Organic molecules, ions, and rare isotopologues in the remnant of the stellar-merger candidate, CK Vulpeculae (Nova 1670)

NASA Astrophysics Data System (ADS)

Kamiński, T.; Menten, K. M.; Tylenda, R.; Karakas, A.; Belloche, A.; Patel, N. A.

2017-11-01

Context. CK Vulpeculae (CK Vul) is an enigmatic star whose outburst was observed in 1670-72. A stellar-merger event was proposed to explain its ancient eruption. Aims: We aim to investigate the composition of the molecular gas recently discovered in the remnant of CK Vul. Deriving the chemical, elemental, and isotopic composition is crucial for identifying the nature of the object and obtaining clues on its progenitor(s). Methods: We observed millimeter and submillimeter-wave spectra of CK Vul using the IRAM 30 m and APEX telescopes. Radiative-transfer modeling of the observed molecular features was performed to yield isotopic ratios for various elements. Results: The spectra of CK Vul reveal a very rich molecular environment of low excitation (Tex ≲ 12 K). Atomic carbon and twenty-seven different molecules, including two ions, were identified. They range from simple diatomic to complex polyatomic species of up to seven atoms large. The chemical composition of the molecular gas is indicative of carbon and nitrogen-driven chemistry but oxides are also present. Additionally, the abundance of fluorine may be enhanced. The spectra are rich in isotopologues that are very rare in most known sources. All stable isotopes of C, N, O, Si, and S are observed and their isotopic ratios are derived. Conclusions: The composition of the remnant's molecular gas is most peculiar and gives rise to a very unique millimeter and submillimeter spectrum. The observation of ions and complex molecules suggests the presence of a photoionizing source but its nature (a central star or shocks) remains unknown. The elemental and isotopic composition of the gas cannot be easily reconciled with standard stellar nucleosynthesis but processing in hot CNO cycles and partial helium burning can explain most of the chemical peculiarities. The isotopic ratios of CK Vul are remarkably close to those of presolar "nova grains" but the link of Nova 1670 to objects responsible for these grains is unclear. The accuracy of isotopic ratios can be improved by future observations at higher angular resolutions and with realistic models of the kinematical structure of the remnant. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A78

[Searching for Rare Celestial Objects Automatically from Stellar Spectra of the Sloan Digital Sky Survey Data Release Eight].

PubMed

Si, Jian-min; Luo, A-li; Wu, Fu-zhao; Wu, Yi-hong

2015-03-01

There are many valuable rare and unusual objects in spectra dataset of Sloan Digital Sky Survey (SDSS) Data Release eight (DR8), such as special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on, so it is extremely significant to search for rare and unusual celestial objects from massive spectra dataset. A novel algorithm based on Kernel dense estimation and K-nearest neighborhoods (KNN) has been presented, and applied to search for rare and unusual celestial objects from 546 383 stellar spectra of SDSS DR8. Their densities are estimated using Gaussian kernel density estimation, the top 5 000 spectra in descend order by their densities are selected as rare objects, and the top 300 000 spectra in ascend order by their densities are selected as normal objects. Then, KNN were used to classify the rest objects, and simultaneously K nearest neighbors of the 5 000 rare spectra are also selected as rare objects. As a result, there are totally 21 193 spectra selected as initial rare spectra, which include error spectra caused by deletion, redden, bad calibration, spectra consisting of different physically irrelevant components, planetary nebulas, QSOs, special white dwarfs (DZ, DQ, DC), carbon stars, white dwarf main-sequence binaries (WDMS), cataclysmic variable (CV) stars and so on. By cross identification with SIMBAD, NED, ADS and major literature, it is found that three DZ white dwarfs, one WDMS, two CVs with company of G-type star, three CVs candidates, six DC white dwarfs, one DC white dwarf candidate and one BL Lacertae (BL lac) candidate are our new findings. We also have found one special DA white dwarf with emission lines of Ca II triple and Mg I, and one unknown object whose spectrum looks like a late M star with emission lines and its image looks like a galaxy or nebula.

New ceramics containing dispersants for improved fracture toughness

DOEpatents

Nevitt, M.V.; Aldred, A.T.; Chan, Sai-Kit

1985-07-01

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRBO/sub 4/, where R is a rare-earth element, B if Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Ceramics containing dispersants for improved fracture toughness

DOEpatents

Nevitt, Michael V.; Aldred, Anthony T.; Chan, Sai-Kit

1987-07-07

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Ceramics containing dispersants for improved fracture toughness

DOEpatents

Nevitt, Michael V.; Aldred, Anthony T.; Chan, Sai-Kit

1987-01-01

The invention is a ceramic composition containing a new class of dispersant for hindering crack propagation by means of one or more energy-dissipative mechanisms. The composition is composed of a ceramic matrix with dispersed particles of a transformation-prone rare-earth niobate, tantalate or mixtures of these with each other and/or with a rare-earth vanadate. The dispersants, having a generic composition tRMO.sub.4, where R is a rare-earth element, B is Nb or Ta and O is oxygen, are mixed in powder form with a powder of the matrix ceramic and sintered to produce a ceramic form or body. The crack-hindering mechanisms operates to provide improved performance over a wide range of temperature and operating conditions.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications.

PubMed

Roca, Christophe; Alves, Vitor D; Freitas, Filomena; Reis, Maria A M

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed.

Fractionation of rare-earth elements in allanite and monazite as related to geology of the Mt. Wheeler mine area, Nevada

USGS Publications Warehouse

Lee, D.E.; Bastron, H.

1967-01-01

Rare-earth contents of 20 allanites and 13 monazites, accessory minerals from a restricted outcrop area of intrusive granitic rocks, are reported. A quantity called sigma (??), which is the sum of the atomic percentages of La, Ce and Pr, is used as an index of composition with respect to the rare-earth elements. Values of sigma vary from 61.3 to 80.9 at.% for these allanites and monazites, representing an appreciable range of composition in terms of the rare-earth elements. Degree of fractionation of rare earths varies directly with CaO content of the granitic rocks, which in turn depends largely on proximity of limestone. Four xenoliths included in the study suggest that spotty mosaic equilibria are superimposed on the regional gradients and that locally the degree of fractionation of rare earths responds to whole rock composition over distances of a few yards or less. The chemistry of the granitic rocks under study appears to be similar in some respects to that of alkalio rocks and carbonatites. Allanites from the most calcium-rich rocks show a pronounced concentration of the most basic rare earths, and whole-rock concentrations of such rare constituents as total cerium earths, Zr, F, Ti, Ba and Sr increase sympathetically with whole-rock calcium. The explanation for the concentration gradients observed in this chemical system must involve assimilation more than magmatic differentiation. ?? 1967.

Compositional and phase relations among rare earth element minerals

NASA Technical Reports Server (NTRS)

Burt, D. M.

1990-01-01

This paper discusses the compositional and phase relationships among minerals in which rare earth elements (REE) occur as essential constituents (e.g., bastnaesite, monazite, xenotime, aeschynite, allanite). Particular consideration is given to the vector representation of complex coupled substitutions in selected REE-bearing minerals and to the REE partitioning between minerals as related to the acid-base tendencies and mineral stabilities. It is shown that the treatment of coupled substitutions as vector quantities facilitates graphical representation of mineral composition spaces.

The effect of prescribed burning on plant rarity in a temperate forest.

PubMed

Patykowski, John; Holland, Greg J; Dell, Matt; Wevill, Tricia; Callister, Kate; Bennett, Andrew F; Gibson, Maria

2018-02-01

Rare species can play important functional roles, but human-induced changes to disturbance regimes, such as fire, can inadvertently affect these species. We examined the influence of prescribed burns on the recruitment and diversity of plant species within a temperate forest in southeastern Australia, with a focus on species that were rare prior to burning. Floristic composition was compared among plots in landscapes before and after treatment with prescribed burns differing in the extent of area burnt and season of burn (before-after, control-impact design). Floristic surveys were conducted before burns, at the end of a decade of drought, and 3 years postburn. We quantified the effect of prescribed burns on species grouped by their frequency within the landscape before burning (common, less common, and rare) and their life-form attributes (woody perennials, perennial herbs or geophytes, and annual herbs). Burn treatment influenced the response of rare species. In spring-burn plots, the recruitment of rare annual herbs was promoted, differentiating this treatment from both autumn-burn and unburnt plots. In autumn-burn plots, richness of rare species increased across all life-form groups, although composition remained statistically similar to control plots. Richness of rare woody perennials increased in control plots. For all other life-form and frequency groups, the floristic composition of landscapes changed between survey years, but there was no effect of burn treatment, suggesting a likely effect of rainfall on species recruitment. A prescribed burn can increase the occurrence of rare species in a landscape, but burn characteristics can affect the promotion of different life-form groups and thus affect functional diversity. Drought-breaking rain likely had an overarching effect on floristic composition during our study, highlighting that weather can play a greater role in influencing recruitment and diversity in plant communities than a prescribed burn.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications

PubMed Central

Roca, Christophe; Alves, Vitor D.; Freitas, Filomena; Reis, Maria A. M.

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed. PMID:25914689

The rare earth element compositions of the Changjiang (Yangtze) and Huanghe (Yellow) river sediments

NASA Astrophysics Data System (ADS)

Yang, Shou Ye; Jung, Hoi Soo; Choi, Man Sik; Li, Cong Xian

2002-07-01

Thirty-four samples from the Changjiang and Huanghe were analyzed to characterize their rare earth element (REE) compositions. Although REE concentrations in the Changjiang sediments are higher than those of the Huanghe sediments, the former are less variable. Bulk samples and acid-leachable fractions have convex REE patterns and middle REE enrichments relative to upper continental crust, whereas flat patterns are present in the residual fractions. Source rock composition is the primary control on REE composition, and weathering processes play a minor role. Grain size exerts some influence on REE composition, as demonstrated by the higher REE contents of clay minerals in sediments from both rivers. Heavy minerals contribute about 10-20% of the total REE in the sediments. Apatite is rare in the river sediments, and contributes less than 2% of the REE content, but other heavy minerals such as sphene, allanite and zircon are important reservoirs of residual REE fractions. The Fe-Mn oxides phase accounts for about 14% of bulk REE content in the Changjiang sediments, which could be one of the more important factors controlling REE fractionation in the leachable fraction.

Multi-objective optimization of chromatographic rare earth element separation.

PubMed

Knutson, Hans-Kristian; Holmqvist, Anders; Nilsson, Bernt

2015-10-16

The importance of rare earth elements in modern technological industry grows, and as a result the interest for developing separation processes increases. This work is a part of developing chromatography as a rare earth element processing method. Process optimization is an important step in process development, and there are several competing objectives that need to be considered in a chromatographic separation process. Most studies are limited to evaluating the two competing objectives productivity and yield, and studies of scenarios with tri-objective optimizations are scarce. Tri-objective optimizations are much needed when evaluating the chromatographic separation of rare earth elements due to the importance of product pool concentration along with productivity and yield as process objectives. In this work, a multi-objective optimization strategy considering productivity, yield and pool concentration is proposed. This was carried out in the frame of a model based optimization study on a batch chromatography separation of the rare earth elements samarium, europium and gadolinium. The findings from the multi-objective optimization were used to provide with a general strategy for achieving desirable operation points, resulting in a productivity ranging between 0.61 and 0.75 kgEu/mcolumn(3), h(-1) and a pool concentration between 0.52 and 0.79 kgEu/m(3), while maintaining a purity above 99% and never falling below an 80% yield for the main target component europium. Copyright © 2015 Elsevier B.V. All rights reserved.

Combinatorial search of rare-earth free permanent magnets

NASA Astrophysics Data System (ADS)

Gao, Tieren; Takeuchi, Ichiro; Fackler, Sean; Fang, Lei; Zhang, Ying; Krammer, Matthew; Anderson, Iver; McCallum, Bill; University of Maryland Collaboration; Ames Laboratory Collaboration

2013-03-01

Permanent magnets play important roles in modern technologies such as in generators, motors, speakers, and relays. Today's high performance permanent magnets contain at least one rare earth element such as Nd, Sm, Pr and Dy. However, rare earth elements are increasingly rare and expensive, and alternative permanent magnet materials which do not contain them are needed by the industry. We are using the thin film composition spread technique to explore novel compositions of permanent magnets without rare-earth. Ternary co-sputtering is used to generate composition spreads. We have thus far looked at Mo doped Fe-Co as one of the initial systems to search for possible compounds with enhanced coercive fields. The films were deposited on Si (100) substrates and annealed at different temperatures. The structural properties of films are mapped by synchrotron diffraction. We find that there is a structural transition from a crystalline to an amorphous state at about 20% atomic Mo. With increasing annealing temperature, the Mo onset concentration of the structural transition increases from 25% for 600°C to 35% for 700°C. We find that some of compounds display enhanced coercive field. With increasing Mo concentration, the magnetization of Fe-Co-Mo begins to switch from in-plane to out-of-plane direction. This work is funded by the BREM (Beyond Rare-earth Magnet) project (DOE EERE).

Unraveling Recrystallization Mechanisms Governing Texture Development from Rare Earth Element Additions to Magnesium

NASA Astrophysics Data System (ADS)

Imandoust, Aidin

The origin of texture components associated with rare-earth (RE) element additions in wrought magnesium (Mg) alloys is a long-standing problem in magnesium technology. The objective of this research is to identify the mechanisms accountable for rare-earth texture during dynamic recrystallization (DRX). Towards this end, we designed binary Mg-Cerium and Mg-Gadolinium alloys along with complex alloy compositions containing zinc, yttrium and Mischmetal. Binary alloys along with pure Mg were designed to individually investigate their effects on texture evolutions, while complex compositions are designed to develop randomized texture, and be used in automotive and aerospace applications. We selected indirect extrusion to thermo-mechanically process our materials. Different extrusion ratios and speeds were designed to produce partially and fully recrystallized microstructures, allowing us to analyze DRX from its early stages to completion. X-ray diffraction, electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) were used to conduct microstructure and texture analyses. Our analyses revealed that rare-earth elements in zinc-containing magnesium alloys promote discontinuous dynamic recrystallization at the grain boundaries. During nucleation, the effect of rare earth elements on orientation selection was explained by the concomitant actions of multiple Taylor axes in the same grain. Isotropic grain growth was observed due to rare earth elements segregating to grain boundaries, which lead to texture randomization. The nucleation in binary Mg-RE alloys took place by continuous formation of necklace structures. Stochastic relaxation of basal and non-basal dislocations into low-angle grain boundaries produced chains of embryos with nearly random orientations. Schmid factor analysis showed a lower net activation of dislocations in RE textured grains compared to ones on the other side of the stereographic triangle. Lower dislocation densities within RE grains favored their growth by setting the boundary migration direction toward grains with higher dislocation density, thereby decreasing the system energy. We investigated the influence of RE elements on extension twinning induced hardening. RE addition enhanced tensile twinning induced hardening significantly. EBSD analysis illustrated that tensile twins cross low angle grain boundaries in Mg-RE alloys, which produced large twins and facilitated transmutation of basal to prismatic dislocations. Higher activity of pyramidal II dislocations in Mg-RE alloys resulted in higher twinning induced hardening.

New data on the substantial composition of Kalba rare metal deposits

NASA Astrophysics Data System (ADS)

Oitseva, T. A.; Dyachkov, B. A.; Vladimirov, A. G.; Kuzmina, O. N.; Ageeva, O. V.

2017-12-01

Geotectonic position, features of the geological structure and rare metal specialization of the Kalba-Narym granitoid belt formed in the Hercynian cycle in the postcollision (orogenic) geodynamic situation are considered. A geological-genetic model for the formation of the leading type of rare-metal pegmatite deposits (Ta, Nb, Be, Li, etc.) is presented. They are spatially and genetically related mainly to the granitoids of the 1st phase of the Kalba complex, P1 (Bakennoye, Jubilee, Belaya Gora, etc.). The rhythmically pulsating orientation of the process of pegmatite formation with the introduction of ore-bearing fluids (H2O, F, B, Cl, Ta, Nb, Be, etc.) is emphasized from the intracamera focus of a semi-closed magmatic system. The preferred location of ore pegmatite veins in granitoids of moderate basicity occupying an intermediate position in the petrochemical composition between normal granites and granodiorites geochemically specialized in Li, Rb, Cs, Sn, Nb, Ta. The leading ore-controlling role of the latitudinal deep faults of the ancient site in the distribution of rare-metal ore fields and deposits (Ognevsk-Bakennoye, Asubulak, Belogorsk, etc.) is determined. There is a zonal structure of pegmatite veins, a gradual development of mineral complexes from the graphic and oligoclase-microcline (non-ore) to microcline-albite and color albite-spodumene (ore). The mineralization of pegmatite veins is determined by the degree of intensity of the manifestation in them of metasomatic processes (microclinization, alibitization, greisenization, spodumenization, tourmalinization, etc.) and the identification of the main ore minerals (tantalite-columbite, cassiterite, spodumene and beryl). The diversity of the material composition of rare-metal pegmatites containing many unique minerals (cleavelandite, lepidolite, ambligonite, color tourmaline, spodumene, pollucite, etc.) is reflected, which brings them closer to the pegmatite deposits of foreign countries (Koktogai, Bernik Lake, etc.). New results of the investigation of the material composition of ore-bearing granites, pegmatites and typomorphic minerals using electron microscopy reflecting the distribution of rare-earth, rare-metal, chalcophile and other elements in them are presented. Indicators of rare metal ore formation are rock-forming minerals of granites (quartz, microcline, biotite, muscovite), ore and associated minerals (cleavelandite, lepidolite, cassiterite, etc.). The most informative minerals include mica (muscovite, giltbertite, lepidolite), colored tourmalines and beryls of different composition and color. Identified typomorphic minerals and geochemical elements-indicators of rare metal pegmatite formation are considered as a leading search criterion in assessing the prospects of the territory of East Kazakhstan.

Applications of RIGAKU Dmax Rapid II micro-X-ray diffractometer in the analysis of archaeological metal objects

NASA Astrophysics Data System (ADS)

Mozgai, Viktória; Szabó, Máté; Bajnóczi, Bernadett; Weiszburg, Tamás G.; Fórizs, István; Mráv, Zsolt; Tóth, Mária

2017-04-01

During material analysis of archaeological metal objects, especially their inlays or corrosion products, not only microstructure and chemical composition, but mineralogical composition is necessary to be determined. X-ray powder diffraction (XRD) is a widely-used method to specify the mineralogical composition. However, when sampling is not or limitedly allowed due to e.g. the high value of the object, the conventional XRD analysis can hardly be used. Laboratory micro-XRD instruments provide good alternatives, like the RIGAKU Dmax Rapid II micro-X-ray diffractometer, which is a unique combination of a MicroMax-003 third generation microfocus, sealed tube X-ray generator and a curved 'image plate' detector. With this instrument it is possible to measure as small as 10 µm area in diameter on the object. Here we present case studies for the application of the micro-XRD technique in the study of archaeological metal objects. In the first case niello inlay of a Late Roman silver augur staff was analysed. Due to the high value of the object, since it is the only piece known from the Roman Empire, only non-destructive analyses were allowed. To reconstruct the preparation of the niello, SEM-EDX analysis was performed on the niello inlays to characterise their chemical composition and microstructure. Two types of niello are present: a homogeneous, silver sulphide niello (acanthite) and an inhomogeneous silver-copper sulphide niello (exsolution of acanthite and jalpaite or jalpaite and stromeyerite). The micro-X-ray diffractometer was used to verify the mineralogical composition of the niello, supposed on the base of SEM results. In the second case corrosion products of a Late Roman copper cauldron with uncertain provenance were examined, since they may hold clues about the burial conditions (pH, Eh, etc.) of the object. A layer by layer analysis was performed in cross sections of small metal samples by using electron microprobe and micro-X-ray diffractometer. The results show two corrosion zones: 1) the original (internal) surface zone of the metallic copper object was replaced by copper(I) oxide (cuprite), while 2) basic copper(II) carbonate (malachite) was deposited (externally) on the original surface. In our view these two minerals were formed during long-time burial, and protected the cauldron from further corrosion. Rarely copper(I) chloride (nantokite), basic copper(II) trihydroxychloride (atacamite/paratacamite) and basic copper(II) sulphate (brochantite) were also identified in the two corrosion zones. Their uneven distribution on the cauldron and their known formation conditions indicate, that these latter mineral phases may be the results of active corrosion, started possibly after excavation.

Review of rare earth element concentrations in oil shales of the Eocene Green River Formation

USGS Publications Warehouse

Birdwell, Justin E.

2012-01-01

Concentrations of the lanthanide series or rare earth elements and yttrium were determined for lacustrine oil shale samples from the Eocene Green River Formation in the Piceance Basin of Colorado and the Uinta Basin of Utah. Unprocessed oil shale, post-pyrolysis (spent) shale, and leached shale samples were examined to determine if oil-shale processing to generate oil or the remediation of retorted shale affects rare earth element concentrations. Results for unprocessed Green River oil shale samples were compared to data published in the literature on reference materials, such as chondritic meteorites, the North American shale composite, marine oil shale samples from two sites in northern Tibet, and mined rare earth element ores from the United States and China. The Green River oil shales had lower rare earth element concentrations (66.3 to 141.3 micrograms per gram, μg g-1) than are typical of material in the upper crust (approximately 170 μg g-1) and were also lower in rare earth elements relative to the North American shale composite (approximately 165 μg g-1). Adjusting for dilution of rare earth elements by organic matter does not account for the total difference between the oil shales and other crustal rocks. Europium anomalies for Green River oil shales from the Piceance Basin were slightly lower than those reported for the North American shale composite and upper crust. When compared to ores currently mined for rare earth elements, the concentrations in Green River oil shales are several orders of magnitude lower. Retorting Green River oil shales led to a slight enrichment of rare earth elements due to removal of organic matter. When concentrations in spent and leached samples were normalized to an original rock basis, concentrations were comparable to those of the raw shale, indicating that rare earth elements are conserved in processed oil shales.

Analysis of “Favorable Growth Element” Based on Rare Earth-aluminum Composite Mechanism of Compound Process

NASA Astrophysics Data System (ADS)

Hao, Baohong; Zeng, Qihui; Zhao, Jin

2018-01-01

Under the background that failure resulted in by high temperature once only aluminum oxide is used as the gasoline additive. This paper, with the purpose to solve this problem, is to synthesize AcAl oxide for gasoline additive. In order to get the rare-earth-aluminum oxide, first, a complex model of rare earth oxide based on theories about ion coordination is established. Then, by the complex model, the type of “compound growth unit” when rare earth elements join the hydrothermal conditions and the inclination that “diversification” might probably happen are deduced. Depending on the results got by complex model, this paper introduces the type of compound and its existence conditions of “Compound growth unit” owned by stable rare-earth-aluminum oxide. By adjusting the compositions of modifier, compound materials of rare earth-aluminum oxide used for gasoline additive is made. By XRD test, aperture test, adsorption test and desorption test, the theoretical deduction is proved to be right. From the experiment, it is concluded that: a dense environment is the pre-condition to form rare-earth-aluminum polymer, which is also an essential condition for the polymer to update to a favorable growth unit and produce mesoporous rare-earth-aluminum oxide with high activity.

Rare gases in cyclosilicates and cogenetic minerals

NASA Technical Reports Server (NTRS)

Saito, K.; Alexander, E. C., Jr.; Dragon, J. C.; Zashu, S.

1984-01-01

The cyclosilicate minerals, beryl, tourmaline, and cordierite, typically contain large amounts of He-4 and Ar-40 which are not in situ radiogenic products. In the study of excess rare gases in cyclosilicates, one of the most enigmatic observations is the age effect, a qualitative tendency for geologically older samples to contain more excess He-4 and Ar-40 than younger samples. The present investigation is concerned with measurements regarding the abundance and isotopic composition of all five rare gases in a number of cyclosilicates as well as in their cogenetic minerals. The significance of the obtained data is discussed. The data indicate that cyclosilicates sample the rare gases present in the environment in which they crystallize. This 'sampling' involves major elemental fractionations which are variable but mineral specific. Cyclosilicates can, therefore, be used to probe the isotopic ratios and elemental compositions.

Filling in the Gaps: Xenoliths in Meteorites are Samples of "Missing" Asteroid Lithologies

NASA Technical Reports Server (NTRS)

Zolensky, Mike

2016-01-01

We know that the stones that fall to earth as meteorites are not representative of the full diversity of small solar system bodies, because of the peculiarities of the dynamical processes that send material into Earth-crossing paths [1] which result in severe selection biases. Thus, the bulk of the meteorites that fall are insufficient to understand the full range of early solar system processes. However, the situation is different for pebble- and smaller-sized objects that stream past the giant planets and asteroid belts into the inner solar system in a representative manner. Thus, micrometeorites and interplanetary dust particles have been exploited to permit study of objects that do not provide meteorites to earth. However, there is another population of materials that sample a larger range of small solar system bodies, but which have received little attention - pebble-sized foreign clasts in meteorites (also called xenoliths, dark inclusions, clasts, etc.). Unfortunately, most previous studies of these clasts have been misleading, in that these objects have simply been identified as pieces of CM or CI chondrites. In our work we have found this to be generally erroneous, and that CM and especially CI clasts are actually rather rare. We therefore test the hypothesis that these clasts sample the full range of small solar system bodies. We have located and obtained samples of clasts in 81 different meteorites, and have begun a thorough characterization of the bulk compositions, mineralogies, petrographies, and organic compositions of this unique sample set. In addition to the standard e-beam analyses, recent advances in technology now permit us to measure bulk O isotopic compositions, and major- though trace-element compositions of the sub-mm-sized discrete clasts. Detailed characterization of these clasts permit us to explore the full range of mineralogical and petrologic processes in the early solar system, including the nature of fluids in the Kuiper belt and the outer main asteroid belt, as revealed by the mineralogy of secondary phases.

Ceramic oxyanion emitter

DOEpatents

Delmore, J.E.; Appelhans, A.D.; Peterson, E.S.

1996-04-09

A rare earth oxide matrix (composition of matter) is formed which emits (upon heating) heavy metal oxide anions (oxyanions) into a gas phase, wherein the anions are emitted with high intensity, and wherein longevity of life of the composition of matter is retained. The matter is formed by blending a major component of a rare earth oxide, europium oxide (Eu{sub 2}O{sub 3}) or ytterbium oxide (Yb{sub 2}O{sub 3}), with a minor component of a barium (Ba), calcium (Ca) or strontium (Sr) salt of a heavy metal oxyanion. Heavy anions are emitted upon heating the composition of matter to a predetermined temperature of about 800 C.

Ceramic oxyanion emitter

DOEpatents

Delmore, James E.; Appelhans, Anthony D.; Peterson, Eric S.

1996-01-01

A rare earth oxide matrix (composition of matter) is formed which emits (upon heating) heavy metal oxide anions (oxyanions) into a gas phase, wherein the anions are emitted with high intensity, and wherein longevity of life of the composition of matter is retained. The matter is formed by blending a major component of a rare earth oxide, Europium oxide (Eu.sub.2 O.sub.3) or Ytterbium oxide (Yb.sub.2 O.sub.3), with a minor component of a Barium (Ba), Calcium (Ca) or Strontium (Sr) salt of a heavy metal oxyanion. Heavy anions are emitted upon heating the composition of matter to a predetermined temperature of about 800.degree. C.

Solvent Extraction of Rare Earth Elements from a Nitric Acid Leach Solution of Apatite by Mixtures of Tributyl Phosphate and Di-(2-ethylhexyl) Phosphoric Acid

NASA Astrophysics Data System (ADS)

Ferdowsi, Ali; Yoozbashizadeh, Hossein

2017-12-01

Solvent extraction of rare earths from nitrate leach liquor of apatite using mixtures of tributyl phosphate (TBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was studied. The effects of nitrate and hydrogen ion concentration of the aqueous phase as well as the composition and concentration of extractants in the organic phase on the extraction behavior of lanthanum, cerium, neodymium, and yttrium were investigated. The distribution ratio of REEs increases by increasing the nitrate concentration in aqueous phase and concentration of extractants in organic phase, but the hydrogen ion concentration in aqueous phase has a decreasing effect. Yttrium as a heavy rare earth is more sensitive to these parameters than light rare earth elements. Although the composition of organic phase has a minor effect on the extraction of light rare earths, the percent of extraction of yttrium decreases dramatically by increasing the TBP content of organic phase. Mixtures of TBP and D2EHPA can show either synergism or antagonism extraction depending on the concentration and composition of extractants in organic phase. The best condition for separating rare earth elements in groups of heavy and light REEs can be achieved at high nitrate concentration, low H+ concentration, and high concentration of D2EHPA in organic phase. Separation of Ce and La by TBP and D2EHPA is practically impossible in the studied conditions; however, low nitrate concentration and high hydrogen ion concentration in aqueous phase and low concentration of extractants in organic phase favor the separation of Nd from other light rare earth elements.

Comparison of Single-Phase and Two-Phase Composite Thermal Barrier Coatings with Equal Total Rare-Earth Content

NASA Astrophysics Data System (ADS)

Rai, Amarendra K.; Schmitt, Michael P.; Dorfman, Mitchell R.; Zhu, Dongming; Wolfe, Douglas E.

2018-04-01

Rare-earth zirconates have been the focus of advanced thermal barrier coating research for nearly two decades; however, their lack of toughness prevents a wide-scale adoption due to lack of erosion and thermal cyclic durability. There are generally two methods of improving toughness: intrinsic modification of the coating chemistry and extrinsic modification of the coating structure. This study compares the efficacy of these two methods for a similar overall rare-earth content via the air plasma spray process. The extrinsically toughened coatings were comprised of a two-phase composite containing 30 wt.% Gd2Zr2O7 (GZO) combined with 70 wt.% of a tougher t' low-k material (ZrO2-2Y2O3-1Gd2O3-1Yb2O3; mol.%), while a single-phase fluorite with the overall rare-earth content equivalent to the two-phase composite (13 mol.% rare-earth) was utilized to explore intrinsically toughened concept. The coatings were then characterized via x-ray diffraction, energy-dispersive spectroscopy, and scanning electron microscopy, and their performance was evaluated via erosion, thermal conductivity, thermal annealing (500 h), and thermal cycling. It was shown that the extrinsic method provided an improved erosion and thermal conductivity response over the single phase, but at the expense of high-temperature stability and cyclic life.

Microgravity Studies of Liquid-Liquid Phase Transitions in Alumina-Yttria Melts

NASA Technical Reports Server (NTRS)

Guynes, Buddy (Technical Monitor); Weber, Richard; Nordine, Paul

2004-01-01

The scientific objective of this research is to increase the fundamental knowledge base for liquid- phase processing of technologically important oxide materials. The experimental objective is to define conditions and hardware requirements for microgravity flight experiments to test and expand the experimental hypotheses that: 1. Liquid phase transitions can occur in undercooled melts by a diffusionless process. 2. Onset of the liquid phase transition is accompanied by a large change in the temperature dependence of melt viscosity. Experiments on undercooled YAG (Y3A15012)- and rare earth oxide aluminate composition liquids demonstrated a large departure from an Arrhenian temperature dependence of viscosity. Liquid YAG is nearly inviscid at its 2240 K melting point. Glass fibers were pulled from melts undercooled by ca. 600 K indicating that the viscosity is on the order of 100 Pans (1000 Poise) at 1600 K. This value of viscosity is 500 times greater than that obtained by extrapolation of data for temperatures above the melting point of YAG. These results show that the liquids are extremely fragile and that the onset of the highly non-Arrhenian viscosity-temperature relationship occurs at a temperature considerably below the equilibrium melting point of the solid phases. Further results on undercooled alumina-yttria melts containing 23-42 mole % yttrium oxide indicate that a congruent liquid-liquid phase transition occurs in the undercooled liquids. The rates of transition are inconsistent with a diffusion-limited process. This research is directed to investigation of the scientifically interesting phenomena of polyamorphism and fragility in undercooled rare earth oxide aluminum oxide liquids. The results bear on the technologically important problem of producing high value rare earth-based optical materials.

Compositions of micas in peraluminous granitoids of the eastern Arabian shield - Implications for petrogenesis and tectonic setting of highly evolved, rare-metal enriched granites

USGS Publications Warehouse

du Bray, E.A.

1994-01-01

Compositions and pleochroism of micas in fourteen peraluminous alkali-feldspar granites in the eastern part of the Late Proterozoic Arabian Shield are unlike those of micas (principally biotite) in most calc-alkaline granitoid rocks. Compositions of these micas are distinguished by elevated abundances of Li2O, F, and numerous cations and by low MgO abundances. These micas, constituents of highly evolved rare-metal enriched granitoids, represent an iron-lithium substitution series that ranges from lithium-poor siderophyllite to lithium-rich ferroan lepidolite. The eastern Arabian Shield also hosts six epizonal granitoids that contain colorless micas. Compositions of these micas, mostly muscovite, and their host granitoids are distinct from those of the iron-lithium micas and their host granitoids. Compositions of the analyzed micas have a number of petrogenetic implications. The twenty granitoids containing these micas form three compositional groups that reflect genesis in particular tectonic regimes; mica compositions define the same three groups. The presence of magmatic muscovite in six of these shallowly crystallized granitoids conflicts with experimental data indicating muscovite stability at pressures greater than 3 kbar. Muscovite in the Arabian granitoids probably results from its non-ideal composition; the presence of muscovite cannot be used as a pressure indicator. Finally, mineral/matrix partition coefficients are significantly greater than 1.0 for a number of cations, the rare-earth elements in particular, in many of the analyzed iron-lithium micas. Involvement of these types of micas in partial melting or fractionation processes can have a major influence on silicate liquid compositions. ?? 1994 Springer-Verlag.

Porous silicon - rare earth doped xerogel and glass composites

NASA Astrophysics Data System (ADS)

Balakrishnan, S.; Gun'ko, Yurii K.; Perova, T. S.; Rafferty, A.; Astrova, E. V.; Moore, R. A.

