianni; Christakopoulos, Paul; Olsson, Lisbeth

2005-08-22

The two most widespread pentose sugars found in the biosphere are d-xylose and l-arabinose. They are both potential substrates for ethanol production. The purpose of this study was to better understand the redox constraints imposed to Fusarium oxysporum during utilization of pentoses. In order to increase ethanol yield and decrease by-product formation, nitrate was used as nitrogen source. The use of NADH, the cofactor in denitrification process when using nitrate as a nitrogen source, improved the ethanol yield on xylose to 0.89 mol mol(-1) compared to the ethanol yield achieved using ammonium as nitrogen source 0.44 mol mol(-1). The improved ethanol yield was followed by a 28% decrease in yield of the by-product xylitol. In order to investigate the metabolic pathway of arabinose and the metabolic limitations for the efficient ethanol production from this sugar, the extracellular and intracellular metabolite profiles were determined under aerobic and anaerobic cultivation conditions. The results of this study clearly show difficulties in channelling of glucose-1-P (G1P) to pentose phosphate pathway (PPP) and reduced NADPH regeneration, suggesting that NADPH becomes a limiting factor for arabinose conversion, resulting in excessive acetate production. Variations of the fungus intracellular amino and non-amino acid pool, under different culture conditions, were evaluated using principal component analysis (PCA). PCA projection of the metabolome data collected from F. oxysporum subjected to environmental perturbations succeeded to visualize different physiological states and the conclusions of this study were that the metabolite profile is unique according to: (1) the carbon source and (2) the oxygen supply, and to a lesser extent to the cultivation phase.

Towards a more comprehensive usage of reflection seismic in near-surface characterization

NASA Astrophysics Data System (ADS)

Blouin, M.; Gloaguen, E.; Bellefleur, G.; Pugin, A.

2014-12-01

For more than a decade, research groups such as the Geological Survey of Canada built the interest for near-surface reflection seismic by proposing small vibrating sources and three components (3C) landstreamers. Developments in the instrumentation combined with extensive use of shear-wave profiling to image stratigraphy of unconsolidated environments at high resolution got this geophysical method more versatile, more accurate, increased cost effectiveness and allowed to cover greater distance per day. With those major upgrades as a starting point and in a context of regional aquifer characterization in St-Lawrence Lowlands in the province of Quebec, Canada, the present study propose a workflow to further enhance reflection seismic usage for near-surface characterization. First, as high resolution near surface surveys require small shot intervals and multiple channels on three axis, a lot of the acquisition information is received under a raw form yielding to unproductive quality control (QC). Hence, a tool was developed to process data "on the fly" and allow adequate real-time QC and on-site decision making. The algorithm was constructed in a Python environment and is accessible through a graphical user interface where the user is prompted for geometry parameters inputs and desired processing flow steps. Second, at the scale of seismic wavelengths, fine grain and poorly consolidated sediments such as marine clay of the St-Lawrence Lowlands can be viewed as a homogeneous medium presenting anisotropy. This section of the study showed that such geological settings yield to significant seismic velocity variations with angle of propagation that should not be ignore for normal move-out correction, migration or time to depth conversion. Finally, accurate delineation of stratigraphic horizons is an important task of any environmental or hydrogeological characterization study. A methodology was put forward to help integrate geophysical measurements with geological knowledge in the construction of stratigraphic maps. The approach accounts for reliability and resolution of the measurements, extracts statistical information from reflection seismic interpretations and can further serve as a tool for reinterpretation of the seismic data.

SOYBEAN.APHID.SD.2017

USDA-ARS?s Scientific Manuscript database

Infestations by soybean aphid (SA) can reduce soybean yield. Thus, SA-resistant soybean may be useful in reducing infestations and limiting yield loss. Expression of resistance was characterized among 746 soybean accessions in 56 growth chamber tests at the North Central Agricultural Research Labo...

Simulating long-term landcover change and water yield dynamics in a forested, snow-dominated Rocky Mountain watershed

Treesearch

R. S. Ahl; S. W. Woods

2006-01-01

Changes in the extent, composition, and configuration of forest cover over time due to succession or disturbance processes can result in measurable changes in streamflow and water yield. Removal of forest cover generally increases streamflow due to reduced canopy interception and evapotranspiration. In watersheds where snow is the dominant source of water, yield...

Land Use for Edible Protein of Animal Origin—A Review

PubMed Central

Flachowsky, Gerhard; Meyer, Ulrich; Südekum, Karl-Heinz

2017-01-01

Simple Summary The growing world population has led to a higher demand for more and better quality food. In the future, there will be increasingly strong competition for arable land and other non-renewable resources. Proteins of animal origin are very valuable sources of essential nutrients, but their production consumes resources and causes emissions. The aim of this study was to calculate exemplarily the land use for production of edible animal protein from different animal species and categories in consideration of important influencing factors. Large differences were found with the highest amounts per kilogram of body weight produced by broiler chickens and the lowest yields in edible protein and the highest land need observed for beef cattle. Abstract The present period is characterized by a growing world population and a higher demand for more and better quality food, as well as other products for an improved standard of living. In the future, there will be increasingly strong competition for arable land and non-renewable resources such as fossil carbon-sources, water, and some minerals, as well as between food, feed, fuel, fiber, flowers, and fun (6 F’s). Proteins of animal origin like milk, meat, fish, eggs and, probably, insects are very valuable sources of essential amino acids, minerals and vitamins, but their production consumes some non-renewable resources including arable land and causes considerable emissions. Therefore, this study´s objective was to calculate some examples of the land use (arable land and grassland) for production of edible animal protein taking into consideration important animal species/categories, levels of plant and animal yields, the latter estimated with and without co-products from agriculture, and the food/biofuel industry in animal feeding. There are large differences between animal species/categories and their potential to produce edible protein depending on many influencing variables. The highest amounts per kilogram body weight are produced by growing broiler chicken followed by laying hens and dairy cows; the lowest yields in edible protein and the highest land need were observed for beef cattle. This review clearly indicates that the production of food of animal origin is a very complex process, and selective considerations, i.e., focusing on single factors, do not provide an assessment that reflects the complexity of the subject. PMID:28335483

Initial Results from the Survey of Organizational Research Climates (SOuRCe) in the U.S. Department of Veterans Affairs Healthcare System

PubMed Central

Martinson, Brian C.; Nelson, David; Hagel-Campbell, Emily; Mohr, David; Charns, Martin P.; Bangerter, Ann; Thrush, Carol R.; Ghilardi, Joseph R.; Bloomfield, Hanna; Owen, Richard; Wells, James A.

2016-01-01

Background In service to its core mission of improving the health and well-being of veterans, Veterans Affairs (VA) leadership is committed to supporting research best practices in the VA. Recognizing that the behavior of researchers is influenced by the organizational climates in which they work, efforts to assess the integrity of research climates and share such information with research leadership in VA may be one way to support research best practices. The Survey of Organizational Research Climate (SOuRCe) is the first validated survey instrument specifically designed to assess the organizational climate of research integrity in academic research organizations. The current study reports on an initiative to use the SOuRCe in VA facilities to characterize the organizational research climates and pilot test the effectiveness of using SOuRCe data as a reporting and feedback intervention tool. Methods We administered the SOuRCe using a cross-sectional, online survey, with mailed follow-up to non-responders, of research-engaged employees in the research services of a random selection of 42 VA facilities (e.g., Hospitals/Stations) believed to employ 20 or more research staff. We attained a 51% participation rate, yielding more than 5,200 usable surveys. Results We found a general consistency in organizational research climates across a variety of sub-groups in this random sample of research services in the VA. We also observed similar SOuRCe scale score means, relative rankings of these scales and their internal reliability, in this VA-based sample as we have previously documented in more traditional academic research settings. Results also showed more substantial variability in research climate scores within than between facilities in the VA research service as reflected in meaningful subgroup differences. These findings suggest that the SOuRCe is suitable as an instrument for assessing the research integrity climates in VA and that the tool has similar patterns of results that have been observed in more traditional academic research settings. Conclusions The local and specific nature of organizational climates in VA research services, as reflected in variability across sub-groups within individual facilities, has important policy implications. Global, “one-size-fits-all” type initiatives are not likely to yield as much benefit as efforts targeted to specific organizational units or sub-groups and tailored to the specific strengths and weaknesses documented in those locations. PMID:26967736

A framework to spatially cluster air pollution monitoring sites in US based on the PM2.5 composition

PubMed Central

Austin, Elena; Coull, Brent A.; Zanobetti, Antonella; Koutrakis, Petros

2013-01-01

Background Heterogeneity in the response to PM2.5 is hypothesized to be related to differences in particle composition across monitoring sites which reflect differences in source types as well as climatic and topographic conditions impacting different geographic locations. Identifying spatial patterns in particle composition is a multivariate problem that requires novel methodologies. Objectives Use cluster analysis methods to identify spatial patterns in PM2.5 composition. Verify that the resulting clusters are distinct and informative. Methods 109 monitoring sites with 75% reported speciation data during the period 2003–2008 were selected. These sites were categorized based on their average PM2.5 composition over the study period using k-means cluster analysis. The obtained clusters were validated and characterized based on their physico-chemical characteristics, geographic locations, emissions profiles, population density and proximity to major emission sources. Results Overall 31 clusters were identified. These include 21 clusters with 2 or more sites which were further grouped into 4 main types using hierarchical clustering. The resulting groupings are chemically meaningful and represent broad differences in emissions. The remaining clusters, encompassing single sites, were characterized based on their particle composition and geographic location. Conclusions The framework presented here provides a novel tool which can be used to identify and further classify sites based on their PM2.5 composition. The solution presented is fairly robust and yielded groupings that were meaningful in the context of air-pollution research. PMID:23850585

Fabrication and characterization of a pd nanowire-based glucose biofuel cell

NASA Astrophysics Data System (ADS)

Amoah, Kweku Obeng

The use of glucose as a source in biofuel cell technology has received a lot of attention in part due to the potential applications of such systems. In addition to the being a clean energy alternative, it provides a pathway for implantable microelectronic devices, such as pacemakers, to be powered by interstitial fluid and eliminate the need for batteries. Furthermore, using interstitial fluid as fuel sources will drastically reduce necessary invasive surgeries to replace batteries. Additionally, cost to such patients will be reduced while quality of life enhanced. The research presents a unique platform for harvesting energy from glucose. Using semiconductor cleanroom techniques, electrically conductive palladium nanowires are grown on anodized aluminum oxide templates using silicon and glass as supporting substrates. Photolithography is used to create two non-continuous gold windows and contact pads on the substrates. AAO templates are attached to the two gold windows and palladium nanowires are electrochemically grown on the AAO templates. Glucose oxidase and catalase are immobilized on the anode and laccase on the cathode. In the presence of glucose, electrons are released that result in the generation of voltage and current. The current-voltage behavior of the fuel cell, as well as electrochemical properties, is characterized using standard performance metrics. In 5 mM glucose solution with a neutral pH of 7.3, the open circuit voltage obtained was 335 mV and the short circuit current of 6 microA to yield a maximum power output of 1.38 microW.