2005-06-01

The development of components for photonics applications is growing exponentially. The sol-gel method is now recognised as a convenient and flexible way to deposit oxide or glass films on a variety of hosts, including porous silicon. In the present work we incorporated erbium and europium doped xerogel into porous silicon and developed new porous silicon - rare earth doped glass composites. Various characteris-ation techniques including FTIR, Raman Spectroscopy, Thermal Gravimetric Analysis and Scanning Electron Microscopy were employed in this work.

Grids in topographic maps reduce distortions in the recall of learned object locations.

PubMed

Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

2014-01-01

To date, it has been shown that cognitive map representations based on cartographic visualisations are systematically distorted. The grid is a traditional element of map graphics that has rarely been considered in research on perception-based spatial distortions. Grids do not only support the map reader in finding coordinates or locations of objects, they also provide a systematic structure for clustering visual map information ("spatial chunks"). The aim of this study was to examine whether different cartographic kinds of grids reduce spatial distortions and improve recall memory for object locations. Recall performance was measured as both the percentage of correctly recalled objects (hit rate) and the mean distance errors of correctly recalled objects (spatial accuracy). Different kinds of grids (continuous lines, dashed lines, crosses) were applied to topographic maps. These maps were also varied in their type of characteristic areas (LANDSCAPE) and different information layer compositions (DENSITY) to examine the effects of map complexity. The study involving 144 participants shows that all experimental cartographic factors (GRID, LANDSCAPE, DENSITY) improve recall performance and spatial accuracy of learned object locations. Overlaying a topographic map with a grid significantly reduces the mean distance errors of correctly recalled map objects. The paper includes a discussion of a square grid's usefulness concerning object location memory, independent of whether the grid is clearly visible (continuous or dashed lines) or only indicated by crosses.

Context dependency and saturating effects of loss of rare soil microbes on plant productivity.

PubMed

Hol, W H Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E; Meisner, Annelein; van der Putten, Wim H

2015-01-01

Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

Using Ingredient Lists to Quantitatively Characterize Composition of Consumer Products

EPA Science Inventory

Assessing exposure to substances in consumer products requires data on the composition of the products. This is a challenge since product composition data are rarely available. Many products, however, provide a list of ingredients. In many cases the list is presented in descendin...

Air electrode composition for solid oxide fuel cell

DOEpatents

Kuo, Lewis; Ruka, Roswell J.; Singhal, Subhash C.

1999-01-01

An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO.sub.3. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell.

Air electrode composition for solid oxide fuel cell

DOEpatents

Kuo, L.; Ruka, R.J.; Singhal, S.C.

1999-08-03

An air electrode composition for a solid oxide fuel cell is disclosed. The air electrode material is based on lanthanum manganite having a perovskite-like crystal structure ABO{sub 3}. The A-site of the air electrode composition comprises a mixed lanthanide in combination with rare earth and alkaline earth dopants. The B-site of the composition comprises Mn in combination with dopants such as Mg, Al, Cr and Ni. The mixed lanthanide comprises La, Ce, Pr and, optionally, Nd. The rare earth A-site dopants preferably comprise La, Nd or a combination thereof, while the alkaline earth A-site dopant preferably comprises Ca. The use of a mixed lanthanide substantially reduces raw material costs in comparison with compositions made from high purity lanthanum starting materials. The amount of the A-site and B-site dopants is controlled in order to provide an air electrode composition having a coefficient of thermal expansion which closely matches that of the other components of the solid oxide fuel cell. 3 figs.

Estimating accuracy of land-cover composition from two-stage cluster sampling

USGS Publications Warehouse

Stehman, S.V.; Wickham, J.D.; Fattorini, L.; Wade, T.D.; Baffetta, F.; Smith, J.H.

2009-01-01

Land-cover maps are often used to compute land-cover composition (i.e., the proportion or percent of area covered by each class), for each unit in a spatial partition of the region mapped. We derive design-based estimators of mean deviation (MD), mean absolute deviation (MAD), root mean square error (RMSE), and correlation (CORR) to quantify accuracy of land-cover composition for a general two-stage cluster sampling design, and for the special case of simple random sampling without replacement (SRSWOR) at each stage. The bias of the estimators for the two-stage SRSWOR design is evaluated via a simulation study. The estimators of RMSE and CORR have small bias except when sample size is small and the land-cover class is rare. The estimator of MAD is biased for both rare and common land-cover classes except when sample size is large. A general recommendation is that rare land-cover classes require large sample sizes to ensure that the accuracy estimators have small bias. ?? 2009 Elsevier Inc.

Dielectric and varistor properties of rare-earth-doped ZnO and CaCu3Ti4O12 composite ceramics

NASA Astrophysics Data System (ADS)

Lu, Huafei; Lin, Yuanhua; Yuan, Jiancong; Nan, Cewen; Chen, Kexin

2013-02-01

To investigate the multi-functional ceramics with both high permittivity and large nonlinear coefficient, we have prepared rare-earth Tb-and-Co doped ZnO and TiO2-rich CaCu3Ti4O12 (TCCTO) powders by chemical co-precipitation and sol-gel methods respectively, and then obtained the TCCTO/ZnO composite ceramics, sintered at 1100°C for 3 h in air. Analyzing the composite ceramics of the microstructure and phase composition indicated that the composite ceramics were composed of the main phases of ZnO and CaCu3Ti4O12 (CCTO). Our results revealed that the TCCTO/ZnO composite ceramics showed both high dielectric and good nonlinear electrical behaviors. The composite ceramic of TCCTO: ZnO = 0.3 exhibited a high dielectric constant of 210(1 kHz) with a nonlinear coefficient of 11. The dielectric behavior of TCCTO/ZnO composite could be explained by the mixture rule. With the high dielectric permittivity and tunable varistor behaviors, the composite ceramics has a potential application for the higher voltage transportation devices.

Collateral fattening: When a deficit in lean body mass drives overeating.

PubMed

Dulloo, Abdul G

2017-02-01

In his last review entitled "Some Adventures in Body Composition," Gilbert Forbes reminded us that "lean body mass and body fat are in a sense companions." To what extent the lean body mass (or fat-free mass) component in this companionship impacts on energy intake is rarely a topic for discussion, amid a dominant adipocentric view of appetite control. Yet an analysis of the few human studies that have investigated the relationships between objectively measured food intake and body composition reveals a potentially important role for both an increase and a decrease in fat-free mass in the drive to eat. These studies are highlighted here, together with the implications of their findings for research directed as much toward the elucidation of peripheral signals and energy-sensing mechanisms that drive hunger and appetite, as toward understanding the mechanisms by which dieting and sedentariness predispose to fatness. © 2017 The Authors. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Superconductivity achieved at over liquid nitrogen temperature by (mixed rare earths)-Ba-Cu oxides

NASA Astrophysics Data System (ADS)

Kishio, Kohji; Kuwahara, Kazuyuki; Kitazawa, Koichi; Fueki, Kazuo; Nakamura, Osamu

1987-05-01

Superconducting oxides were fabricated by reaction of powders of BaCO3, CuO and mixed rare earth (RE) carbonates at compositions expressed as (RE)1Ba2Cu3O(9-y). Two types of incompletely separated raw materials of mixed rare earths, namely, heavy rare earths (HRE) and medium rare earths (MRE), were examined. The zero-resistivity critical temperatures were observed at 92.5 K for the (HRE)-Ba-Cu-O and 85.0 K for the (MRE)-Ba-Cu-O systems, respectively, both of which were well above the boiling point of liquid nitrogen.

[Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of Pangxidong Composite Granitoid Pluton and Its Implications for Magmatic Differentiation].

PubMed

Zeng, Chang-yu; Ding, Ru-xin; Li, Hong-zhong; Zhou, Yong-zhang; Niu, Jia; Zhang, Jie-tang

2015-11-01

Pangxidong composite granitoid pluton located in the southwestern margin of Yunkai massif. The metamorphic grade of this pluton increases from outside to inside, that is, banded-augen granitic gneisses, gneissoid granites and granites distribute in order from edge to core. X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry are conducted to study the geochemical characteristics of the three types of rocks. The result shows that all the three types of rocks are peraluminous rocks and their contents of main elements and rare earth elements change gradually. From granitic gneisses to granites, the contents of Al₂O₃, CaO, MgO, TiO₂, total rare earth elements and light rare earth elements increase, but the contents of SiO₂ and heavy rare earth elements decrease. It is suggested that the phylogenetic relationship exists between granitic gneisses, gneissoid granites and granites during the multi-stage tectonic evolution process. Furthermore, the remelting of metamorphosed supracrustal rocks in Yunkai massif is probably an important cause of granitoid rocks forming. The evolutionary mechanism is probably that SiO₂ and heavy rare earth elements were melt out from the protolith and gradually enriched upward, but Al₂O₃, CaO, MgO, TiO₂ and light rare earth elements enriched downward.

The pressure-induced structural response of rare earth hafnate and stannate pyrochlore from 0.1-50 GPa

NASA Astrophysics Data System (ADS)

Turner, K. M.; Rittman, D.; Heymach, R.; Turner, M.; Tracy, C.; Mao, W. L.; Ewing, R. C.

2017-12-01

Complex oxides with the pyrochlore (A2B2O7) and defect-fluorite ((A,B)4O7) structure-types undergo structural transformations under high-pressure. These compounds are under consideration for applications including as a proposed waste-form for actinides generated in the nuclear fuel cycle. High-pressure transformations in rare earth hafnates (A2Hf2O7, A=Sm, Eu, Gd, Dy, Y, Yb) and stannates (A2Sn2O7, A=Nd, Gd, Er) were investigated to 50 GPa by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD). Rare-earth hafnates form the pyrochlore structure for A=La-Tb and the defect-fluorite structure for A=Dy-Lu. Lanthanide stannates form the pyrochlore structure. Raman spectra revealed that at ambient pressure all compositions have pyrochlore-type short-range order. Stannate compositions show a larger degree of pyrochlore-type short-range ordering relative to hafnates. In situ high-pressure synchrotron XRD showed that rare earth hafnates and stannates underwent a pressure-induced phase transition to a cotunnite-like (Pnma) structure that begins between 18-25 GPa in hafnates and between 30-33 GPa in stannates. The phase transition is not complete at 50 GPa, and upon decompression, XRD indicates that all compositions transform to defect-fluorite with an amorphous component. In situ Raman spectroscopy showed that disordering in stannates and hafnates occurs gradually upon compression. Pyrochlore-structured hafnates retain short-range order to a higher pressure (30 GPa vs. <10 GPa) than defect-fluorite-structured hafnates. Hafnates and stannates decompressed from 50 GPa show Raman spectra consistent with weberite-type structures, also reported in irradiated stannates. The second-order Birch-Murnaghan equation of state fit gives a bulk modulus of 250 GPa for hafnate compositions with the pyrochlore structure, and 400 GPa for hafnate compositions with the defect-fluorite structure. Stannates have a lower bulk modulus relative to hafnates (between 80-150 GPa). Stannate and hafnate pyrochlore compositions taken to high pressure show structural transformations consistent with irradiated pyrochlore, and compositionally disordered pyrochlore: a long-range structure best described by defect-fluorite, and a short-range structure best described by weberite.

Effects of rare earth oxide additive on surface and tribological properties of polyimide composites

NASA Astrophysics Data System (ADS)

Pan, Zihe; Wang, Tianchang; Chen, Li; Idziak, Stefan; Huang, Zhaohui; Zhao, Boxin

2017-09-01

Rare earth oxide La2O3 microparticles-reinforced polyimide (PI) composites (La-PI-Cs) were fabricated, aiming to improve the tribological property of PI. Surface roughness, surface composition, bulk structure, friction force (Ff) and coefficient of friction (COF) at macro/micro preload, and anti-wear performances of La-PI-Cs were studied and compared with neat PI. With La2O3 microparticles, La-PI-Cs showed larger surface roughness, lower surface energy, and higher hydrophobicity than neat PI, and displayed beneficial layered structure different from the compact structure of PI. Owing to these advantages, La-PI-Cs were found to show a 70% reduction in Ff and COF, and a 30% reduction in wear rate, indicating significantly lowered friction and enhanced anti-wear properties after adding La2O3 microparticles. Our research findings demonstrated an easy and low cost method to fabricate polymer composites with low friction and high wear resistance, and help meet the demanding of polymer composites with high tribological performances in broaden applications.

Comparison of Wood Composite Properties Using Cantilever-Beam Bending

Treesearch

Houjiang Zhang; John F. Hunt; Lujing Zhou

2015-01-01

Wood-based composite panels generally are first tested out-of-plane in the primarypanel directionfollowed by the cross panel direction, but rarely edgewise. While most applications use wood-based composites in the flat-wise orientation and only need the out-of-plane properties, there are construction configurations where edgewise properties are needed for improved...

Effects of rare-earth co-doping on the local structure of rare-earth phosphate glasses using high and low energy X-ray diffraction.

PubMed

Cramer, Alisha J; Cole, Jacqueline M; FitzGerald, Vicky; Honkimaki, Veijo; Roberts, Mark A; Brennan, Tessa; Martin, Richard A; Saunders, George A; Newport, Robert J

2013-06-14

Rare-earth co-doping in inorganic materials has a long-held tradition of facilitating highly desirable optoelectronic properties for their application to the laser industry. This study concentrates specifically on rare-earth phosphate glasses, (R2O3)x(R'2O3)y(P2O5)(1-(x+y)), where (R, R') denotes (Ce, Er) or (La, Nd) co-doping and the total rare-earth composition corresponds to a range between metaphosphate, RP3O9, and ultraphosphate, RP5O14. Thereupon, the effects of rare-earth co-doping on the local structure are assessed at the atomic level. Pair-distribution function analysis of high-energy X-ray diffraction data (Q(max) = 28 Å(-1)) is employed to make this assessment. Results reveal a stark structural invariance to rare-earth co-doping which bears testament to the open-framework and rigid nature of these glasses. A range of desirable attributes of these glasses unfold from this finding; in particular, a structural simplicity that will enable facile molecular engineering of rare-earth phosphate glasses with 'dial-up' lasing properties. When considered together with other factors, this finding also demonstrates additional prospects for these co-doped rare-earth phosphate glasses in nuclear waste storage applications. This study also reveals, for the first time, the ability to distinguish between P-O and P[double bond, length as m-dash]O bonding in these rare-earth phosphate glasses from X-ray diffraction data in a fully quantitative manner. Complementary analysis of high-energy X-ray diffraction data on single rare-earth phosphate glasses of similar rare-earth composition to the co-doped materials is also presented in this context. In a technical sense, all high-energy X-ray diffraction data on these glasses are compared with analogous low-energy diffraction data; their salient differences reveal distinct advantages of high-energy X-ray diffraction data for the study of amorphous materials.

Geochemistry of biotite from charnockitoids in the granite-forming series (Nimnyr Block of the Aldan Shield)

NASA Astrophysics Data System (ADS)

Sedova, I. S.; Glebovitskii, V. A.; Skublov, S. G.

2016-10-01

The geochemical evolution of biotite (Bt) from garnet-bearing associations in the granite-forming series of the Nimnyr Block (Aldan Shield) is considered. The series includes the primary rock (gneiss or basic rock), autochthonous enderbite- or charnockite-gneiss (Lc1), migmatitic leucosome (Lc2, Lc4), and paraautochthonous charnockite (Lc3-ch1) and (Lc5-ch2 → grn). Bt in each series is characterized by an individual, significant difference in the concentrations of Ti, V, Cr; rarely Al, Fe, Mg, and Rb; and very rarely La, Ce, Nd, and Gd. The uniform trend of evolution of Bt compositions in the series was established for Al, KAl, (K + Na)/Al, rarely for Mg, Ti, and K. In contrast to the series with ch2, Bt becomes enriched in LREEs from autochthonous Lc1 to allochthonous Lc2 and Lc3. The different compositional variations of Bt in relation some minor elements is explained by the different composition of the material, which underwent melting, temperature variations (from 820 to 750°C), and changes in pH of the mineral-forming medium.

A combined calorimetric and computational study of the energetics of rare earth substituted UO 2 systems

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

Zhang, Lei; Solomon, Jonathan M.; Asta, Mark

2015-09-01

The energetics of rare earth substituted UO2 solid solutions (U1-xLnxO2-0.5x+y, where Ln = La, Y, and Nd) are investigated employing a combination of calorimetric measurements and density functional theory based computations. Calculated and measured formation enthalpies agree within 10 kJ/mol for stoichiometric oxygen/metal compositions. To better understand the factors governing the stability and defect binding in rare earth substituted urania solid solutions, systematic trends in the energetics are investigated based on the present results and previous computational and experimental thermochemical studies of rare earth substituted fluorite oxides (A1-xLnxO2-0.5x, where A = Hf, Zr, Ce, and Th). A consistent trend towardsmore » increased energetic stability with larger size mismatch between the smaller host tetravalent cation and the larger rare earth trivalent cation is found for both actinide and non-actinide fluorite oxide systems where aliovalent substitution of Ln cations is compensated by oxygen vacancies. However, the large exothermic oxidation enthalpy in the UO2 based systems favors oxygen rich compositions where charge compensation occurs through the formation of uranium cations with higher oxidation states.« less

Rare Earth Oxide Fluoride Nanoparticles And Hydrothermal Method For Forming Nanoparticles

DOEpatents

Fulton, John L.; Hoffmann, Markus M.

2003-12-23

A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

Rare earth oxide fluoride nanoparticles and hydrothermal method for forming nanoparticles

DOEpatents

Fulton, John L [Richland, WA; Hoffmann, Markus M [Richland, WA

2001-11-13

A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.

Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment.

PubMed

Kibria, Muhammad Golam; Ali, Sajjad; Jarwar, Muhammad Aslam; Kumar, Sunil; Chong, Ilyoung

2017-09-22

Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented.

Logistic Model to Support Service Modularity for the Promotion of Reusability in a Web Objects-Enabled IoT Environment

PubMed Central

Chong, Ilyoung

2017-01-01

Due to a very large number of connected virtual objects in the surrounding environment, intelligent service features in the Internet of Things requires the reuse of existing virtual objects and composite virtual objects. If a new virtual object is created for each new service request, then the number of virtual object would increase exponentially. The Web of Objects applies the principle of service modularity in terms of virtual objects and composite virtual objects. Service modularity is a key concept in the Web Objects-Enabled Internet of Things (IoT) environment which allows for the reuse of existing virtual objects and composite virtual objects in heterogeneous ontologies. In the case of similar service requests occurring at the same, or different locations, the already-instantiated virtual objects and their composites that exist in the same, or different ontologies can be reused. In this case, similar types of virtual objects and composite virtual objects are searched and matched. Their reuse avoids duplication under similar circumstances, and reduces the time it takes to search and instantiate them from their repositories, where similar functionalities are provided by similar types of virtual objects and their composites. Controlling and maintaining a virtual object means controlling and maintaining a real-world object in the real world. Even though the functional costs of virtual objects are just a fraction of those for deploying and maintaining real-world objects, this article focuses on reusing virtual objects and composite virtual objects, as well as discusses similarity matching of virtual objects and composite virtual objects. This article proposes a logistic model that supports service modularity for the promotion of reusability in the Web Objects-enabled IoT environment. Necessary functional components and a flowchart of an algorithm for reusing composite virtual objects are discussed. Also, to realize the service modularity, a use case scenario is studied and implemented. PMID:28937590

[Contents of macromineral and trace elements in spirulina (Arthrospira platensis) from France, Chad, Togo, Niger, Mali, Burkina-Faso and Central African Republic].

PubMed

Vicat, Jean-Paul; Doumnang Mbaigane, Jean-Claude; Bellion, Yves

2014-01-01

Data on mineral elements in spirulinas being limited, we analyzed macrominerals and trace elements of samples from France and Africa. Spirulinas cultivated in France have a composition in macromineral elements similar to those of the literature. The entire contents of trace elements are low. Unlike marine cyanobacteria, they do not concentrate rare-earth elements. Spirulina harvested in Chad has high levels in macrominerals and trace elements, due to traditional drying and harvesting methods. Rare-earth element levels are attributed to this pollution and not to their concentration in spirulinas, because rare-earth element normalized profiles of spirulina are strictly parallel to those of ouadis mud and very different from those of ouadis water. Despite the sometimes high content of total As, normal water consumption in Chad presents no health problems. Spirulinas grown in Togo, Niger, Mali, Burkina-Faso and Central African Republic have chemical compositions similar to those of Chad spirulinas, but with a lower content of macromineral and trace elements, reflecting a lower mineral pollution. Rare-earth element normalized patterns dismiss an aeolian pollution and the pollution is rather of pedological origin. They show no toxicity problem except spirulinas from Burkina-Faso, whose Pb content is too high. The variability of composition of spirulinas can be largely attributed to the mineral pollution of the samples. Significant levels of rare-earth elements sometimes found in the literature reflect this pollution. Copyright © 2013 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Persistence of an unusual pelagic zooplankton assemblage in a clear, mountain lake

USGS Publications Warehouse

Larson, G.L.; Hoffman, R.L.; C. David, McIntire

2002-01-01

The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988-1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

Persistence of an unusual pelagic zooplankton assemblage in a clear mountain lake

USGS Publications Warehouse

Larson, Gary L.; Hoffman, Robert L.; McIntire, C.D.

2002-01-01

The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988a??1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

Influence of iron substitution by selected rare-earth ions on the properties of NiZn ferrite fillers and PVC magneto-polymer composites

NASA Astrophysics Data System (ADS)

Ušák, Elemír; Ušáková, Mariana; Dosoudil, Rastislav; Šoka, Martin; Dobročka, Edmund

2018-04-01

Nickel-zinc ferrites are very important soft magnetic materials from the point of view of diverse technical applications (such as, e.g., various electronic devices and components) for their high magnetic permeability and permittivity, low core loss, high resistivity, high Curie temperature as well as mechanical strength and chemical stability. Due to their good absorbing properties, they can be used as microwave absorbing and shielding materials with the aim of decreasing the environmental pollution caused by non-ionizing microwave radiation. The ferrite material incorporated into the polymer matrix creates qualitatively new magneto-polymer composite material taking benefits from both components. The properties typical for polymers (elasticity, mouldability, etc.) are combined with good high-frequency magnetic parameters, thus allowing to utilize these materials, e.g., in high-frequency applications where especially flexibility of composite materials plays a key role. Small amounts of selected rare-earth (RE) ions, in particular Y3+, La3+, Eu3+ and Gd3+ have been embedded into the nickel-zinc ferrite that has been used as the magnetic filler in magnetic polymer composites with polyvinylchloride (PVC) acting as the polymeric matrix. The effect of various types of rare-earth ions on the structural as well as quasi-static and dynamic (electro)magnetic properties of the ferrite fillers as well as ferrite/PVC composites, in particular the frequency dispersion of the complex permeability, has been studied.

The SDSS-III Multi-object Apo Radial-velocity Exoplanet Large-area Survey

NASA Astrophysics Data System (ADS)

Ge, Jian; Mahadevan, S.; Lee, B.; Wan, X.; Zhao, B.; van Eyken, J.; Kane, S.; Guo, P.; Ford, E. B.; Agol, E.; Gaudi, S.; Fleming, S.; Crepp, J.; Cohen, R.; Groot, J.; Galvez, M.; Liu, J.; Ford, H.; Schneider, D.; Seager, S.; Hawley, S. L.; Weinberg, D.; Eisenstein, D.

2007-12-01

As part of SDSS-III survey in 2008-2014, the Multi-object APO Radial-Velocity Exoplanet Large-area Survey (MARVELS) will conduct the largest ground-based Doppler planet survey to date using the SDSS telescope and new generation multi-object Doppler instruments with 120 object capability and 10-20 m/s Doppler precision. The baseline survey plan is to monitor a total of 11,000 V=8-12 stars ( 10,000 main sequence stars and 1000 giant stars) over 800 square degrees over the 6 years. The primary goal is to produce a large, statistically well defined sample of giant planets ( 200) with a wide range of masses ( 0.2-10 Jupiter masses) and orbits (1 day-2 years) drawn from a large of host stars with a diverse set of masses, compositions, and ages for studying the diversity of extrasolar planets and constraining planet formation, migration & dynamical evolution of planetary systems. The survey data will also be used for providing a statistical sample for theoretical comparison and discovering rare systems and identifying signposts for lower-mass or more distant planets. Early science results from the pilot program will be reported. We would like to thank the SDSS MC for allocation of the telescope time and the W.M. Keck Foundation, NSF, NASA and UF for support.

Combined computational-experimental design of high temperature, high-intensity permanent magnetic alloys with minimal addition of rare-earth elements

NASA Astrophysics Data System (ADS)

Jha, Rajesh

AlNiCo magnets are known for high-temperature stability and superior corrosion resistance and have been widely used for various applications. Reported magnetic energy density ((BH) max) for these magnets is around 10 MGOe. Theoretical calculations show that ((BH) max) of 20 MGOe is achievable which will be helpful in covering the gap between AlNiCo and Rare-Earth Elements (REE) based magnets. An extended family of AlNiCo alloys was studied in this dissertation that consists of eight elements, and hence it is important to determine composition-property relationship between each of the alloying elements and their influence on the bulk properties. In the present research, we proposed a novel approach to efficiently use a set of computational tools based on several concepts of artificial intelligence to address a complex problem of design and optimization of high temperature REE-free magnetic alloys. A multi-dimensional random number generation algorithm was used to generate the initial set of chemical concentrations. These alloys were then examined for phase equilibria and associated magnetic properties as a screening tool to form the initial set of alloy. These alloys were manufactured and tested for desired properties. These properties were fitted with a set of multi-dimensional response surfaces and the most accurate meta-models were chosen for prediction. These properties were simultaneously extremized by utilizing a set of multi-objective optimization algorithm. This provided a set of concentrations of each of the alloying elements for optimized properties. A few of the best predicted Pareto-optimal alloy compositions were then manufactured and tested to evaluate the predicted properties. These alloys were then added to the existing data set and used to improve the accuracy of meta-models. The multi-objective optimizer then used the new meta-models to find a new set of improved Pareto-optimized chemical concentrations. This design cycle was repeated twelve times in this work. Several of these Pareto-optimized alloys outperformed most of the candidate alloys on most of the objectives. Unsupervised learning methods such as Principal Component Analysis (PCA) and Heirarchical Cluster Analysis (HCA) were used to discover various patterns within the dataset. This proves the efficacy of the combined meta-modeling and experimental approach in design optimization of magnetic alloys.

Drivers of metacommunity structure diverge for common and rare Amazonian tree species.

PubMed

Bispo, Polyanna da Conceição; Balzter, Heiko; Malhi, Yadvinder; Slik, J W Ferry; Dos Santos, João Roberto; Rennó, Camilo Daleles; Espírito-Santo, Fernando D; Aragão, Luiz E O C; Ximenes, Arimatéa C; Bispo, Pitágoras da Conceição

2017-01-01

We analysed the flora of 46 forest inventory plots (25 m x 100 m) in old growth forests from the Amazonian region to identify the role of environmental (topographic) and spatial variables (obtained using PCNM, Principal Coordinates of Neighbourhood Matrix analysis) for common and rare species. For the analyses, we used multiple partial regression to partition the specific effects of the topographic and spatial variables on the univariate data (standardised richness, total abundance and total biomass) and partial RDA (Redundancy Analysis) to partition these effects on composition (multivariate data) based on incidence, abundance and biomass. The different attributes (richness, abundance, biomass and composition based on incidence, abundance and biomass) used to study this metacommunity responded differently to environmental and spatial processes. Considering standardised richness, total abundance (univariate) and composition based on biomass, the results for common species differed from those obtained for all species. On the other hand, for total biomass (univariate) and for compositions based on incidence and abundance, there was a correspondence between the data obtained for the total community and for common species. Our data also show that in general, environmental and/or spatial components are important to explain the variability in tree communities for total and common species. However, with the exception of the total abundance, the environmental and spatial variables measured were insufficient to explain the attributes of the communities of rare species. These results indicate that predicting the attributes of rare tree species communities based on environmental and spatial variables is a substantial challenge. As the spatial component was relevant for several community attributes, our results demonstrate the importance of using a metacommunities approach when attempting to understand the main ecological processes underlying the diversity of tropical forest communities.

System-level strategies for conserving rare or little-known species

Treesearch

Bruce G. Marcot; Carolyn Hull Sieg

2007-01-01

In this chapter we review the literature on system-level strategies for conserving rare or little-known (RLK) species, continuing from the species-level approaches addressed in the previous chapter. We define system-level approaches as those that result in conservation actions focused on providing for community or ecosystem composition, structure, or function.

Rare earth elements upon assessment of reasons of the geophagy in Sikhote-Alin region (Russian Federation), Africa and other world regions.

PubMed

Panichev, Alexander M; Popov, Vladimir K; Chekryzhov, Igor Yu; Seryodkin, Ivan V; Stolyarova, Tatiana A; Zakusin, Sergey V; Sergievich, Alexandr A; Khoroshikh, Pavel P

2016-12-01

Rocks eaten by wild animals on the Bolshoy Shanduyskiy kudur in the Sikhote-Alin region (Russian Federation) are zeolite-clay mineral complexes-products of weathering of zeolitized vitric tuffs of rhyolite composition, deposited in aqueous medium within the volcanic caldera of about 55 million years ago. By composition of rock-forming oxides, the tuffs refer to high-potassium calc-alkaline series. In trace elements of most favorite kudurites of the Bolshoy Shanduyskiy kudur, there are significantly increased contents of most of rare earth elements (2-5 times in comparison with surrounding rocks). The results of our analysis of geological and geochemical data on kudurs and kudurites in another part of the Sikhote-Alin, as well as on other regions of the world (particularly, in Africa and Indonesia), taking into account new data on the prevalence of rare earth elements in living matter and their medical and biological properties, enable us to consider the version of causal connection of the geophagy with rare earth elements.

Electrical Conductivity of Molten DyCl3-NaCl and DyCl3-KCl Systems: An Approach to Structural Interpretations of Rare Earth Chloride Melts

NASA Astrophysics Data System (ADS)

Iwadate, Yasuhiko; Ohkubo, Takahiro

2017-11-01

Electrical conductivities (κs) of molten DyCl3-NaCl and DyCl3-KCl systems were estimated by measuring the impedances of each mixture melt at any temperature and/or frequency. The molar volumes (Vms) were measured by dilatometry and represented as a polynomial empirical equation of temperature and composition. Due to both the properties, the molar conductivities (Λms) were calculated and their temperature and/or composition dependences were discussed from the standpoint of structural features as well. The κs increased curvilinearly with increasing temperature across the whole composition ranges. This trend was also applied to the Λms which was fitted by an Arrhenius-type equation. The relationship of Λms with melt composition was studied and the Λms were found to decrease with increasing composition of DyCl3. These findings were interpreted based on the results of structural science so far reported, and finally, the relationship between Λms and the structures of pure rare earth chloride melts was discussed.

Multiple enrichment of the Carpathian-Pannonian mantle: Pb-Sr-Nd isotope and trace element constraints

NASA Astrophysics Data System (ADS)

Rosenbaum, Jeffrey M.; Wilson, Marjorie; Downes, Hilary

1997-07-01

Pb isotope compositions of acid-leached clinopyroxene and amphibole mineral separates from spinel peridotite mantle xenoliths entrained in Tertiary-Quaternary alkali basalts from the Carpathian-Pannonian Region of eastern Europe provide important constraints on the processes of metasomatic enrichment of the mantle lithosphere in an extensional tectonic setting associated with recent subduction. Principal component analysis of Pb-Sr-Nd isotope and rare earth element compositions of the pyroxenes is used to identify the geochemical characteristics of the original lithospheric mantle protolith and a spectrum of infiltrating metasomatic agents including subduction-related aqueous fluids and silicate melts derived from a subduction-modified mantle wedge which contains a St. Helena-type (HIMU) plume component. The mantle protolith is highly depleted relative to mid-ocean ridge basalt-source mantle with Pb-Nd-Sr isotope compositions consistent with an ancient depletion event. Silicate melt infiltration into the protolith accounts for the primary variance in the Pb-Sr-Nd isotope compositions of the xenoliths and has locally generated metasomatic amphibole. Infiltration of aqueous fluids has introduced radiogenic Pb and Sr without significantly perturbing the rare earth element signature of the protolith. The Pb isotope compositions of the fluid-modified xenoliths suggest that they reacted with aqueous fluids released from a subduction zone which had equilibrated with sediment derived from an ancient basement terrain. We propose a model for mantle lithosphere evolution consistent with available textural and geochemical data for the xenolith population. The Pb-Sr-Nd isotope compositions of both alkaline mafic magmas and rare, subduction-related, calc-alkaline basaltic andesites from the region provide important constraints for the nature of the asthenospheric mantle wedge and confirm the presence of a HIMU plume component. These silicate melts contribute to the metasomatism of the mantle lithosphere rather than being derived therefrom.

High Temperature Solid Lubricant Coating for High Temperature Wear Applications

NASA Technical Reports Server (NTRS)

DellaCorte, Christopher (Inventor); Edmonds, Brian J (Inventor)

2014-01-01

A self-lubricating, friction and wear reducing composite useful over a wide temperature range is described herein. The composite includes metal bonded chromium oxide dispersed in a metal binder having a substantial amount of nickel. The composite contains a fluoride of at least one Group I, Group II, or rare earth metal, and optionally a low temperature lubricant metal.

Composition spread studies of Nd1-xLaxNiO3 combinatorial thin films

NASA Astrophysics Data System (ADS)

Suchoski, Richard; Jin, Kui; Yasui, Shintaro; Greene, Richard; Takeuchi, Ichiro

2013-03-01

Rare earth nickelates have attracted a great deal of attention in recent years due to a host of interesting features, one being a transition from paramagnetic metal to antiferromagnetic insulator through distortions from the ideal perovskite unit cell. This metal-to-insulator transition (MIT) can be manipulated by modifying variables such as temperature, rare earth ion size, oxygen content, or stress from lattice-mismatched epitaxial thin film growth. Research on this family has been extensive, though there still exists an absence of thin film studies focusing on intermediate compositions. We have fabricated epitaxial thin film composition spreads of Nd1-xLaxNiO3 grown via combinatorial PLD to investigate these transitional compositions. While our films exhibit a smooth composition progression, we observe a composition threshold where orthorhombic NdNiO3 transforms to rhombohedral LaNiO3, correlating with disappearance of the MIT, and displays a non-Vegard evolution of the film's in-plane lattice constant in HRXRD and Raman scattering data of the A1g rotational mode. This work was performed at the Center for Nanophysics and Advanced Materials (CNAM) at UMD, and supported by AFO SR MURI Grant #FA95500910603.

Light rare earth element systematics as a tool for investigating the petrogenesis of phoscorite-carbonatite associations, as exemplified by the Phalaborwa Complex, South Africa

NASA Astrophysics Data System (ADS)

Milani, Lorenzo; Bolhar, Robert; Frei, Dirk; Harlov, Daniel E.; Samuel, Vinod O.

2017-12-01

In-situ trace element analyses of fluorapatite, calcite, dolomite, olivine, and phlogopite have been undertaken on representative phoscorite and carbonatite rocks of the Palaeoproterozoic Phalaborwa Complex. Textural and compositional characterization reveals uniformity of fluorapatite and calcite among most of the intrusions, and seems to favor a common genetic origin for the phoscorite-carbonatite association. Representing major repositories for rare earth elements (REE), fluorapatite and calcite exhibit tightly correlated light REE (LREE) abundances, suggesting that partitioning of LREE into these rock forming minerals was principally controlled by simple igneous differentiation. However, light rare earth element distribution in apatite and calcite cannot be adequately explained by equilibrium and fractional crystallization and instead favors a complex crystallization history involving mixing of compositionally distinct magma batches, in agreement with previously reported mineral isotope variability that requires open-system behaviour.

Microbial diversity and community structure across environmental gradients in an seawater intruded shallow confined aquifer

NASA Astrophysics Data System (ADS)

Zhang, X.; Hu, B.

2017-12-01

Seawater intrusion has been an important topic in coastal hydrogeology and making previously freshwater ecosystems saline. Plant and animal responses to variation in the freshwater-saline interface have been well studied in the coastal zone. However, little is known about the biogeography or stability of microbial community response to seawater intrusion. The objective of this study is to characterize and compare bacterial and archaea community diversity and composition in 15 groundwater samples with varied salinity using high-throughput-sequencing of 16S ribosomal RNA genes. The dominant taxonomic group identified in all samples are proteobacteria for bacteria and crenarchaeota for archaea. The other main bacterial groups are varied in samples with different salinities including bacteroidetes, firmicutes and several unidentified taxonomys. A combination of environmental factors seems to influence the microbial community composition where organic carbon is a primary factor shaping microbial communities. Correlation analysis between the relative abundance of bacterial taxa and geochemical parameters uggested that rare taxa may contribute to biogeochemical processes taking place at the mixing zone of freshewater and saltwater. Our results help to understand how the physical and chemical factors shape the microbial community composition and set a baseline for upcoming studies to evaluate the response of this ecosystem to future changes and the efficacy of new remediation efforts.

[Spectroscopic Research on Slag Nanocrystal Glass Ceramics Containing Rare Earth Elements].

PubMed

Ouyang, Shun-li; Li, Bao-wei; Zhang, Xue-feng; Jia, Xiao-lin; Zhao, Ming; Deng, Lei-bo

2015-08-01

The research group prepared the high-performance slag nanocrystal glass ceramics by utilizing the valuable elements of the wastes in the Chinese Bayan Obo which are characterized by their symbiotic or associated existence. In this paper, inductively coupled plasma emission spectroscopy (ICP), X-ray diffraction (XRD), Raman spectroscopy (Raman) and scanning electron microscopy (SEM) are all used in the depth analysis for the composition and structure of the samples. The experiment results of ICP, XRD and SEM showed that the principal crystalline phase of the slag nanocrystal glass ceramics containing rare earth elements is diopside, its grain size ranges from 45 to 100 nm, the elements showed in the SEM scan are basically in consistent with the component analysis of ICP. Raman analysis indicated that its amorphous phase is a three-dimensional network structure composed by the structural unit of silicon-oxy tetrahedron with different non-bridging oxygen bonds. According to the further analysis, we found that the rare earth microelement has significant effect on the network structure. Compared the nanocrystal slag glass ceramic with the glass ceramics of similar ingredients, we found that generally, the Raman band wavenumber for the former is lower than the later. The composition difference between the glass ceramics and the slag nanocrystal with the similar ingredients mainly lies on the rare earth elements and other trace elements. Therefore, we think that the rare earth elements and other trace elements remains in the slag nanocrystal glass ceramics have a significant effect on the network structure of amorphous phase. The research method of this study provides an approach for the relationship among the composition, structure and performance of the glass ceramics.

Application of composite small calibration objects in traffic accident scene photogrammetry.

PubMed

Chen, Qiang; Xu, Hongguo; Tan, Lidong

2015-01-01

In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies.

Rare-Earth Metals and Their Applications in Aviation

DTIC Science & Technology

1984-08-01

metals are not as common as iron and steel which are visible everywhere, yet they are not unfamiliar to us. We often encounter them in everyday life...the flint of a lighter. It is an alloy of rare-earth metal and iron . It contains about 30% iron and the remainder is a composite rare-earth alloy...used to manufacture the detonators of bullets and shells as well as the pyrophoric alloys of firing devices. This type of alloy has a 49.5% content of

Abell 48 - a rare WN-type central star of a planetary nebula

NASA Astrophysics Data System (ADS)

Todt, H.; Kniazev, A. Y.; Gvaramadze, V. V.; Hamann, W.-R.; Buckley, D.; Crause, L.; Crawford, S. M.; Gulbis, A. A. S.; Hettlage, C.; Hooper, E.; Husser, T.-O.; Kotze, P.; Loaring, N.; Nordsieck, K. H.; O'Donoghue, D.; Pickering, T.; Potter, S.; Romero-Colmenero, E.; Vaisanen, P.; Williams, T.; Wolf, M.

2013-04-01

A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission-line spectra resembling those of massive WC stars. Therefore these stars are classed as CSPNe of spectral type [WC]. Recently, quantitative spectral analysis of two emission-line CSs, PB 8 and IC 4663, revealed that these stars do not belong to the [WC] class. Instead PB 8 has been classified as [WN/WC] type and IC 4663 as [WN] type. In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48. We performed a spectral analysis of Abell 48 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. We find that the expanding atmosphere of Abell 48 is mainly composed of helium (85 per cent by mass), hydrogen (10 per cent) and nitrogen (5 per cent). The residual hydrogen and the enhanced nitrogen abundance make this object different from the other [WN] star IC 4663. We discuss the possible origin of this atmospheric composition.

Nd and Sm isotopic composition of spent nuclear fuels from three material test reactors

DOE PAGES

Sharp, Nicholas; Ticknor, Brian W.; Bronikowski, Michael; ...

2016-11-17

Rare earth elements such as neodymium and samarium are ideal for probing the neutron environment that spent nuclear fuels are exposed to in nuclear reactors. The large number of stable isotopes can provide distinct isotopic signatures for differentiating the source material for nuclear forensic investigations. The rare-earth elements were isolated from the high activity fuel matrix via ion exchange chromatography in a shielded cell. The individual elements were then separated using cation exchange chromatography. In conclusion, the neodymium and samarium aliquots were analyzed via MC–ICP–MS, resulting in isotopic compositions with a precision of 0.01–0.3%.

Nd and Sm isotopic composition of spent nuclear fuels from three material test reactors

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

Sharp, Nicholas; Ticknor, Brian W.; Bronikowski, Michael

Rare earth elements such as neodymium and samarium are ideal for probing the neutron environment that spent nuclear fuels are exposed to in nuclear reactors. The large number of stable isotopes can provide distinct isotopic signatures for differentiating the source material for nuclear forensic investigations. The rare-earth elements were isolated from the high activity fuel matrix via ion exchange chromatography in a shielded cell. The individual elements were then separated using cation exchange chromatography. In conclusion, the neodymium and samarium aliquots were analyzed via MC–ICP–MS, resulting in isotopic compositions with a precision of 0.01–0.3%.

Emission efficiency optimization of RE 2O 3 doped molybdenum thermionic cathode by application of pattern recognition method

NASA Astrophysics Data System (ADS)

Wang, Jinshu; Liu, Wei; Liu, Yanqin; Zhou, Meiling

2005-09-01

As an alternative for thoriated tungsten thermionic cathodes, molybdenum doped with either a single rare earth oxide such as La 2O 3, Y 2O 3 and Sc 2O 3 or a mixture thereof has been produced by powder metallurgy. It is shown that carbonization can greatly improve the emission properties (i.e. emission capability and stability) of RE 2O 3 doped molybdenum due to the formation of a (metallic) rare earth atomic layer on the surface of the cathode by the reduction reaction of molybdenum carbide and rare earth oxide. Among all the carbonized samples, La 2O 3 and Y 2O 3 co-doped molybdenum cathode showed the best performance in emission. In addition, computer pattern recognition technique has been used to optimize the composition of the material and of the cathode preparation technique. We derive the equation of the emission efficiency as a function of cathode composition and carbonization degree. Based on the projecting coordinates obtained from the equation, the optimum projection region was identified, which can serve as guide for the composition and carbonization degree design.

Morphologically and size uniform monodisperse particles and their shape-directed self-assembly

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

Collins, Joshua E.; Bell, Howard Y.; Ye, Xingchen

2017-09-12

Monodisperse particles having: a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology are disclosed. Due to their uniform size and shape, the monodisperse particles self assemble into superlattices. The particles may be luminescent particles such as down-converting phosphor particles and up-converting phosphors. The monodisperse particles of the invention have a rare earth-containing lattice which in one embodiment may be an yttrium-containing lattice or in another may be a lanthanide-containing lattice. The monodisperse particles may have different optical properties based on their composition, their size, and/or their morphology (or shape). Alsomore » disclosed is a combination of at least two types of monodisperse particles, where each type is a plurality of monodisperse particles having a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology; and where the types of monodisperse particles differ from one another by composition, by size, or by morphology. In a preferred embodiment, the types of monodisperse particles have the same composition but different morphologies. Methods of making and methods of using the monodisperse particles are disclosed.« less

Morphologically and size uniform monodisperse particles and their shape-directed self-assembly

DOEpatents

Collins, Joshua E.; Bell, Howard Y.; Ye, Xingchen; Murray, Christopher Bruce

2015-11-17

Monodisperse particles having: a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology are disclosed. Due to their uniform size and shape, the monodisperse particles self assemble into superlattices. The particles may be luminescent particles such as down-converting phosphor particles and up-converting phosphors. The monodisperse particles of the invention have a rare earth-containing lattice which in one embodiment may be an yttrium-containing lattice or in another may be a lanthanide-containing lattice. The monodisperse particles may have different optical properties based on their composition, their size, and/or their morphology (or shape). Also disclosed is a combination of at least two types of monodisperse particles, where each type is a plurality of monodisperse particles having a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology; and where the types of monodisperse particles differ from one another by composition, by size, or by morphology. In a preferred embodiment, the types of monodisperse particles have the same composition but different morphologies. Methods of making and methods of using the monodisperse particles are disclosed.

Advanced Environmental Barrier Coating and SA Tyrannohex SiC Composites Integration for Improved Thermomechanical and Environmental Durability

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Halbig, Michael; Singh, Mrityunjay

2018-01-01

The development of 2700 degF capable environmental barrier coating (EBC) systems, particularly, the Rare Earth "Hafnium" Silicon bond coat systems, have significantly improved the temperature capability and environmental stability of SiC/SiC Ceramic Matrix Composite Systems. We have specifically developed the advanced 2700 degF EBC systems, integrating the EBC to the high temperature SA Tyrannohex SiC fiber composites, for comprehensive performance and durability evaluations for potential turbine engine airfoil component applications. The fundamental mechanical properties, environmental stability and thermal gradient cyclic durability performance of the EBC - SA Tyrannohex composites were investigated. The paper will particularly emphasize the high pressure combustion rig recession, cyclic thermal stress resistance and thermomechanical low cycle fatigue testing of uncoated and environmental barrier coated Tyrannohex SiC SA composites in these simulated turbine engine combustion water vapor, thermal gradients, and mechanical loading conditions. We have also investigated high heat flux and flexural fatigue degradation mechanisms, determined the upper limits of operating temperature conditions for the coated SA composite material systems in thermomechanical fatigue conditions. Recent progress has also been made by using the self-healing rare earth-silicon based EBCs, thus enhancing the SA composite hexagonal fiber columns bonding for improved thermomechanical and environmental durability in turbine engine operation environments. More advanced EBC- composite systems based on the new EBC-Fiber Interphases will also be discussed.

Rare Earth Element Partition Coefficients from Enstatite/Melt Synthesis Experiments

NASA Technical Reports Server (NTRS)

Schwandt, Craig S.; McKay, Gordon A.

1997-01-01

Enstatite (En(80)Fs(19)Wo(01)) was synthesized from a hypersthene normative basaltic melt doped at the same time with La, Ce, Nd, Sm, Eu, Dy, Er, Yb and Lu. The rare earth element concentrations were measured in both the basaltic glass and the enstatite. Rare earth element concentrations in the glass were determined by electron microprobe analysis with uncertainties less than two percent relative. Rare earth element concentrations in enstatite were determined by secondary ion mass spectrometry with uncertainties less than five percent relative. The resulting rare earth element partition signature for enstatite is similar to previous calculated and composite low-Ca pigeonite signatures, but is better defined and differs in several details. The partition coefficients are consistent with crystal structural constraints.

Anthropogenic Litter in Urban Freshwater Ecosystems: Distribution and Microbial Interactions

PubMed Central

Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

2014-01-01

Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem types, and will benefit management and reduction of global AL accumulations. PMID:24955768

Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

PubMed

Hoellein, Timothy; Rojas, Miguel; Pink, Adam; Gasior, Joseph; Kelly, John

2014-01-01

Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem types, and will benefit management and reduction of global AL accumulations.

Buffer layers for coated conductors

DOEpatents

Stan, Liliana [Los Alamos, NM; Jia, Quanxi [Los Alamos, NM; Foltyn, Stephen R [Los Alamos, NM

2011-08-23

A composite structure is provided including a base substrate, an IBAD oriented material upon the base substrate, and a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material. Additionally, an article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and a thick film upon the cubic metal oxide material. Finally, a superconducting article is provided including a base substrate, an IBAD oriented material upon the base substrate, a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the IBAD oriented material, and an yttrium barium copper oxide material upon the cubic metal oxide material.

A Global Approach to Rare Diseases Research and Orphan Products Development: The International Rare Diseases Research Consortium (IRDiRC).

PubMed

Cutillo, Christine M; Austin, Christopher P; Groft, Stephen C

2017-01-01

Rare diseases present unique challenges to researchers due to the global distribution of patients, complexity and low prevalence of each disease, and limited availability of data. They are also overwhelming and costly for patients, their families, communities, and society. As such, global integration of rare diseases research is necessary to accelerate the understanding, diagnosis, and treatment of rare disorders. The International Rare Diseases Research Consortium (IRDiRC) was born out of that need for a coordinated international community. IRDiRC was launched in 2011 to facilitate cooperation and collaboration on a global scale among the many stakeholders active in rare diseases research to stimulate better coordination, and thereby maximize output of rare diseases research efforts around the world. Members include funders, academic researchers, companies, and patient advocacy organizations all of whom share the common goals and principles of IRDiRC. The overarching objectives of the Consortium are to contribute to the development of 200 new therapies and a means to diagnose most rare diseases, by 2020. As IRDiRC approaches the end of its fifth year, these initial objectives have been largely achieved and new partners from across the globe are joining. This presents the Consortium with the exciting opportunity to set new and even more ambitious goals for the next phase with the ultimate goal of improved health through faster and better diagnostic capabilities and novel therapies for people living with rare diseases and conditions throughout the world.

Application of Composite Small Calibration Objects in Traffic Accident Scene Photogrammetry

PubMed Central

Chen, Qiang; Xu, Hongguo; Tan, Lidong

2015-01-01

In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies. PMID:26011052

Effects of Neighborhood Socioeconomic Characteristics and Class Composition on Highly Competent Children.

ERIC Educational Resources Information Center

Maggi, Stefania; Hertzman, Clyde; Kohen, Dafina; D'Angiulli, Amedio

2004-01-01

The conditions that prevent highly competent children from fully developing their learning potential rarely have been addressed. The authors investigated the relationship between neighborhood socioeconomic characteristics, class composition, and changes in the proportion of highly competent children in kindergarten and in Grades 4 and 7. The…

Mosaic protein and nucleic acid vaccines against hepatitis C virus

DOEpatents

Yusim, Karina; Korber, Bette T. M.; Kuiken, Carla L.; Fischer, William M.

2013-06-11

The invention relates to immunogenic compositions useful as HCV vaccines. Provided are HCV mosaic polypeptide and nucleic acid compositions which provide higher levels of T-cell epitope coverage while minimizing the occurrence of unnatural and rare epitopes compared to natural HCV polypeptides and consensus HCV sequences.

A Study of Compaction and Deformation of a Powder Composite Material of the `Aluminum - Rare Earth Elements' System

NASA Astrophysics Data System (ADS)

Rudskoy, A. I.; Tsemenko, V. N.; Ganin, S. V.

2015-01-01

The possibility of fabrication of preforms of a composite material with special radiation-protective properties on the base of mechanically alloyed powders of the Al - REM system with the use of methods of severe plastic deformation is shown.

Flexible composite radiation detector

DOEpatents

Cooke, D Wayne [Santa Fe, NM; Bennett, Bryan L [Los Alamos, NM; Muenchausen, Ross E [Los Alamos, NM; Wrobleski, Debra A [Los Alamos, NM; Orler, Edward B [Los Alamos, NM

2006-12-05

A flexible composite scintillator was prepared by mixing fast, bright, dense rare-earth doped powdered oxyorthosilicate (such as LSO:Ce, LSO:Sm, and GSO:Ce) scintillator with a polymer binder. The binder is transparent to the scintillator emission. The composite is seamless and can be made large and in a wide variety of shapes. Importantly, the composite can be tailored to emit light in a spectral region that matches the optimum response of photomultipliers (about 400 nanometers) or photodiodes (about 600 nanometers), which maximizes the overall detector efficiency.

Strength and microstructure of sintered Si3N4 with rare-earth-oxide additions

NASA Technical Reports Server (NTRS)

Sanders, W. A.; Mieskowski, D. M.

1985-01-01

Room temperature, 700-, 1000-, 1200-, and 1370-C examinations of the effect of 1.7-2.6 mol pct rare earth oxide additions to sintered Si3N4 are conducted. While the room temperature-1000 C bend strengths were higher for this material with Y2O3 additions than with CeO2, La2O3, or Sm2O3, the reverse was true at 1200-1370 C. This phenomenon is explained on the basis of microstructural differences, since quantitative microscopy of SEM replicas showed the Si3N4-Y2O3 composition to contain both a higher percentage of elongated grains and a coarser microstructure than the other three alternatives. The elongated grains appear to increase this composition's low temperature strength irrespective of microstructural coarseness; this coarseness, however, decreases strength relative to the other compositions at higher temperatures.

Bird, mammal, and vegetation community surveys of research natural areas in the Tongass National Forest.

Treesearch

W.P. Smith; M.J. Stotts; B.A. Andres; J.M. Melton; A. Garibaldi; K. Boggs

2001-01-01

In June 1977, we surveyed seven research natural areas (RNAs) in the Tongass National Forest (Tongass). We documented the composition of biotic communities using rare plant and tidal community surveys, targeted searches for rare animals, and samples of permanent vegetation plots. Birds were sampled once along each transect with 10-minute point counts at stations 8...

Application of an integrated biomarker response index to assess ground water contamination in the vicinity of a rare earth mine tailings site.

PubMed

Si, Wantong; He, Xiaoying; Li, Ailing; Liu, Li; Li, Jisheng; Gong, Donghui; Liu, Juan; Liu, Jumei; Shen, Weishou; Zhang, Xuefeng

2016-09-01

We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl(-), SO4 (2-), Na(+), K(+), Mg(2+), Ca(2+), TH, CODMn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7 km.

Evaluation of stability region for scandium-containing rare-earth garnet single crystals and their congruent-melting compositions

NASA Astrophysics Data System (ADS)

Kaurova, I. A.; Domoroshchina, E. N.; Kuz'micheva, G. M.; Rybakov, V. B.

2017-06-01

Single crystals of scandium-containing rare-earth garnets in system R-Sc-C-O (R3+=Y, Gd; C3+=Al, Ga) have been grown by the Czochralski technique. X-ray diffraction analysis has been used to refine crystal compositions. The fundamental difference between the melt compositions and compositions of grown crystals has been found (except for compositions of congruent-melting compounds, CMC). The specific features of garnet solid solution formation have been established and the ternary diagrams with real or hypothetical phases have been built. The dinamics of coordination polyhedra changes with the formation of substitutional solid solutions have been proposed based on the mathematical modeling and experimental data. Possible existence of CMC with garnet structure in different systems as well as limit content of Sc ions in dodecahedral and octahedral sites prior to their partial substitution of ions, located in other sites, have been evaluated. It was established that the redistribution of cations over crystallographic sites (antistructural point defects) due to system self-organization to maintain its stability may be accompanied by cation ordering and the symmetry change of individual polyhedrons and/or the whole crystal.

The UV reflectance of Patroclus: Exploring the surface composition and origins of Jupiter Trojans

NASA Astrophysics Data System (ADS)

Molyneux, Pippa

2017-08-01

(617) Patroclus is a binary system comprising two almost equally sized Trojan asteroids, Patroclus and Menoetius. (617) Patroclus has never been observed in the UV spectral region, which contains important diagnostic features of major Trojan surface constituents inferred from fits to visible-near IR spectra. Previous spectral observations have not been spatially resolved, precluding a direct spectral comparison of the two bodies. We propose to obtain full surface UV reflectance maps of both Patroclus and Menoetius using the STIS G230L mode, to search for characteristic absorption features of silicates, carbons/graphites and NH3, which together make up the major inferred Jupiter Trojan surface constituents, and for signs of ''spectral bluing'' that occurs for space-weathered objects. The Jupiter Trojans are believed to represent the most readily accessible Kuiper Belt material in the solar system, having been scattered from that region to their current orbits following a dynamical instability. A direct spectral comparison of Patroclus and Menoetius, indicating whether the objects share a common origin and evolution, will explore the hypothesis that the system is a rare binary survivor of this scattering. (617) Patroclus is also a target of the upcoming Lucy mission, and constraints on surface composition would represent a valuable input to instrument configuration and observation planning work for the mission. As Lucy will not carry a UV instrument, the proposed observations would remain unique and complementary to the results of the mission.

Synthesis and characterization of rare-earth-doped calcium tungstate nanocrystals

NASA Astrophysics Data System (ADS)

Suneeta, P.; Rajesh, Ch.; Ramana, M. V.

2018-02-01

In this paper, we report synthesis and characterization of rare-earth-ion-doped calcium tungstate (CaWO4) nanocrystals (NCs). Rare-earth ions, such as gadolinium (Gd), neodymium (Nd), praseodymium (Pr), samarium (Sm) and holmium (Ho), were successfully doped in the CaWO4 NCs by changing the synthesis conditions. The adopted synthesis route was found to be fast and eco-friendly. Structural characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and compositional analysis, were performed using energy dispersive analysis of X-rays (EDAX) on as-synthesized NCs. The results indicate the size of the NCs ranging between 47 to 68nm and incorporation of rare-earth ions in CaWO4 NCs.

Rare Isotopes in Cosmic Explosions and Accelerators on Earth

ScienceCinema

Schatz, Hendrick

2017-12-28

Rare isotopes are nature’s stepping stones to produce the heavy elements, and they are produced in large quantities in stellar explosions. Despite their fleeting existence, they shape the composition of the universe and the observable features of stellar explosions. The challenge for nuclear science is to produce and study the very same rare isotopes so as to understand the origin of the elements and a range of astronomical observations. I will review the progress that has been made to date in astronomy and nuclear physics, and the prospects of finally addressing many of the outstanding issues with the future Facility for Rare Isotope Beams (FRIB), which DOE will build at Michigan State University.

Studies on hydrothermal synthesis of photolumniscent rare earth (Eu3+ & Tb3+) doped NG@FeMoO4 for enhanced visible light photodegradation of methylene blue dye

NASA Astrophysics Data System (ADS)

Singh, R.; Kumar, M.; Khajuria, H.; Sharma, S.; Sheikh, H. Nawaz

2018-02-01

FeMoO4 nanorods and their rare earth (Eu3+ and Tb3+) doped composites with nitrogen doped graphene (NG) were synthesized by facile hydrothermal method in aqueous medium. X-ray diffraction (XRD) analysis of the as-synthesized samples was done to study the phase purity and crystalline nature. FTIR and Raman Spectroscopy have been studied for investigating the bonding in nanostructures. The surface morphology of the samples was investigated with field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The photolumniscent nature of the samples was investigated by the using the fluorescence spectrophotometer. The photocatalytic degradation efficiency of the prepared pure FeMoO4 and its rare earth doped composites with nitrogen doped graphene was evaluated as function of visible light irradiation versus concentration of methylene blue (MB dye). The prepared nanocomposites show enhanced photocatalytic efficiency as compared to the bare FeMoO4 nanorods.

The 'North American shale composite' - Its compilation, major and trace element characteristics

NASA Technical Reports Server (NTRS)

Gromet, L. P.; Dymek, R. F.; Haskin, L. A.; Korotev, R. L.

1984-01-01

North American shale composite (NASC) major element composition and compilation are presented, together with rare earth element (REE) redeterminations obtained by high precision analytical methods. The major element composition of the NASC compares closely with other average shale compositions, and significant portions of the REE and some other trace elements are contained in minor phases. The uneven REE distribution in NASC powder appears to yield the heterogeneity in analyzed aliquants. REE distributions of detrital sediments may to some extent be dependent on their minor mineral assemblages and the sedimentological factors controlling these assemblages.

REM-containing silicate concentrates

NASA Astrophysics Data System (ADS)

Pavlov, V. F.; Shabanova, O. V.; Pavlov, I. V.; Pavlov, M. V.; Shabanov, A. V.

2016-01-01

A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

Improving the analysis of composite endpoints in rare disease trials.

PubMed

McMenamin, Martina; Berglind, Anna; Wason, James M S

2018-05-22

Composite endpoints are recommended in rare diseases to increase power and/or to sufficiently capture complexity. Often, they are in the form of responder indices which contain a mixture of continuous and binary components. Analyses of these outcomes typically treat them as binary, thus only using the dichotomisations of continuous components. The augmented binary method offers a more efficient alternative and is therefore especially useful for rare diseases. Previous work has indicated the method may have poorer statistical properties when the sample size is small. Here we investigate small sample properties and implement small sample corrections. We re-sample from a previous trial with sample sizes varying from 30 to 80. We apply the standard binary and augmented binary methods and determine the power, type I error rate, coverage and average confidence interval width for each of the estimators. We implement Firth's adjustment for the binary component models and a small sample variance correction for the generalized estimating equations, applying the small sample adjusted methods to each sub-sample as before for comparison. For the log-odds treatment effect the power of the augmented binary method is 20-55% compared to 12-20% for the standard binary method. Both methods have approximately nominal type I error rates. The difference in response probabilities exhibit similar power but both unadjusted methods demonstrate type I error rates of 6-8%. The small sample corrected methods have approximately nominal type I error rates. On both scales, the reduction in average confidence interval width when using the adjusted augmented binary method is 17-18%. This is equivalent to requiring a 32% smaller sample size to achieve the same statistical power. The augmented binary method with small sample corrections provides a substantial improvement for rare disease trials using composite endpoints. We recommend the use of the method for the primary analysis in relevant rare disease trials. We emphasise that the method should be used alongside other efforts in improving the quality of evidence generated from rare disease trials rather than replace them.

A retinoic acid response element that overlaps an estrogen response element mediates multihormonal sensitivity in transcriptional activation of the lactoferrin gene.

PubMed

Lee, M O; Liu, Y; Zhang, X K

1995-08-01

The lactoferrin gene is highly expressed in many different tissues, and its expression is controlled by different regulators. In this report, we have defined a retinoic acid response element (RARE) in the 5'-flanking region of the lactoferrin gene promoter. The lactoferrin-RARE is composed of two AGGTCA-like motifs arranged as a direct repeat with 1-bp spacing (DR-1). A gel retardation assay demonstrated that it bound strongly with retinoid X receptor (RXR) homodimers and RXR-retinoic acid receptor (RAR) heterodimers as well as chicken ovalbumin upstream promoter transcription factor (COUP-TF) orphan receptor. In CV-1 cells, the lactoferrin-RARE linked with a heterologous thymidine kinase promoter was strongly activated by RXR homodimers in response to 9-cis-retinoic acid (9-cis-RA) but not to all-trans-RA. When the COUP-TF orphan receptor was cotransfected, the 9-cis-RA-induced RXR homodimer activity was strongly repressed. A unique feature of the lactoferrin-RARE is that it has an AGGTCA-like motif in common with an estrogen-responsive element (ERE). The composite RARE/ERE contributes to the functional interaction between retinoid receptors and the estrogen receptor (ER) and their ligands. In CV-1 cells, cotransfection of the retinoid and estrogen receptors led to mutual inhibition of the other's activity, while an RA-dependent inhibition of ER activity was observed in breast cancer cells. Furthermore, the lactoferrin-RARE/ERE showed differential transactivation activity in different cell types. RAs could activate the lactoferrin-RARE/ERE in human leukemia HL-60 cells and U937 cells but not in human breast cancer cells. By gel retardation analyses, we demonstrated that strong binding of the endogenous COUP-TF in breast cancer cells to the composite element contributed to diminished RA response in these cells. Thus, the lactoferrin-RARE/ERE functions as a signaling switch module that mediates multihormonal responsiveness in the regulation of lactoferrin gene expression.

Respiratory diseases registries in the national registry of rare diseases.

PubMed

Lara Gallego, Beatriz; Abaitua Borda, Ignacio; Galán Gil, Genaro; Castillo Villegas, Diego; Casanova Espinosa, Álvaro; Cano Jiménez, Esteban; Ojanguren Arranz, Iñigo; Posada de la Paz, Manuel

2014-09-01

This report describes the general characteristics, objectives and organizational aspects of the registries of rare respiratory diseases included in the National Registry of Rare Diseases of the Research Institute for Rare Diseases (ISCIII), in order to publicize their existence and encourage the participation of professionals. Information is collected on the following conditions: alpha-1 antitrypsin deficiency, idiopathic tracheal stenosis, adult pulmonary Langerhans' cell histiocytosis, lymphangioleiomyomatosis, alveolar proteinosis, and sarcoidosis. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

Chemical composition and deterioration of glass excavated in the 15th 16th century fishermen town of Raversijde (Belgium)

NASA Astrophysics Data System (ADS)

Schalm, O.; Caluwé, D.; Wouters, H.; Janssens, K.; Verhaeghe, F.; Pieters, M.

2004-10-01

The chemical composition, as determined by electron probe X-ray microanalysis of a series of ca. 100 archaeological glass fragments, excavated at the Raversijde site (Belgium) is discussed. In the 15th-16th century, Raversijde was a flourishing fishermen town located on the shore of the North Sea, close to the city of Ostend. As a consequence of several battles that were fought in its vicinity, the site was abandoned in the 16th century and was not occupied since then. It is one of the rare archaeological sites in Europe that contains a significant amount of information on the daily life inside a small but affluent medieval community. A comparison of the chemical composition of fragments of vessels and window glass encountered in Raversijde to those found in urban centres in Belgium and to literature date on German and French archaeological finds shows that glass made with wood ash dominates. Usually, it concerns artifacts with a predominantly utilitarian use. A few objects made with sodic (i.e., Na-rich) glass were also encountered, likely to have been imported from Venice during the 15th century or in later periods from an urban centre such as Antwerp, where Façon-de-Venice glass manufacturing activities were established near the start of the 16th century.

Effects of selective logging on bat communities in the southeastern Amazon.

PubMed

Peters, Sandra L; Malcolm, Jay R; Zimmerman, Barbara L

2006-10-01

Although extensive areas of tropical forest are selectively logged each year, the responses of bat communities to this form of disturbance have rarely been examined. Our objectives were to (1) compare bat abundance, species composition, and feeding guild structure between unlogged and low-intensity selectively logged (1-4 logged stems/ha) sampling grids in the southeastern Amazon and (2) examine correlations between logging-induced changes in bat communities and forest structure. We captured bats in understory and canopy mist nets set in five 1-ha study grids in both logged and unlogged forest. We captured 996 individuals, representing 5 families, 32 genera, and 49 species. Abundances of nectarivorous and frugivorous taxa (Glossophaginae, Lonchophyllinae, Stenodermatinae, and Carolliinae) were higher at logged sites, where canopy openness and understory foliage density were greatest. In contrast, insectivorous and omnivorous species (Emballonuridae, Mormoopidae, Phyllostominae, and Vespertilionidae) were more abundant in unlogged sites, where canopy foliage density and variability in the understory stratum were greatest. Multivariate analyses indicated that understory bat species composition differed strongly between logged and unlogged sites but provided little evidence of logging effects for the canopy fauna. Different responses among feeding guilds and taxonomic groups appeared to be related to foraging and echolocation strategies and to changes in canopy cover and understory foliage densities. Our results suggest that even low-intensity logging modifies habitat structure, leading to changes in bat species composition.

Rare gases in Samoan xenoliths

NASA Astrophysics Data System (ADS)

Poreda, R. J.; Farley, K. A.