Statistical implications of using moving violations to determine crash responsibility in young driver crashes

PubMed Central

Curry, Allison E.; Pfeiffer, Melissa R.; Myers, Rachel K.; Durbin, Dennis R.; Elliott, Michael R.

2014-01-01

Traditional methods for determining crash responsibility—most commonly moving violation citations—may not accurately characterize at-fault status among crash-involved drivers given that: (1) issuance may vary by factors that are independent of fault (e.g., driver age, gender), and (2) these methods do not capture driver behaviors that are not illegal but still indicative of fault. We examined the statistical implications of using moving violations to determine crash responsibility in young driver crashes by comparing it with a method based on crash-contributing driver actions. We selected all drivers in police-reported passenger-vehicle crashes (2010–2011) that involved a New Jersey driver <21 years old (79,485 drivers < age 21, 61,355 drivers ≥ age 21.) For each driver, crash responsibility was determined from the crash report using two alternative methods: (1) issuance of a moving violation citation; and (2) presence of a driver action (e.g., failure to yield, inattention). Overall, 18% of crash-involved drivers were issued a moving violation while 50% had a driver action. Only 32.2% of drivers with a driver action were cited for a moving violation. Further, the likelihood of being cited given the presence of a driver action was higher among certain driver subgroups—younger drivers, male drivers, and drivers in single-vehicle and more severe crashes. Specifically among young drivers, those driving at night, carrying peer passengers, and having a suspended or no license were more often cited. Conversely, fatally-injured drivers were almost never cited. We also demonstrated that using citation data may lead to statistical bias in the characterization of at-fault drivers and of quasi-induced exposure measures. Studies seeking to accurately determine crash responsibility should thoughtfully consider the potential sources of bias that may result from using legal culpability methods. For many studies, determining driver responsibility via the identification of driver actions may yield more accurate characterizations of at-fault drivers. PMID:24398139

Live imaging of dense-core vesicles in primary cultured hippocampal neurons.

PubMed

Kwinter, David M; Silverman, Michael A; Kwinter, David; Michael, Silverman

2009-05-29

Observing and characterizing dynamic cellular processes can yield important information about cellular activity that cannot be gained from static images. Vital fluorescent probes, particularly green fluorescent protein (GFP) have revolutionized cell biology stemming from the ability to label specific intracellular compartments and cellular structures. For example, the live imaging of GFP (and its spectral variants) chimeras have allowed for a dynamic analysis of the cytoskeleton, organelle transport, and membrane dynamics in a multitude of organisms and cell types [1-3]. Although live imaging has become prevalent, this approach still poses many technical challenges, particularly in primary cultured neurons. One challenge is the expression of GFP-tagged proteins in post-mitotic neurons; the other is the ability to capture fluorescent images while minimizing phototoxicity, photobleaching, and maintaining general cell health. Here we provide a protocol that describes a lipid-based transfection method that yields a relatively low transfection rate (~0.5%), however is ideal for the imaging of fully polarized neurons. A low transfection rate is essential so that single axons and dendrites can be characterized as to their orientation to the cell body to confirm directionality of transport, i.e., anterograde v. retrograde. Our approach to imaging GFP expressing neurons relies on a standard wide-field fluorescent microscope outfitted with a CCD camera, image capture software, and a heated imaging chamber. We have imaged a wide variety of organelles or structures, for example, dense-core vesicles, mitochondria, growth cones, and actin without any special optics or excitation requirements other than a fluorescent light source. Additionally, spectrally-distinct, fluorescently labeled proteins, e.g., GFP and dsRed-tagged proteins, can be visualized near simultaneously to characterize co-transport or other coordinated cellular events. The imaging approach described here is flexible for a variety of imaging applications and can be adopted by a laboratory for relatively little cost provided a microscope is available.

Optimization and production of curdlan gum using Bacillus cereus PR3 isolated from rhizosphere of leguminous plant.

PubMed

Prakash, S; Rajeswari, K; Divya, P; Ferlin, M; Rajeshwari, C T; Vanavil, B

2018-05-28

Curdlan gum is a neutral water-insoluble bacterial exopolysaccharide composed primarily of linear β-(1,3) glycosidic linkages. Recently, there has been increasing interest in the applications of curdlan and its derivatives. Curdlan is found to inhibit tumors and its sulfated derivative possess anti-HIV activity. Curdlan is biodegradable, non-toxic towards human, environment and edible which makes it suitable as drug-delivery vehicles for sustained drug release. The increasing demand for the growing applications of curdlan requires an efficient high yield fermentation production process so as to satisfy the industrial needs. In this perspective, the present work is aimed to screen and isolate an efficient curdlan gum producing bacteria from rhizosphere of ground nut plant using aniline-blue agar. High yielding isolate was selected based on curdlan yield and identified as Bacillus cereus using gas-chromatography fatty acid methyl ester analysis. B. cereus PR3 curdlan gum was characterized using FT-IR spectroscopy, SEM, XRD and TGA. Fermentation time for curdlan production using B. cereus PR3 was optimized. Media constituents like carbon, nitrogen and mineral sources were screened using Plackett-Burman design. Subsequent statistical analysis revealed that Starch, NH 4 NO 3 , K 2 HPO 4 , Na 2 SO 4 , KH 2 SO 4 and CaCl 2 were significant media constituents and these concentrations were optimized for enhancement of curdlan production up to 20.88 g/l.

Characterization of Hanwoo Bovine By-products by Means of Yield, Physicochemical and Nutritional Compositions

PubMed Central

Moon, Sung Sil

2014-01-01

Though the edible bovine by-products are widely used for human consumption in most countries worldwide but the scientific information regarding the nutritional quality of these by-products is scarce. In the present study, the basic information regarding the yields, physicochemical and nutritional compositions of edible Hanwoo bovine by-products was studied. Our results showed that the yields, physicochemical and nutritional composition widely varied between the by-products examined. The highest pH values were found in rumen, reticulum, omasum and reproductive organ. Heart, liver, kidney and spleen had the lowest CIE L* values and highest CIE a* values. Liver had the highest vitamin A, B2 and niacin contents whereas the highest B1 and B5 contents were found in kidney. The highest Ca content was found in rumen, reticulum, omasum, head and leg while the highest Mn and Fe contents were found in rumen, omasum and spleen, respectively. Liver had the highest Cu content. Total essential amino acids (EAA)/amino acids (AA) ratios ranged between the by-products from 38.37% to 47.41%. Total polyunsaturated fatty acids (PUFA) levels ranged between the by-products from 2.26% to 26.47%, and most by-products showed favorable PUFA/SFA ratios. It is concluded that most of by-products examined are good sources of essential nutrients and these data will be of great importance for promotion of consumption and utilization of beef by-products in future. PMID:26761281

A fingerprinting mixing model approach to generate uniformly representative solutions for distributed contributions of sediment sources in a Pyrenean drainage basin

NASA Astrophysics Data System (ADS)

Palazón, Leticia; Gaspar, Leticia; Latorre, Borja; Blake, Will; Navas, Ana

2014-05-01

Spanish Pyrenean reservoirs are under pressure from high sediment yields in contributing catchments. Sediment fingerprinting approaches offer potential to quantify the contribution of different sediment sources, evaluate catchment erosion dynamics and develop management plans to tackle the reservoir siltation problems. The drainage basin of the Barasona reservoir (1509 km2), located in the Central Spanish Pyrenees, is an alpine-prealpine agroforest basin supplying sediments to the reservoir at an annual rate of around 350 t km-2 with implications for reservoir longevity. The climate is mountain type, wet and cold, with both Atlantic and Mediterranean influences. Steep slopes and the presence of deep and narrow gorges favour rapid runoff and large floods. The ability of geochemical fingerprint properties to discriminate between the sediment sources was investigated by conducting the nonparametric Kruskal-Wallis H-test and a stepwise discriminant function analysis (minimization of Wilk's lambda). This standard procedure selects potential fingerprinting properties as optimum composite fingerprint to characterize and discriminate between sediment sources to the reservoir. Then the contribution of each potential sediment source was assessed by applying a Monte Carlo mixing model to obtain source proportions for the Barasona reservoir sediment samples. The Monte Carlo mixing model was written in C programming language and designed to deliver a user-defined number possible solutions. A Combinatorial Principals method was used to identify the most probable solution with associated uncertainty based on source variability. The unique solution for each sample was characterized by the mean value and the standard deviation of the generated solutions and the lower goodness of fit value applied. This method is argued to guarantee a similar set of representative solutions in all unmixing cases based on likelihood of occurrence. Soil samples for the different potential sediment sources of the drainage basin were compared with samples from the reservoir using a range of different fingerprinting properties (i.e. mass activities of environmental radionuclides, elemental composition and magnetic susceptibility) analyzed in the < 63 μm sediment fraction. In this case, the 100 best results from 106 generated iterations were selected obtaining a goodness of fit higher than 0.76. The preliminary results using this new data processing methodology for samples collected in the reservoir allowed us to identify cultivated fields and badlands as main potential sources of sediments to the reservoir. These findings support the appropriate use of the fingerprinting methodology in a Spanish Pyrenees basin, which will enable us to better understand the basin sediment production of the Barasona reservoir.

Monte Carlo based protocol for cell survival and tumour control probability in BNCT.