1992-09-01

The rare gas isotopic compositions of residual harzburgite xenoliths from Savai'i (SAV locality) and an unnamed seamount south of the Samoan chain (PPT locality) provide important constraints on the rare gas evolution of the mantle and atmosphere. Despite heterogeneous trace element compositions, the rare gas characteristics of the xenoliths from each of the two localities are strikingly similar. SAV and PPT xenoliths have 3He/ 4He ratios of11.1 ± 0.5 R A and21.6 ± 1 R A, respectively; this range is comparable to the 3He/ 4He ratios in Samoan lavas and clearly demonstrates that they have trapped gases from a relatively undegassed reservoir. The neon results are not consistent with mixing between MORB and a plume source with an atmospheric signature. Rather, the neon isotopes reflect either a variably degassed mantle (with a relative order of degassing of Loihi < PPT < Reunion < SAV < MORB), or mixing between the Loihi source and MORB. The data supports the conclusions of Honda et al. that the 20Ne/ 22Ne ratio in the mantle more closely resembles the solar ratio than the atmospheric one. 40Ar/ 36Ar ratios in the least contaminated samples range from 4,000 to 12,000 with the highest values in the 22 RA PPT xenoliths. There is no evidence for atmospheric 40Ar/ 36Ar ratios in the mantle source of these samples, which indicates that the lower mantle may have 40Ar/ 36Ar ratios in excess of 5,000. Xenon isotopic anomalies in 129Xe and 136Xe are as high as 6%, or about half of the maximum MORB excess and are consistent with the less degassed nature of the Samoan mantle source. These results contradict previous suggestions that the high 3He/ 4He mantle has a near-atmospheric heavy rare gas isotopic composition.

Are C1 chondrites chemically fractionated - A trace element study

NASA Technical Reports Server (NTRS)

Ebihara, M.; Wolf, R.; Anders, E.

1982-01-01

Six C1 chondrite samples and a C2 xenolith from the Plainview H5 chondrite were analyzed by radiochemical neutron activation for a large variety of elements, including rare earths. The sample processing is described, including the irradiation, chemical procedure, rare earths separation, counting techniques, radiochemical purity check, and chemical yields. The results of consistency checks on a number of elements are discussed. Abundances for siderophiles, volatiles, and rare earths are presented and discussed. Tests are presented for fractionation of rare earths and other refractories, compositional uniformity of C1's, and interelement correlations. There is no conclusive evidence for nebular fractionation affecting C1's. Three fractionation-prone rare earths have essentially the same relative abundances in C1's and all other chondrite classes, and hence are apparently not fractionated in C1's.

Community structure of rare methanogenic archaea: insight from a single functional group

PubMed Central

Winkel, Matthias; Wagner, Dirk

2017-01-01

Abstract The rare biosphere, the low abundant microbial populations, is suggested to be a conserved way of microbial life. Here we conducted a molecular survey of rare methanogenic archaea in the environment targeting the mcrA gene in order to test if general concepts associated with the structure of the rare bacterial biosphere also apply to single functional groups. Similar to what is known about rare bacterial communities, the contribution of rare methanogens to the alpha diversity is much larger than to Bray-Curtis measures. Moreover, a similar core group of methanogens harbored by the abundant and rare communities suggests similar sources and environmental controls of both groups. Among the communities of different levels of rarity, the conditionally rare methanogenic taxa largely account for the overall community dynamics of the rare biosphere and likely enter the dominant community under favorable environmental conditions. In addition, we observed a positive correlation between the alpha diversity and the production of methane when the rare taxa were taken into account. This supports the concept that increasing microbial biodiversity enhances ecological function. The composition and environmental associations of the rare methanogenic biosphere allow us to conclude that rarity is a conserved way also for single functional groups. PMID:29029047

Regional variation in Caribbean dry forest tree species composition

Treesearch

Janet Franklin; Julie Ripplinger; Ethan H. Freid; Humfredo Marcano-Vega; David W. Steadman

2015-01-01

How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Bahamian Archipelago (...

Further Contributions from the Ethical Turn in Composition/Rhetoric: Analyzing Ethics in Interaction

ERIC Educational Resources Information Center

Barton, Ellen

2008-01-01

In this essay, I propose that the field of composition/rhetoric can make important contributions to the understanding of ethics based on our critical perspective on language as interactional and rhetorical. The actual language of decision making with ethical dimensions has rarely been studied directly in the literature, a crucial gap our field can…

Rare earth-doped materials with enhanced thermoelectric figure of merit

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

Venkatasubramanian, Rama; Cook, Bruce Allen; Levin, Evgenii M.

A thermoelectric material and a thermoelectric converter using this material. The thermoelectric material has a first component including a semiconductor material and a second component including a rare earth material included in the first component to thereby increase a figure of merit of a composite of the semiconductor material and the rare earth material relative to a figure of merit of the semiconductor material. The thermoelectric converter has a p-type thermoelectric material and a n-type thermoelectric material. At least one of the p-type thermoelectric material and the n-type thermoelectric material includes a rare earth material in at least one ofmore » the p-type thermoelectric material or the n-type thermoelectric material.« less

A Case of a Composite Adrenal Medullary Tumor of Pheochromocytoma and Ganglioneuroma Masquerading as Acute Pancreatitis

PubMed Central

Choi, Eun-Kyoung; Kim, Wan-Ho

2006-01-01

Composite adrenal medullary tumors, composed of both pheochromocytoma and ganglioneuroma, are extremely rare, as are pheochromocytomas masquerading as acute relapsing pancreatitis. We recently experienced a case of a 48-year-old male with both these phenomena. The patient complained of an acute onset of intense abdominal discomfort. At the same time, pancreatic enzymes were increased in concentration. An abdominal computed tomographic scan revealed an enlarged pancreas and a 3-cm left adrenal incidentaloma. Biochemical and 131I-MIBG scintigraphic findings were compatible with a pheochromocytoma. Yet, he had no clinical manifestations suggesting pheochromocytoma. An adrenalectomy was performed and a composite adrenal medullary tumor of pheochromocytoma and ganglioneuroma was confirmed during a pathologic examination. This case illustrates two points: 1) acute abdominal intense discomfort and hyperamylasemia may be unusual presentations of pheochromocytomas; and 2) the possibility of the pheochromocytoma, albeit rare, should be considered when a relapsing pancreatitis of uncertain etiology develops. PMID:16913447

Distinct patterns and processes of abundant and rare eukaryotic plankton communities following a reservoir cyanobacterial bloom.

PubMed

Xue, Yuanyuan; Chen, Huihuang; Yang, Jun R; Liu, Min; Huang, Bangqin; Yang, Jun

2018-06-13

Plankton communities normally consist of few abundant and many rare species, yet little is known about the ecological role of rare planktonic eukaryotes. Here we used a 18S ribosomal DNA sequencing approach to investigate the dynamics of rare planktonic eukaryotes, and to explore the co-occurrence patterns of abundant and rare eukaryotic plankton in a subtropical reservoir following a cyanobacterial bloom event. Our results showed that the bloom event significantly altered the eukaryotic plankton community composition and rare plankton diversity without affecting the diversity of abundant plankton. The similarities of both abundant and rare eukaryotic plankton subcommunities significantly declined with the increase in time-lag, but stronger temporal turnover was observed in rare taxa. Further, species turnover of both subcommunities explained a higher percentage of the community variation than species richness. Both deterministic and stochastic processes significantly influenced eukaryotic plankton community assembly, and the stochastic pattern (e.g., ecological drift) was particularly pronounced for rare taxa. Co-occurrence network analysis revealed that keystone taxa mainly belonged to rare species, which may play fundamental roles in network persistence. Importantly, covariations between rare and non-rare taxa were predominantly positive, implying multispecies cooperation might contribute to the stability and resilience of the microbial community. Overall, these findings expand current understanding of the ecological mechanisms and microbial interactions underlying plankton dynamics in changing aquatic ecosystems.

Development of the "rare-earth" hypothesis to explain the reasons of geophagy in Teletskoye Lake are kudurs (Gorny Altai, Russia).

PubMed

Panichev, Alexander M; Seryodkin, Ivan V; Kalinkin, Yuri N; Makarevich, Raisa A; Stolyarova, Tatiana A; Sergievich, Alexander A; Khoroshikh, Pavel P

2017-12-18

The mineral and chemical composition of the liquid and lithogenous substances, consumed by the wild ungulate animals, at the kudurs of the Teletskoye Lake, Gorny Altai, Russia, was studied. It was investigated that all examined kudurits are argillous-aleurolitic and get in the interval from 1 to 100 μm with the predominance of the fraction 10 μm. By the mineral composition, the lithogenous kudurits present the quartz-feldspathic-hydromicaceous-chloritic mineral formations with the large content of the quartz particles (20-43%) and sodium-containing plagioclases (albite, 15-32 wt%). The lithogenous kudurits are the products of the reconstitution of the metamorphic cleaving stones as a result of the glacier abrasive effect, subsequent its aqueous deposits and then eolation in the subaerial conditions. The fontinal waters consumed at the kudurs are subsaline chloride-hydrocarbonate-sodium and sulphated-hydrocarbonate-calcium types. It essentially differs by the increased content of rare-earth elements in reference to the lake water. The acid (HCl, pH-1) extracts from the kudurits more actively extract calcium (10-35% of the gross contents; sodium extracts at the level of 1-3%). The most fluent in the microelements composition are Cu, Be, Sr, Co, Cd, Pb, Sc, Y and rare-earth elements. The transit of all these elements into the dissoluted form fluctuates about 10% from the gross contents. The reason of geophagy is related to tendency of herbivores to absorb mineralized subsoils enriched by the biologically accessible forms of rare-earth elements, arisen as a result of vital activity of specific microflora.

Effectiveness of alternative management strategies in meeting conservation objectives

Treesearch

Richards S. Holthausen; Carolyn Hull Sieg

2007-01-01

This chapter evaluates how well various management strategies meet a variety of conservation objectives, summarizes their effectiveness in meeting objectives for rare or little-known (RLK) species, and proposes ways to combine strategies to meet overall conservation objectives. We address two broad categories of management strategies. Species approaches result in...

Influence of phase composition on microstructure and properties of Mg-5Al-0.4Mn-xRE (x = 0, 3 and 5 wt.%) alloys

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

Braszczyńska-Malik, K.N., E-mail: kacha@wip.pcz.pl; Grzybowska, A.

2016-05-15

The microstructure and mechanical properties investigations of two AME503 and AME505 experimental alloys in as-cast conditions were presented. The investigated materials were fabricated on the basis of the AM50 commercial magnesium alloy with 3 and 5 wt.% cerium rich mischmetal. In the as-cast condition, both experimental alloys were mainly composed of α-Mg, Al{sub 11}RE{sub 3} and Al{sub 10}RE{sub 2}Mn{sub 7} intermetallic phases. Additionally, due to non-equilibrium solidification conditions, a small amount of α + γ divorced eutectic and Al{sub 2}RE intermetallic phase were revealed. The obtained results also show a significant influence of rare earth elements on Brinell hardness, tensilemore » and compression properties at ambient temperature and especially on creep properties at 473 K. Improved alloy properties with a rise in rare earth elements mass fraction results from an increase in Al{sub 11}RE{sub 3} phase volume fraction and suppression of α + γ eutectic volume fraction in the alloy microstructure. Additionally, the influence of rare earth elements on the dendrite arm space value was discussed. The presented results also proved the thermal stability of the intermetallic phases during creep testing. - Highlights: • Two different Mg-5Al-0.4Mn alloys containing 3 and 5 wt.% of rare earth elements were fabricated. • Addition of rare earth elements leads to a reduction of dendrite arm spaces. • Mechanical properties depend on the phase composition of the alloys. • The increase of the rare earth elements content causes rise of the creep resistance.« less

Rare-earth-free high energy product manganese-based magnetic materials.

PubMed

Patel, Ketan; Zhang, Jingming; Ren, Shenqiang

2018-06-14

The constant drive to replace rare-earth metal magnets has initiated great interest in an alternative. Manganese (Mn) has emerged to be a potential candidate as a key element in rare-earth-free magnets. Its five unpaired valence electrons give it a large magnetocrystalline energy and the ability to form several intermetallic compounds. These factors have led Mn-based magnets to be a potential replacement for rare-earth permanent magnets for several applications, such as efficient power electronics, energy generators, magnetic recording and tunneling applications, and spintronics. For past few decades, Mn-based magnets have been explored in many different forms, such as bulk magnets, thin films, and nanoparticles. Here, we review the recent progress in the synthesis and structure-magnetic property relationships of Mn-based rare-earth-free magnets (MnBi, MnAl and MnGa). Furthermore, we discuss their potential to replace rare-earth magnetic materials through the control of their structure and composition to achieve the theoretically predicted magnetic properties.

Long-term data set analysis of stable isotopic composition in German rivers

NASA Astrophysics Data System (ADS)

Reckerth, Anne; Stichler, Willibald; Schmidt, Axel; Stumpp, Christine

2017-09-01

Stable isotopes oxygen-18 (18O) and deuterium (2H) are commonly used to investigate hydrological processes in catchments. However, only a few isotope studies have been conducted on a large scale and rarely over long time periods. The objective of this study was to identify the spatial and seasonal variability of isotopic composition in river water and how it is affected by geographical and hydrological factors. The stable isotopic composition of river water has been measured in nine large river catchments in Germany for a time period of 12 years or 26 years. We conducted time series and correlation analyses to identify spatial and temporal patterns of the isotopic composition in the rivers. Further, we compared it to isotopic composition in local precipitation and catchments characteristics. In the majority of the rivers, the spatial and temporal patterns of precipitation were directly reflected in river water. The isotopic signals of the river water were time shifted and show attenuated amplitudes. Further deviations from isotopic compositions in local precipitation were observed in catchments with complex flow systems. These deviations were attributed to catchment processes and influences like evaporation, damming and storage. The seasonality of the isotopic composition was mainly determined by the discharge regimes of the rivers. We found correlations between isotopic long-term averages and catchment altitude as well as latitude and longitude, resulting in a northwest-southeast gradient. Furthermore, it was shown that long-term averages of d-excess were inversely related to flow length and catchment size, which indicates that evaporation enrichment has an impact on the isotopic composition even in catchments of humid climates. This study showed that isotopic composition in rivers can serve as a proxy for the local precipitation and can be utilized as an indicator for hydrological processes even in large river basins. In future, such long time series will help to also understand the impact of changes in the hydrological cycle on the larger scales. They can also be used for calibration and validation of flow and transport models at catchment and sub-catchment scale.

Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers.

PubMed

Sidiroglou, F; Roberts, A; Baxter, G

2016-04-01

Rare-earth doped optical fibers have captivated the interest of many researchers around the world across the past three decades. The growth of this research field has been stimulated primarily through their application in optical communications as fiber lasers and amplifiers, although rare-earth doped optical fiber based devices are now finding important uses in many other scientific and industrial areas (for example, medicine, sensing, the military, and material processing). Such wide commercial interest has provided a strong incentive for innovative fiber designs, alternative glass compositions, and novel fabrication processes. A prerequisite for the ongoing progress of this research field is developing the capacity to provide high resolution information about the rare-earth dopant distribution profiles within the optical fibers. This paper constitutes a comprehensive review of the imaging techniques that have been utilized in the analysis of the distribution of the rare-earth ion erbium within the core of optical fibers.

Cerium-based, intermetallic-strengthened aluminum casting alloy: High-volume co-product development

DOE PAGES

Sims, Zachary C.; Weiss, David; McCall, S. K.; ...

2016-05-23

Here, several rare earth elements are considered by-products to rare earth mining efforts. By using one of these by-product elements in a high-volume application such as aluminum casting alloys, the supply of more valuable rare earths can be globally stabilized. Stabilizing the global rare earth market will decrease the long-term criticality of other rare earth elements. The low demand for Ce, the most abundant rare earth, contributes to the instability of rare earth extraction. In this article, we discuss a series of intermetallic-strengthened Al alloys that exhibit the potential for new high-volume use of Ce. The castability, structure, and mechanicalmore » properties of binary, ternary, and quaternary Al-Ce based alloys are discussed. We have determined Al-Ce based alloys to be highly castable across a broad range of compositions. Nanoscale intermetallics dominate the microstructure and are the theorized source of the high ductility. In addition, room-temperature physical properties appear to be competitive with existing aluminum alloys with extended high-temperature stability of the nanostructured intermetallic.« less

SURVEY OF THE STEROL COMPOSITION OF THE MARINE DINOFLAGELLATES KARENIA BREVIS, KARENIA MIKIMOTOI, AND KARLODINIUM MICRUM: DISTRIBUTION OF STEROLS WITHIN OTHER MEMBERS OF THE CLASS DINOPHYCEAE

EPA Science Inventory

The sterol composition of different marine microalgae was examined to determine the utility of sterols as biomarkers to distinguish members of various algal classes. For example, members of the class Dinophyceae possess certain 4-methyl sterols, such as dinosterol, which are rare...

LC-MS phenolic profiling combined with multivariate analysis as an approach for the characterization of extra virgin olive oils of four rare Tunisian cultivars during ripening.

PubMed

Ben Brahim, Samia; Kelebek, Hasim; Ammar, Sonda; Abichou, Mounir; Bouaziz, Mohamed

2017-08-15

In this work, the phenolic composition of four rare cultivars grown under the same agronomical and environmental conditions was studied. This is to test the effects of cultivars and ripening index essentially on phenolic composition in olive oils as well as tocopherols composition, organoleptic profiling and oxidative properties. Furthermore, some agronomical traits were determined in which a general increase in the size of the fruit and oil contents were recorded for all cultivars. The phenolic fractions were identified and quantified using liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) in multiple reaction monitoring mode (MRM). A total of 13 phenolic compounds belonging to different chemical families were determined. Qualitative and quantitative differences in phenolic composition were observed among cultivars and also among sampling times. On the contrary to the agronomical traits, a general decrease (p<0.05) of total phenolic compounds was observed during maturation. Likewise, a decrease in tocopherols concentrations and oxidative properties was observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution of supercritical fluid in deeply subducted continental crust: a case study of composite granite-quartz veins in the Sulu belt, China

NASA Astrophysics Data System (ADS)

Wang, S.; Wang, L.; Brown, M.

2016-12-01

Although fluid plays a key role in element transport and rock strength during subduction to and exhumation from ultrahigh pressure (UHP) metamorphic conditions, the source of supercritical fluid at P above the second critical endpoints (SCE) and the subsequent evolution are not well constrained. To provide insight into the evolution of supercritical fluid in continental subduction zones, we undertook an integrated study of composite granite-quartz veins in retrogressed and migmatitic UHP eclogite at General's Hill, N of Qingdao, in the central Sulu belt. The composite veins are irregularly distributed in the eclogite, which occurs as blocks within gneiss. The granite component is enriched in large ion lithophile elements and light rare earth elements but depleted in high field strength elements and heavy rare earth elements, indicating crystallization from a melt phase of crustal origin. Additionally, the granite contains high modal phengite (22-30 vol%) and clinozoisite/epidote (3-10 vol%), implying precipitation from a H2O-rich silicate melt. By contrast, the quartz component is dominated by SiO2 (99.10 wt%), and contains low total rare earth elements (ΣREE = 0.46 ppm), indicating precipitation from an aqueous fluid. The crystallization age of the composite veins is 221 ± 2 Ma, which is younger than the UHP metamorphism in the Sulu belt at ca 230 Ma, consistent with formation during exhumation. Initial 176Hf/177Hf ratios and δ18O values of metamorphic zircons from the composite veins, and Sr-Nd isotope compositions of the granites all lie between values for eclogite and gneiss, indicating a mixed source. Accordingly, we propose that a supercritical fluid generated from the gneiss and the included blocks of eclogite at P-T conditions above the SCE for both compositions became trapped in the eclogite during exhumation. At P below the SCE for the hydrous granite system, the mixed supercritical fluid separated into immiscible aqueous melt and aqueous fluid and crystallized as the composite veins. Thus, these vein systems provide information critical to understanding the evolution of supercritical fluid during exhumation and the partitioning of elements between hydrous granite and aqueous fluid. These data inform our understanding of crust-mantle interactions in continental subduction zones.

Flavour issues in warped custodial models: B anomalies and rare K decays

NASA Astrophysics Data System (ADS)

D'Ambrosio, Giancarlo; Iyer, Abhishek M.

2018-06-01

We explore the flavour structure of custodial Randall-Sundrum (RS) models in the context of semi-leptonic decay of the B mesons. Anomalies in the b→ s ll processes can be easily fit with partially composite second generation leptons and third generation quarks. Given the explanations of the B anomalies, we obtain predictions for rare K- decays which are likely to be another candle for new physics (NP). Two scenarios are considered: (A) The source of non-universality is the right handed muons (unorthodox case). (B) Standard scenario, with anomalies explained primarily by non-universal couplings to the lepton doublets. The prediction for the rare K-decays are different according to the scenario, thereby serving as a useful discriminatory tool. We note that, in this setup R(D^*) is at best consistent with the SM and increasing the compositeness of the τ _L generates a net contribution becoming below the SM expectation. Finally, we also comment on the implications of flavour violation in the lepton sector and present an explicit example with the implementation of bulk leptonic MFV which helps in alleviating the constraints.

Random sampling causes the low reproducibility of rare eukaryotic OTUs in Illumina COI metabarcoding.

PubMed

Leray, Matthieu; Knowlton, Nancy

2017-01-01

DNA metabarcoding, the PCR-based profiling of natural communities, is becoming the method of choice for biodiversity monitoring because it circumvents some of the limitations inherent to traditional ecological surveys. However, potential sources of bias that can affect the reproducibility of this method remain to be quantified. The interpretation of differences in patterns of sequence abundance and the ecological relevance of rare sequences remain particularly uncertain. Here we used one artificial mock community to explore the significance of abundance patterns and disentangle the effects of two potential biases on data reproducibility: indexed PCR primers and random sampling during Illumina MiSeq sequencing. We amplified a short fragment of the mitochondrial Cytochrome c Oxidase Subunit I (COI) for a single mock sample containing equimolar amounts of total genomic DNA from 34 marine invertebrates belonging to six phyla. We used seven indexed broad-range primers and sequenced the resulting library on two consecutive Illumina MiSeq runs. The total number of Operational Taxonomic Units (OTUs) was ∼4 times higher than expected based on the composition of the mock sample. Moreover, the total number of reads for the 34 components of the mock sample differed by up to three orders of magnitude. However, 79 out of 86 of the unexpected OTUs were represented by <10 sequences that did not appear consistently across replicates. Our data suggest that random sampling of rare OTUs (e.g., small associated fauna such as parasites) accounted for most of variation in OTU presence-absence, whereas biases associated with indexed PCRs accounted for a larger amount of variation in relative abundance patterns. These results suggest that random sampling during sequencing leads to the low reproducibility of rare OTUs. We suggest that the strategy for handling rare OTUs should depend on the objectives of the study. Systematic removal of rare OTUs may avoid inflating diversity based on common β descriptors but will exclude positive records of taxa that are functionally important. Our results further reinforce the need for technical replicates (parallel PCR and sequencing from the same sample) in metabarcoding experimental designs. Data reproducibility should be determined empirically as it will depend upon the sequencing depth, the type of sample, the sequence analysis pipeline, and the number of replicates. Moreover, estimating relative biomasses or abundances based on read counts remains elusive at the OTU level.

Survey of Contamination in Fuel Tanks of DD-963 Class Ships.

DTIC Science & Technology

1982-07-23

and Identifly by block num0b.’) Diesel fuel Fuel sludge Bacteria Fuel contamination Cladosporium resinae Sludge composition assess sources of... resinae ) predominated. Viable sulfate reducers were sometimes present but rarely sulfide. Below pH 4 bacteria were rare and fungi and yeasts were numerous...but the variety tended to be restricted to C. resinae and Candida. Differences in viable microbial varieties present in these sludge categories are

Estimating relative values for multiple objectives on private forests

Treesearch

Donald F. Dennis; Thomas H. Stevens; David B. Kittredge; Mark G. Rickenbach

2001-01-01

Conjoint and other techniques were used to examine private forest-land owner's willingness to manage for timber and nontimber objectives. The objectives were to: maintain apple trees to benefit wildlife, protect rare ferns to enhance aesthetics and biodiversity, improve recreational trails, and harvest timber. Ecological objectives were found to be more important...

Evidence for an active rare biosphere within freshwater protists community.

PubMed

Debroas, Didier; Hugoni, Mylène; Domaizon, Isabelle

2015-03-01

Studies on the active rare biosphere at the RNA level are mainly focused on Bacteria and Archaea and fail to include the protists, which are involved in the main biogeochemical cycles of the earth. In this study, the richness, composition and activity of the rare protistan biosphere were determined from a temporal survey of two lakes by pyrosequencing. In these ecosystems, the always rare OTUs represented 77.2% of the total OTUs and 76.6% of the phylogenetic diversity. From the various phylogenetic indices computed, the phylogenetic units (PUs) constituted exclusively by always rare OTUs were discriminated from the other PUs. Therefore, the rare biosphere included mainly taxa that are distant from the reference databases compared to the dominant ones. In addition, the rarest OTUs represented 59.8% of the active biosphere depicted by rRNA and the activity (rRNA:rDNA ratio) increased with the rarity. The high rRNA:rDNA ratio determined in the rare fraction highlights that some protists were active at low abundances and contribute to ecosystem functioning. Interestingly, the always rare and active OTUs were characterized by seasonal changes in relation with the main environmental parameters measured. In conclusion, the rare eukaryotes represent an active, dynamic and overlooked fraction in the lacustrine ecosystems. © 2015 John Wiley & Sons Ltd.

Diversity of macrofaunal Mollusca of the abyssal Vema Fracture Zone and hadal Puerto Rico Trench, Tropical North Atlantic

NASA Astrophysics Data System (ADS)

Linse, Katrin; Schwabe, Enrico

2018-02-01

While biodiversity patterns of Atlantic deep-sea bivalves and gastropods have served as model taxa for setting global latitudinal and bathymetric hypotheses, less is known on abyssal, amphi-Atlantic molluscan assemblage compositions. The Vema-TRANSIT expedition sampled 17 stations in the Vema Fracture Zone (VFZ) and the Puerto Rico Trench (PRT) by epibenthic sledge. These samples comprised a total of 1333 specimens and 64 morphospecies of the classes Caudofoveata (7 species), Solenogastres (7 spp.), Bivalvia (22 spp.), Gastropoda (24 spp.), and Scaphopoda (4 spp.) while Cephalopoda, Monoplacophora and Polyplacophora were absent. The majority of species was rare with 21 uniques (32.8% of all species) and 10 duplicates (15.6% of all species) and of these 15 (48% of rare/23.4% of all species) morphospecies were singletons and 8 (25.8% of rare/12.5% of all species) morphospecies were doubletons. Overall bivalves (686 specimens) were most abundant, followed by scaphopods (314 spec.), while solenogastres (180 spec.), caudofoveates (86 spec.) and gastropods (67 spec.) were less abundant. The abyssal macro-molluscan species composition did not vary significantly between the eastern and western Atlantic sides of the VFZ while abundances standardized to 1000 m2 trawled area were higher on the eastern side. The abyssal PRT stations resembled the VFZ ones in species composition and abundances, in the latter the eastern VFZ. The hadal PRT differed in species composition from the abyssal VFZ and PRT and abundances were similarly low like the western VFZ. The Mid-Atlantic Ridge appeared not to be a barrier for the dispersal of the mostly lecitotrophic or plankotrophic larval stages of the reported molluscan species in this study.

Fine-Grained Rims in the Allan Hills 81002 and Lewis Cliff 90500 CM2 Meteorites: Their Origin and Modification

NASA Technical Reports Server (NTRS)

Hua, X.; Wang, J.; Buseck, P. R.

2002-01-01

Antarctic CM meteorites Allan Hills (ALH) 8 1002 and Lewis Cliff (LEW) 90500 contain abundant fine-grained rims (FGRs) that surround a variety of coarse-grained objects. FGRs from both meteorites have similar compositions and petrographic features, independent of their enclosed objects. The FGRs are chemically homogeneous at the 10 m scale for major and minor elements and at the 25 m scale for trace elements. They display accretionary features and contain large amounts of volatiles, presumably water. They are depleted in Ca, Mn, and S but enriched in P. All FGRs show a slightly fractionated rare earth element (REE) pattern, with enrichments of Gd and Yb and depletion of Er. Gd is twice as abundant as Er. Our results indicate that those FGRs are not genetically related to their enclosed cores. They were sampled from a reservoir of homogeneously mixed dust, prior to accretion to their parent body. The rim materials subsequently experienced aqueous alteration under identical conditions. Based on their mineral, textural, and especially chemical similarities, we conclude that ALH 8 1002 and LEW 90500 likely have a similar or identical source.

Patterns of rare and abundant marine microbial eukaryotes.

PubMed

Logares, Ramiro; Audic, Stéphane; Bass, David; Bittner, Lucie; Boutte, Christophe; Christen, Richard; Claverie, Jean-Michel; Decelle, Johan; Dolan, John R; Dunthorn, Micah; Edvardsen, Bente; Gobet, Angélique; Kooistra, Wiebe H C F; Mahé, Frédéric; Not, Fabrice; Ogata, Hiroyuki; Pawlowski, Jan; Pernice, Massimo C; Romac, Sarah; Shalchian-Tabrizi, Kamran; Simon, Nathalie; Stoeck, Thorsten; Santini, Sébastien; Siano, Raffaele; Wincker, Patrick; Zingone, Adriana; Richards, Thomas A; de Vargas, Colomban; Massana, Ramon

2014-04-14

Biological communities are normally composed of a few abundant and many rare species. This pattern is particularly prominent in microbial communities, in which most constituent taxa are usually extremely rare. Although abundant and rare subcommunities may present intrinsic characteristics that could be crucial for understanding community dynamics and ecosystem functioning, microbiologists normally do not differentiate between them. Here, we investigate abundant and rare subcommunities of marine microbial eukaryotes, a crucial group of organisms that remains among the least-explored biodiversity components of the biosphere. We surveyed surface waters of six separate coastal locations in Europe, independently considering the picoplankton, nanoplankton, and microplankton/mesoplankton organismal size fractions. Deep Illumina sequencing of the 18S rRNA indicated that the abundant regional community was mostly structured by organismal size fraction, whereas the rare regional community was mainly structured by geographic origin. However, some abundant and rare taxa presented similar biogeography, pointing to spatiotemporal structure in the rare microeukaryote biosphere. Abundant and rare subcommunities presented regular proportions across samples, indicating similar species-abundance distributions despite taxonomic compositional variation. Several taxa were abundant in one location and rare in other locations, suggesting large oscillations in abundance. The substantial amount of metabolically active lineages found in the rare biosphere suggests that this subcommunity constitutes a diversity reservoir that can respond rapidly to environmental change. We propose that marine planktonic microeukaryote assemblages incorporate dynamic and metabolically active abundant and rare subcommunities, with contrasting structuring patterns but fairly regular proportions, across space and time. Copyright © 2014 Elsevier Ltd. All rights reserved.

DISCO: An object-oriented system for music composition and sound design

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

Kaper, H. G.; Tipei, S.; Wright, J. M.

2000-09-05

This paper describes an object-oriented approach to music composition and sound design. The approach unifies the processes of music making and instrument building by using similar logic, objects, and procedures. The composition modules use an abstract representation of musical data, which can be easily mapped onto different synthesis languages or a traditionally notated score. An abstract base class is used to derive classes on different time scales. Objects can be related to act across time scales, as well as across an entire piece, and relationships between similar objects can replicate traditional music operations or introduce new ones. The DISCO (Digitalmore » Instrument for Sonification and Composition) system is an open-ended work in progress.« less

Method of determining lanthanidies in a transition element host

DOEpatents

De Kalb, Edward L.; Fassel, Velmer A.

1976-02-03

A phosphor composition contains a lanthanide activator element within a host matrix having a transition element as a major component. The host matrix is composed of certain rare earth phosphates or vanadates such as YPO.sub.4 with a portion of the rare earth replaced with one or more of the transition elements. On X-ray or other electromagnetic excitation, trace lanthanide impurities or additives within the phosphor are spectrometrically determined from their characteristic luminescence.

Development and Optimization of Tailored Composite TBC Design Architectures for Improved Erosion Durability

NASA Astrophysics Data System (ADS)

Schmitt, Michael P.; Schreiber, Jeremy M.; Rai, Amarendra K.; Eden, Timothy J.; Wolfe, Douglas E.

2017-08-01

Rare-earth pyrochlores, RE2Zr2O7, have been identified as potential thermal barrier coating (TBC) materials due to their attractive thermal properties and CMAS resistance. However, they possess a low fracture toughness which results in poor erosion durability/foreign object damage resistance. This research focuses on the development of tailored composite air plasma spray (APS) TBC design architectures utilizing a t' Low-k secondary toughening phase (ZrO2-2Y2O3-1Gd2O3-1Yb2O3; mol.%) to enhance the erosion durability of a hyper-stoichiometric pyrochlore, NZO (ZrO2-25Nd2O3-5Y2O3-5Yb2O3; mol.%). In this study, composite coatings have been deposited with 30, 50, and 70% (wt.%) t' Low-k toughening phase in a horizontally aligned lamellar morphology which enhances the toughening response of the coating. The coatings were characterized via SEM and XRD and were tested for erosion durability before and after isothermal heat treatment at 1100 °C. Analysis with mixing laws indicated improved erosion performance; however, a lack of long-term thermal stability was shown via isothermal heat treatments at 1316 °C. An impact stress analysis was performed using finite element analysis of a coating cross section, representing the first microstructurally realistic study of mechanical properties of TBCs with the results correlating well with observed behavior.

Resequencing of IRS2 reveals rare variants for obesity but not fasting glucose homeostasis in Hispanic children.