PubMed

Ye, S J

1999-02-01

A mathematical model to calculate the theoretical cell survival probability (nominally, the cell survival fraction) is developed to evaluate preclinical treatment conditions for boron neutron capture therapy (BNCT). A treatment condition is characterized by the neutron beam spectra, single or bilateral exposure, and the choice of boron carrier drug (boronophenylalanine (BPA) or boron sulfhydryl hydride (BSH)). The cell survival probability defined from Poisson statistics is expressed with the cell-killing yield, the 10B(n,alpha)7Li reaction density, and the tolerable neutron fluence. The radiation transport calculation from the neutron source to tumours is carried out using Monte Carlo methods: (i) reactor-based BNCT facility modelling to yield the neutron beam library at an irradiation port; (ii) dosimetry to limit the neutron fluence below a tolerance dose (10.5 Gy-Eq); (iii) calculation of the 10B(n,alpha)7Li reaction density in tumours. A shallow surface tumour could be effectively treated by single exposure producing an average cell survival probability of 10(-3)-10(-5) for probable ranges of the cell-killing yield for the two drugs, while a deep tumour will require bilateral exposure to achieve comparable cell kills at depth. With very pure epithermal beams eliminating thermal, low epithermal and fast neutrons, the cell survival can be decreased by factors of 2-10 compared with the unmodified neutron spectrum. A dominant effect of cell-killing yield on tumour cell survival demonstrates the importance of choice of boron carrier drug. However, these calculations do not indicate an unambiguous preference for one drug, due to the large overlap of tumour cell survival in the probable ranges of the cell-killing yield for the two drugs. The cell survival value averaged over a bulky tumour volume is used to predict the overall BNCT therapeutic efficacy, using a simple model of tumour control probability (TCP).

A study of Kapton degradation under simulated shuttle environment

NASA Technical Reports Server (NTRS)

Eck, T. G.; Hoffman, R. W.

1986-01-01

A system was developed which employs a source of low energy oxygen ion to simulate the shuttle low Earth orbit environment. This source, together with diagnostic tools including surface analysis ans mass spectroscopic capability, was used to measure the dependence of ion energy of the oxygen induced CO signals from pyrolytic graphite and Kapton. For graphite the CO signal was examined at energies ranging form 4.5 to 465 eV and for Kapton from 4.5 to 188 eV. While the relative quantum yields inferred from the data are reasonably precise, there are large uncertainties in the absolute yields because of the assumptions necessary to covert the measured signal strengths to quantum yields. These assumptions are discussed in detail.

Rate and yield relationships in the production of xanthan gum by batch fermentations using complex and chemically defined growth media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinches, A.; Pallent, L.J.

1986-10-01

Rate and yield information relating to biomass and product formation and to nitrogen, glucose and oxygen consumption are described for xanthan gum batch fermentations in which both chemically defined (glutamate nitrogen) and complex (peptone nitrogen) media are employed. Simple growth and product models are used for data interpretation. For both nitrogen sources, rate and yield parameter estimates are shown to be independent of initial nitrogen concentrations. For stationary phases, specific rates of gum production are shown to be independent of nitrogen source but dependent on initial nitrogen concentration. The latter is modeled empirically and suggests caution in applying simple productmore » models to xanthan gum fermentations. 13 references.« less

Use of collagen hydrolysate as a complex nitrogen source for the synthesis of penicillin by Penicillium chrysogenum.

PubMed

Leonhartsberger, S; Lafferty, R M; Korneti, L

1993-09-01

Optimal conditions for both biomass formation and penicillin synthesis by a strain of Penicillium chrysogenum were determined when using a collagen-derived nitrogen source. Preliminary investigations were carried out in shaken flask cultures employing a planned experimental program termed the Graeco-Latin square technique (Auden et al., 1967). It was initially determined that up to 30% of a conventional complex nitrogen source such as cottonseed meal could be replaced by the collagen-derived nitrogen source without decreasing the productivity with respect to the penicillin yield. In the pilot scale experiments using a 30 l stirred tank type of bioreactor, higher penicillin yields were obtained when 70% of the conventional complex nitrogen source in the form of cottonseed meal was replaced by the collagen hydrolysate. Furthermore, the maximum rate of penicillin synthesis continued for over a longer period when using collagen hydrolysate as a complex nitrogen source. Penicillin synthesis rates were determined using a linear regression.

Primary gas- and particle-phase emissions and secondary organic aerosol production from gasoline and diesel off-road engines.

PubMed

Gordon, Timothy D; Tkacik, Daniel S; Presto, Albert A; Zhang, Mang; Jathar, Shantanu H; Nguyen, Ngoc T; Massetti, John; Truong, Tin; Cicero-Fernandez, Pablo; Maddox, Christine; Rieger, Paul; Chattopadhyay, Sulekha; Maldonado, Hector; Maricq, M Matti; Robinson, Allen L

2013-12-17

Dilution and smog chamber experiments were performed to characterize the primary emissions and secondary organic aerosol (SOA) formation from gasoline and diesel small off-road engines (SOREs). These engines are high emitters of primary gas- and particle-phase pollutants relative to their fuel consumption. Two- and 4-stroke gasoline SOREs emit much more (up to 3 orders of magnitude more) nonmethane organic gases (NMOGs), primary PM and organic carbon than newer on-road gasoline vehicles (per kg of fuel burned). The primary emissions from a diesel transportation refrigeration unit were similar to those of older, uncontrolled diesel engines used in on-road vehicles (e.g., premodel year 2007 heavy-duty diesel trucks). Two-strokes emitted the largest fractional (and absolute) amount of SOA precursors compared to diesel and 4-stroke gasoline SOREs; however, 35-80% of the NMOG emissions from the engines could not be speciated using traditional gas chromatography or high-performance liquid chromatography. After 3 h of photo-oxidation in a smog chamber, dilute emissions from both 2- and 4-stroke gasoline SOREs produced large amounts of semivolatile SOA. The effective SOA yield (defined as the ratio of SOA mass to estimated mass of reacted precursors) was 2-4% for 2- and 4-stroke SOREs, which is comparable to yields from dilute exhaust from older passenger cars and unburned gasoline. This suggests that much of the SOA production was due to unburned fuel and/or lubrication oil. The total PM contribution of different mobile source categories to the ambient PM burden was calculated by combining primary emission, SOA production and fuel consumption data. Relative to their fuel consumption, SOREs are disproportionately high total PM sources; however, the vastly greater fuel consumption of on-road vehicles renders them (on-road vehicles) the dominant mobile source of ambient PM in the Los Angeles area.

The Chandra Source Catalog: Statistical Characterization

NASA Astrophysics Data System (ADS)

Primini, Francis A.; Nowak, M. A.; Houck, J. C.; Davis, J. E.; Glotfelty, K. J.; Karovska, M.; Anderson, C. S.; Bonaventura, N. R.; Chen, J. C.; Doe, S. M.; Evans, I. N.; Evans, J. D.; Fabbiano, G.; Galle, E. C.; Gibbs, D. G., II; Grier, J. D.; Hain, R.; Hall, D. M.; Harbo, P. N.; He, X.; Lauer, J.; McCollough, M. L.; McDowell, J. C.; Miller, J. B.; Mitschang, A. W.; Morgan, D. L.; Nichols, J. S.; Plummer, D. A.; Refsdal, B. L.; Rots, A. H.; Siemiginowska, A. L.; Sundheim, B. A.; Tibbetts, M. S.; van Stone, D. W.; Winkelman, S. L.; Zografou, P.

2009-09-01

The Chandra Source Catalog (CSC) will ultimately contain more than ˜250000 x-ray sources in a total area of ˜1% of the entire sky, using data from ˜10000 separate ACIS and HRC observations of a multitude of different types of x-ray sources (see Evans et al. this conference). In order to maximize the scientific benefit of such a large, heterogeneous dataset, careful characterization of the statistical properties of the catalog, i.e., completeness, sensitivity, false source rate, and accuracy of source properties, is required. Our Characterization efforts include both extensive simulations of blank-sky and point source datasets, and detailed comparisons of CSC results with those of other x-ray and optical catalogs. We present here a summary of our characterization results for CSC Release 1 and preliminary plans for future releases. This work is supported by NASA contract NAS8-03060 (CXC).

Construction and Analysis of High-Ethanol-Producing Fusants with Co-Fermentation Ability through Protoplast Fusion and Double Labeling Technology

PubMed Central

Ge, Jingping; Zhao, Jingwen; Zhang, Luyan; Zhang, Mengyun; Ping, Wenxiang

2014-01-01

Double labeling of resistance markers and report genes can be used to breed engineered Saccharomyces cerevisiae strains that can assimilate xylose and glucose as a mixed carbon source for ethanol fermentation and increased ethanol production. In this study Saccharomyces cerevisiae W5 and Candida shehatae 20335 were used as parent strains to conduct protoplast fusion and the resulting fusants were screened by double labeling. High performance liquid chromatography (HPLC) was used to assess the ethanol yield following the fermentation of xylose and glucose, as both single and mixed carbon sources, by the fusants. Interestingly, one fusant (ZLYRHZ7) was demonstrated to have an excellent fermentation performance, with an ethanol yield using the mixed carbon source of 0.424 g g−1, which compares with 0.240 g g−1 (W5) and 0.353 g g−1 (20335) for the parent strains. This indicates an improvement in the ethanol yield of 43.4% and 16.7%, respectively. PMID:25268957

Waveform inversion of acoustic waves for explosion yield estimation

DOE PAGES

Kim, K.; Rodgers, A. J.

2016-07-08

We present a new waveform inversion technique to estimate the energy of near-surface explosions using atmospheric acoustic waves. Conventional methods often employ air blast models based on a homogeneous atmosphere, where the acoustic wave propagation effects (e.g., refraction and diffraction) are not taken into account, and therefore, their accuracy decreases with increasing source-receiver distance. In this study, three-dimensional acoustic simulations are performed with a finite difference method in realistic atmospheres and topography, and the modeled acoustic Green's functions are incorporated into the waveform inversion for the acoustic source time functions. The strength of the acoustic source is related to explosionmore » yield based on a standard air blast model. The technique was applied to local explosions (<10 km) and provided reasonable yield estimates (<~30% error) in the presence of realistic topography and atmospheric structure. In conclusion, the presented method can be extended to explosions recorded at far distance provided proper meteorological specifications.« less

Neutron Radiation Characteristics of Plutonium Dioxide Fuel

NASA Technical Reports Server (NTRS)

Taherzadeh, M.