PubMed

Butte, Nancy F; Voruganti, V Saroja; Cole, Shelley A; Haack, Karin; Comuzzie, Anthony G; Muzny, Donna M; Wheeler, David A; Chang, Kyle; Hawes, Alicia; Gibbs, Richard A

2011-09-22

Our objective was to resequence insulin receptor substrate 2 (IRS2) to identify variants associated with obesity- and diabetes-related traits in Hispanic children. Exonic and intronic segments, 5' and 3' flanking regions of IRS2 (∼14.5 kb), were bidirectionally sequenced for single nucleotide polymorphism (SNP) discovery in 934 Hispanic children using 3730XL DNA Sequencers. Additionally, 15 SNPs derived from Illumina HumanOmni1-Quad BeadChips were analyzed. Measured genotype analysis tested associations between SNPs and obesity and diabetes-related traits. Bayesian quantitative trait nucleotide analysis was used to statistically infer the most likely functional polymorphisms. A total of 140 SNPs were identified with minor allele frequencies (MAF) ranging from 0.001 to 0.47. Forty-two of the 70 coding SNPs result in nonsynonymous amino acid substitutions relative to the consensus sequence; 28 SNPs were detected in the promoter, 12 in introns, 28 in the 3'-UTR, and 2 in the 5'-UTR. Two insertion/deletions (indels) were detected. Ten independent rare SNPs (MAF = 0.001-0.009) were associated with obesity-related traits (P = 0.01-0.00002). SNP 10510452_139 in the promoter region was shown to have a high posterior probability (P = 0.77-0.86) of influencing BMI, fat mass, and waist circumference in Hispanic children. SNP 10510452_139 contributed between 2 and 4% of the population variance in body weight and composition. None of the SNPs or indels were associated with diabetes-related traits or accounted for a previously identified quantitative trait locus on chromosome 13 for fasting serum glucose. Rare but not common IRS2 variants may play a role in the regulation of body weight but not an essential role in fasting glucose homeostasis in Hispanic children.

China launched a pilot project to improve its rare disease healthcare levels.

PubMed

Cui, Yazhou; Zhou, Xiaoyan; Han, Jinxiang

2014-01-27

China is facing the great challenge of serving the world's largest rare disease population. It is necessary to develop a specific medical plan to increase the levels of optimal prevention, diagnosis and treatment of rare diseases under the existing clinical service structures in China. In 2013, China launched its first pilot project focused on 20 representative rare diseases. A national network including approximately 100 provincial or municipal medical centers has been established to enable collaboration on rare diseases across China. The main objectives for this project are to develop and apply medical guidelines and clinical pathways for rare diseases, to establish a rare disease patient registry and data repository system, and to promote molecular testing for rare genetic disorders. This project also emphasizes building close links among the collaborative network, clinicians on the frontlines in basic medical services institutions and rare disease patient organizations. Primarily, this project expects to develop an actionable medical services plan to increase the delivery of quality healthcare for individuals and families living with rare diseases in China within five years.

Origin of planetary primordial rare gas - The possible role of adsorption.

NASA Technical Reports Server (NTRS)

Fanale, F. P.; Cannon, W. A.

1972-01-01

The degree of physical adsorption of Ne, Ar, Kr, and Xe on pulverized samples of the Allende meteorite at 113 K has been measured. The observed pattern of equilibrium enrichment of heavy rare gases over light on the pulverized meteorite surfaces relative to the gas phase is similar to the enrichment pattern exhibited by planetary primordial rare gas when compared with the composition of solar rare gas. Results indicate that, at 113 K, a total nebular pressure of from .01 to .001 atm would be required to explain the Ar, Kr, and Xe abundances in carbonaceous chondrites with an adsorption mechanism. This pressure estimate is compatible with the range of possible nebular pressures suggested by astrophysical arguments. However, the subsequent mechanism by which initially adsorbed gas might have been transferred into the interiors of grains cannot be identified at present.

Composition of monazites from pegmatites in eastern Minas Gerais, Brazil

USGS Publications Warehouse

Murata, K.J.; Dutra, C.V.; da Costa, M.T.; Branco, J.J.R.

1959-01-01

Two zoned pegmatites in south-eastern Minas Gerais were sampled in detail for their content of monazite and xenotime and the monazite was analysed for certain of the rare-earth elements and thorium. The ratio of xenotime to monazite increases in both pegmatites from the wall toward the quartz core. The content of the less basic rare-earth elements and of thorium in monazite rises in the same direction. These variation trends suggest that during the crystallization of these pegmatites there was a fractionation of the elements leading to a more or less steady enrichment of the less basic rare-earth elements and of thorium in the residual fluids. One mode of explaining these observed effects postulates that the rare-earth elements and thorium were present in pegmatitic fluids as co-ordination complexes rather than as simple cations. ?? 1959.

High modulus rare earth and beryllium containing silicate glass compositions. [for glass reinforcing fibers

NASA Technical Reports Server (NTRS)

Bacon, J. F. (Inventor)

1976-01-01

Glass compositions having a Young's modulus of at least 16 million psi and a specific modulus of at least 110 million inches consisting essentially of approximately, by weight, 20 to 43% SiO2, 8 to 21% Al2O3, 4 to 10% BeO, 27 to 58% of at least one oxide selected from a first group consisting of Y2O3, La2O3, Nd2O3, Ce2O3, Ce2O3, and the mixed rare earth oxides, and 3 to 12% of at least one oxide selected from a second group consisting of MgO, ZrO2, ZnO and CaO are described. The molar ratio of BeO to the total content of the first group oxides is from 1.0 to 3.0.

An overview of the association between lamprophyric intrusions and rare-metal mineralization

NASA Astrophysics Data System (ADS)

Štemprok, Miroslav; Seifert, Thomas

2011-01-01

Granite-related rare metal districts in orogenic settings are occasionally associated with lamprophyre dikes. We recorded 63 occurrences of lamprophyres in bimodal dike suites of about 200 granite bodies related to rare metal deposits. Most lamprophyres occur in Paleozoic and Mesozoic metallogenic provinces in the northern hemisphere. Lamprophyres which are associated with rare metal deposits are calc-alkaline (kersantites, minettes, spessartites) or more rarely alkaline lamprophyres (camptonites, monchiquites) which occur in the roof zone of complex granitic bodies as pre-granitic, intra-granitic, intra-ore or post-ore dikes. Most lamprophyres are spatially associated with dominant felsic dikes and/or with mafic dikes represented by diorites or diabases. Diorites and lamprophyres occasionally exhibit transitional compositions from one to another. Lamprophyres share common geochemical characteristics of highly evolved granitoids such as enrichment in K and F, increased abundances of Li, Rb, and Cs and enrichment in some HFSE (e.g. Zr, U, Th, Mo, Sn, W). Lamprophyres in rare metal districts testify to accessibility of the upper crust to mantle products at the time of rare metal mineralization and possible influence of mantle melts or mantle-derived fluids in the differentiation of granitic melts in the lower crust.

Were komatiites wet?

NASA Astrophysics Data System (ADS)

Arndt, N.; Ginibre, C.; Chauvel, C.; Albarède, F.; Cheadle, M.; Herzberg, C.; Jenner, G.; Lahaye, Y.

1998-08-01

The main arguments used to support the concept that komatiites form by melting of hydrous mantle are as follows: (1) Water reduces liquidus temperatures from extreme values to lower, more “normal” temperatures. (2) Some komatiites are pyroclastic and some contain vesicles, features that have been attributed to magmatic volatiles. (3) It is claimed from experimental studies of peridotite melting that the chemical composition of komatiite requires the presence of water, as does their characteristic spinifex textures. Counterarguments are the following: (1) Loss of volatiles as hydrous komatiite approaches the surface should produce degassing textures and structures, which, though not unknown, are rare in komatiites. Degassing should produce a highly supercooled liquid that partially crystallizes to porphyritic magma; komatiites commonly erupt as phenocryst-poor, highly magnesian lavas. (2) Chemical and isotopic compositions of most komatiites indicate that their mantle source became depleted in incompatible elements soon before magma formation. Such depletion removes water, leaving a dry source. (3) The experimental data are at best ambiguous; neither the chemical composition of komatiites, nor the crystallization of spinifex, requires the presence of water. We conclude that although some rare komatiites may be hydrous, most are dry.

Numerical simulation on the seismic absorption effect of the cushion in rigid-pile composite foundation

NASA Astrophysics Data System (ADS)

Han, Xiaolei; Li, Yaokun; Ji, Jing; Ying, Junhao; Li, Weichen; Dai, Baicheng

2016-06-01

In order to quantitatively study the seismic absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using seismic waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground acceleration on the seismic absorption effect of the cushion are analyzed. The results show that: 1) the seismic absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the seismic absorption effect is strongly affected by cushion thickness and ground acceleration.

Elemental Compositions of Extrasolar Planetesimals

NASA Astrophysics Data System (ADS)

Xu, Siyi; Jura, M.

2014-01-01

The composition of extrasolar rocky planets is essential for understanding the formation and evolution of these alien worlds. Studying externally-polluted white dwarfs provides the only method to directly measure the elemental compositions of extrasolar planetesimals, the building blocks of planets. The standard model is that some planetesimals can survive to the white dwarf phase, get perturbed, enter into the tidal radius of the white dwarf and get accreted, polluting its pure hydrogen or helium atmosphere. We have been performing high-resolution spectroscopic observations on a number of polluted white dwarfs to measure the bulk compositions of the accreted objects. To have a full picture of the abundance pattern, we gathered data from both Keck/HIRES and HST/COS. I will present the analysis for one of the most interesting objects -- G29-38. It is the first white dwarf identified with an infrared excess from debris of pulverized planetesimals and among the very first identified polluted hydrogen atmosphere white dwarfs. Our analysis indicates that the accreted extrasolar planetesimal is enhanced in refractory elements and depleted in volatile elements. A detailed comparison with solar system objects show that the observed composition can be best interpreted as a blend of chondritic object with some refractory-rich material, a result from post-nebular processing. When all polluted white dwarfs are viewed as an ensemble, we find that the elemental compositions of accreted extrasolar planetesimals resemble to those of solar system objects to zeroth order. (i) The big four elements, O, Fe, Mg and Si are also dominant. Objects with exotic compositions, e.g. diamond planets and refractory-dominated planets, are yet to be found. (ii) Volatiles, such as carbon and water, are only trace constituents. In terms of bulk composition, solar system objects are essentially normal.

Titanium isotopes and rare earth patterns in CAIs: Evidence for thermal processing and gas-dust decoupling in the protoplanetary disk

NASA Astrophysics Data System (ADS)

Davis, Andrew M.; Zhang, Junjun; Greber, Nicolas D.; Hu, Jingya; Tissot, François L. H.; Dauphas, Nicolas

2018-01-01

Titanium isotopic compositions (mass-dependent fractionation and isotopic anomalies) were measured in 46 calcium-, aluminum-rich inclusions (CAIs) from the Allende CV chondrite. After internal normalization to 49Ti/47Ti, we found that ε50Ti values are somewhat variable among CAIs, and that ε46Ti is highly correlated with ε50Ti, with a best-fit slope of 0.162 ± 0.030 (95% confidence interval). The linear correlation between ε46Ti and ε50Ti extends the same correlation seen among bulk solar objects (slope 0.184 ± 0.007). This observation provides constraints on dynamic mixing of the solar disk and has implications for the nucleosynthetic origin of titanium isotopes, specifically on the possible contributions from various types of supernovae to the solar system. Titanium isotopic mass fractionation, expressed as δ‧49Ti, was measured by both sample-standard bracketing and double-spiking. Most CAIs are isotopically unfractionated, within a 95% confidence interval of normal, but a few are significantly fractionated and the range δ‧49Ti is from ∼-4 to ∼+4. Rare earth element patterns were measured in 37 of the CAIs. All CAIs with significant titanium mass fractionation effects have group II and related REE patterns, implying kinetically controlled volatility fractionation during the formation of these CAIs.

Contributed Review: A review of the investigation of rare-earth dopant profiles in optical fibers

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

Sidiroglou, F.; Baxter, G.; Roberts, A.

Rare-earth doped optical fibers have captivated the interest of many researchers around the world across the past three decades. The growth of this research field has been stimulated primarily through their application in optical communications as fiber lasers and amplifiers, although rare-earth doped optical fiber based devices are now finding important uses in many other scientific and industrial areas (for example, medicine, sensing, the military, and material processing). Such wide commercial interest has provided a strong incentive for innovative fiber designs, alternative glass compositions, and novel fabrication processes. A prerequisite for the ongoing progress of this research field is developingmore » the capacity to provide high resolution information about the rare-earth dopant distribution profiles within the optical fibers. This paper constitutes a comprehensive review of the imaging techniques that have been utilized in the analysis of the distribution of the rare-earth ion erbium within the core of optical fibers.« less

Separation of the rare-earth fission product poisons from spent nuclear fuel

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

Christian, Jerry D.; Sterbentz, James W.

A method for the separation of the rare-earth fission product poisons comprising providing a spent nuclear fuel. The spent nuclear fuel comprises UO.sub.2 and rare-earth oxides, preferably Sm, Gd, Nd, Eu oxides, with other elements depending on the fuel composition. Preferably, the provided nuclear fuel is a powder, preferably formed by crushing the nuclear fuel or using one or more oxidation-reduction cycles. A compound comprising Th or Zr, preferably metal, is provided. The provided nuclear fuel is mixed with the Th or Zr, thereby creating a mixture. The mixture is then heated to a temperature sufficient to reduce the UO.sub.2more » in the nuclear fuel, preferably to at least to 850.degree. C. for Th and up to 600.degree. C. for Zr. Rare-earth metals are then extracted to form the heated mixture thereby producing a treated nuclear fuel. The treated nuclear fuel comprises the provided nuclear fuel having a significant reduction in rare-earths.« less

Integrating end-to-end threads of control into object-oriented analysis and design

NASA Technical Reports Server (NTRS)

Mccandlish, Janet E.; Macdonald, James R.; Graves, Sara J.

1993-01-01

Current object-oriented analysis and design methodologies fall short in their use of mechanisms for identifying threads of control for the system being developed. The scenarios which typically describe a system are more global than looking at the individual objects and representing their behavior. Unlike conventional methodologies that use data flow and process-dependency diagrams, object-oriented methodologies do not provide a model for representing these global threads end-to-end. Tracing through threads of control is key to ensuring that a system is complete and timing constraints are addressed. The existence of multiple threads of control in a system necessitates a partitioning of the system into processes. This paper describes the application and representation of end-to-end threads of control to the object-oriented analysis and design process using object-oriented constructs. The issue of representation is viewed as a grouping problem, that is, how to group classes/objects at a higher level of abstraction so that the system may be viewed as a whole with both classes/objects and their associated dynamic behavior. Existing object-oriented development methodology techniques are extended by adding design-level constructs termed logical composite classes and process composite classes. Logical composite classes are design-level classes which group classes/objects both logically and by thread of control information. Process composite classes further refine the logical composite class groupings by using process partitioning criteria to produce optimum concurrent execution results. The goal of these design-level constructs is to ultimately provide the basis for a mechanism that can support the creation of process composite classes in an automated way. Using an automated mechanism makes it easier to partition a system into concurrently executing elements that can be run in parallel on multiple processors.

Activated phosphors having matrices of yttrium-transition metal compound

DOEpatents

De Kalb, E.L.; Fassel, V.A.

1975-07-01

A method is described for preparing a phosphor composition containing a lanthanide activator element with a host matrix having a transition element as a major component. The host matrix is composed of certain rare earth phosphates or vanadates such as YPO$sub 4$ with a portion of the rare earth replaced with one or more of the transition elements. On x-ray or other electromagnetic excitation, trace lanthanide impurities or additives within the phosphor are spectrometrically determined from their characteristic luminescence. (auth)

Surface decontamination compositions and methods

DOEpatents

Wright,; Karen, E [Idaho Falls, ID; Cooper, David C [Idaho Falls, ID; Peterman, Dean R [Idaho Falls, ID; Demmer, Ricky L [Idaho Falls, ID; Tripp, Julia L [Pocatello, ID; Hull, Laurence C [Idaho Falls, ID

2011-03-29

Clay-based compositions capable of absorbing contaminants from surfaces or objects having surface faces may be applied to a surface and later removed, the removed clay-based compositions absorbing at least a portion of the contaminant from the surface or object to which it was applied.

(BRI) Direct and Inverse Design Optimization of Magnetic Alloys with Minimized Use of Rare Earth Elements

DTIC Science & Technology

2016-02-02

Earths ”, MS&T15-Materials Science and Technology 2015 Conference, Columbus, Ohio, October 4-8, 2015. 3. Dulikrvich, G.S., Reddy, S., Orlande, H.R.B...Schwartz, J.and Koch, C.C., “Multi-Objective Design and Optimization of Hard Magnetic Alloys Free of Rare Earths ”, MS&T15-Materials Science and Technology...AFRL-AFOSR-VA-TR-2016-0091 (BRI) Direct and Inverse Design Optimization of Magnetic Alloys with Minimized Use of Rare Earth Elements George

J-type Carbon Stars: A Dominant Source of 14 N-rich Presolar SiC Grains of Type AB

DOE PAGES

Liu, Nan; Stephan, Thomas; Boehnke, Patrick; ...

2017-07-21

Here, we report Mo isotopic data of 27 new presolar SiC grains, including 12 14N-rich AB ( 14N/ 15N > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s-process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s-process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture process (i-process) takesmore » place, as their stellar source. On the other hand, low-mass CO novae and early R- and J-type carbon stars show 13C and 14N excesses but no s-process enhancements and are thus potential stellar sources of AB2 grains. And because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%–15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.« less

J-type Carbon Stars: A Dominant Source of {sup 14}N-rich Presolar SiC Grains of Type AB

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

Liu, Nan; Nittler, Larry R.; Alexander, Conel M. O’D.

We report Mo isotopic data of 27 new presolar SiC grains, including 12 {sup 14}N-rich AB ({sup 14}N/{sup 15}N > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s -process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s -process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture processmore » ( i -process) takes place, as their stellar source. On the other hand, low-mass CO novae and early R- and J-type carbon stars show {sup 13}C and {sup 14}N excesses but no s -process enhancements and are thus potential stellar sources of AB2 grains. Because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%–15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.« less

J-type Carbon Stars: A Dominant Source of 14 N-rich Presolar SiC Grains of Type AB

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

Liu, Nan; Stephan, Thomas; Boehnke, Patrick

Here, we report Mo isotopic data of 27 new presolar SiC grains, including 12 14N-rich AB ( 14N/ 15N > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s-process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s-process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture process (i-process) takesmore » place, as their stellar source. On the other hand, low-mass CO novae and early R- and J-type carbon stars show 13C and 14N excesses but no s-process enhancements and are thus potential stellar sources of AB2 grains. And because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%–15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.« less

J-type Carbon Stars: A Dominant Source of 14 N-rich Presolar SiC Grains of Type AB

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

Liu, Nan; Stephan, Thomas; Boehnke, Patrick

We report Mo isotopic data of 27 new presolar SiC grains, including 12 N-14-rich AB (N-14/N-15 > 440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS grains, which came from low-mass asymptotic giant branch (AGB) stars with large s-process isotope enhancements, with the AB2 grain data demonstrates that AB2 grains show near-solar isotopic compositions and lack s-process enhancements. The near-normal Sr, Mo, and Ba isotopic compositions of AB2 grains clearly exclude born-again AGB stars, where the intermediate neutron-capture process (i-process) takes place, as theirmore » stellar source. On the other hand, low-mass CO novae and early R-and J-type carbon stars show C-13 and N-14 excesses but no s-process enhancements and are thus potential stellar sources of AB2 grains. Because both early R-type carbon stars and CO novae are rare objects, the abundant J-type carbon stars (10%-15% of all carbon stars) are thus likely to be a dominant source of AB2 grains.« less

Rare event computation in deterministic chaotic systems using genealogical particle analysis

NASA Astrophysics Data System (ADS)

Wouters, J.; Bouchet, F.

2016-09-01

In this paper we address the use of rare event computation techniques to estimate small over-threshold probabilities of observables in deterministic dynamical systems. We demonstrate that genealogical particle analysis algorithms can be successfully applied to a toy model of atmospheric dynamics, the Lorenz ’96 model. We furthermore use the Ornstein-Uhlenbeck system to illustrate a number of implementation issues. We also show how a time-dependent objective function based on the fluctuation path to a high threshold can greatly improve the performance of the estimator compared to a fixed-in-time objective function.

Geological and Petrological Characteristics of Oligocene Magmatic Rocks in The Biga Peninsula, NW Turkey

NASA Astrophysics Data System (ADS)

Erenoglu, Oya

2016-04-01

Oligocene magmatic activity in the Biga Peninsula (NW-Anatolia) produced widespread volcano-plutonic complexes. The study region, where in north of the Evciler village in the middle of Biga Peninsula includes these igneous assemblages. In this study, the petrographic and geochemical characteristics of igneous rocks in the region were investigated as well as the geological locations. The magmatic rocks are classified as 6 different units using their lithostratigraphical properties. The volcanism in the region starts with basaltic andesite lava including basalt dykes in the Lower Oligocene. In the Upper Oligocene, the evolved magma by crustal contamination produced commonly dacitic and andesitic lavas. The volcanism continued with andesitic lavas which had significant alterations in the region during this period. Evciler pluton including granite and granodiorite composition with shallow intrusive, was located with the related volcanism at the same time. The volcanic products, i.e. andesitic and trachydacitic lavas, was completed in the interval between Upper Oligocene and Lower Miocene. The post-collisional Oligocene sequence is associated with calc-alkaline composition and it has middle, high-K. Trace and rare earth elements (REE) diagrams show the enrichment in both large-ion lithophile elements (LILE) and light rare earth elements (LREE) with respect to the high field strength elements (HFSE), and a significant increment in heavy rare earth element consumption (HREE). The features of major, trace and rare earth elements of plutonic and volcanic rocks and the compositional variations of Oligocene volcanic group indicate increasing amounts of partial melting, crustal contamination and/or assimilation. The Oligocene post-collisional volcanism in Biga Peninsula points out the lithospheric mantle source enriched by subduction which controlled by slab break-off and lithospheric delamination. Acknowledgement. This study was supported by Canakkale Onsekiz Mart University Scientific Research Project Coordination Unit (Project no: FBA-2015-566) Keywords: Biga Peninsula, oligocene, post-collisional volcanism, petrology

Adopting Quality Criteria for Websites Providing Medical Information About Rare Diseases

PubMed Central

Göbel, Jens; Storf, Holger; Litzkendorf, Svenja; Babac, Ana; Frank, Martin; Lührs, Verena; Schauer, Franziska; Schmidtke, Jörg; Biehl, Lisa; Wagner, Thomas OF; Ückert, Frank; Graf von der Schulenburg, Johann-Matthias; Hartz, Tobias

2016-01-01

Background The European Union considers diseases to be rare when they affect less than 5 in 10,000 people. It is estimated that there are between 5000 and 8000 different rare diseases. Consistent with this diversity, the quality of information available on the Web varies considerably. Thus, quality criteria for websites about rare diseases are needed. Objective The objective of this study was to generate a catalog of quality criteria suitable for rare diseases. Methods First, relevant certificates and quality recommendations for health information websites were identified through a comprehensive Web search. Second, all considered quality criteria of each certification program and catalog were examined, extracted into an overview table, and analyzed by thematic content. Finally, an interdisciplinary expert group verified the relevant quality criteria. Results We identified 9 quality certificates and criteria catalogs for health information websites with 304 single criteria items. Through this, we aggregated 163 various quality criteria, each assigned to one of the following categories: thematic, technical, service, content, and legal. Finally, a consensus about 13 quality criteria for websites offering medical information on rare diseases was determined. Of these categories, 4 (data protection concept, imprint, creation and updating date, and possibility to contact the website provider) were identified as being the most important for publishing medical information about rare diseases. Conclusions The large number of different quality criteria appearing within a relatively small number of criteria catalogs shows that the opinion of what is important in the quality of health information differs. In addition, to define useful quality criteria for websites about rare diseases, which are an essential source of information for many patients, a trade-off is necessary between the high standard of quality criteria for health information websites in general and the limited provision of information about some rare diseases. Finally, transparently presented quality assessments can help people to find reliable information and to assess its quality. PMID:27562540

Speech characteristics in a Ugandan child with a rare paramedian craniofacial cleft: a case report.

PubMed

Van Lierde, K M; Bettens, K; Luyten, A; De Ley, S; Tungotyo, M; Balumukad, D; Galiwango, G; Bauters, W; Vermeersch, H; Hodges, A

2013-03-01

The purpose of this study is to describe the speech characteristics in an English-speaking Ugandan boy of 4.5 years who has a rare paramedian craniofacial cleft (unilateral lip, alveolar, palatal, nasal and maxillary cleft, and associated hypertelorism). Closure of the lip together with the closure of the hard and soft palate (one-stage palatal closure) was performed at the age of 5 months. Objective as well as subjective speech assessment techniques were used. The speech samples were perceptually judged for articulation, intelligibility and nasality. The Nasometer was used for the objective measurement of the nasalance values. The most striking communication problems in this child with the rare craniofacial cleft are an incomplete phonetic inventory, a severely impaired speech intelligibility with the presence of very severe hypernasality, mild nasal emission, phonetic disorders (omission of several consonants, decreased intraoral pressure in explosives, insufficient frication of fricatives and the use of a middorsum palatal stop) and phonological disorders (deletion of initial and final consonants and consonant clusters). The increased objective nasalance values are in agreement with the presence of the audible nasality disorders. The results revealed that several phonetic and phonological articulation disorders together with a decreased speech intelligibility and resonance disorders are present in the child with a rare craniofacial cleft. To what extent a secondary surgery for velopharyngeal insufficiency, combined with speech therapy, will improve speech intelligibility, articulation and resonance characteristics is a subject for further research. The results of such analyses may ultimately serve as a starting point for specific surgical and logopedic treatment that addresses the specific needs of children with rare facial clefts. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Aesthetic Issues in Spatial Composition: Effects of Vertical Position and Perspective on Framing Single Objects

ERIC Educational Resources Information Center

Sammartino, Jonathan; Palmer, Stephen E.

2012-01-01

Aesthetic preference for the vertical composition of single-object pictures was studied through a series of two-alternative forced-choice experiments. The results reveal the influence of several factors, including spatial asymmetries in the functional properties of the object and the typical position of the object relative to the observer. With…

Pressure-induced structural modifications of rare-earth hafnate pyrochlore

NASA Astrophysics Data System (ADS)

Turner, Katlyn M.; Rittman, Dylan R.; Heymach, Rachel A.; Tracy, Cameron L.; Turner, Madison L.; Fuentes, Antonio F.; Mao, Wendy L.; Ewing, Rodney C.

2017-06-01

Complex oxides with the pyrochlore (A2B2O7) and defect-fluorite ((A,B)4O7) structure-types undergo structural transformations under high-pressure. Rare-earth hafnates (A2Hf2O7) form the pyrochlore structure for A  =  La-Tb and the defect-fluorite structure for A  =  Dy-Lu. High-pressure transformations in A2Hf2O7 pyrochlore (A  =  Sm, Eu, Gd) and defect-fluorite (A  =  Dy, Y, Yb) were investigated up to ~50 GPa and characterized by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD). Raman spectra at ambient pressure revealed that all compositions, including the defect-fluorites, have some pyrochlore-type short-range order. In situ high-pressure synchrotron XRD showed that all of the rare earth hafnates investigated undergo a pressure-induced phase transition to a cotunnite-like (orthorhombic) structure that begins between 18 and 25 GPa. The phase transition to the cotunnite-like structure is not complete at 50 GPa, and upon release of pressure, the hafnates transform to defect-fluorite with an amorphous component. For all compositions, in situ Raman spectroscopy showed that disordering occurs gradually with increasing pressure. Pyrochlore-structured hafnates retain their short-range order to a higher pressure (30 GPa vs.  <10 GPa) than defect-fluorite-structured hafnates. Rare earth hafnates quenched from 50 GPa show Raman spectra consistent with weberite-type structures, as also reported for irradiated rare-earth stannates. The second-order Birch-Murnaghan equation of state fit gives a bulk modulus of ~250 GPa for hafnates with the pyrochlore structure, and ~400 GPa for hafnates with the defect-fluorite structure. Dy2Hf2O7 is intermediate in its response, with some pyrochlore-type ordering, based on Raman spectroscopy and the equation of state, with a bulk modulus of ~300 GPa. As predicted based on the similar ionic radius of Zr4+ and Hf4+, rare-earth hafnates show similar behavior to that reported for rare earth zirconates at high pressure.

Pressure-induced structural modifications of rare-earth hafnate pyrochlore.

PubMed

Turner, Katlyn M; Rittman, Dylan R; Heymach, Rachel A; Tracy, Cameron L; Turner, Madison L; Fuentes, Antonio F; Mao, Wendy L; Ewing, Rodney C

2017-06-28

Complex oxides with the pyrochlore (A 2 B 2 O 7 ) and defect-fluorite ((A,B) 4 O 7 ) structure-types undergo structural transformations under high-pressure. Rare-earth hafnates (A 2 Hf 2 O 7 ) form the pyrochlore structure for A  =  La-Tb and the defect-fluorite structure for A  =  Dy-Lu. High-pressure transformations in A 2 Hf 2 O 7 pyrochlore (A  =  Sm, Eu, Gd) and defect-fluorite (A  =  Dy, Y, Yb) were investigated up to ~50 GPa and characterized by in situ Raman spectroscopy and synchrotron x-ray diffraction (XRD). Raman spectra at ambient pressure revealed that all compositions, including the defect-fluorites, have some pyrochlore-type short-range order. In situ high-pressure synchrotron XRD showed that all of the rare earth hafnates investigated undergo a pressure-induced phase transition to a cotunnite-like (orthorhombic) structure that begins between 18 and 25 GPa. The phase transition to the cotunnite-like structure is not complete at 50 GPa, and upon release of pressure, the hafnates transform to defect-fluorite with an amorphous component. For all compositions, in situ Raman spectroscopy showed that disordering occurs gradually with increasing pressure. Pyrochlore-structured hafnates retain their short-range order to a higher pressure (30 GPa vs.  <10 GPa) than defect-fluorite-structured hafnates. Rare earth hafnates quenched from 50 GPa show Raman spectra consistent with weberite-type structures, as also reported for irradiated rare-earth stannates. The second-order Birch-Murnaghan equation of state fit gives a bulk modulus of ~250 GPa for hafnates with the pyrochlore structure, and ~400 GPa for hafnates with the defect-fluorite structure. Dy 2 Hf 2 O 7 is intermediate in its response, with some pyrochlore-type ordering, based on Raman spectroscopy and the equation of state, with a bulk modulus of ~300 GPa. As predicted based on the similar ionic radius of Zr 4+ and Hf 4+ , rare-earth hafnates show similar behavior to that reported for rare earth zirconates at high pressure.

Major, minor, trace and rare earth elements in sediments of the Bijagós archipelago, Guinea-Bissau.

PubMed

Carvalho, Lina; Figueira, Paula; Monteiro, Rui; Reis, Ana Teresa; Almeida, Joana; Catry, Teresa; Lourenço, Pedro Miguel; Catry, Paulo; Barbosa, Castro; Catry, Inês; Pereira, Eduarda; Granadeiro, José Pedro; Vale, Carlos

2018-04-01

Sixty sediment samples from four sites in the Bijagós archipelago were characterized for fine fraction, loss on ignition, major, minor and trace elemental composition (Al, Fe, Ca, Mg, Ti, P, Zr, Mn, Cr, Sr, Ba, B, V, Li, Zn, Ni, Pb, As, Co, U, Cu, Cs and Cd), and the elements of the La-Lu series. Element concentrations were largely explained by the Al content and the proportion of fine fraction content, with the exception of Ca and Sr. Sediments showed enhanced Ti, U, Cr, As and Cd concentrations with respect to estimated upper crust values, most likely mirroring a regional signature. Rare earth elements were in deficit relatively to the North American Shale Composite (NASC), mainly in coarser material. No pronounced Ce-anomaly was observed, while Eu-anomalies were positive in most analyzed sediments. Copyright © 2017 Elsevier Ltd. All rights reserved.

A new method for locating changes in a tree reveals distinct nucleotide polymorphism vs. divergence patterns in mouse mitochondrial control region.

PubMed

Galtier, N; Boursot, P

2000-03-01

A new, model-based method was devised to locate nucleotide changes in a given phylogenetic tree. For each site, the posterior probability of any possible change in each branch of the tree is computed. This probabilistic method is a valuable alternative to the maximum parsimony method when base composition is skewed (i.e., different from 25% A, 25% C, 25% G, 25% T): computer simulations showed that parsimony misses more rare --> common than common --> rare changes, resulting in biased inferred change matrices, whereas the new method appeared unbiased. The probabilistic method was applied to the analysis of the mutation and substitution processes in the mitochondrial control region of mouse. Distinct change patterns were found at the polymorphism (within species) and divergence (between species) levels, rejecting the hypothesis of a neutral evolution of base composition in mitochondrial DNA.

Effect of CeO2 on TiC Morphology in Ni-Based Composite Coating

NASA Astrophysics Data System (ADS)

Cai, Yangchuan; Luo, Zhen; Chen, Yao

2018-03-01

The TiC/Ni composite coating with different content of CeO2 was fabricated on the Cr12MoV steel by laser cladding. The microstructure of cladding layers with the different content of CeO2 from the bottom to the surface is columnar crystal, cellular crystal, and equiaxed crystal. When the content of CeO2 is 0 %, the cladding layer has a coarse and nonuniform microstructure and TiC particles gathering in the cladding layer, and then the wear resistance was reduced. Appropriate rare-earth elements refined and homogenised the microstructure and enhanced the content of carbides, precipitated TiC particles and original TiC particles were spheroidised and refined, the wear resistance of the cladding layer was improved significantly. Excessive rare-earth elements polluted the grain boundaries and made the excessive burning loss of TiC particles that reduced the wear resistance of the cladding layer.