1972-01-01

The major sources of neutrons from plutonium dioxide nuclear fuel are considered in detail. These sources include spontaneous fission of several of the Pu isotopes, reactions with low Z impurities in the fuel, and reactions with O-18. For spontaneous fission neutrons a value of (1.95 plus or minus 0.07) X 1,000 n/s/q PuO2 is obtained. The neutron yield from (alpha, neutron) reactions with oxygen is calculated by integrating the reaction rate equation over all alpha particle energies and all center-of-mass angles. The results indicate a neutron emission rate of (1.42 plus or minus 0.32) X 10,000 n/s/q PuO2. The neutron yield from (alpha, neutron) reactions with low Z impurities in the fuel is presented in tabular form for one part per million of each impurity. The total neutron flux emitted from a particular fuel geometry is estimated by adding the neutron yield due to the induced fission to the other neutron sources.

Waveform inversion of acoustic waves for explosion yield estimation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, K.; Rodgers, A. J.

We present a new waveform inversion technique to estimate the energy of near-surface explosions using atmospheric acoustic waves. Conventional methods often employ air blast models based on a homogeneous atmosphere, where the acoustic wave propagation effects (e.g., refraction and diffraction) are not taken into account, and therefore, their accuracy decreases with increasing source-receiver distance. In this study, three-dimensional acoustic simulations are performed with a finite difference method in realistic atmospheres and topography, and the modeled acoustic Green's functions are incorporated into the waveform inversion for the acoustic source time functions. The strength of the acoustic source is related to explosionmore » yield based on a standard air blast model. The technique was applied to local explosions (<10 km) and provided reasonable yield estimates (<~30% error) in the presence of realistic topography and atmospheric structure. In conclusion, the presented method can be extended to explosions recorded at far distance provided proper meteorological specifications.« less

Comparative study of X-ray emission from plasma focus relative to different preionization schemes

NASA Astrophysics Data System (ADS)

Ahmad, S.; Qayyum, A.; Hassan, M.; Zakaullah, M.

2017-07-01

A 2.7-kJ Mather-type plasma focus has been investigated for X-ray emission with preionization produced by an α-source, a β-source, and a shunt resistor. Time-resolved and time integrated measurements are carried out using a PIN-diode-based X-ray spectrometer and pinhole camera. The β-source (28Ni63) assisted preionization enhances the X-ray emission up to 25%, while preionization induced by depleted uranium (92U238) increases both Cu-Kα and total X-ray yield of about 100%. The preionization caused by the optimum shunt resistor enhances the Cu-Kα and total X-ray yield of about 53%. It is found that preionization also broadens the working pressure range for the high X-ray yield and improves the shot-to-shot reproducibility of the system. Pinhole images reveal that the X-ray emission from the anode tip is dominant owing to impact of electron bombardment, while the X-ray emission from hot spots is also visible.

Construction and analysis of high-ethanol-producing fusants with co-fermentation ability through protoplast fusion and double labeling technology.

PubMed

Ge, Jingping; Zhao, Jingwen; Zhang, Luyan; Zhang, Mengyun; Ping, Wenxiang

2014-01-01

Double labeling of resistance markers and report genes can be used to breed engineered Saccharomyces cerevisiae strains that can assimilate xylose and glucose as a mixed carbon source for ethanol fermentation and increased ethanol production. In this study Saccharomyces cerevisiae W5 and Candida shehatae 20335 were used as parent strains to conduct protoplast fusion and the resulting fusants were screened by double labeling. High performance liquid chromatography (HPLC) was used to assess the ethanol yield following the fermentation of xylose and glucose, as both single and mixed carbon sources, by the fusants. Interestingly, one fusant (ZLYRHZ7) was demonstrated to have an excellent fermentation performance, with an ethanol yield using the mixed carbon source of 0.424 g g-1, which compares with 0.240 g g-1 (W5) and 0.353 g g-1 (20335) for the parent strains. This indicates an improvement in the ethanol yield of 43.4% and 16.7%, respectively.

An integrated approach using orthogonal analytical techniques to characterize heparan sulfate structure.

PubMed

Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Gunay, Nur Sibel; Wang, Jing; Sun, Elaine Y; Pradines, Joël R; Farutin, Victor; Shriver, Zachary; Kaundinya, Ganesh V; Capila, Ishan

2017-02-01

Heparan sulfate (HS), a glycosaminoglycan present on the surface of cells, has been postulated to have important roles in driving both normal and pathological physiologies. The chemical structure and sulfation pattern (domain structure) of HS is believed to determine its biological function, to vary across tissue types, and to be modified in the context of disease. Characterization of HS requires isolation and purification of cell surface HS as a complex mixture. This process may introduce additional chemical modification of the native residues. In this study, we describe an approach towards thorough characterization of bovine kidney heparan sulfate (BKHS) that utilizes a variety of orthogonal analytical techniques (e.g. NMR, IP-RPHPLC, LC-MS). These techniques are applied to characterize this mixture at various levels including composition, fragment level, and overall chain properties. The combination of these techniques in many instances provides orthogonal views into the fine structure of HS, and in other instances provides overlapping / confirmatory information from different perspectives. Specifically, this approach enables quantitative determination of natural and modified saccharide residues in the HS chains, and identifies unusual structures. Analysis of partially digested HS chains allows for a better understanding of the domain structures within this mixture, and yields specific insights into the non-reducing end and reducing end structures of the chains. This approach outlines a useful framework that can be applied to elucidate HS structure and thereby provides means to advance understanding of its biological role and potential involvement in disease progression. In addition, the techniques described here can be applied to characterization of heparin from different sources.

Nutrient mass balance and trends, Mobile River Basin, Alabama, Georgia, and Mississippi

USGS Publications Warehouse

Harned, D.A.; Atkins, J.B.; Harvill, J.S.

2004-01-01

A nutrient mass balance - accounting for nutrient inputs from atmospheric deposition, fertilizer, crop nitrogen fixation, and point source effluents; and nutrient outputs, including crop harvest and storage - was calculated for 18 subbasins in the Mobile River Basin, and trends (1970 to 1997) were evaluated as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program. Agricultural nonpoint nitrogen and phosphorus sources and urban nonpoint nitrogen sources are the most important factors associated with nutrients in this system. More than 30 percent of nitrogen yield in two basins and phosphorus yield in eight basins can be attributed to urban point source nutrient inputs. The total nitrogen yield (1.3 tons per square mile per year) for the Tombigbee River, which drains a greater percentage of agricultural (row crop) land use, was larger than the total nitrogen yield (0.99 tons per square mile per year) for the Alabama River. Decreasing trends of total nitrogen concentrations in the Tombigbee and Alabama Rivers indicate that a reduction occurred from 1975 to 1997 in the nitrogen contributions to Mobile Bay from the Mobile River. Nitrogen concentrations also decreased (1980 to 1995) in the Black Warrior River, one of the major tributaries to the Tombigbee River. Total phosphorus concentrations increased from 1970 to 1996 at three urban influenced sites on the Etowah River in Georgia. Multiple regression analysis indicates a distinct association between water quality in the streams of the Mobile River drainage basin and agricultural activities in the basin.

Preparation, isolation, and characterization of cutin monomers and oligomers from tomato peels.

PubMed

Osman, S F; Irwin, P; Fett, W F; O'Connor, J V; Parris, N

1999-02-01

Cutin in tomato peels was depolymerized in methanolic base to yield cutin monomers or a mixture of cutin oligomers. These products were isolated by typical solvent extraction methods or by precipitation, and the isolates were characterized by chromatographic and spectroscopic analyses. It was determined that the compositions of the isolates from both isolation procedures were similar, although solvent extraction gave higher yields. However, the precipitation method, which is easy to carry out and avoids the use of undesirable organic solvents, may be preferable in commercial processes for recovering these compounds.

Statistical Characterization of the Chandra Source Catalog

NASA Astrophysics Data System (ADS)

Primini, Francis A.; Houck, John C.; Davis, John E.; Nowak, Michael A.; Evans, Ian N.; Glotfelty, Kenny J.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Doe, Stephen M.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G.; Grier, John D.; Hain, Roger M.; Hall, Diane M.; Harbo, Peter N.; He, Xiangqun Helen; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Plummer, David A.; Refsdal, Brian L.; Rots, Arnold H.; Siemiginowska, Aneta; Sundheim, Beth A.; Tibbetts, Michael S.; Van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2011-06-01

The first release of the Chandra Source Catalog (CSC) contains ~95,000 X-ray sources in a total area of 0.75% of the entire sky, using data from ~3900 separate ACIS observations of a multitude of different types of X-ray sources. In order to maximize the scientific benefit of such a large, heterogeneous data set, careful characterization of the statistical properties of the catalog, i.e., completeness, sensitivity, false source rate, and accuracy of source properties, is required. Characterization efforts of other large Chandra catalogs, such as the ChaMP Point Source Catalog or the 2 Mega-second Deep Field Surveys, while informative, cannot serve this purpose, since the CSC analysis procedures are significantly different and the range of allowable data is much less restrictive. We describe here the characterization process for the CSC. This process includes both a comparison of real CSC results with those of other, deeper Chandra catalogs of the same targets and extensive simulations of blank-sky and point-source populations.

Dissolved Solids in Streams of the Conterminous United States

NASA Astrophysics Data System (ADS)

Anning, D. W.; Flynn, M.

2014-12-01

Studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey's National Water-Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model to improve the understanding of dissolved solids in streams of the United States. Using the SPARROW model, annual dissolved-solids loads from 2,560 water-quality monitoring stations were statistically related to several spatial datasets serving as surrogates for dissolved-solids sources and transport processes. Sources investigated in the model included geologic materials, road de-icers, urban lands, cultivated lands, and pasture lands. Factors affecting transport from these sources to streams in the model included climate, soil, vegetation, terrain, population, irrigation, and artificial-drainage characteristics. The SPARROW model was used to predict long-term mean annual conditions for dissolved-solids sources, loads, yields, and concentrations in about 66,000 stream reaches and corresponding incremental catchments nationwide. The estimated total amount of dissolved solids delivered to the Nation's streams is 272 million metric tons (Mt) annually, of which 194 million Mt (71%) are from geologic sources, 38 million Mt (14%) are from road de-icers, 18 million Mt (7%) are from pasture lands, 14 million Mt (5 %) are from urban lands, and 8 million Mt (3%) are from cultivated lands. The median incremental-catchment yield delivered to local streams is 26 metric tons per year per square kilometer [(Mt/yr)/km2]. Ten percent of the incremental catchments yield less than 4 (Mt/yr)/km2, and 10 percent yield more than 90 (Mt/yr)/km2. In 13% of the reaches, predicted flow-weighted concentrations exceed 500 mg/L—the U.S. Environmental Protection Agency secondary non-enforceable drinking-water standard.