Phase Stability and Thermal Conductivity of Composite Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Benkel, Samantha; Zhu, Dongming

2011-01-01

Advanced environmental barrier coatings are being developed to protect SiC/SiC ceramic matrix composites in harsh combustion environments. The current coating development emphasis has been placed on the significantly improved cyclic durability and combustion environment stability in high-heat-flux and high velocity gas turbine engine environments. Environmental barrier coating systems based on hafnia (HfO2) and ytterbium silicate, HfO2-Si nano-composite bond coat systems have been processed and their stability and thermal conductivity behavior have been evaluated in simulated turbine environments. The incorporation of Silicon Carbide Nanotubes (SiCNT) into high stability (HfO2) and/or HfO2-silicon composite bond coats, along with ZrO2, HfO2 and rare earth silicate composite top coat systems, showed promise as excellent environmental barriers to protect the SiC/SiC ceramic matrix composites.

Unexplored possibilities of all-polysaccharide composites.

PubMed

Simkovic, Ivan

2013-06-20

Composites made solely from polysaccharides are mostly ecological because they can degrade without leaving behind ecologically harmful residues, in contrast to composites which contain synthetic polymers. Herein, the following groups of all-polysaccharide composites (APCs) are discussed: an all-cellulose group that includes cotton composites, cellulose combined with other polysaccharides, as well as those based on chitin/chitosan, heparin, hyaluronan, xylan, glucomannan, pectin, xyloglucan, arabinan, starch, carrageenan, alginate, galactan as one of the components in combination with other polysaccharides. They can be used in medical, paper, food, packing, textile, electronic, mechanical engineering and other applications. The composites were tested for absorptivity, biodegradability, crystallinity, rheology, and mechanical, optical, separation, gelling, pasting, film-forming, adhesive, antimicrobial properties, as well as water vapor permeability, water repellency, dye uptake, and fire-retardancy. Except for food applications, composites based on more than two types of polysaccharides have rarely been used and many possible combinations remain unexplored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diverse proportion in composite pheochromocytoma-ganglioneuroma may induce varied clinical symptom: comparison of two cases

PubMed Central

Zhang, Bu-Yi; Zhao, Mingfei; Li, Baizhou; Zhang, Jian-Min

2015-01-01

Composite pheochromocytoma-ganglioneuroma is extremely rare. We described two cases of composite pheochromocytomas in the adrenal medullar. Case 1 was a 70-year-old male presenting with lower abdominal pain and normal blood electrolytes. Case 2 was a 48-year-old female with palpitation and back tenderness. Biochemical investigations showed hypocalcium, hypokalemia and high level of vma. The histological images and the immunohistochemical staining demonstrated the two cases composed of pheochromocytoma and ganglioneuromoma components. Ganglioneuroma component in case 2 accounted for more proportion than that in case 1. We speculated that the varied clinical symptoms were related with the diverse proportions in composite pheochromocytome-ganglioneuroma. PMID:26823896

Cost of illness and economic evaluation in rare diseases.

PubMed

López-Bastida, Julio; Oliva-Moreno, Juan

2010-01-01

Rare diseases are a major cause of morbidity and mortality in high income countries and have major repercussions on individuals and health care systems. This chapter examines the health economy of rare diseases from two different perspectives: firstly, the study of the economic impact of rare diseases (Cost of Illness studies); and, secondly, cost-effectiveness evaluation, which evaluates both the costs and results of the health care technologies applied in rare diseases. From the point of view of economics, health resource allocation is based on the principle of scarcity, as there are not - and never will be- sufficient resources for all worthy objectives. Hence, policy makers should balance costs and health outcomes. Rare diseases may well represent a significant societal burden that should rightly receive appropriate prioritisation of health care resources. As new and seemingly expensive health care technologies are developed for rare diseases, it will become increasingly important to evaluate potential and real impact of these new technologies in both dimensions: social costs and health outcomes.

An abstract approach to music.

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

Kaper, H. G.; Tipei, S.

1999-04-19

In this article we have outlined a formal framework for an abstract approach to music and music composition. The model is formulated in terms of objects that have attributes, obey relationships, and are subject to certain well-defined operations. The motivation for this approach uses traditional terms and concepts of music theory, but the approach itself is formal and uses the language of mathematics. The universal object is an audio wave; partials, sounds, and compositions are special objects, which are placed in a hierarchical order based on time scales. The objects have both static and dynamic attributes. When we realize amore » composition, we assign values to each of its attributes: a (scalar) value to a static attribute, an envelope and a size to a dynamic attribute. A composition is then a trajectory in the space of aural events, and the complex audio wave is its formal representation. Sounds are fibers in the space of aural events, from which the composer weaves the trajectory of a composition. Each sound object in turn is made up of partials, which are the elementary building blocks of any music composition. The partials evolve on the fastest time scale in the hierarchy of partials, sounds, and compositions. The ideas outlined in this article are being implemented in a digital instrument for additive sound synthesis and in software for music composition. A demonstration of some preliminary results has been submitted by the authors for presentation at the conference.« less

Igneous Complexes of the Orochenka Caldera of the East Sikhote-Alin Belt: U-Pb (SHRIMP) Age, Trace and Rare Earth Element Composition, and Au-Ag Mineralization

NASA Astrophysics Data System (ADS)

Sakhno, V. G.; Kovalenko, S. V.

2018-04-01

New data are presented on the geology and composition of volcanic and intrusive rocks of the Orochenka caldera, which is located in the western part of the East Sikhote Alin volcanic belt. The SHRIMP and ICP MS age of zircons of volcanic and intrusive rocks, respectively, and the composition of the volcanic rocks allow comparison of these complexes with volcanic rocks of the eastern part of the volcanic structure. New data indicate the period of transition between subduction to transform regimes.

Evaluating United States and world consumption of neodymium, dysprosium, terbium, and praseodymium in final products

NASA Astrophysics Data System (ADS)

Hart, Matthew

This paper develops scenarios of future rare-earth-magnet metal (neodymium, dysprosium, terbium, and praseodymium) consumption in the permanent magnets used in wind turbines and hybrid electric vehicles. The scenarios start with naive base-case scenarios for growth in wind-turbine and hybrid-electric-vehicle sales over the period 2011 to 2020, using historical data for each good. These naive scenarios assume that future growth follows time trends in historical data and does not depend on any exogenous variable. Specifically, growth of each technological market follows historical time trends, and the amount of rare earths used per unit of technology remains fixed. The chosen reference year is 2010. Implied consumptions of the rare earth magnet metals are calculated from these scenarios. Assumptions are made for the material composition of permanent magnets, the market share of permanent-magnet wind turbines and vehicles, and magnet weight per unit of technology. Different scenarios estimate how changes in factors like the material composition of magnets, growth of the economy, and the price of a substitute could affect future consumption. Each scenario presents a different method for reducing rare earth consumption and could be interpreted as potential policy choices. In 2010, the consumption (metric tons, rare-earth-oxide equivalent) of each rare-earth-magnet metal was as follows. Total neodymium consumption in the world for both technologies was 995 tons; dysprosium consumption was 133 tons; terbium consumption was 50 tons; praseodymium consumption was zero tons. The base scenario for wind turbines shows there could be strong, exponential growth in the global wind turbine market. New U.S. sales of hybrid vehicles would decline (in line with the current economic recession) while non-U.S. sales increase through 2020. There would be an overall increase in the total amount of magnetic rare earths consumed in the world. Total consumption of each rare earth in the short-term (2015) and mid-term (2020) scenarios could be between: 1,984 to 6,475 tons (2015) and 3,487 to 13,763 tons (2020) of neodymium; 331 to 864 tons (2015) and 587 to 1,834 tons (2020) of dysprosium; 123 to 325 tons (2015) and 219 to 687 tons (2020) of terbium; finally, zero to 871 tons (2015) and zero to 1,493 tons (2020) of praseodymium. Hybrid vehicle sales in non-U.S. countries could account for a large portion of magnetic rare earth consumption. Wind turbine and related rare earth consumption growth will also be driven by non-U.S. countries, especially developing nations like China. Despite wind turbines using bigger magnets, the sheer volume of hybrids sold and non-U.S. consumers could account for most future consumption of permanent magnets and their rare earths.

International strategic minerals inventory summary report; rare-earth oxides

USGS Publications Warehouse

Jackson, W.D.; Christiansen, Grey

1993-01-01

Bastnaesite, monazite, and xenotime are currently the most important rare-earth minerals. Bastnaesite occurs as a primary mineral in carbonatites. Monazite and xenotime also can be found in primary deposits but are recovered principally from heavy-mineral placers that are mined for titanium or tin. Each of these minerals has a different composition of the 15 rare-earth elements. World resources of economically exploitable rare-earth oxides (REO) are estimated at 93.4 million metric tons in place, composed of 93 percent in primary deposits and 7 percent in placers. The average mineral composition is 83 percent bastnaesite, 13 percent monazite, and 4 percent of 10 other minerals. Annual global production is about 67,000 metric tons of which 41 percent is from placers and 59 percent is from primary deposits; mining methods consist of open pits (94 percent) and dredging (6 percent). This output could be doubled if the operations that do not currently recover rare earths would do so. Resources are more than sufficient to meet the demand for the predictable future. About 52 percent of the world's REO resources are located in China. Ranking of other countries is as follows: Namibia (22 percent), the United States (15 percent), Australia (6 percent), and India (3 percent); the remainder is in several other countries. Conversely, 38 percent of the production is in China, 33 percent in the United States, 12 percent in Australia, and 5 percent each in Malaysia and India. Several other countries, including Brazil, Canada, South Africa, Sri Lanka, and Thailand, make up the remainder. Markets for rare earths are mainly in the metallurgical, magnet, ceramic, electronic, chemical, and optical industries. Rare earths improve the physical and rolling properties of iron and steel and add corrosion resistance and strength to structural members at high temperatures. Samarium and neodymium are used in lightweight, powerful magnets for electric motors. Cerium and yttrium increase the density and heat resistance of sintered ceramics. Yttrium and gadolinium contribute to the efficiency of electronic switches and sensors. Cerium improves the effectiveness of catalysts in the petroleum and automotive industries. Cerium oxides speed glass melting and are used to polish glass by chemical, rather than mechanical, means. Cerium, europium, terbium, and yttrium, as phosphoric compounds, promote the vivid colors of television screens. Consumption of rare earths is expected to grow by about 2.6 percent per year.

[Effects of arbuscular mycorrhizal fungi on the growth and rare earth elements uptake of soybean grown in rare earth mine tailings].

PubMed

Guo, Wei; Zhao, Ren-xin; Zhao, Wen-jing; Fu, Rui-ying; Guo, Jiang-yuan; Zhang, Jun

2013-05-01

A greenhouse pot experiment was conducted to investigate the influence of arbuscular mycorrhizal (AM) fungi Glomus versiforme on the plant growth, nutrient uptake, C: N: P stoichiometric, uptake of heavy metals and rare earth elements by soybean (Glycine max) grown in rare earth mine tailings. The aim was to provide a basis for the revegetation of rare earth mine tailings. The results indicated that soybean had a high mycorrhizal colonization and symbiotic associations were successfully established with G. versiforme, with an average rate of approximately 67%. The colonization of G. versiforme significantly promoted the growth of soybean, increased P, K contents, and decreased C: N: P ratios, supporting the growth rate hypothesis. Inoculation with G. versiforme significantly decreased shoots and roots La, Ce, Pr and Nd concentrations of soybean compared to the control treatment. However, inoculation with G. versiforme had no significant effect on the heavy metal concentrations, except for significantly decreased shoot Fe and Cr concentrations and increased root Cd concentrations. The experiment demonstrates that AM fungi have a potential role for soybean to adapt the composite adversity of rare earth tailings and play a positive role in revegetation of rare earth mine tailings. Further studies on the role of AM fungi under natural conditions should be conducted.

Adsorption of Rare Earths(Ⅲ) Using an Efficient Sodium Alginate Hydrogel Cross-Linked with Poly-γ-Glutamate

PubMed Central

Xu, Shuxia; Wang, Zhiwei; Gao, Yuqian; Zhang, Shimin; Wu, Kun

2015-01-01

With the exploitation of rare earth ore, more and more REEs came into groundwater. This was a waste of resources and could be harmful to the organisms. This study aimed to find an efficient adsorption material to mitigate the above issue. Through doping sodium alginate (SA) with poly-γ-glutamate (PGA), an immobilized gel particle material was produced. The composite exhibited excellent capacity for adsorbing rare earth elements (REEs). The amount of La3+ adsorbed on the SA-PGA gel particles reached approximately 163.93 mg/g compared to the 81.97 mg/g adsorbed on SA alone. The factors that potentially affected the adsorption efficiency of the SA-PGA composite, including the initial concentration of REEs, the adsorbent dosage, and the pH of the solution, were investigated. 15 types of REEs in single and mixed aqueous solutions were used to explore the selective adsorption of REEs on gel particles. Scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy analyses of the SA and SA-PGA gel beads suggested that the carboxyl groups in the composite might play a key role in the adsorption process and the morphology of SA-PGA changed from the compact structure of SA to a porous structure after doping PGA. The kinetics and thermodynamics of the adsorption of REEs were well fit with the pseudo-second-order equation and the Langmuir adsorption isotherm model, respectively. It appears that SA-PGA is useful for recycling REEs from wastewater. PMID:25996388

Bioleaching of rare earth elements from monazite sand.

PubMed

Brisson, Vanessa L; Zhuang, Wei-Qin; Alvarez-Cohen, Lisa

2016-02-01

Three fungal strains were found to be capable of bioleaching rare earth elements from monazite, a rare earth phosphate mineral, utilizing the monazite as a phosphate source and releasing rare earth cations into solution. These organisms include one known phosphate solubilizing fungus, Aspergillus niger ATCC 1015, as well as two newly isolated fungi: an Aspergillus terreus strain ML3-1 and a Paecilomyces spp. strain WE3-F. Although monazite also contains the radioactive element Thorium, bioleaching by these fungi preferentially solubilized rare earth elements over Thorium, leaving the Thorium in the solid residual. Adjustments in growth media composition improved bioleaching performance measured as rare earth release. Cell-free spent medium generated during growth of A. terreus strain ML3-1 and Paecilomyces spp. strain WE3-F in the presence of monazite leached rare earths to concentrations 1.7-3.8 times those of HCl solutions of comparable pH, indicating that compounds exogenously released by these organisms contribute substantially to leaching. Organic acids released by the organisms included acetic, citric, gluconic, itaconic, oxalic, and succinic acids. Abiotic leaching with laboratory prepared solutions of these acids was not as effective as bioleaching or leaching with cell-free spent medium at releasing rare earths from monazite, indicating that compounds other than the identified organic acids contribute to leaching performance. © 2015 Wiley Periodicals, Inc.

Provenance and composition of unusually chrome and nickel-rich bucket-shaped pottery from Rogaland (southwestern Norway)

NASA Astrophysics Data System (ADS)

Zimmermann, Udo; Kristoffersen, Elna Siv; Fredriksen, Per Ditlef; Bertolino, Silvana A. R.; Andò, Sergio; Bersani, Danilo

2016-05-01

We report results from FE-SEM-EDS, geochemical, mineralogical analyses and Raman spectroscopy of pottery of bucket-shaped ceramic from Rogaland (southwestern Norway) dated between the 5th and 6th Century. The study reveals a very rare pottery composition including asbestos-group minerals and an unusual enrichment in compatible elements like Cr (8-27 × Post Archean average shale (PAS), McLennan et al., 2006), Ni (2-8 × normal shale) and Co (2-3 × PAS). X-Rray diffraction and Raman spectroscopy could pinpoint that Ni is introduced by specific Ni-rich talc mineral and chlorite minerals and Cr occurs in a rare Cr-rich talc, and possibly in a Cr-chlorite, these minerals are the most abundant in the pottery, which is supported by strong enrichment in Mg (10-20 × PAS). The addition of Mg, Cr, Ni and Co and other compatible trace elements is to our current knowledge not caused by anthropogenic activity but related to the used materials, which are alteration products of mafic and ultramafic rocks or genetically related to mafic and ultramafic rocks. Rocks of this type are exposed in vicinity of the sampling areas in a region called Karmøy, hosting a world famous ophiolite complex, which is identified as the major source for the mafic and ultramafic component, as the next succession of a similar composition is far further north located in Norway and a number of rock types on Karmøy matches the chemical composition of the pottery. The here reported composition is spectacular and extremely rare - if ever found - in pottery. Our study shows that unusual material sources have been used in pottery production, and this opens for discussion whether the materials were deliberately selected by the manufacturers, thereby expressing a specific social function, in a time period where more functional clay types and additives, and certainly functional and sufficient for use in pottery, where abundant in areas of Rogaland closer to where the pots were found.

Stimuli-responsive cellulose-based nematogels

NASA Astrophysics Data System (ADS)

Liu, Qingkun; Smalyukh, Ivan

Physical properties of composite materials can be pre-engineered by controlling their structure and composition at the mesoscale. Yet, approaches for achieving this are limited and rarely scalable. We introduce a new breed of self-assembled nematogels formed by an orientationally ordered network of thin cellulose nanofibers infiltrated with a thermotropic nematic fluid. The interplay of orientational ordering within the nematic network and that of the small-molecule liquid crystal around it yields a composite with highly tunable optical properties. By means of combining experimental characterization and analytical modeling, we demonstrate sub-milisecond electric switching of transparency and also facile response of the composite to temperature changes and light illumination. Finally, we discuss a host of potential technological uses of these self-assembled nematogel composites, ranging from smart and privacy windows to novel flexible display modes.

Liquid crystalline cellulose-based nematogels

DOE PAGES

Liu, Qingkun; Smalyukh, Ivan I.

2017-08-18

Physical properties of composite materials can be pre-engineered by controlling their structure and composition at the mesoscale. However, approaches to achieving this are limited and rarely scalable. We introduce a new breed of self-assembled nematogels formed by an orientationally ordered network of thin cellulose nanofibers infiltrated with a thermotropic nematic fluid. The interplay between orientational ordering within the nematic network and that of the small-molecule liquid crystal around it yields a composite with highly tunable optical properties. By means of combining experimental characterization and modeling, we demonstrate submillisecond electric switching of transparency and facile responses of the composite to temperaturemore » changes. Finally, we discuss a host of potential technological uses of these self-assembled nematogel composites, ranging from smart and privacy windows to novel flexible displays.« less

Structural characterisation of advanced optical materials

NASA Astrophysics Data System (ADS)

Krsmanovic, Radenka

The rare earth systems discussed in this thesis belong to a class of new, advanced optical materials. Two different nanostuctured materials are studied: nanocrystalline oxide phosphors and glass ceramics containing luminescent nanocrystals. In both cases, the optical activity is based on the luminescence properties of rare earth dopants incorporated into the crystal structure of the insulator nanocrystals themselves. The structure, morphology and composition of these luminescent composite materials are investigated and used to demonstrate the benefits as well as the drawbacks of the synthesis and the processing techniques used, aiming to their improvement for possible industrial production. An investigation of the microstructure was done by XRD, TEM and HREM, while EDX, EELS and EFTEM spectroscopy techniques were used for the chemical identification. Our research clearly demonstrated that these techniques can be successfully applied, and in combination with optical spectroscopy can provide the complete characterization of nanostructured luminescent materials. Three different oxide phosphors in the form of nanocrystalline powders are obtained with the solution combustion technique: yttrium aluminum garnet (YAG), gadolinium gallium garnet (GGG) and scandium oxide, Sc2O 3. We found out that GGG and Sc2O3 samples have "perfect" nanocrystals, without defects or amorphous surface layer, and with uniform distribution of rare earth activators. Good crystal quality results in a long-lived phosphor and much stronger emission, which makes them promising candidate for display industry. Moreover, these luminescent nanocrystals are biocompatible and when functionalized with some molecules or biocompatible polymers can be used for bio-applications like "in vivo" markers in cell biology. For luminescence glass ceramics samples the ternary glass system Li 2O-Al2O3-SiO2 (LAS) is used as host matrix, and ZrO2 as nucleating agent for luminescent ions introduced as Eu2O3 or Er2O3. We wanted to obtain a composite with crystal-like optical properties, keeping the transparency and the processibility of the glass host. The spatial distribution of the precipitates throughout the material, their morphology, structure and composition are investigated with various TEM modes to check if we succeed in draining all rare earth dopant ions from the matrix into ZrO2 crystals. The best results are obtained for the samples containing Er as dopant.

Language Arts: Composition Skills K-12.

ERIC Educational Resources Information Center

Instructional Objectives Exchange, Los Angeles, CA.

There are 127 basic composition objectives in this revised collection for use in kindergarten through high school. At least one evaluation per objective is given. The objectives are organized as follows: (1) Story Writing which covers fanciful and realistic types such as: myths, fable, short story, fiction, and writing dialogue; (2) Letters both…

Polarization Raman spectroscopy to explain rodent models of brittle bone

NASA Astrophysics Data System (ADS)

Makowski, Alexander J.; Nyman, Jeffry S.; Mahadevan-Jansen, Anita

2013-03-01

Activation Transcription Factor 4 (Atf-4) is essential for osteoblast maturation and proper collagen synthesis. We recently found that these bones demonstrate a rare brittleness phenotype, which is independent of bone strength. We utilized a confocal Renishaw Raman microscope (50x objective; NA=.75) to evaluate embedded, polished cross-sections of mouse tibia from both wild-type and knockout mice at 8 weeks of age (24 mice, n<=8 per group). Analysis of peak ratios indicated statistically significant changes in both mineral and collagen; however, compositional changes did not fully encompass biomechanical differences. To investigate the impact of material organization, we acquired colocalized spectra aligning the polarization angle parallel and perpendicular to the long bone axis from wet intact femurs. To validate our results, we used MMP9-/- mice, which have a brittleness phenotype that is not explained by compositional Raman measures. Polarization angle difference spectra show marked significant changes in orientation of these compositional differences when comparing wild type to knockout bones. Relative to wild-type, Atf4 -/- and MMP9 -/- bones show significant differences (t-test; p<0.05) in prominent collagen peaks. Further investigation of known peak ratios illustrates that this physical anisotropy of molecular organization is tightly clustered in brittle knockout bones. Such findings could have alternate interpretations about net collagen orientation or the angular distribution of collagen molecules. Use of polarization specific Raman measurements has implicated a structural profile that furthers our understanding of models of bone brittleness. Polarization content of Raman spectra may prove significant in future studies of brittle fracture and human fracture risk.

Use of ground-based telescopes in determining the composition of the surfaces of solar system objects

NASA Technical Reports Server (NTRS)

Mccord, T. B.; Adams, J. B.

1977-01-01

Recent evidence suggests that the way that the surfaces of the solar system objects reflect solar radiation is controlled by the composition and mineralogy of the surface materials. The way sunlight is reflected from the surface as a function of wavelength, i.e., the spectral reflectance, is the most important property. Laboratory efforts to use ground-based optical telescope measurements to determine the composition of the surfaces of the solar system objects are reviewed.

Natural genetic variability reduces recalcitrance in poplar

DOE PAGES

Bhagia, Samarthya; Muchero, Wellington; Kumar, Rajeev; ...

2016-05-20

Here, lignin content and structure are known to affect recalcitrance of lignocellulosic biomass to chemical/biochemical conversion. Previously, we identified rare Populus trichocarpa natural variants with significantly reduced lignin content. Because reduced lignin content may lower recalcitrance, 18 rare variants along with 4 comparators, and BESC standard Populus was analyzed for composition of structural carbohydrates and lignin. Sugar yields from these plants were measured at 5 process conditions: one for just enzymatic hydrolysis without pretreatment and four via our combined high-throughput hot water pretreatment and co-hydrolysis (HTPH) technique.

Application of spark plasma sintering for fabricating Nd-Fe-B composite

NASA Astrophysics Data System (ADS)

Sivkov, A. A.; Ivashutenko, A. S.; Lomakina, A. A.

2015-10-01

Constant magnets are applied in such fields as electric equipment and electric generators with fixed rotor. Rare earth metal neodymium is well known as promising material. Production of magnets by sintering three elements (neodymium, iron and boron) is one the most promising methods. But there are difficulties in choosing the right temperature for sintering and further processing. Structure and properties of the product, consisted of rare earth metals, was analyzed. X-ray analysis of the resulting product and the finished constant magnet was performed. Vickers microhardness was obtained.

Microfluidic active mixers employing ultra-high aspect-ratio rare-earth magnetic nano-composite polymer artificial cilia

NASA Astrophysics Data System (ADS)

Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

2014-02-01

We present a new micromixer based on highly magnetic, flexible, high aspect-ratio, artificial cilia that are fabricated as individual micromixer elements or in arrays for improved mixing performance. These new cilia enable high efficiency, fast mixing in a microchamber, and are controlled by small electromagnetic fields. The artificial cilia are fabricated using a new micromolding process for nano-composite polymers. Cilia fibers with aspect-ratios as high as 8:0.13 demonstrate the fabrication technique's capability in creating ultra-high aspect-ratio microstructures. Cilia, which are realized in polydimethylsiloxane doped with rare-earth magnetic powder, are magnetized to produce permanent magnetic structures with bidirectional deflection capabilities, making them highly suitable as mixers controlled by electromagnetic fields. Due to the high magnetization level of the polarized nano-composite polymer, we are able to use miniature electromagnets providing relatively small magnetic fields of 1.1 to 7 mT to actuate the cilia microstructures over a very wide motion range. Mixing performances of a single cilium, as well as different arrays of multiple cilia ranging from 2 to 8 per reaction chamber, are characterized and compared with passive diffusion mixing performance. The mixer cilia are actuated at different amplitudes and frequencies to optimize mixing performance. We demonstrate that more than 85% of the total volume of the reaction chamber is fully mixed after 3.5 min using a single cilium mixer at 7 mT compared with only 20% of the total volume mixed with passive diffusion. The time to achieve over 85% mixing is further reduced to 70 s using an array of eight cilia microstructures. The novel microfabrication technique and use of rare-earth permanently-magnetizable nano-composite polymers in mixer applications has not been reported elsewhere by other researchers. We further demonstrate improved mixing over other cilia micromixers as enabled by the high aspect-ratio, high flexibility, and magnetic properties of our cilia micromixer elements.

Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease.

PubMed

Lambertus, Stanley; Bax, Nathalie M; Fakin, Ana; Groenewoud, Joannes M M; Klevering, B Jeroen; Moore, Anthony T; Michaelides, Michel; Webster, Andrew R; van der Wilt, Gert Jan; Hoyng, Carel B

2017-01-01

Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options-including gene therapy-are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration. We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14) and the United Kingdom (external validation cohort, n = 18). The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30-0.52). Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904). These properties were largely preserved in the validation cohort (0.43°/year [0.33-0.53]; prediction: R2, 0.872). We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients. These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a sensitive measurement of disease progression in Stargardt disease. It can be very useful in the evaluation of novel therapeutic modalities in rare disorders.

Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

PubMed Central

Bax, Nathalie M.; Fakin, Ana; Groenewoud, Joannes M. M.; Klevering, B. Jeroen; Moore, Anthony T.; Michaelides, Michel; Webster, Andrew R.; van der Wilt, Gert Jan; Hoyng, Carel B.

2017-01-01

Background Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options—including gene therapy—are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration. Methods and findings We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14) and the United Kingdom (external validation cohort, n = 18). The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30–0.52). Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904). These properties were largely preserved in the validation cohort (0.43°/year [0.33–0.53]; prediction: R2, 0.872). We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients. Conclusions These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a sensitive measurement of disease progression in Stargardt disease. It can be very useful in the evaluation of novel therapeutic modalities in rare disorders. PMID:28355279

Organization for rare diseases India (ORDI) - addressing the challenges and opportunities for the Indian rare diseases' community.

PubMed

Rajasimha, Harsha Karur; Shirol, Prasannakumar Basayya; Ramamoorthy, Preveen; Hegde, Madhuri; Barde, Sangeeta; Chandru, Vijay; Ravinandan, M E; Ramchandran, Ramani; Haldar, Kasturi; Lin, Jimmy C; Babar, Imran A; Girisha, Katta M; Srinivasan, Sudha; Navaneetham, Duraiswamy; Battu, Rajani; Devarakonda, Rajashree; Kini, Usha; Vijayachandra, Kinnimulki; Verma, Ishwar C

2014-08-13

In order to address the unmet needs and create opportunities that benefit patients with rare disease in India, a group of volunteers created a not-for-profit organization named Organization for Rare Diseases India (ORDI; www.ordindia.org). ORDI plans to represent the collective voice and advocate the needs of patients with rare diseases and other stakeholders in India. The ORDI team members come from diverse backgrounds such as genetics, molecular diagnostics, drug development, bioinformatics, communications, information technology, patient advocacy and public service. ORDI builds on the lessons learned from numerous similar organizations in the USA, European Union and disease-specific rare disease foundations in India. In this review, we provide a background on the landscape of rare diseases and the organizations that are active in this area globally and in India. We discuss the unique challenges in tackling rare diseases in India, and highlight the unmet needs of the key stakeholders of rare diseases. Finally, we define the vision, mission, goals and objectives of ORDI, identify the key developments in the health care context in India and welcome community feedback and comments on our approach.

Chiral Analyses of Organic Compounds in Carbonaceous Meteorites

NASA Technical Reports Server (NTRS)

Pizzarello, Sandra

2004-01-01

Contents include the following: 1. Characterization of Tagish Lake organic content. The first two grant years were largely devoted to the molecular and isotopic analyses of Tagish Lake organic composition. This carbonaceous meteorite fell in Canada in the winter of the year 2000, and its exceptional atmospheric entry and subsequent recovery (e. g., the sample was recovered and stored by avoiding hand contact and above freezing temperatures) contributed in providing a rare and pristine extraterrestrial material. 2. Chiral analyses of Murchison and Murray soluble organics. One of the most intriguing finding in regard to soluble meteorite organics is the presence within the amino acid suite of some compounds displaying L-enantiomeric excesses. This configuration is exclusive in the amino acids of terrestrial proteins and the finding has raised speculations of a possible role of amino acids from meteorites in the origin of homochirality on the early Earth. The main objective for this NASA funding was the characterization of enantiomeric excesses in meteorites and we have conducted several studies toward establishing their distribution and indignity.

Follow up observationes of extremely metal-poor stars identified from SDSS and LAMOST

NASA Astrophysics Data System (ADS)

Aguado, David; Allende Prieto, Carlos; González Hernández, Jonay I.; Rebolo, Rafael

2017-06-01

The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or very few supernovae. Here we present a program to search for and characterize new ultra metal-poor stars in the Galactic halo. These stars are extremely rare; despite significant efforts, only a handful of stars have been identified with a metallicity [Fe/H]< -5. We select candidates from SDSS and LAMOST. Dozens of them have already been observed with the ISIS spectrograph on the 4.2 m William Herschel Telescope. The most interesting objects have been confirmed with OSIRIS on the 10.4m-GTC and HRS on the 9.2 m HET. Our analysis is highly automated, and based on the FERRE code. We report the discovery of a new carbon-rich ultra metal-poor (CRUMP) dwarf star at [Fe/H]~ -5.8 with an extreme carbon over-abundance [C/Fe]~ +5.0.

Objectives and conditions for protection of unique peatlands in the south of Western Siberia in connection with issues of conservation and use of unique reed mire in suburbs of Tomsk

NASA Astrophysics Data System (ADS)

Semenova, N. M.

2018-03-01

The article covers the issues of protection of the wetlands located in different natural and economic conditions of Western Siberia. The main focus is on preservation and wise use of the peatlands in the southern part of the West Siberian Plain, which was greatly altered and transformed during the long-term economic development. The field research was conducted in the southern suburbs of Tomsk. A unique peatland, which is an object of a special protection effort, is described in this work. The peatland develops in the conditions of a rich groundwater feed. The peatland deposits are a mixture of peat and travertine. The extension area and the maximum thickness of organo-mineral deposits were determined. The composition of the peat deposits waters and feeding springs was studied. The specific properties of the surface waters formed under the influence of the wedging-out underground waters of the Paleozoic horizons were considered. The flora and vegetation of the study area were analyzed. A list of rare and endangered plant species was compiled. The ecological and social value of the investigated territory was substantiated. As a result we defined pertinent measures needed to protect the natural landscape and to use wisely its resources.

Trapping and dynamic manipulation of polystyrene beads mimicking circulating tumor cells using targeted magnetic/photoacoustic contrast agents

NASA Astrophysics Data System (ADS)

Wei, Chen-Wei; Xia, Jinjun; Pelivanov, Ivan; Hu, Xiaoge; Gao, Xiaohu; O'Donnell, Matthew

2012-10-01

Results on magnetically trapping and manipulating micro-scale beads circulating in a flow field mimicking metastatic cancer cells in human peripheral vessels are presented. Composite contrast agents combining magneto-sensitive nanospheres and highly optical absorptive gold nanorods were conjugated to micro-scale polystyrene beads. To efficiently trap the targeted objects in a fast stream, a dual magnet system consisting of two flat magnets to magnetize (polarize) the contrast agent and an array of cone magnets producing a sharp gradient field to trap the magnetized contrast agent was designed and constructed. A water-ink solution with an optical absorption coefficient of 10 cm-1 was used to mimic the optical absorption of blood. Magnetomotive photoacoustic imaging helped visualize bead trapping, dynamic manipulation of trapped beads in a flow field, and the subtraction of stationary background signals insensitive to the magnetic field. The results show that trafficking micro-scale objects can be effectively trapped in a stream with a flow rate up to 12 ml/min and the background can be significantly (greater than 15 dB) suppressed. It makes the proposed method very promising for sensitive detection of rare circulating tumor cells within high flow vessels with a highly absorptive optical background.