Updated database for K-shell fluorescence yields

NASA Astrophysics Data System (ADS)

Akdemir, Fatma; Araz, Aslı; Akman, Ferdi; Kaçal, Mustafa Recep; Durak, Rıdvan

2017-04-01

This study presents a summary of experimental data of K-shell fluorescence yields (ωK) published in the period of time between 2010 to february-2017. The fluorescence yields (ωK) of elements in the range 23≤Z≤60 taken directly from different sources were reviewed and presented in a table form. Finally, the experimental and empirical values in the literature have been reported and commented.

Separating Multiple Episodes of Partial Melting in Polyorogenic Crust: AN Example from the Haiyangsuo Complex, Northern Sulu Belt, Eastern China

NASA Astrophysics Data System (ADS)

Feng, P.; Wang, L.; Brown, M.; Wang, S.

2017-12-01

Determining the timing, mechanism and source of partial melts in polyorogenic crust is challenging. In the Sulu belt, the tectonic affinity of the Haiyangsuo (HYS) complex is controversial due to its polyphase metamorphic history. Here we use detailed field mapping, petrology, microstructural analysis and zircon geochronology to study thin stromatic leucosomes in host granite gneiss, and crosscutting leucogranite dykes to decipher the melting history. Zircon grains from both granite gneiss and thin leucosomes exhibit core-mantle-rim structures. Zircon cores yield protolith ages of 2.86-2.81 Ga, whereas the mantles and rims yield younger metamorphic/melt crystallization ages of ca. 1.82-1.80 Ga. The mantles are characterized by gray luminescence, flat HREE distribution patterns and relatively low Th/U ratios, indicating crystallization during granulite-facies metamorphism. Whereas rims show bright luminescence, steep HREE distribution patterns and higher Th/U ratios, suggesting they crystallized from melt. The mantles and rims have ɛHf (t) of -18.2 to -11.0. Using 176Lu/177Hf = 0.001, these data project back to the array of ɛHf (t) values for the zircon cores. This demonstrates that the thin leucosomes were derived from the gneiss without any mass input from a mantle source. These features are consistent with an origin of the HYS as part of the eastern margin of the NCC prior to juxtaposition with the Sulu belt. Zircons from the leucogranite dykes also show core-mantle-rim structure. Inherited cores yield concordant 206Pb/238U ages of 776-701 Ma consistent with the dominant age range for protoliths of the UHP metamorphic rocks in the Sulu belt. Zircon mantle and rim domains, which both contain multiphase solid inclusions (Kfs + Pl + Qz and Hem + Pl + Qz in mantles and Kfs + Pl + Qz + Bt in rims), yield melt crystallization ages of 226-217 and 169-156 Ma, respectively. High Sr, low Y and Yb contents, high Sr/Y ratios, and the range of ɛNd (t) values (-18.2- -15.0) and initial 87Sr/86Sr ratios (0.7106 - 0.7146) for the leucogranites are consistent with melting of thickened lower continental crust of the Sulu belt. We interpret the dykes to have been emplaced during post-collisional collapse of the orogenic root of this belt in the Middle-Upper Jurassic.

Effect of feeding dried distillers' grains with solubles on milk yield and milk composition of cows in mid-lactation and digestibility in sheep.

PubMed

Westreicher-Kristen, E; Kaiser, R; Steingass, H; Rodehutscord, M

2014-04-01

We evaluated the effect of three sources of dried distillers' grains with solubles (DDGS) in diets of mid-lactating dairy cows on milk production and milk composition and on digestibility in sheep. DDGS from wheat, corn and barley (DDGS1 ), wheat and corn (DDGS2 ) and wheat (DDGS3 ) were studied and compared with a rapeseed meal (RSM). RSM and DDGS were characterized through in situ crude protein (CP) degradability. Nutrient digestibility was determined in sheep. Twenty-four multiparous cows were used in a 4 × 4 Latin square design with 28-day periods. Treatments included total mixed rations containing as primary protein sources RSM (control), DDGS1 (D1), DDGS2 (D2) or DDGS3 (D3). RSM contained less rapidly degradable CP (fraction a), more potentially degradable CP (fraction b) and more rumen undegradable CP (UDP) than the three DDGS. In vivo digestibility of RSM organic matter was similar to DDGS. Calculated net energy for lactation (NEL ) was lower for RSM (7.4 MJ/kg DM) than for DDGS, which averaged 7.7 MJ/kg DM. Cows' dry matter intake did not differ between diets (21.7 kg/day). Cows fed D1 yielded more milk than those fed D3 (31.7 vs. 30.4 kg/day); no differences were found between control and DDGS diets (31.3 vs. 31.1 kg/day). Energy-corrected milk was similar among diets (31.2 kg/day). Diets affected neither milk fat concentration (4.0%) nor milk fat yield (1.24 kg/day). Milk protein yield of control (1.12 kg/day) was significantly higher than D3 (1.06 kg/day) but not different form D1 and D2 (1.08 kg/day each). Feeding DDGS significantly increased milk lactose concentration (4.91%) in relation to control (4.81%). DDGS can be a suitable feed in relation to RSM and can be fed up to 4 kg dry matter per day in rations of dairy cows in mid-lactation. However, high variation of protein and energy values of DDGS should be considered when included in diets of dairy cows. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Comparison of Seismic Sources and Frequencies in West Texas

NASA Astrophysics Data System (ADS)

Kaip, G.; Harder, S. H.; Karplus, M. S.

2017-12-01

During October 2017 the Seismic Source Facility (SSF) located at the University of Texas at El Paso (UTEP) Department of Geological Sciences collected seismic data at SSF test facility located near Fabens, TX. The project objective was to compare source amplitudes and frequencies of various seismic sources available through the SSF. Selecting the appropriate seismic source is important to reach geological objectives. We compare seismic sources between explosive sources (pentolite and shotgun) and mechanical sources (accelerated weight drop and hammer on plate), focusing on amplitude and frequency. All sources were tested in same geologic environment. Although this is not an ideal geologic formation for source coupling, it does allow an "apples to apples" comparison. Twenty Reftek RT125A seismic recorders with 4.5 Hz geophones were laid out in a line with 3m station separation. Mechanical sources were tested first to minimize changes in the subsurface related to explosive sources Explosive sources, while yielding higher amplitudes, have lower frequency content. The explosions exhibit a higher signal-to-noise ratio, allowing us to recognize seismic energy deeper and farther from the source. Mechanical sources yield higher frequencies allowing better resolution at shallower depths, but have a lower signal-to-noise ratio and lower amplitudes, even with source stacking. We analyze the details of the shot spectra from the different types of sources. A combination of source types can improve data resolution and amplitude, thereby improving imaging potential. However, cost, logistics, and complexities also have a large influence on source selection.

VizieR Online Data Catalog: XMM-Newton point-source catalogue of the SMC (Sturm+, 2013)

NASA Astrophysics Data System (ADS)

Sturm, R.; Haberl, F.; Pietsch, W.; Ballet, J.; Hatzidimitriou, D.; Buckley, D. A. H.; Coe, M.; Ehle, M.; Filipovic, M. D.; La Palombara, N.; Tiengo, A.

2013-07-01

The XMM-Newton survey of the Small Magellanic Cloud (SMC) yields a complete coverage of the bar and eastern wing in the 0.2-12.0keV band. This catalogue comprises 3053 unique X-ray point sources and sources with moderate extent that have been reduced from 5236 individual detections found in observations between April 2000 and April 2010. Sources have a median position uncertainty of 1.3" (1σ) and limiting fluxes down to ~1*10-14erg/s/cm2 in the 0.2-4.5keV band, corresponding to 5*1033erg/s for sources in the SMC. Sources have been classified using hardness ratios, X-ray variability, and their multi-wavelength properties. In addition to the main-field (5.58deg2) available outer fields have been included in the catalogue, yielding a total field area of 6.32deg2. X-ray sources with high extent (>40", e.g. supernova remnants and galaxy cluster) have been presented by Haberl et al. (2012, Cat. J/A+A/545/A128) (2 data files).

SPARROW models used to understand nutrient sources in the Mississippi/Atchafalaya River Basin

USGS Publications Warehouse

Robertson, Dale M.; Saad, David A.

2013-01-01

Nitrogen (N) and phosphorus (P) loading from the Mississippi/Atchafalaya River Basin (MARB) has been linked to hypoxia in the Gulf of Mexico. To describe where and from what sources those loads originate, SPAtially Referenced Regression On Watershed attributes (SPARROW) models were constructed for the MARB using geospatial datasets for 2002, including inputs from wastewater treatment plants (WWTPs), and calibration sites throughout the MARB. Previous studies found that highest N and P yields were from the north-central part of the MARB (Corn Belt). Based on the MARB SPARROW models, highest N yields were still from the Corn Belt but centered over Iowa and Indiana, and highest P yields were widely distributed throughout the center of the MARB. Similar to that found in other studies, agricultural inputs were found to be the largest N and P sources throughout most of the MARB: farm fertilizers were the largest N source, whereas farm fertilizers, manure, and urban inputs were dominant P sources. The MARB models enable individual N and P sources to be defined at scales ranging from SPARROW catchments (∼50 km2) to the entire area of the MARB. Inputs of P from WWTPs and urban areas were more important than found in most other studies. Information from this study will help to reduce nutrient loading from the MARB by providing managers with a description of where each of the sources of N and P are most important, thus providing a basis for prioritizing management actions and ultimately reducing the extent of Gulf hypoxia.

Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003

USGS Publications Warehouse

Wise, Daniel R.; Rinella, Frank A.; Rinella, Joseph F.; Fuhrer, Greg J.; Embrey, Sandra S.; Clark, Gregory M.; Schwarz, Gregory E.; Sobieszczyk, Steven

2007-01-01

This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments (drainage basins), and (3) trends in TN, TP, and SS concentrations and loads in comparison to changes in landscape and climatic conditions in the catchments. During water year 2000, an average streamflow year in the Pacific Northwest, the Columbia River discharged about 570,000 pounds per day of TN, about 55,000 pounds per day of TP, and about 14,000 tons per day of SS to the Pacific Ocean. The Snake, Yakima, Deschutes, and Willamette Rivers contributed most of the load discharged to the Columbia River. Point-source nutrient loads to the catchments (almost exclusively from municipal wastewater treatment plants) generally were a small percentage of the total in-stream nutrient loads; however, in some reaches of the Spokane, Boise, Walla Walla, and Willamette River Basins, point sources were responsible for much of the annual in-stream nutrient load. Point-source nutrient loads generally were a small percentage of the total catchment nutrient loads compared to nonpoint sources, except for a few catchments where point-source loads comprised as much as 30 percent of the TN load and as much as 80 percent of the TP load. The annual TN and TP loads from point sources discharging directly to the Puget Sound were about equal to the annual loads from eight major tributaries. Yields of TN, TP, and SS generally were greater in catchments west of the Cascade Range. A multiple linear regression analysis showed that TN yields were significantly (p < 0.05) and positively related to precipitation, atmospheric nitrogen load, fertilizer and manure load, and point-source load, and were negatively related to average slope. TP yields were significantly related positively to precipitation, and point-source load and SS yields were significantly related positively to precipitation. Forty-eight percent of the available monitoring sites for TN had significant trends in concentration (2 increasing, 19 decreasing), 32 percent of the available sites for TP had significant trends in concentration (7 increasing, 9 decreasing), and 40 percent of the available sites for SS had significant trends in concentration (4 increasing, 15 decreasing). The trends in load followed a similar pattern, but with fewer sites showing significant trends. The results from this study indicate that inputs from nonpoint sources of nutrients probably have decreased over time in many of the catchments. Despite the generally small contribution of point-source nutrient loads, they still may have been partially responsible for the significant decreasing trends for nutrients at sites where the total point-source nutrient loads to the catchments equaled a substantial proportion of the in-stream load.

BIODEGRADATIVE ANALYSIS OF MUNICIPAL SOLID WASTE IN LABORATORY-SCALE LANDFILLS

EPA Science Inventory

The report gives results of research to characterize the anaerobic biodegradability of the major biodegradable components of municipal solid waste (MSW). Tests were conducted in quadruplicate in 2-L reactors operated to obtain maximum yields. Measured methane (CH4) yields for gra...

The Molecular Origin of Enthalpy/Entropy Compensation in Biomolecular Recognition.

PubMed

Fox, Jerome M; Zhao, Mengxia; Fink, Michael J; Kang, Kyungtae; Whitesides, George M

2018-05-20

Biomolecular recognition can be stubborn; changes in the structures of associating molecules, or the environments in which they associate, often yield compensating changes in enthalpies and entropies of binding and no net change in affinities. This phenomenon-termed enthalpy/entropy (H/S) compensation-hinders efforts in biomolecular design, and its incidence-often a surprise to experimentalists-makes interactions between biomolecules difficult to predict. Although characterizing H/S compensation requires experimental care, it is unquestionably a real phenomenon that has, from an engineering perspective, useful physical origins. Studying H/S compensation can help illuminate the still-murky roles of water and dynamics in biomolecular recognition and self-assembly. This review summarizes known sources of H/ S compensation (real and perceived) and lays out a conceptual framework for understanding and dissecting-and, perhaps, avoiding or exploiting-this phenomenon in biophysical systems.

Colloidal transport by active filaments

NASA Astrophysics Data System (ADS)

Manna, Raj Kumar; Kumar, P. B. Sunil; Adhikari, R.

2017-01-01

Enhanced colloidal transport beyond the limit imposed by diffusion is usually achieved through external fields. Here, we demonstrate the ballistic transport of a colloidal sphere using internal sources of energy provided by an attached active filament. The latter is modeled as a chain of chemo-mechanically active beads connected by potentials that enforce semi-flexibility and self-avoidance. The fluid flow produced by the active beads and the forces they mediate are explicitly taken into account in the overdamped equations of motion describing the colloid-filament assembly. The speed and efficiency of transport depend on the dynamical conformational states of the filament. We characterize these states using filament writhe as an order parameter and identify ones yielding maxima in speed and efficiency of transport. The transport mechanism reported here has a remarkable resemblance to the flagellar propulsion of microorganisms which suggests its utility in biomimetic systems.

Fabrication of in-situ grown graphene reinforced Cu matrix composites

NASA Astrophysics Data System (ADS)

Chen, Yakun; Zhang, Xiang; Liu, Enzuo; He, Chunnian; Shi, Chunsheng; Li, Jiajun; Nash, Philip; Zhao, Naiqin

2016-01-01

Graphene/Cu composites were fabricated through a graphene in-situ grown approach, which involved ball-milling of Cu powders with PMMA as solid carbon source, in-situ growth of graphene on flaky Cu powders and vacuum hot-press sintering. SEM and TEM characterization results indicated that graphene in-situ grown on Cu powders guaranteed a homogeneous dispersion and a good combination between graphene and Cu matrix, as well as the intact structure of graphene, which was beneficial to its strengthening effect. The yield strength of 244 MPa and tensile strength of 274 MPa were achieved in the composite with 0.95 wt.% graphene, which were separately 177% and 27.4% enhancement over pure Cu. Strengthening effect of in-situ grown graphene in the matrix was contributed to load transfer and dislocation strengthening.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharp, D.J.; Panitz, J.K.G.; Mattox, D.M.

The erosion of materials by low energy ions is of concern in fusion reactors since high Z impurities in the plasma cause radiation cooling. Ion bombardment of the fusion reactor chamber walls arises from ions of fuel (D, T) material, gaseous impurities (O, C), and impurities from eroded components (Fe, Co, Ni, C, Mo, etc.) being accelerated across the wall sheath potential (0.1 to 1 keV). A Kaufman type ion source has been characterized for use with hydrogen, and subsequently used to determine the relative erosion rates of bulk Mo, C, Cu, coating of TiB/sub 2/, B/sub 4/C, Be, VBe/submore » 12/ and other materials. Ions of hydrogen (Z=1), argon (Z=18), and xenon (Z=54) at acceleration potentials of 250, 500, and 1000 V have been used to determine erosion yields.« less

Sources and haloacetic acid/trihalomethane formation potentials of aquatic humic substances in the Wakarusa River and Clinton Lake near Lawrence, Kansas

USGS Publications Warehouse

Pomes, M.L.; Larive, C.K.; Thurman, E.M.; Green, W.R.; Orem, W.H.; Rostad, C.E.; Coplen, T.B.; Cutak, B.J.; Dixon, A.M.

2000-01-01

Gram quantities of aquatic humic substances (AHS) were extracted from the Wakarusa River-Clinton Lake Reservoir system, near Lawrence, KS, to support nuclear magnetic resonance (NMR) experimental studies, report concentrations of dissolved organic carbon (DOC) and AHS, define sources of the AHS, and determine if the AHS yield sufficient quantities of haloacetic acids (HAA5) and trihalomethanes (THM4) that exceed U.S. Environmental Protection Agency (EPA) Maximum Contaminant Levels (MCL) in drinking water. AHS from the Wakarusa River and Clinton Lake originated from riparian forest vegetation, reflected respective effects of soil organic matter and aquatic algal/bacterial sources, and bore evidence of biological degradation and photodegradation. AHS from the Wakarusa River showed the effect of terrestrial sources, whereas Clinton Lake humicacid also reflected aquatic algal/bacterial sources. Greater amounts of carbon attributable to tannin-derived chemical structures may correspond with higher HAA5 and THM4 yields for Clinton Lake fulvic acid. Prior to appreciable leaf-fall from deciduous trees, the combined (humic and fulvic acid) THM4 formation potentials for the Wakarusa River approached the proposed EPA THM4 Stage I MCL of 80 ??g/L, and the combined THM4 formation potential for Clinton Lake slightly exceeded the proposed THM4 Stage II MCL of 40 ??g/L. Finally, AHS from Clinton Lake could account for most (>70%) of the THM4 concentrations in finished water from the Clinton Lake Water Treatment Plant based on September 23, 1996, THM4 results.Gram quantities of aquatic humic substances (AHS) were extracted from the Wakarusa River-Clinton Lake Reservoir system, near Lawrence, KS, to support nuclear magnetic resonance (NMR) experimental studies, report concentrations of dissolved organic carbon (DOC) and AHS, define sources of the AHS, and determine if the AHS yield sufficient quantities of haloacetic acids (HAA5) and trihalomethanes (THM4) that exceed U.S. Environmental Protection Agency (EPA) Maximum Contaminant Levels (MCL) in drinking water. AHS from the Wakarusa River and Clinton Lake originated from riparian forest vegetation, reflected respective effects of soil organic matter and aquatic algal/bacterial sources, and bore evidence of biological degradation and photodegradation. AHS from the Wakarusa River showed the effect of terrestrial sources, whereas Clinton Lake humic acid also reflected aquatic algal/bacterial sources. Greater amounts of carbon attributable to tannin-derived chemical structures may correspond with higher HAA5 and THM4 yields for Clinton Lake fulvic acid. Prior to appreciable leaf-fall from deciduous trees, the combined (humic and fulvic acid) THM4 formation potentials for the Wakarusa River approached the proposed EPA THM4 Stage I MCL of 80 ??g/L, and the combined THM4 formation potential for Clinton Lake slightly exceeded the proposed THM4 Stage II MCL of 40 ??g/L. Finally, AHS from Clinton Lake could account for most (>70%) of the THM4 concentrations in finished water from the Clinton Lake Water Treatment Plant based on September 23, 1996, THM4 results.Gram quantities of aquatic humic substances were extracted from the Wakarusa River-Clinton Lake Reservoir system near Lawrence, KS, and concentrations of dissolved organic carbon (DOC) and the proportions of DOC accountable as aquatic humic substances were determined. In addition, the sources of the aquatic humic substances were defined, and the haloacetic acids/trihalomethanes formation potentials were assessed. The samples were collected over the period September 10-October 10, before any appreciable leaf-fall occurred from deciduous trees. Results showed that the humic substances produced considerable yields of haloacetic acids and trihalomethanes, with higher yields noted for fulvic acid from Clinton Lake. The aquatic humic substances were derived from sources outside and within the Wakarusa River and Clinton Lake and could yield sufficient trih

Lower Limits on Aperture Size for an ExoEarth Detecting Coronagraphic Mission

NASA Technical Reports Server (NTRS)

Stark, Christopher C.; Roberge, Aki; Mandell, Avi; Clampin, Mark; Domagal-Goldman, Shawn D.; McElwain, Michael W.; Stapelfeldt, Karl R.