R CORONAE BOREALIS STARS ARE VIABLE FACTORIES OF PRE-SOLAR GRAINS

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

Karakas, Amanda I.; Ruiter, Ashley J.; Hampel, Melanie, E-mail: amanda.karakas@anu.edu.au

2015-08-20

We present a new theoretical estimate for the birthrate of R Coronae Borealis (RCB) stars that is in agreement with recent observational data. We find the current Galactic birthrate of RCB stars to be ≈25% of the Galactic rate of Type Ia supernovae, assuming that RCB stars are formed through the merger of carbon–oxygen and helium-rich white dwarfs. Our new RCB birthrate (1.8 × 10{sup −3} yr{sup −1}) is a factor of 10 lower than previous theoretical estimates. This results in roughly 180–540 RCB stars in the Galaxy, depending on the RCB lifetime. From the theoretical and observational estimates, wemore » calculate the total dust production from RCB stars and compare this rate to dust production from novae and born-again asymptotic giant branch (AGB) stars. We find that the amount of dust produced by RCB stars is comparable to the amounts produced by novae or born-again post-AGB stars, indicating that these merger objects are a viable source of carbonaceous pre-solar grains in the Galaxy. There are graphite grains with carbon and oxygen isotopic ratios consistent with the observed composition of RCB stars, adding weight to the suggestion that these rare objects are a source of stardust grains.« less

Microstructure Evolution and Durability of Advanced Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Evans, Laura J.; McCue, Terry R.; Harder, Bryan

2016-01-01

Environmental barrier coated SiC-SiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. Advanced HfO2 and rare earth silicate environmental barrier coatings (EBCs), along with multicomponent hafnium and rare earth silicide EBC bond coats have been developed. The coating degradation mechanisms in the laboratory simulated engine thermal cycling, and fatigue-creep operating environments are also being investigated. This paper will focus on the microstructural and compositional evolutions of an advanced environmental barrier coating system on a SiC-SiC CMC substrate during the high temperature simulated durability tests, by using a Field Emission Gun Scanning Electron Microscopy, Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS). The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will also be discussed. The detailed analysis results help understand the EBC-CMC system performance, aiming at the durability improvements to achieve more robust, prime-reliant environmental barrier coatings.

The scarcity heuristic impacts reward processing within the medial-frontal cortex.

PubMed

Williams, Chad C; Saffer, Boaz Y; McCulloch, Robert B; Krigolson, Olave E

2016-05-04

Objects that are rare are often perceived to be inherently more valuable than objects that are abundant - a bias brought about in part by the scarcity heuristic. In the present study, we sought to test whether perception of rarity impacted reward evaluation within the human medial-frontal cortex. Here, participants played a gambling game in which they flipped rare and abundant 'cards' on a computer screen to win financial rewards while electroencephalographic data were recorded. Unbeknownst to participants, reward outcome and frequency was random and equivalent for both rare and abundant cards; thus, only a perception of scarcity was true. Analysis of the electroencephalographic data indicated that the P300 component of the event-related brain potential differed in amplitude for wins and losses following the selection of rare cards, but not following the selection of abundant cards. Importantly, then, we found that the perception of card rarity impacted reward processing even though reward feedback was independent of and subsequent to card selection. Our data indicate a top-down influence of the scarcity heuristic on reward evaluation, and specifically the processing of reward magnitude, within the human medial-frontal cortex.

Preparation of Polyurethane/Graphite Composite Films with Stable Mechanical Property and Wear Resistance Underwater.

PubMed

Wang, Miaomiao; Wang, Zubin; Chen, Qirong; Meng, Xiangfu; Heng, Liping

2018-06-01

The wear resistance and stable mechanical properties affect the service life of the underwater functional materials to a certain extent. Unfortunately, the current study of underwater functional materials is rarely related to these aspects. Herein, we successfully designed and prepared polyurethane/graphite nanosheet (PU/GN) composite materials, which exhibited excellent wear resistance and stable mechanical properties underwater. The PU/GN composite films were prepared by evaporating a mixed solution of PU and GN on concave hexagonal honeycomb silicon templates. The mechanical properties of the composite films were determined by tensile test, and the wear resistance was evaluated by comparing the surface morphology before and after grind. By adjusting the content of graphite in the composite films, we found that the composite films containing 23 wt% GN had higher tensile strength and superior wear resistance. Moreover, this composite film showed an outstanding stability when expose to water. The impressive results along with simple preparation process made PU/GN composite films had potential applications in robust underwater functional materials.

Surface tension mediated conversion of light to work

DOEpatents

Okawa, David; Pastine, Stefan J; Zettl, Alexander K; Frechet, Jean M. J

2014-12-02

Disclosed are a method and apparatus for converting light energy to mechanical energy by modification of surface tension on a supporting fluid. The apparatus comprises an object which may be formed as a composite object comprising a support matrix and a highly light absorptive material. The support matrix may comprise a silicon polymer. The highly light absorptive material may comprise vertically aligned carbon nanotubes (VANTs) embedded in the support matrix. The composite object is supported on a fluid. By exposing the highly light absorptive material to light, heat is generated, which changes the surface tension of the composite object, causing it to move physically within the fluid.

Methods for preparation of three-dimensional bodies

DOEpatents

Mulligan, Anthony C.; Rigali, Mark J.; Sutaria, Manish P.; Artz, Gregory J.; Gafner, Felix H.; Vaidyanathan, K. Ranji

2004-09-28

Processes for mechanically fabricating two and three-dimensional fibrous monolith composites include preparing a fibrous monolith filament from a core composition of a first powder material and a boundary material of a second powder material. The filament includes a first portion of the core composition surrounded by a second portion of the boundary composition. One or more filaments are extruded through a mechanically-controlled deposition nozzle onto a working surface to create a fibrous monolith composite object. The objects may be formed directly from computer models and have complex geometries.

Methods for preparation of three-dimensional bodies

DOEpatents

Mulligan, Anthony C [Tucson, AZ; Rigali, Mark J [Carlsbad, NM; Sutaria, Manish P [Malden, MA; Artz, Gregory J [Tucson, AZ; Gafner, Felix H [Tucson, AZ; Vaidyanathan, K Ranji [Tucson, AZ

2008-06-17

Processes for mechanically fabricating two and three-dimensional fibrous monolith composites include preparing a fibrous monolith filament from a core composition of a first powder material and a boundary material of a second powder material. The filament includes a first portion of the core composition surrounded by a second portion of the boundary composition. One or more filaments are extruded through a mechanically-controlled deposition nozzle onto a working surface to create a fibrous monolith composite object. The objects may be formed directly from computer models and have complex geometries.

Quantifiers more or less quantify online: ERP evidence for partial incremental interpretation

PubMed Central

Urbach, Thomas P.; Kutas, Marta

2010-01-01

Event-related brain potentials were recorded during RSVP reading to test the hypothesis that quantifier expressions are incrementally interpreted fully and immediately. In sentences tapping general knowledge (Farmers grow crops/worms as their primary source of income), Experiment 1 found larger N400s for atypical (worms) than typical objects (crops). Experiment 2 crossed object typicality with non-logical subject-noun phrase quantifiers (most, few). Off-line plausibility ratings exhibited the crossover interaction predicted by full quantifier interpretation: Most farmers grow crops and Few farmers grow worms were rated more plausible than Most farmers grow worms and Few farmers grow crops. Object N400s, although modulated in the expected direction, did not reverse. Experiment 3 replicated these findings with adverbial quantifiers (Farmers often/rarely grow crops/worms). Interpretation of quantifier expressions thus is neither fully immediate nor fully delayed. Furthermore, object atypicality was associated with a frontal slow positivity in few-type/rarely quantifier contexts, suggesting systematic processing differences among quantifier types. PMID:20640044

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Loewy, R. G.; Wiberley, S. E.

1981-01-01

The composite aircraft program component (CAPCOMP) is a graduate level project conducted in parallel with a composite structures program. The composite aircraft program glider (CAPGLIDE) is an undergraduate demonstration project which has as its objectives the design, fabrication, and testing of a foot launched ultralight glider using composite structures. The objective of the computer aided design (COMPAD) portion of the composites project is to provide computer tools for the analysis and design of composite structures. The major thrust of COMPAD is in the finite element area with effort directed at implementing finite element analysis capabilities and developing interactive graphics preprocessing and postprocessing capabilities. The criteria for selecting research projects to be conducted under the innovative and supporting research (INSURE) program are described.

Thermochemistry of Rare Earth Silicates for Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Costa, Gustavo; Jacobson, Nathan

2015-01-01

Rare earth silicates are promising candidates as environmental protective coatings (EBCs) for silica-forming ceramics and composites in combustion environments since they are predicted to have lower reactivity with the water vapor combustion products. The reactivity of rare earth silicates is assessed by the thermodynamic activity of the silica component which is best measured by Knudsen effusion mass spectrometry (KEMS). Here, we discuss a novel method based on a reducing agent to increase the partial pressure of SiO(g) which is then used to calculate thermodynamic activity of silica in Y2O3-SiO2 and Yb2O3-SiO2 systems. After the KEMS measurements, samples were probed by X-ray diffraction and their phase content was calculated from Rietveld refinement.

Quickly updatable hologram images with high performance photorefractive polymer composites

NASA Astrophysics Data System (ADS)

Tsutsumi, Naoto; Kinashi, Kenji; Nonomura, Asato; Sakai, Wataru

2012-02-01

We present here quickly updatable hologram images using high performance photorefractive (PR) polymer composite based on poly(N-vinyl carbazole) (PVCz). PVCz is one of the pioneer materials for photoconductive polymer. PVCz/7- DCST/CzEPA/TNF (44/35/20/1 by wt) gives high diffraction efficiency of 68 % at E = 45 V/μm with fast response speed. Response speed of optical diffraction is the key parameter for real-time 3D holographic display. Key parameter for obtaining quickly updatable hologram images is to control the glass transition temperature lower enough to enhance chromophore orientation. Object image of the reflected coin surface recorded with reference beam at 532 nm (green beam) in the PR polymer composite is simultaneously reconstructed using a red probe beam at 642 nm. Instead of using coin object, object image produced by a computer was displayed on a spatial light modulator (SLM) is used as an object for hologram. Reflected object beam from a SLM interfered with reference beam on PR polymer composite to record a hologram and simultaneously reconstructed by a red probe beam. Movie produced in a computer was recorded as a realtime hologram in the PR polymer composite and simultaneously clearly reconstructed with a video rate.

Lightweight, Room-Temperature CO2 Gas Sensor Based on Rare-Earth Metal-Free Composites-An Impedance Study.

PubMed

Willa, Christoph; Schmid, Alexander; Briand, Danick; Yuan, Jiayin; Koziej, Dorota

2017-08-02

We report a light, flexible, and low-power poly(ionic liquid)/alumina composite CO 2 sensor. We monitor the direct-current resistance changes as a function of CO 2 concentration and relative humidity and demonstrate fast and reversible sensing kinetics. Moreover, on the basis of the alternating-current impedance measurements we propose a sensing mechanism related to proton conduction and gas diffusion. The findings presented herein will promote the development of organic/inorganic composite CO 2 gas sensors. In the future, such sensors will be useful for numerous practical applications ranging from indoor air quality control to the monitoring of manufacturing processes.

Leveraging Terminological Resources for Mapping between Rare Disease Information Sources

PubMed Central

Rance, Bastien; Snyder, Michelle; Lewis, Janine; Bodenreider, Olivier

2015-01-01

Background Rare disease information sources are incompletely and inconsistently cross-referenced to one another, making it difficult for information seekers to navigate across them. The development of such cross-references established manually by experts is generally labor intensive and costly. Objectives To develop an automatic mapping between two of the major rare diseases information sources, GARD and Orphanet, by leveraging terminological resources, especially the UMLS. Methods We map the rare disease terms from Orphanet and ORDR to the UMLS. We use the UMLS as a pivot to bridge between the rare disease terminologies. We compare our results to a mapping obtained through manually established cross-references to OMIM. Results Our mapping has a precision of 94%, a recall of 63% and an F1-score of 76%. Our automatic mapping should help facilitate the development of more complete and consistent cross-references between GARD and Orphanet, and is applicable to other rare disease information sources as well. PMID:23920611

The value of fine needle aspiration cytology in the clinical management of rare salivary gland tumors

PubMed Central

Mezei, Tibor; Mocan, Simona; Ormenisan, Alina; Baróti, Beáta; Iacob, Alina

2018-01-01

Abstract Salivary gland tumors are relatively rare neoplasms, mostly located in the parotid gland, and few are malignant. Preoperative evaluation of salivary gland tumors includes fine needle aspiration cytology (FNAC). Objective The purpose of this study was to determine the importance of FNAC in the evaluation of rare salivary gland neoplasms. Material and Methods Four cases of rare salivary gland tumors were included, which were preoperatively assessed by clinical investigation, computed tomography, and FNAC. Results The presented cases include myoepithelial carcinoma, oncocytic carcinoma, undifferentiated lymphoepithelial carcinoma, and marginal zone lymphoma. Conclusion FNAC is a reliable diagnostic tool for common salivary gland neoplasms; however, rare tumors often represent diagnostic challenges. Clinical relevance In such rare tumors, the role of aspiration cytology may be limited to establishing the dignity of the lesion (benign/malignant). This knowledge enables the surgeon to choose the most appropriate therapeutic procedure. A definitive diagnosis of rare tumors (either epithelial or nonepithelial) is obtained by histological examination; cytology is limited in this regard due to overlapping features. PMID:29489937

Mantle rare gas relative abundances in a steady-state mass transport model

NASA Technical Reports Server (NTRS)

Porcelli, D.; Wasserburg, G. J.

1994-01-01

A model for He and Xe was presented previously which incorporates mass transfer of rare gases from an undegassed lower mantle (P) and the atmosphere into a degassed upper mantle (D). We extend the model to include Ne and Ar. Model constraints on rare gas relative abundances within P are derived. Discussions of terrestrial volatile acquisition have focused on the rare gas abundance pattern of the atmosphere relative to meteoritic components, and the pattern of rare gases still trapped in the Ear,th is important in identifying volatile capture and loss processes operating during Earth formation. The assumptions and principles of the model are discussed in Wasserburg and Porcelli (this volume). For P, the concentrations in P of the decay/nuclear products 4 He, 21 Ne, 40 Ar, and 136 Xe can be calculated from the concentrations of the parent elements U, Th, K, and Pu. The total concentration of the daughter element in P is proportional to the isotopic shifts in P. For Ar, ((40)Ar/(36)Ar)p - ((40)Ar/(36)Ar)o =Delta (exp 40) p= 40 Cp/(exp 36)C where(i)C(sub j) the concentration of isotope i in j. In D, isotope compositions are the result of mixing rare gases from P, decay/nuclear products generated in the upper mantle, and subducted rare gases (for Ar and Xe).

Addressing Rare-Earth Element Criticality: An Example from the Aviation Industry

NASA Astrophysics Data System (ADS)

Ku, Anthony Y.; Dosch, Christopher; Grossman, Theodore R.; Herzog, Joseph L.; Maricocchi, Antonio F.; Polli, Drew; Lipkin, Don M.

2014-11-01

Rare-earth (RE) elements are enablers for a wide range of technologies, including high-strength permanent magnets, energy-efficient lighting, high-temperature thermal barrier coatings, and catalysts. While direct material substitution is difficult in many of these applications because of the specific electronic, optical, or electrochemical properties imparted by the individual rare-earth elements, we describe an example from the aviation industry where supply chain optimization may be an option. Ceramic matrix composite engine components require environmental barrier coatings (EBCs) to protect them from extreme temperatures and adverse reactions with water vapor in the hot gas path. EBC systems based on rare-earth silicates offer a unique combination of environmental resistance, thermal expansion matching, thermal conductivity, and thermal stability across the service temperature window. Several pure rare-earth silicates and solid solutions have been demonstrated in EBC applications. However, all rely on heavy rare-earth elements (HREEs) for phase stability. This article considers the possibility of using separation tailings containing a mixture of HREEs as a source material in lieu of using the high-purity HREE oxides. This option arises because the desired properties of RE-silicate EBCs derive from the average cation size rather than the electronic properties of the individual rare-earth cations. Because separation tailings have not incurred the costs associated with the final stages of separation, they offer an economical alternative to high-purity oxides for this emerging application.

Transposition and implementation of EU rare disease policy in Eastern Europe.

PubMed

Pejcic, Ana V; Iskrov, Georgi; Raycheva, Ralitsa; Stefanov, Rumen; Jakovljevic, Mihajlo Michael

2017-12-01

А series of European Union (EU) political decisions have made rare diseases one of the cornerstones of the common European health policy. Adopted in 2009, Council Recommendation on an action in the field of rare diseases aimed to serve as a policy-making guideline. However, the implementation report, which followed it, neither performed detailed cross-country comparison, nor assessed the impact of the policies. Areas covered: A 10-indicator set was elaborated to structure the review and to describe rare disease activities in 14 Eastern European countries. Expert commentary: Taking into account all indicators, EU member states outperform candidate and potential candidate countries in terms of rare disease policy planning and implementation. Hungary is the top performer, followed by Bulgaria and Czech Republic. Non-EU countries form the bottom tier, with Serbia being the best ranked among them. While EU adhesion is a major facilitator for planning and adopting rare disease policies, local stakeholders are the triggering factor for their successful implementation. European reference networks are likely to be the future of rare disease activities in the EU. They need to synchronize and closely collaborate with all important EU projects in the field of rare diseases if they are to achieve their objectives.

Extraction of rare earth elements from low-grade Bauxite via precipitation reaction

NASA Astrophysics Data System (ADS)

Kusrini, E.; Nurani, Y.; Bahari, ZJ

2018-03-01

The aim of this research was to determine the optimum hydrometallurgical parameters to extract the rare earth elements (REE) from low-grade bauxite through acid leaching and precipitation reaction. REE or lanthanide recovery by a precipitation method with sodium sulphate and sodium phosphate as precipitation agents is reported where the effect of pH and recovery of REE are described. The metal composition of REE in low-grade bauxite after treatment were analyzed by ICP-OES. The total recovery values of REE elements at the first precipitation reaction using sodium sulphate as the precipitation agent at pH 3.5 showed ~68.2% of lanthanum, ~18.9% cerium, and ~7.8% yttrium. Lanthanum was the rare-earth element present at the highest concentration in the low-grade bauxite after the series treatments. An optimum pH of 3.5 for precipitation of rare-earth elements using sodium sulphate was demonstrated where this method is recommended for the extraction of REE elements from low-grade bauxite.

Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads:

NASA Technical Reports Server (NTRS)

1981-01-01

Artist: Ken Hodges Composite image explaining Objective and Motivation for Galileo Probe Heat Loads: Galileo Probe descending into Jupiters Atmosphere shows heat shield separation with parachute deployed. (Ref. JPL P-19180)

Carbide-reinforced metal matrix composite by direct metal deposition

NASA Astrophysics Data System (ADS)

Novichenko, D.; Thivillon, L.; Bertrand, Ph.; Smurov, I.

Direct metal deposition (DMD) is an automated 3D laser cladding technology with co-axial powder injection for industrial applications. The actual objective is to demonstrate the possibility to produce metal matrix composite objects in a single-step process. Powders of Fe-based alloy (16NCD13) and titanium carbide (TiC) are premixed before cladding. Volume content of the carbide-reinforced phase is varied. Relationships between the main laser cladding parameters and the geometry of the built-up objects (single track, 2D coating) are discussed. On the base of parametric study, a laser cladding process map for the deposition of individual tracks was established. Microstructure and composition of the laser-fabricated metal matrix composite objects are examined. Two different types of structures: (a) with the presence of undissolved and (b) precipitated titanium carbides are observed. Mechanism of formation of diverse precipitated titanium carbides is studied.

Rare k-mer DNA: Identification of sequence motifs and prediction of CpG island and promoter.

PubMed

Mohamed Hashim, Ezzeddin Kamil; Abdullah, Rosni

2015-12-21

Empirical analysis on k-mer DNA has been proven as an effective tool in finding unique patterns in DNA sequences which can lead to the discovery of potential sequence motifs. In an extensive study of empirical k-mer DNA on hundreds of organisms, the researchers found unique multi-modal k-mer spectra occur in the genomes of organisms from the tetrapod clade only which includes all mammals. The multi-modality is caused by the formation of the two lowest modes where k-mers under them are referred as the rare k-mers. The suppression of the two lowest modes (or the rare k-mers) can be attributed to the CG dinucleotide inclusions in them. Apart from that, the rare k-mers are selectively distributed in certain genomic features of CpG Island (CGI), promoter, 5' UTR, and exon. We correlated the rare k-mers with hundreds of annotated features using several bioinformatic tools, performed further intrinsic rare k-mer analyses within the correlated features, and modeled the elucidated rare k-mer clustering feature into a classifier to predict the correlated CGI and promoter features. Our correlation results show that rare k-mers are highly associated with several annotated features of CGI, promoter, 5' UTR, and open chromatin regions. Our intrinsic results show that rare k-mers have several unique topological, compositional, and clustering properties in CGI and promoter features. Finally, the performances of our RWC (rare-word clustering) method in predicting the CGI and promoter features are ranked among the top three, in eight of the CGI and promoter evaluations, among eight of the benchmarked datasets. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements

NASA Astrophysics Data System (ADS)

Kato, Yasuhiro; Fujinaga, Koichiro; Nakamura, Kentaro; Takaya, Yutaro; Kitamura, Kenichi; Ohta, Junichiro; Toda, Ryuichi; Nakashima, Takuya; Iwamori, Hikaru

2011-08-01

World demand for rare-earth elements and the metal yttrium--which are crucial for novel electronic equipment and green-energy technologies--is increasing rapidly. Several types of seafloor sediment harbour high concentrations of these elements. However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient. Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean. We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific. We estimate that an area of just one square kilometre, surrounding one of the sampling sites, could provide one-fifth of the current annual world consumption of these elements. Uptake of rare-earth elements and yttrium by mineral phases such as hydrothermal iron-oxyhydroxides and phillipsite seems to be responsible for their high concentration. We show that rare-earth elements and yttrium are readily recovered from the mud by simple acid leaching, and suggest that deep-sea mud constitutes a highly promising huge resource for these elements.

Date prints on stranded macroplastics: Marine litter as a chronological marker in recent coastal deposits

NASA Astrophysics Data System (ADS)

Sander, Lasse

2017-04-01

Plastic is a collective term describing a group of synthetic materials, most of which were invented over the course of the last century. Already in the 1970s, the magnitude of plastic pollution has been recognized as an issue of concern for the global marine environment. It is hence no longer a rare event to encounter plastic fragments and objects in coastal or marine deposits. Plastic holds a chronological indication: a deposit containing plastic must be younger than the invention of the material. The potential of this approach was tested in an investigation into the spatial distribution of stranded macroplastics in recent overwash deposits in SW Denmark. Larger litter items can be surveyed as discrete objects and allow the retrieval of more precise, though indirect age-information, such as production-date prints. A subgroup of >110 georeferenced surface samples containing date information were surveyed in summer 2015. Objects with ages from the late 1970s until 2014 were encountered. The distribution of the litter was clearly non-random in relation to overwash morphology, and based on the collected samples, it was possible to reconstruct indication on both the timing and the extent of extreme events since the 1990s. These observations were cross-compared with a dense time series of satellite images and orthophotos. It is proposed that an improved interpretation of indications from the plastic record may be obtained by broader surveys including additional parameters, such as the exact location, elevation, chemical composition, assemblage, origin, product design, decay, fracturing or the colonization by marine sessile organisms, from all encountered macroplastic objects. If calibrated properly, the plastic assemblages may serve as fast, cheap and reliable chronological markers in recent coastal deposits.

Engineering Ceramic Nanophosphors for Optical Applications

DTIC Science & Technology

2009-06-11

spacing) AMPR : multiphonon relaxation losses (surface defects, traps) AOH : losses from –OH quenching OHMPRETradnon rad lum radnonirad irad AAAA AA A...methacrylate ( PMMA ) and Polystyrene (PS) • Obtained transparent composites of rare-earth doped CeF3 nanoparticles with high solid loading MC Tan, SD Patil

Rock-forming and rare elements in lunar surface material from the Sea of Tranquillity and the Ocean of Storms

NASA Technical Reports Server (NTRS)

Shevaleyevskiy, I. D.; Chupakhin, M. S.

1974-01-01

Methodological and analytical capabilities associated with spark mass spectrometry and X-ray spectroscopy are presented for the determination of the elemental composition of samples of lunar regolith returned to the earth by Apollo 11 and Apollo 12. Using X-ray spectroscopy, the main constituents of samples of lunar surface material were determined, and using mass spectrometry -- the main admixtures. The principal difference of Apollo 11 samples from Apollo 12 samples was found for elements contained in microconcentrations. This is especially true of rare earth elements.

Compositional and phase relations among rare earth element minerals

NASA Technical Reports Server (NTRS)

Burt, D. M.

1989-01-01

A review is presented that mainly treats minerals in which the rare-earth elements are essential constituents, e.g., bastnaesite, monazite, xenotime, aeschynite, allanite. The chemical mechanisms and limits of REE substitution in some rock-forming minerals (zircon, apatite, titanite, garnet) are also derived. Vector representation of complex coupled substitutions in selected REE-bearing minerals is examined and some comments on REE-partitioning between minerals as related to acid-based tendencies and mineral stabilities are presented. As the same or analogous coupled substitutions involving the REE occur in a wide variety of mineral structures, they are discussed together.

Solvent for the simultaneous recovery of radionuclides from liquid radioactive wastes

DOEpatents

Romanovskiy, Valeriy Nicholiavich; Smirnov, Igor V.; Babain, Vasiliy A.; Todd, Terry A.; Brewer, Ken N.

2002-01-01

The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.

Method for the simultaneous recovery of radionuclides from liquid radioactive wastes using a solvent

DOEpatents

Romanovskiy, Valeriy Nicholiavich; Smirnov, Igor V.; Babain, Vasiliy A.; Todd, Terry A.; Brewer, Ken N.

2001-01-01

The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.

Experimental Evidence of Chiral Ferrimagnetism in Amorphous GdCo Films

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

Streubel, Robert; Lambert, Charles-Henri; Kent, Noah

Inversion symmetry breaking has become a vital research area in modern magnetism with phenomena including the Rashba effect, spin Hall effect, and the Dzyaloshinskii-Moriya interaction (DMI)-a vector spin exchange. The latter one may stabilize chiral spin textures with topologically nontrivial properties, such as Skyrmions. So far, chiral spin textures have mainly been studied in helimagnets and thin ferromagnets with heavy-element capping. Here, the concept of chirality driven by interfacial DMI is generalized to complex multicomponent systems and demonstrated on the example of chiral ferrimagnetism in amorphous GdCo films. Utilizing Lorentz microscopy and X-ray magnetic circular dichroism spectroscopy, and tailoring thickness,more » capping, and rare-earth composition, reveal that 2 nm thick GdCo films preserve ferrimagnetism and stabilize chiral domain walls. Finally, the type of chiral domain walls depends on the rare-earth composition/saturation magnetization, enabling a possible temperature control of the intrinsic properties of ferrimagnetic domain walls.« less

Gamma rays shielding and sensing application of some rare earth doped lead-alumino-phosphate glasses

NASA Astrophysics Data System (ADS)

Kaur, Preet; Singh, Devinder; Singh, Tejbir

2018-03-01

Seven rare earth (Sm3+, Eu3+ and Nd3+) doped lead alumino phosphate glasses were prepared. The protective and sensing measures from gamma rays were analysed in terms of parameters viz. density (ρ), refractive index, energy band gap (Eg), mean free path (mfp), effective atomic number (Zeff) and buildup factors (energy absorption EABF as well as exposure buildup factor EBF). The energy dependent parameters (mfp, Zeff, EABF and EBF) were investigated in the energy region from 15 keV to 15 MeV. EABF and EBF values were observed to be maximum in the intermediate energy region. Besides, the EABF and EBF values for the prepared samples are shown to have strong dependence on chemical composition of the glass at lower energy, whereas, it is almost independent of chemical composition in higher energy region. The prepared glass samples are found to have potential applications in radiation shielding as well as radiation sensing, which further find numerous applications in the field of medicine and industry.

Experimental Evidence of Chiral Ferrimagnetism in Amorphous GdCo Films

DOE PAGES

Streubel, Robert; Lambert, Charles-Henri; Kent, Noah; ...

2018-05-23

Inversion symmetry breaking has become a vital research area in modern magnetism with phenomena including the Rashba effect, spin Hall effect, and the Dzyaloshinskii-Moriya interaction (DMI)-a vector spin exchange. The latter one may stabilize chiral spin textures with topologically nontrivial properties, such as Skyrmions. So far, chiral spin textures have mainly been studied in helimagnets and thin ferromagnets with heavy-element capping. Here, the concept of chirality driven by interfacial DMI is generalized to complex multicomponent systems and demonstrated on the example of chiral ferrimagnetism in amorphous GdCo films. Utilizing Lorentz microscopy and X-ray magnetic circular dichroism spectroscopy, and tailoring thickness,more » capping, and rare-earth composition, reveal that 2 nm thick GdCo films preserve ferrimagnetism and stabilize chiral domain walls. Finally, the type of chiral domain walls depends on the rare-earth composition/saturation magnetization, enabling a possible temperature control of the intrinsic properties of ferrimagnetic domain walls.« less

Resequencing of IRS2 reveals rare variants for obesity but not fasting glucose homeostasis in Hispanic children

PubMed Central

Voruganti, V. Saroja; Cole, Shelley A.; Haack, Karin; Comuzzie, Anthony G.; Muzny, Donna M.; Wheeler, David A.; Chang, Kyle; Hawes, Alicia; Gibbs, Richard A.

2011-01-01

Our objective was to resequence insulin receptor substrate 2 (IRS2) to identify variants associated with obesity- and diabetes-related traits in Hispanic children. Exonic and intronic segments, 5′ and 3′ flanking regions of IRS2 (∼14.5 kb), were bidirectionally sequenced for single nucleotide polymorphism (SNP) discovery in 934 Hispanic children using 3730XL DNA Sequencers. Additionally, 15 SNPs derived from Illumina HumanOmni1-Quad BeadChips were analyzed. Measured genotype analysis tested associations between SNPs and obesity and diabetes-related traits. Bayesian quantitative trait nucleotide analysis was used to statistically infer the most likely functional polymorphisms. A total of 140 SNPs were identified with minor allele frequencies (MAF) ranging from 0.001 to 0.47. Forty-two of the 70 coding SNPs result in nonsynonymous amino acid substitutions relative to the consensus sequence; 28 SNPs were detected in the promoter, 12 in introns, 28 in the 3′-UTR, and 2 in the 5′-UTR. Two insertion/deletions (indels) were detected. Ten independent rare SNPs (MAF = 0.001–0.009) were associated with obesity-related traits (P = 0.01–0.00002). SNP 10510452_139 in the promoter region was shown to have a high posterior probability (P = 0.77–0.86) of influencing BMI, fat mass, and waist circumference in Hispanic children. SNP 10510452_139 contributed between 2 and 4% of the population variance in body weight and composition. None of the SNPs or indels were associated with diabetes-related traits or accounted for a previously identified quantitative trait locus on chromosome 13 for fasting serum glucose. Rare but not common IRS2 variants may play a role in the regulation of body weight but not an essential role in fasting glucose homeostasis in Hispanic children. PMID:21771880

Self-Lubricating Composite Containing Chromium Oxide

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher (Inventor); Edmonds, Brian J. (Inventor)

1999-01-01

A self lubricating. friction and wear reducing composite material useful over a wide temperature range of from cryogenic temperature up to about 900 C. contains 60 80 wt. % of particulate Cr2O3, dispersed in a metal binder of a metal alloy containing Cr and at least 50 wt. % of Ni, Cr or a mature of Ni and Cr. It also contains 5-20 wt. % of a fluoride of at least one Group I, Group II or rare earth metal and. optionally, 5-20 wt. % of a low temperature lubricant metal, such as Ag. Au, Pt, Pd, Rh and Cu. This composite exhibits less oxidation instability and less abrasiveness than composites containing chromium carbide, is readily applied using plasma spray and can be ground and polished with a silicon carbide abrasive.

How Surface Composition and Meteoroid Impacts Mediate Sodium and Potassium in the Lunar Exosphere

NASA Technical Reports Server (NTRS)

Colaprete, A.; Sarantos, M.; Wooden, D. H.; Stubbs, T. J.; Cook, A. M.; Shirley, M.

2016-01-01

Despite being trace constituents of the lunar exosphere, sodium and potassium are the most readily observed species due to their bright line emission. Measurements of these species by the Ultraviolet and Visible Spectrometer (UVS) on the Lunar Atmosphere and Dust Environment Explorer (LADEE) have revealed unambiguous temporal and spatial variations indicative of a strong role for meteoroid bombardment and surface composition in determining the composition and local time dependence of the Moon's exosphere. Observations show distinct lunar day (monthly) cycles for both species as well as an annual cycle for sodium. The first continuous measurements for potassium show a more repeatable variation across lunations and an enhancement over KREEP (Potassium Rare Earth Elements and Phosphorus) surface regions, revealing a strong dependence on surface composition.

Study on influence of vibration behavior of composite material damage by holography

NASA Astrophysics Data System (ADS)

Guo, Linfeng; Zhao, Zhimin; Gao, Mingjuan; Zhuang, Xianzhong

2006-01-01

Composite material has been applied widely in aeronautics, astronautics and some other fields due to their high strength, light weight and antifatigue and etc. But in the application, composite material may be destroyed or damaged, which may have impact on its further applications. Therefore, study on the influence of behavior of composite material damage becomes a hot research. In this paper, the common composite material for aircraft is used as the test object, and a study is conducted to investigate the influence of vibration behavior of composite material damage. The authors adopt the method of light-carrier wave and time-average holography. Compared the interference fringes of composite materials before and after damage, the width of the interference fringes of hologram of the damaged composite material is narrower than that of the fringes before. It means that the off-plane displacement of each point on the test object is larger than before. Based on the elastic mechanics theory, the off-plane displacement is inverse to the bending stiffness, and the bending stiffness of the test object will decrease after it is damaged. In other words, the vibration property of the composite material changes after damages occur. The research results of the paper show that the results accord with the analysis of theory.

Rare species of the genus Oxytropis DC. (Fabaceae) from the flora of the Republic of Bashkortostan under cultivation within the city of Ufa

NASA Astrophysics Data System (ADS)

Maslova, N. V.; Elizaryeva, O. A.; Galikeeva, G. M.; Tyutyunova, N. M.