2015-01-01

The yield of Earth-like planets will likely be a primary science metric for future space-based missions that will drive telescope aperture size. Maximizing the exoEarth candidate yield is therefore critical to minimizing the required aperture. Here we describe a method for exoEarth candidate yield maximization that simultaneously optimizes, for the first time, the targets chosen for observation, the number of visits to each target, the delay time between visits, and the exposure time of every observation. This code calculates both the detection time and multiwavelength spectral characterization time required for planets. We also refine the astrophysical assumptions used as inputs to these calculations, relying on published estimates of planetary occurrence rates as well as theoretical and observational constraints on terrestrial planet sizes and classical habitable zones. Given these astrophysical assumptions, optimistic telescope and instrument assumptions, and our new completeness code that produces the highest yields to date, we suggest lower limits on the aperture size required to detect and characterize a statistically motivated sample of exoEarths.

Influence of material quality and process-induced defects on semiconductor device performance and yield

NASA Technical Reports Server (NTRS)

Porter, W. A.; Mckee, W. R.

1974-01-01

An overview of major causes of device yield degradation is presented. The relationships of device types to critical processes and typical defects are discussed, and the influence of the defect on device yield and performance is demonstrated. Various defect characterization techniques are described and applied. A correlation of device failure, defect type, and cause of defect is presented in tabular form with accompanying illustrations.

Mineralogical and microstructural studies of mortars from the bath complex of the Roman villa rustica near Mosnje (Slovenia)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kramar, Sabina, E-mail: sabina.kramar@rescen.si; Zalar, Vesna; Urosevic, Maja

This study deals with the characterization of mortars collected from bath complex of the Roman villa rustica from an archeological site near Mosnje (Slovenia). The mortar layers of the mosaics, wall paintings and mortar floors were investigated. A special aggregate consisting of brick fragments was present in the mortars studied. The mineralogical and petrographic compositions of the mortars were determined by means of optical microscopy, X-ray powder diffraction and FTIR spectroscopy. Analysis of aggregate-binder interfaces using SEM-EDS revealed various types of reactivity rims. In order to assess the hydraulic characteristics of the mortars, the acid-soluble fractions were determined by ICP-OES.more » Furthermore, the results of Hg-porosimetry and gas sorption isotherms showed that mortars with a higher content of brick fragments particles exhibited a higher porosity and a greater BET surface area but a lower average pore diameter compared to mortars lacking this special aggregate. - Highlights: {yields} Mineral and microstructural characterizations of brick-lime mortars. {yields} Hydraulic character of mortars in Roman baths complex. {yields} Reaction rims were observed around brick fragments and dolomitic grains. {yields} Higher content of brick particles yielded a higher BET surface area. {yields} Addition of brick particles increased porosity and diminished pore size diameter.« less

How To Characterize Individual Nanosize Liposomes with Simple Self-Calibrating Fluorescence Microscopy.

PubMed

Mortensen, Kim I; Tassone, Chiara; Ehrlich, Nicky; Andresen, Thomas L; Flyvbjerg, Henrik

2018-05-09

Nanosize lipid vesicles are used extensively at the interface between nanotechnology and biology, e.g., as containers for chemical reactions at minute concentrations and vehicles for targeted delivery of pharmaceuticals. Typically, vesicle samples are heterogeneous as regards vesicle size and structural properties. Consequently, vesicles must be characterized individually to ensure correct interpretation of experimental results. Here we do that using dual-color fluorescence labeling of vesicles-of their lipid bilayers and lumens, separately. A vesicle then images as two spots, one in each color channel. A simple image analysis determines the total intensity and width of each spot. These four data all depend on the vesicle radius in a simple manner for vesicles that are spherical, unilamellar, and optimal encapsulators of molecular cargo. This permits identification of such ideal vesicles. They in turn enable calibration of the dual-color fluorescence microscopy images they appear in. Since this calibration is not a separate experiment but an analysis of images of vesicles to be characterized, it eliminates the potential source of error that a separate calibration experiment would have been. Nonideal vesicles in the same images were characterized by how their four data violate the calibrated relationship established for ideal vesicles. In this way, our method yields size, shape, lamellarity, and encapsulation efficiency of each imaged vesicle. Applying this procedure to extruded samples of vesicles, we found that, contrary to common assumptions, only a fraction of vesicles are ideal.

Application of blind source separation to real-time dissolution dynamic nuclear polarization.

PubMed

Hilty, Christian; Ragavan, Mukundan

2015-01-20

The use of a blind source separation (BSS) algorithm is demonstrated for the analysis of time series of nuclear magnetic resonance (NMR) spectra. This type of data is obtained commonly from experiments, where analytes are hyperpolarized using dissolution dynamic nuclear polarization (D-DNP), both in in vivo and in vitro contexts. High signal gains in D-DNP enable rapid measurement of data sets characterizing the time evolution of chemical or metabolic processes. BSS is based on an algorithm that can be applied to separate the different components contributing to the NMR signal and determine the time dependence of the signals from these components. This algorithm requires minimal prior knowledge of the data, notably, no reference spectra need to be provided, and can therefore be applied rapidly. In a time-resolved measurement of the enzymatic conversion of hyperpolarized oxaloacetate to malate, the two signal components are separated into computed source spectra that closely resemble the spectra of the individual compounds. An improvement in the signal-to-noise ratio of the computed source spectra is found compared to the original spectra, presumably resulting from the presence of each signal more than once in the time series. The reconstruction of the original spectra yields the time evolution of the contributions from the two sources, which also corresponds closely to the time evolution of integrated signal intensities from the original spectra. BSS may therefore be an approach for the efficient identification of components and estimation of kinetics in D-DNP experiments, which can be applied at a high level of automation.

Suspended Sediment Load and Sediment Yield During Floods and Snowmelt Runoff In The Rio Cordon (northeastern Italy)

NASA Astrophysics Data System (ADS)

Lenzi, M. A.

Suspended sediment transport in high mountain streams display a grater time-space variability and a shorter duration (normally concentrated during the snowmelt period and the duration time of single floods) than in larger lowland rivers. Suspended sedi- ment load and sediment yield were analysed in a small, high-gradient stream of East- ern Italian Alps which was instrumented to measure in continuous water discharge and sediment transport. The research was conducted in the Rio Cordon, a 5 Km2 small catchment of the Dolomites. The ratio of suspended to total sediment yield and the re- lations between sediment concentration and water discharge were analysed for eleven floods which occurred from 1991 to 2001. Different patterns of hysteresis in the re- lation between suspended sediment and discharge were related to types and locations of active sediment sources. The within-storm variation of particle size of suspended sediment during a mayor flood (September 1994, 30 years

Stratigraphy and geochemical characterization of the Oligocene Miocene Maikop series: Implications for the paleogeography of Eastern Azerbaijan

NASA Astrophysics Data System (ADS)

Hudson, Samuel M.; Johnson, Cari L.; Efendiyeva, Malakhat A.; Rowe, Harold D.; Feyzullayev, Akper A.; Aliyev, Chingiz S.

2008-04-01

The Oligocene-Miocene Maikop Series is a world-class source rock responsible for much of the oil and gas found in the South Caspian Basin. It is composed of up to 3 km of marine mudstone, and contains a nearly continuous record of deposition during progressive tectonic closure of the basin as the Arabian Peninsula converged northward into Eurasia. Historically, the stratigraphy of this interval has been difficult to define due to the homogenous nature of the fine-grained, clay-dominated strata. Outcrop exposures in eastern Azerbaijan allow direct observation and detailed sampling of the interval, yielding a more comprehensive stratigraphic context and a more advanced understanding of syndepositional conditions in the eastern Paratethys Sea. Specifically, the present investigation reveals that coupling field-based stratigraphic characterization with geochemical analyses (e.g., bulk elemental geochemistry, Rock-Eval pyrolysis, bulk stable isotope geochemistry) yields a more robust understanding of internal variations within the Maikop Series. Samples from seven sections located within the Shemakha-Gobustan oil province reveal consistent stratigraphic and spatial geochemical trends. It is proposed that the Maikop Series be divided into three members based on these data along with lithostratigraphic and biostratigraphic data reported herein. When comparing Rupelian (Early Oligocene) and Chattian (Late Oligocene) strata, the Rupelian-age strata commonly possess higher TOC values, more negative δ 15N tot values, more positive δ 13C org values, and higher radioactivity relative to Chattian-age rocks. The trace metals Mo and V (normalized to Al) are positively correlated with TOC, with maximum values occurring at the Rupelian-Chattian boundary and overall higher average values in the Rupelian. Across the Oligocene-Miocene boundary, a slight drop in V/Al, Mo/Al ratios is observed, along with drops in %S and TOC. These results indicate that geochemical signatures of the Maikop Series are regional in nature, and furthermore that analogous fine-grained sections may be better characterized and subdivided using similar techniques. In general, geochemical indicators suggest that the basin was in limited communication with the Tethys Sea throughout the Oligocene-Early Miocene, with suboxic to anoxic conditions present during the Oligocene and to a lesser extent in the Miocene. This increased isolation was likely due to tectonic uplift to both the south and north of the study area, and greatly enhanced by global sea-level fluctuations. These data serve as the basis for a more detailed understanding of the tectonic evolution of the region, and support a standardized chemostratigraphic division of the important petroleum source interval.

Influence of declining mean annual rainfall on the behavior and yield of sediment and particulate organic carbon from tropical watersheds

NASA Astrophysics Data System (ADS)

Strauch, Ayron M.; MacKenzie, Richard A.; Giardina, Christian P.; Bruland, Gregory L.

2018-04-01

The capacity to forecast climate and land-use driven changes to runoff, soil erosion and sediment transport in the tropics is hindered by a lack of long-term data sets and model study systems. To address these issues we utilized three watersheds characterized by similar shape, geology, soils, vegetation cover, and land use arranged across a 900 mm gradient in mean annual rainfall (MAR). Using this space-for-time design, we quantified suspended sediment (SS) and particulate organic carbon (POC) export over 18 months to examine how large-scale climate trends (MAR) affect sediment supply and delivery patterns (hysteresis) in tropical watersheds. Average daily SS yield ranged from 0.128 to 0.618 t km- 2 while average daily POC ranged from 0.002 to 0.018 t km- 2. For the largest storm events, we found that sediment delivery exhibited similar clockwise hysteresis patterns among the watersheds, with no significant differences in the similarity function between watershed pairs, indicating that: (1) in-stream and near-stream sediment sources drive sediment flux; and (2) the shape and timing of hysteresis is not affected by MAR. With declining MAR, the ratio of runoff to baseflow and inter-storm length between pulse events both increased. Despite increases in daily rainfall and the number of days with large rainfall events increasing with MAR, there was a decline in daily SS yield possibly due to the exhaustion of sediment supply by frequent runoff events in high MAR watersheds. By contrast, mean daily POC yield increased with increasing MAR, possibly as a result of increased soil organic matter decomposition, greater biomass, or increased carbon availability in higher MAR watersheds. We compared results to modeled values using the Load Estimator (LOADEST) FORTRAN model, confirming the negative relationship between MAR and sediment yield. However, because of its dependency on mean daily flow, LOADEST tended to under predict sediment yield, a result of its poor ability to capture the high variability in tropical streamflow. Taken together, results indicate that declines in MAR can have contrasting effects on hydrological processes in tropical watersheds, with consequences for instream ecology, downstream water users, and nearshore habitat.

Pyrolysis of attapulgite clay blended with yak dung enhances pasture growth and soil health: Characterization and initial field trials.

PubMed

Rafiq, Muhammad Khalid; Joseph, Stephen D; Li, Fei; Bai, Yanfu; Shang, Zhanhuan; Rawal, Aditya; Hook, James M; Munroe, Paul R; Donne, Scott; Taherymoosavi, Sara; Mitchell, David R G; Pace, Ben; Mohammed, Mohanad; Horvat, Joseph; Marjo, Christopher E; Wagner, Avital; Wang, Yanlong; Ye, Jun; Long, Rui-Jun

2017-12-31

Recent studies have shown that the pyrolysis of biomass combined with clay can result in both lower cost and increase in plant yields. One of the major sources of nutrients for pasture growth, as well as fuel and building materials in Tibet is yak dung. This paper reports on the initial field testing in a pasture setting in Tibet using yak dung, biochar, and attapulgite clay/yak dung biochars produced at ratios of 10/90 and 50/50 clay to dung. We found that the treatment with attapulgite clay/yak dung (50/50) biochar resulted in the highest pasture yields and grass nutrition quality. We also measured the properties and yields of mixtures of clay/yak dung biochar used in the field trials produced at 400°C and 500°C to help determine a possible optimum final pyrolysis temperature and dung/clay ratio. It was observed that increasing clay content increased carbon stability, overall biochar yield, pore size, carboxyl and ketone/aldehyde functional groups, hematite and ferrous/ferric sulphate/thiosulphate concentration, surface area and magnetic moment. Decreasing clay content resulted in higher pH, CEC, N content and an enhanced ability to accept and donate electrons. The resulting properties were a complex function of both processing temperature and the percentage of clay for the biochars processed at both 400°C and 500°C. It is possible that the increase in yield and nutrient uptake in the field trial is related to the higher concentration of C/O functional groups, higher surface area and pore volume and higher content of Fe/O/S nanoparticles of multiple oxidation state in the 50/50 clay/dung. These properties have been found to significantly increase the abundance of beneficial microorganisms and hence improve the nutrient cycling and availability in soil. Further field trials are required to determine the optimum pyrolysis production conditions and application rate on the abundance of beneficial microorganisms, yields and nutrient quality. Copyright © 2017 Elsevier B.V. All rights reserved.

A continental scale model for dissolved silica mobilization in North America

NASA Astrophysics Data System (ADS)

Jansen, N.; Lauerwald, R.; Hartmann, J.; Dürr, H. H.; Loos, S.; Kempe, S.; Middelkoop, H.

2009-04-01

Silicon is one of the few elements that link to both the organic and inorganic carbon cycles. Dissolved silicon (DSi) is an important nutrient in terrestrial and aquatic ecosystems. Cations accompanying the release of DSi by chemical silicate rock weathering are generally balanced by soil/atmospheric CO2. Chemical weathering is the major source of "new" bioavailable DSi for continental aquatic systems to compensate for the loss of DSi by outflow or organic precipitation and burial. We use river water chemistry data from 164 monitoring stations from the conterminous United States (WQN and NAWQA networks). Selected stations are characterized by low population density and low influence of water bodies to minimize human and DSi retention impact. Observed DSi yield in these catchments is assumed to represent natural DSi mobilization by chemical weathering. The catchments have an average size of 4400 km2 (Median: 991 km2) with a discharge weighted average DSi yield of 4.34 t SiO2 km-2a-1. To predict mobilization of DSi from chemical weathering a lumped non-linear empirical model is developed, considering control factors such as climate, morphology, hydrology, land cover, soil and lithology. A multi-lithological model approach is chosen because only very few mono-lithological catchments were identified in the dataset. The model is then extrapolated to the conterminous United States to regionally quantify the amount of DSi that is released into the river systems by chemical weathering. Small outcrops of certain lithological classes characterized by a high DSi yield are not represented on previously available small scale lithological maps. Because such localities may have a major influence on DSi fluxes from small catchments (Hartmann et al., 2009) a new high resolution lithological vector-map for North America is developed and applied in the introduced model. In accordance with previous studies, runoff and lithology are identified as the major predictors for specific DSi flux (Bluth and Kump, 1994; Hartmann et al., 2009). Only in relation to some lithological classes, temperature and terrain slope constitute significant predictors. An influence of land cover, soil properties or other predictors is not observed. This is partly attributed to geodata resolution and classification. Lithological classes "Basic Volcanics and Pyroclastics" and "Basic and Intermediate Plutonics" show the highest DSi yields, with respect to a given discharge. The lithological class "Siliciclastic Sedimentary Rocks" is characterized by the lowest DSi yield. The model explains 89% of the DSi yield variance; the average yield of catchments employed in model calibration is 4.32 t SiO2 km-2a-1, somewhat above the global average yield of 3.3 t SiO2 km-2a-1 (Dürr et al., 2009). The model quantifies DSi fluxes from the terrestrial into the continental aquatic systems. This helps to estimate DSi retention within fluvial systems (Lauerwald et al., submitted) and improves understanding of this part of the silicon cycle. References: Bluth, G.J.S., and Kump, L.R., 1994, Lithologic and Climatologic Controls of River Chemistry: Geochimica Cosmochimica Acta, 58, 2341-2359. Dürr, H.H., Meybeck, M., Hartmann, J., Laruelle, G.G., and Roubeix, V., 2009, Global Spatial distribution of natural riverine silica inputs to the coastal zone: Biogeosciences, (in review), bgd-2008-0173. Hartmann, J., Jansen, N., Dürr, H.H., Harashima, A., Okubo, K., and Kempe, S., 2009, Predicting riverine dissolved silica fluxes into coastal zones from a hyperactive region and analysis of their first order controls: International Journal of Earth Sciences, (DOI 10.1007/s00531-008-0381-5). Lauerwald, R., Jansen N., Hartmann, J., Dürr, H.H., Loos, S., Kempe, S., Middelkoop, H., submitted, Modeling dissolved silica retention in the limnic system of North America. (Submitted to this session).

Genetic characterization of Arcobacter isolates from various sources.

PubMed

Shah, A H; Saleha, A A; Zunita, Z; Cheah, Y K; Murugaiyah, M; Korejo, N A

2012-12-07

Arcobacter is getting more attention due to its detection from wide host-range and foods of animal origin. The objective of this study was to determine the prevalence of Arcobacter spp. in various sources at farm level and beef retailed in markets in Malaysia and to assess the genetic relatedness among them. A total of 273 samples from dairy cattle including cattle (n=120), floor (n=30), water (n=18) and milk (n=105) as well as 148 beef samples collected from retail markets were studied. The overall prevalence of Arcobacter in various sources was 15% (63/421). However, source-wise detection rate of Arcobacter spp. was recorded as 26.66% (8/30) in floor, 26.3% (39/148) in beef, 11.11% (2/18) in water, 7.6% (8/105) in milk and 6.66% (8/120) in cattle. Arcobacter butzleri was the frequently isolated species however, a total of 75%, 66.7%, 53.8%, 50% and 12.5%% samples from floor, milk, beef, water and cattle, respectively, were carrying more than one species simultaneously. One (12.5%) cattle and beef sample (2.5%) found to be carrying one Arcobacter spp., A. skirrowii, only. Typing of Arcobacter isolates was done though pulsed field gel electrophoresis (PFGE) after digested with Eag1 restriction endonuclease (RE). Digestion of genomic DNA of Arcobacter from various sources yielded 12 major clusters (≥ 50% similarity) which included 29 different band patterns. A number of closely related A. butzleri isolates were found from beef samples which indicate cross contamination of common type of Arcobacter. Fecal shedding of Arcobacter by healthy animals can contaminate water and milk which may act as source of infection in humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Ambient seismic noise interferometry in Hawai'i reveals long-range observability of volcanic tremor

USGS Publications Warehouse

Ballmer, Silke; Wolfe, Cecily; Okubo, Paul G.; Haney, Matt; Thurber, Clifford H.

2013-01-01

The use of seismic noise interferometry to retrieve Green's functions and the analysis of volcanic tremor are both useful in studying volcano dynamics. Whereas seismic noise interferometry allows long-range extraction of interpretable signals from a relatively weak noise wavefield, the characterization of volcanic tremor often requires a dense seismic array close to the source. We here show that standard processing of seismic noise interferometry yields volcanic tremor signals observable over large distances exceeding 50 km. Our study comprises 2.5 yr of data from the U.S. Geological Survey Hawaiian Volcano Observatory short period seismic network. Examining more than 700 station pairs, we find anomalous and temporally coherent signals that obscure the Green's functions. The time windows and frequency bands of these anomalous signals correspond well with the characteristics of previously studied volcanic tremor sources at Pu'u 'Ō'ō and Halema'uma'u craters. We use the derived noise cross-correlation functions to perform a grid-search for source location, confirming that these signals are surface waves originating from the known tremor sources. A grid-search with only distant stations verifies that useful tremor signals can indeed be recovered far from the source. Our results suggest that the specific data processing in seismic noise interferometry—typically used for Green's function retrieval—can aid in the study of both the wavefield and source location of volcanic tremor over large distances. In view of using the derived Green's functions to image heterogeneity and study temporal velocity changes at volcanic regions, however, our results illustrate how care should be taken when contamination by tremor may be present.