2018-01-01

This paper presents the results of investigations introducing eight rare species of the genus Oxytropis DC. from the flora of the Republic of Bashkortostan into the city of Ufa. Seven species are characterized as promising ornamental plants. According to the integrated evaluation scale of introduction effectiveness based on seven indices, two species were considered as very promising (O. spicata (Pall.) O. et B. Fedtsch., O. knjazevii Vasjukov), five species as promising (O. approximata Less., O. baschkirensis Knjasev, O. hippolyti Boriss., O. gmelinii Boriss., O. kungurensis Knjasev) and one species as non-promising (O. sordida (Willd.) Pers.). The ornamental quality assessment of rare species of the genus Oxytropis based on ten indices showed that these species can be used to create ornamental compositions in the landscape design style.

Extraction of composite visual objects from audiovisual materials

NASA Astrophysics Data System (ADS)

Durand, Gwenael; Thienot, Cedric; Faudemay, Pascal

1999-08-01

An effective analysis of Visual Objects appearing in still images and video frames is required in order to offer fine grain access to multimedia and audiovisual contents. In previous papers, we showed how our method for segmenting still images into visual objects could improve content-based image retrieval and video analysis methods. Visual Objects are used in particular for extracting semantic knowledge about the contents. However, low-level segmentation methods for still images are not likely to extract a complex object as a whole but instead as a set of several sub-objects. For example, a person would be segmented into three visual objects: a face, hair, and a body. In this paper, we introduce the concept of Composite Visual Object. Such an object is hierarchically composed of sub-objects called Component Objects.

Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

DOEpatents

McCallum, R.W.; Branagan, D.J.

1996-01-23

A method of making a permanent magnet is disclosed wherein (1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and (2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties. 33 figs.

Carbide/nitride grain refined rare earth-iron-boron permanent magnet and method of making

DOEpatents

McCallum, R. William; Branagan, Daniel J.

1996-01-23

A method of making a permanent magnet wherein 1) a melt is formed having a base alloy composition comprising RE, Fe and/or Co, and B (where RE is one or more rare earth elements) and 2) TR (where TR is a transition metal selected from at least one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al) and at least one of C and N are provided in the base alloy composition melt in substantially stoichiometric amounts to form a thermodynamically stable compound (e.g. TR carbide, nitride or carbonitride). The melt is rapidly solidified in a manner to form particulates having a substantially amorphous (metallic glass) structure and a dispersion of primary TRC, TRN and/or TRC/N precipitates. The amorphous particulates are heated above the crystallization temperature of the base alloy composition to nucleate and grow a hard magnetic phase to an optimum grain size and to form secondary TRC, TRN and/or TRC/N precipitates dispersed at grain boundaries. The crystallized particulates are consolidated at an elevated temperature to form a shape. During elevated temperature consolidation, the primary and secondary precipitates act to pin the grain boundaries and minimize deleterious grain growth that is harmful to magnetic properties.

Essential oil composition and antimicrobial activity of wild and cultivated Moroccan Achillea ageratum L.: a rare and threatened medicinal species.

PubMed

El Bouzidi, Laila; Abbad, Abdelaziz; Hassani, Lahcen; Fattarsi, Karine; Leach, David; Markouk, Mohammed; Legendre, Laurent; Bekkouche, Khalid

2012-03-01

The essential oils of leaves and flowers of the wild and cultivated Moroccan Achillea ageratum L., a rare and threatened medicinal species, were examined by GC/MS, and their chemical compositions were compared. At least nine components were identified in both wild and cultivated A. ageratum oils, representing more than 95% of the oils. Artemisyl acetate (62.34-78.79%), yomogi alcohol (4.89-12.40%), santolina alcohol (4.86-11.77%), and artemisia alcohol (3.36-7.04%) were the major compounds. Terpene-alcohol proportion was higher in wild A. ageratum than in cultivated A. ageratum. The antibacterial analysis showed that both oils presented high activity against all the studied Gram-positive strains in a range of MIC values from 2.55 to 7.02 mg/ml, but they appeared not effective against the tested Gram-negative ones (MIC values 20.40-41.10 mg/ml). They also exhibited remarkable antifungal activities against Candida species with MIC values ranging from 5.83 to 8.42 mg/ml. From these results, it was concluded that domestication of this threatened medicinal species using clonal propagation did not significantly affect its chemical composition and consequently its antimicrobial properties. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

USDA-ARS?s Scientific Manuscript database

Ecosystem-service models are increasingly implemented in diverse decision-making contexts, from land-use planning to corporate risk management. Though widely valued, biological control of crop pests is rarely considered in such decisions in part because suitable pest-control models do not exist. Her...

Stratigraphy, composition and form of the Deccan Basalts, Western Ghats, India

NASA Astrophysics Data System (ADS)

Beane, J. E.; Turner, C. A.; Hooper, P. R.; Subbarao, K. V.; Walsh, J. N.

1986-02-01

In the Western Ghats between latitudes 18° 20' N and 19° 15' N, 7000 km2 of Deccan Basalt have been mapped with the primary objective of establishing a flow stratigraphy as a guide to the volcanic history of the flood basalts. Using over 70 measured vertical sections, major and trace element analyses of nearly 1200 samples, and rare-earth and87Sr/86Sr determinations for over 60 samples, we divide the basalt into three subgroups and ten formations. In this paper we describe the seven principal formations in the area and the most prominent individual flows. The Kalsubai Subgroup is formed by the lower five formations, the Jawhar, Igatpuri, Neral, Thakurvadi, and Bhimashankar formations, from botton to top. In these formations amygdaloidal compound flows predominate and have a typically high MgO content, including picrite basalt (> 10% MgO) and picrite (> 18% MgO) with phenocrysts of olivine and clinopyroxene. These flows are separated by others which contain giant plagioclase phenocrysts and have more evolved chamical compositions. The Lonavala Subgroup overlies the Kalsubai and is composed of two formations, the Khandala and the Bushe. Both are readily recognized in the field and by their chemical compositions. The Wai Subgroup includes the upper three formations, the Poladpur, the Ambenali, and the Mahabaleshwar. The whole subgroup is composed of simple flows with well-developed flow tops, small phenocrysts of plagioclase, pyroxene and olivine, and relatively evolved bulk compositions. Distribution and variation in thickness of the straitigraphic units within the Western Ghats provide a first comprehensive view of the development of the Deccan volcanic edifice. The persistent southerly dip and gentle southerly plunging anticlinal form of the flows, the lensoid shape of many of the formations, and nearly randomly oriented feeder-dike system are together interpreted as evidence of a central volcanic edifice formed as the Indian plate drifted northward over a mantle plume or hot spot.

Composite catalyst for carbon monoxide and hydrocarbon oxidation

DOEpatents

Liu, W.; Flytzani-Stephanopoulos, M.

1996-03-19

A method and composition are disclosed for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdenum, copper, cobalt, manganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

Composite catalyst for carbon monoxide and hydrocarbon oxidation

DOEpatents

Liu, Wei; Flytzani-Stephanopoulos, Maria

1996-01-01

A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

An immunophenotypic and molecular diagnosis of composite hairy cell leukaemia and chronic lymphocytic leukaemia.

PubMed

Liptrot, Stuart; O' Brien, David; Langabeer, Stephen E; Quinn, Fiona; Mackarel, A Jill; Elder, Patrick; Vandenberghe, Elisabeth; Hayden, Patrick J

2013-12-01

Hairy cell leukaemia (HCL) and chronic lymphocytic leukaemia (CLL) are distinct clinicopathological B cell chronic lymphoproliferative disorders (B-CLPD). Both diseases have characteristic immunophenotypic and molecular features. The co-existence of two B-CLPD is perhaps more common than previously thought but a composite HCL and CLL has been rarely documented. A case is reported in which the morphology, integrated with an extensive immunophenotyping panel, and incorporation of the recently described HCL-associated BRAF V600E mutation, enabled the prompt diagnosis of composite HCL and CLL thus allowing appropriate treatment selection. This case serves to highlight the benefit of a multidisciplinary approach to the diagnosis of bi-clonal B-CLPD.

Isotopic compositions of cometary matter returned by Stardust.

PubMed

McKeegan, Kevin D; Aléon, Jerome; Bradley, John; Brownlee, Donald; Busemann, Henner; Butterworth, Anna; Chaussidon, Marc; Fallon, Stewart; Floss, Christine; Gilmour, Jamie; Gounelle, Matthieu; Graham, Giles; Guan, Yunbin; Heck, Philipp R; Hoppe, Peter; Hutcheon, Ian D; Huth, Joachim; Ishii, Hope; Ito, Motoo; Jacobsen, Stein B; Kearsley, Anton; Leshin, Laurie A; Liu, Ming-Chang; Lyon, Ian; Marhas, Kuljeet; Marty, Bernard; Matrajt, Graciela; Meibom, Anders; Messenger, Scott; Mostefaoui, Smail; Mukhopadhyay, Sujoy; Nakamura-Messenger, Keiko; Nittler, Larry; Palma, Russ; Pepin, Robert O; Papanastassiou, Dimitri A; Robert, François; Schlutter, Dennis; Snead, Christopher J; Stadermann, Frank J; Stroud, Rhonda; Tsou, Peter; Westphal, Andrew; Young, Edward D; Ziegler, Karen; Zimmermann, Laurent; Zinner, Ernst

2006-12-15

Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single (17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is (16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.

Influence of superconductor film composition on adhesion strength of coated conductors

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

Kesgin, Ibrahim; Khatri, Narayan; Liu, Yuhao

The effect of high temperature superconductor (HTS) film composition on the adhesion strength of rare- earth barium copper oxide coated conductors (CCs) has been studied. It has been found that the mechanical integrity of the superconductor layer is very susceptible to the defects especially those along the ab plane, probably due to the weak interfaces between the defects and the matrix. Gd and Y in the standard composition were substituted with Sm and the number of in-plane defects was drastically reduced. Consequently, a four-fold increase in adhesion or peeling strength in Sm-based CCs was achieved compared to the standard GdYBCOmore » samples.« less

Chemistry of the subalkalic silicic obsidians

USGS Publications Warehouse

MacDonald, Ray; Smith, Robert L.; Thomas, John E.

1992-01-01

Nonhydrated obsidians are quenched magmatic liquids that record in their chemical compositions details of the tectonic environment of formation and of the differentiation mechanisms that affected their subsequent evolution. This study attempts to analyze, in terms of geologic processes, the compositional variations in the subalkalic silicic obsidians (Si02≥70 percent by weight, molecular (Na2O+K20)>Al2O3). New major- and trace-element determinations of 241 samples and a compilation of 130 published major-element analyses are reported and interpreted. Obsidians from five different tectonic settings are recognized: (1) primitive island arcs, (2) mature island arcs, (3) continental margins, (4) continental interiors, and (5) oceanic extensional zones. Tectonomagmatic discrimination between these groups is successfully made on Nb-Ta, Nb-FeOt and Th-Hf-Ta plots, and compositional ranges and averages for each group are presented. The chemical differences between groups are related to the type of crust in which magmas were generated. With increasingly sialic (continental type) crust, the obsidians show overall enrichment in F, Be, Li, Mo, Nb, Rb, Sn, Ta, U, W, Zn, and the rare-earth elements, and depletion in Mg, Ca, Ba, Co, Sc, Sr, and Zr. They become more potassic, have higher Fe/Mg and F/Cl ratios, and lower Zr/Hf, Nb/Ta, and Th/U ratios. Higher values of total rare-earth elements are accompanied by light rare-earth-element enrichment and pronounced negative Eu anomalies. An attempt is made to link obsidian chemistry to genetic mechanlism. Two broad groups of rocks are distinguished: one generated where crystal-liquid processes dominated (CLPD types), which are the products of crustal anatexis, possibly under conditions of low halogen fugacity, ± crystal fractionation ± magma mixing; and a second group represented by rocks formed in the upper parts of large magma chambers by interplays of crystal fractionation, volatile transfer, magma mixing, and possibly various liquid-state differentiation mechanisms, or in other words a complex interaction of petrogenetic processes (CIPP types). Such rocks may also form by volatile-fluxed partial melting of the wallrocks, and subsequent mixing into the magma reservoir. Compositional ranges and averages for CLPD and CIPP obsidians are given. It is shown by analogy with well-documented, zoned ash-flow ruffs that obsidians fractionated by CIPP have very low Mg, P, Ba, and Sr contents, flat rare-earth-element patterns with extensive Eu anomalies, low K/Rb and Zr/Nb ratios, and relatively high Na2O/K2O ratios. There is, however, considerable compositional overlap between CLPD and CIPP obsidians. The effects of magma mixing, assimilation, and vapor-phase transport in producing compositional variations in the obsidians are briefly assessed. The geochemistry of the subalkalic silicic obsidians is described on an element-by-element basis, in order to provide a database for silicic magma compositions that will hopefully contribute to studies of granitic rocks. Attempts are also made to isolate the geochemical effects of tectonic environment and genetic mechanism for each element, by comparison with data from crystal-liquid equilibria-controlled systems, from ash-flow sheets zoned by CIPP, and from mixed-magma series. A final tabulation relates the complexities of obsidian geochemistry to all the tectonic and genetic variables.

A Component Analysis of the Impact of Evaluative and Objective Feedback on Performance

ERIC Educational Resources Information Center

Johnson, Douglas A.

2013-01-01

Despite the frequency with which performance feedback interventions are used in organizational behavior management, component analyses of such feedback are rare. It has been suggested that evaluation of performance and objective details about performance are two necessary components for performance feedback. The present study was designed to help…

Levels of major and trace elements, including rare earth elements, and ²³⁸U in Croatian tap waters.

PubMed

Fiket, Željka; Rožmarić, Martina; Krmpotić, Matea; Benedik, Ljudmila

2015-05-01

Concentrations of 46 elements, including major, trace, and rare earth elements, and (238)U in Croatian tap waters were investigated. Selected sampling locations include tap waters from various hydrogeological regions, i.e., different types of aquifers, providing insight into the range of concentrations of studied elements and (238)U activity concentrations in Croatian tap waters. Obtained concentrations were compared with the Croatian maximum contaminant levels for trace elements in water intended for human consumption, as well as WHO and EPA drinking water standards. Concentrations in all analyzed tap waters were found in accordance with Croatian regulations, except tap water from Šibenik in which manganese in concentration above maximum permissible concentration (MPC) was measured. Furthermore, in tap water from Osijek, levels of arsenic exceeded the WHO guidelines and EPA regulations. In general, investigated tap waters were found to vary considerably in concentrations of studied elements, including (238)U activity concentrations. Causes of variability were further explored using statistical methods. Composition of studied tap waters was found to be predominately influenced by hydrogeological characteristics of the aquifer, at regional and local level, the existing redox conditions, and the household plumbing system. Rare earth element data, including abundances and fractionation patterns, complemented the characterization and facilitated the interpretation of factors affecting the composition of the analyzed tap waters.

Enrichment allows identification of diverse, rare elements in metagenomic resistome-virulome sequencing.

PubMed

Noyes, Noelle R; Weinroth, Maggie E; Parker, Jennifer K; Dean, Chris J; Lakin, Steven M; Raymond, Robert A; Rovira, Pablo; Doster, Enrique; Abdo, Zaid; Martin, Jennifer N; Jones, Kenneth L; Ruiz, Jaime; Boucher, Christina A; Belk, Keith E; Morley, Paul S

2017-10-17

Shotgun metagenomic sequencing is increasingly utilized as a tool to evaluate ecological-level dynamics of antimicrobial resistance and virulence, in conjunction with microbiome analysis. Interest in use of this method for environmental surveillance of antimicrobial resistance and pathogenic microorganisms is also increasing. In published metagenomic datasets, the total of all resistance- and virulence-related sequences accounts for < 1% of all sequenced DNA, leading to limitations in detection of low-abundance resistome-virulome elements. This study describes the extent and composition of the low-abundance portion of the resistome-virulome, using a bait-capture and enrichment system that incorporates unique molecular indices to count DNA molecules and correct for enrichment bias. The use of the bait-capture and enrichment system significantly increased on-target sequencing of the resistome-virulome, enabling detection of an additional 1441 gene accessions and revealing a low-abundance portion of the resistome-virulome that was more diverse and compositionally different than that detected by more traditional metagenomic assays. The low-abundance portion of the resistome-virulome also contained resistance genes with public health importance, such as extended-spectrum betalactamases, that were not detected using traditional shotgun metagenomic sequencing. In addition, the use of the bait-capture and enrichment system enabled identification of rare resistance gene haplotypes that were used to discriminate between sample origins. These results demonstrate that the rare resistome-virulome contains valuable and unique information that can be utilized for both surveillance and population genetic investigations of resistance. Access to the rare resistome-virulome using the bait-capture and enrichment system validated in this study can greatly advance our understanding of microbiome-resistome dynamics.

Microbial Mat Compositional and Functional Sensitivity to Environmental Disturbance

PubMed Central

Preisner, Eva C.; Fichot, Erin B.; Norman, Robert S.

2016-01-01

The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. While studies have indicated that rare microbial taxa may provide a biological reservoir that supports long-term ecosystem stability, how this dynamic population is influenced by environmental parameters remains unclear. In this study, a microbial mat ecosystem located on San Salvador Island, The Bahamas was used as a model to examine how environmental disturbance affects the protein synthesis potential (PSP) of rare and abundant archaeal and bacterial communities and how these changes impact potential biogeochemical processes. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1) during 2011–2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of 16S rRNA and rRNA genes from samples before and after the pulse disturbance showed significant changes in the diversity and PSP of abundant and rare taxa, suggesting overall compositional and functional sensitivity to environmental change. In both archaeal and bacterial communities, while the majority of taxa showed low PSP across conditions, the overall community PSP increased post-disturbance, with significant shifts occurring among abundant and rare taxa across and within phyla. Broadly, following the post-disturbance reduction in salinity, taxa within Halobacteria decreased while those within Crenarchaeota, Thaumarchaeota, Thermoplasmata, Cyanobacteria, and Proteobacteria, increased in abundance and PSP. Quantitative PCR of genes and transcripts involved in nitrogen and sulfur cycling showed concomitant shifts in biogeochemical cycling potential. Post-disturbance conditions increased the expression of genes involved in N-fixation, nitrification, denitrification, and sulfate reduction. Together, our findings show complex community adaptation to environmental change and help elucidate factors connecting disturbance, biodiversity, and ecosystem function that may enhance ecosystem models. PMID:27799927

China's Rare Earth Supply Chain: Illegal Production, and Response to new Cerium Demand

NASA Astrophysics Data System (ADS)

Nguyen, Ruby Thuy; Imholte, D. Devin

2016-07-01

As the demand for personal electronic devices, wind turbines, and electric vehicles increases, the world becomes more dependent on rare earth elements. Given the volatile, Chinese-concentrated supply chain, global attempts have been made to diversify supply of these materials. However, the overall effect of supply diversification on the entire supply chain, including increasing low-value rare earth demand, is not fully understood. This paper is the first attempt to shed some light on China's supply chain from both demand and supply perspectives, taking into account different Chinese policies such as mining quotas, separation quotas, export quotas, and resource taxes. We constructed a simulation model using Powersim Studio that analyzes production (both legal and illegal), production costs, Chinese and rest-of-world demand, and market dynamics. We also simulated new demand of an automotive aluminum-cerium alloy in the US market starting from 2018. Results showed that market share of the illegal sector has grown since 2007-2015, ranging between 22% and 25% of China's rare earth supply, translating into 59-65% illegal heavy rare earths and 14-16% illegal light rare earths. There will be a shortage in certain light and heavy rare earths given three production quota scenarios and constant demand growth rate from 2015 to 2030. The new simulated Ce demand would require supply beyond that produced in China. Finally, we illustrate revenue streams for different ore compositions in China in 2015.

China’s rare earth supply chain: Illegal production, and response to new cerium demand

DOE PAGES

Nguyen, Ruby Thuy; Imholte, D. Devin

2016-03-29

As the demand for personal electronic devices, wind turbines, and electric vehicles increases, the world becomes more dependent on rare earth elements. Given the volatile, Chinese-concentrated supply chain, global attempts have been made to diversify supply of these materials. However, the overall effect of supply diversification on the entire supply chain, including increasing low-value rare earth demand, is not fully understood. This paper is the first attempt to shed some light on China’s supply chain from both demand and supply perspectives, taking into account different Chinese policies such as mining quotas, separation quotas, export quotas, and resource taxes. We constructedmore » a simulation model using Powersim Studio that analyzes production (both legal and illegal), production costs, Chinese and rest-of-world demand, and market dynamics. We also simulated new demand of an automotive aluminum-cerium alloy in the U.S. market starting from 2018. Results showed that market share of the illegal sector has grown since 2007 to 2015, ranging between 22% and 25% of China’s rare earth supply, translating into 59–65% illegal heavy rare earths and 14–16% illegal light rare earths. There would be a shortage in certain light and heavy rare earths given three production quota scenarios and constant demand growth rate from 2015 to 2030. The new simulated Ce demand would require supply beyond that produced in China. Lastly, we illustrated revenue streams for different ore compositions in China in 2015.« less

A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

PubMed

Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

2017-09-15

Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

China’s rare earth supply chain: Illegal production, and response to new cerium demand

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

Nguyen, Ruby Thuy; Imholte, D. Devin

As the demand for personal electronic devices, wind turbines, and electric vehicles increases, the world becomes more dependent on rare earth elements. Given the volatile, Chinese-concentrated supply chain, global attempts have been made to diversify supply of these materials. However, the overall effect of supply diversification on the entire supply chain, including increasing low-value rare earth demand, is not fully understood. This paper is the first attempt to shed some light on China’s supply chain from both demand and supply perspectives, taking into account different Chinese policies such as mining quotas, separation quotas, export quotas, and resource taxes. We constructedmore » a simulation model using Powersim Studio that analyzes production (both legal and illegal), production costs, Chinese and rest-of-world demand, and market dynamics. We also simulated new demand of an automotive aluminum-cerium alloy in the U.S. market starting from 2018. Results showed that market share of the illegal sector has grown since 2007 to 2015, ranging between 22% and 25% of China’s rare earth supply, translating into 59–65% illegal heavy rare earths and 14–16% illegal light rare earths. There would be a shortage in certain light and heavy rare earths given three production quota scenarios and constant demand growth rate from 2015 to 2030. The new simulated Ce demand would require supply beyond that produced in China. Lastly, we illustrated revenue streams for different ore compositions in China in 2015.« less

Methodology of clinical research in rare diseases: development of a research program in juvenile neuronal ceroid lipofuscinosis (JNCL) via creation of a patient registry and collaboration with patient advocates

PubMed Central

de Blieck, Elisabeth A.; Augustine, Erika F.; Marshall, Frederick J.; Adams, Heather; Cialone, Jennifer; Dure, Leon; Kwon, Jennifer M.; Newhouse, Nicole; Rose, Katherine; Rothberg, Paul G.; Vierhile, Amy; Mink, Jonathan W.

2013-01-01

Introduction Juvenile neuronal ceroid lipofuscinosis (JNCL; Batten disease) is a rare, inherited, fatal lysosomal storage childhood disorder. True for many rare diseases, there are no treatments that impact the course of JNCL. The University of Rochester Batten Center’s (URBC) mission is to find treatments to slow, halt, or prevent JNCL. Objectives Our initial objective was to develop clinical research infrastructure preparatory to clinical trials, establish a JNCL research cohort, construct a disease-specific clinical outcome measure, and validate a non-invasive diagnostic sampling method. The long-term objective is to design and implement JNCL clinical trials. Methods The Unified Batten Disease Rating Scale (UBDRS) was developed. The Batten Disease Support and Research Association (BDSRA) referred participants; annual BDSRA meetings provided a mobile research setting for registry enrollment and UBDRS piloting. Neuropsychological examinations were performed, enabling external validation of the UBDRS. Buccal epithelial cell collection for genotyping was introduced. Telemedicine for remote UBDRS assessment was piloted. Results The registry enrolled 198 families representing 237 children with NCL. The UBDRS was piloted, validated and has been used to collect natural history data from 120 subjects. Funding and regulatory approval were obtained for a recently launched phase II clinical trial. Several additional lines of inquiry were reported. Conclusion The registry and BDSRA collaboration have enabled development of a clinical rating scale, natural history and neuropsychological studies, and genetic studies for disease confirmation. This work highlights an approach for preparatory natural history research and infrastructure development needed to facilitate efficient implementation of clinical trials in rare diseases. PMID:23628560

Analysis of plant soil seed banks and seed dispersal vectors: Its potential and limits for forensic investigations.

PubMed

Šumberová, Kateřina; Ducháček, Michal

2017-01-01

Plant seeds exhibit many species-specific traits, thus potentially being especially helpful for forensic investigations. Seeds of a broad range of plant species occur in soil seed banks of various habitats and may become attached in large quantities to moving objects. Although plant seeds are now routinely used as trace evidence in forensic practice, only scant information has been published on this topic in the scientific literature. Thus, the standard methods remain unknown to specialists in such botanical subjects as plant ecology and plant geography. These specialists, if made aware of the forensic uses of seeds, could help in development of new, more sophisticated approaches. We aim to bridge the gap between forensic analysts and botanists. Therefore, we explore the available literature and compare it with our own experiences to reveal both the potential and limits of soil seed bank and seed dispersal analysis in forensic investigations. We demonstrate that habitat-specific and thus relatively rare species are of the greatest forensic value. Overall species composition, in terms of species presence/absence and relative abundance can also provide important information. In particular, the ecological profiles of seeds found on any moving object can help us identify the types of environments through which the object had travelled. We discuss the applicability of this approach to various European environments, with the ability to compare seed samples with georeferenced vegetation databases being particularly promising for forensic investigations. We also explore the forensic limitations of soil seed bank and seed dispersal vector analyses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

[The use of Facebook in Spanish associations of rare diseases: how and what is it used for?].

PubMed

Armayones, Manuel; Requena, Samantha; Gómez-Zúñiga, Beni; Pousada, Modesta; Bañón, Antonio M

2015-01-01

To study whether the use of Facebook is widespread in the field of patient associations for rare diseases and, if so, the purpose for which the site is being used. A descriptive study was conducted to determine whether associations within the Spanish Federation for Rare Diseases use Facebook and, if so, the type of use and its objectives. The analysis was performed based on a categorization system that has been used in the field of chronic diseases and has been adapted to the specific characteristics of rare diseases. Associations use Facebook to raise awareness of rare diseases in general and particularly to share content related to psychological, medical and social support, the promotion and dissemination of research, and fundraising. The alignment between the interests of associations through their presence on Facebook and policy areas of the national strategy for rare diseases is a reason for optimism about the feasibility of using Facebook as a tool for encounters and collaborative work. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Rare lung disease research: strategies for improving identification and recruitment of research participants.

PubMed

Gupta, Samir; Bayoumi, Ahmed M; Faughnan, Marie E

2011-11-01

Research in rare lung diseases faces methodologic limitations by virtue of the small number of participants available to be studied. We explored several strategies that may improve researchers' ability to identify and recruit research participants with rare lung diseases. We provide an overview of strategies based on available evidence, previously used approaches, and reasoning. First, disease detection is generally poor and may be improved through strategies targeted at primary care practitioners or directly at patients, thus increasing the pool of patients available for research studies. Next, standardization of case definitions in rare lung diseases is often lacking, hindering research recruitment efforts because of confusion over appropriate recruitment criteria. Expert consensus statements can enhance both clinical care and research recruitment by standardizing definitions. Finally, recruitment strategies using rare lung disease registries, clinical research networks, novel Internet-based direct patient recruitment approaches, and patient organizations may facilitate recruitment of patients with rare lung diseases. In summary, although several strategies for improving the identification and recruitment of research participants with rare lung diseases have been proposed, published examples are few. Objective measurement and reporting of novel recruitment methods and collaboration among researchers facing the same limitations across various rare lung diseases are required. Advancements in this area are vital to the design and performance of much-needed robust clinical studies across the spectrum of rare lung diseases.

Inventing Metagenres: How Four College Seniors Connect Writing across Domains

ERIC Educational Resources Information Center

Lindenman, Heather

2015-01-01

In this article, I challenge the scholarly consensus that suggests students only rarely forge meaningful connections between the genres they compose in different domains of writing (Reiff and Bawashi; Yancey, Robertson, and Taczak). I argue that the genre and domain categories composition researchers have imposed through data collection and…

Evaluation of rare Helianthus eggertii achenes for oil concentration and fatty acid composition

USDA-ARS?s Scientific Manuscript database

Sunflower (Helianthus annuus L.) oil has the potential to be improved for nutritional and industrial purposes through selection and breeding. The narrow genetic base of cultivated sunflower has been broadened by the infusion of genes from wild species, resulting in a continuous improvement in agrono...

Multi-objective optimization of composite structures. A review

NASA Astrophysics Data System (ADS)

Teters, G. A.; Kregers, A. F.

1996-05-01

Studies performed on the optimization of composite structures by coworkers of the Institute of Polymers Mechanics of the Latvian Academy of Sciences in recent years are reviewed. The possibility of controlling the geometry and anisotropy of laminar composite structures will make it possible to design articles that best satisfy the requirements established for them. Conflicting requirements such as maximum bearing capacity, minimum weight and/or cost, prescribed thermal conductivity and thermal expansion, etc. usually exist for optimal design. This results in the multi-objective compromise optimization of structures. Numerical methods have been developed for solution of problems of multi-objective optimization of composite structures; parameters of the structure of the reinforcement and the geometry of the design are assigned as controlling parameters. Programs designed to run on personal computers have been compiled for multi-objective optimization of the properties of composite materials, plates, and shells. Solutions are obtained for both linear and nonlinear models. The programs make it possible to establish the Pareto compromise region and special multicriterial solutions. The problem of the multi-objective optimization of the elastic moduli of a spatially reinforced fiberglass with stochastic stiffness parameters has been solved. The region of permissible solutions and the Pareto region have been found for the elastic moduli. The dimensions of the scatter ellipse have been determined for a multidimensional Gaussian probability distribution where correlation between the composite's properties being optimized are accounted for. Two types of problems involving the optimization of a laminar rectangular composite plate are considered: the plate is considered elastic and anisotropic in the first case, and viscoelastic properties are accounted for in the second. The angle of reinforcement and the relative amount of fibers in the longitudinal direction are controlling parameters. The optimized properties are the critical stresses, thermal conductivity, and thermal expansion. The properties of a plate are determined by the properties of the components in the composite, eight of which are stochastic. The region of multi-objective compromise solutions is presented, and the parameters of the scatter ellipses of the properties are given.

Vegetation associations in a rare community type - Coastal tallgrass prairie

USGS Publications Warehouse

Grace, James B.; Allain, Larry K.; Allen, Charles

2000-01-01

The coastal prairie ecoregion is located along the northwestern coastal plain of the Gulf of Mexico in North America. Because of agricultural and urban development, less than 1% of the original 3.4 million ha of this ecosystem type remains in native condition, making it one of the most endangered ecosystems in North America. The objective of this study was to characterize the vegetation and environmental relationships in a relatively pristine example of lowland coastal prairie in order to provide information for use in conservation and restoration. The study area was a small, isolated prairie located near the southern boundary of the coastal prairie region. Samples were taken along three parallel transects that spanned the prairie. Parameters measured included species composition, elevation, soil characteristics, indications of recent disturbance, above-ground biomass, and light penetration through the plant canopy. Fifty-four species were found in the 107 0.25-m2 plots and a total of 96 species were found at the site. Only two non-native species occurred in sample plots, both of which were uncommon. Cluster analysis was used to identify six vegetation groups, which were primarily dominated by members of the Poaceae or Asteraceae. A conspicuous, natural edaphic feature of the prairie was the presence of 'mima' mounds, which are raised areas approximately 0.5 to 1 m high and 5 to 10 m across. Indicator species analysis revealed a significant number of species that were largely restricted to mounds and these were predominately upland and colonizing species. Ordination was performed using nonmetric, multidimensional scaling. The dominant environmental influence on species composition was found to be elevation and a host of correlated factors including those associated with soil organic content. A secondary group of factors, consisting primarily of soil cations, was found to explain additional variance among plots. Overall, this prairie was found to contain plant associations that are now rare in the surrounding landscape. Within the prairie, plant groups were largely separated by a suite of environmental conditions associated with topography. These results suggest that conservation and restoration efforts will need to carefully consider local topographic influences in order to be successful.

Guide to Academic Research Career Development

PubMed Central

Smith, Richard J.; Graboyes, Evan M.; Paniello, Randal C.; Paul Gubbels, Samuel

2016-01-01

Objectives/Hypothesis Development of an academic career easily follows a clinical course for which there are multiple role models; however, development of an academic research career involves few role models, and rarely do instructional guides reach out to the new faculty. The purpose of this article is to present the cumulative experiences of previously and currently funded authors to serve as a guide to young as well as older faculty for developing their research careers. Study Design Cumulative experiences of research‐dedicated faculty. Methods This article is the result of lessons learned from developing a Triological Society National Physician‐Scientist Program and Network, as well as the cumulative experiences of the authors. Results Table I illustrates key elements in developing a serious research career. Table II records the career courses of five surgeon‐scientists, highlighting the continued theme focus with theme‐specific publications and progressive grants. These cumulative experiences have face validity but have not been objectively tested. The value added is a composite of 50 years of experiences from authors committed to research career development for themselves and others. Conclusion Crucial elements in developing a research career are a desire for and commitment to high‐quality research, a focus on an overall theme of progressive hypothesis‐driven investigations, research guidance, a willingness to spend the time required, and an ability to learn from and withstand failure. Level of Evidence 5. PMID:28894799

A retrospective analysis of pollen host plant use by stable and declining bumble bee species.

PubMed

Kleijn, David; Raemakers, Ivo

2008-07-01

Understanding population declines has been the objective of a wide range of ecological studies. When species have become rare such studies are complicated because particular behavior or life history traits may be the cause but also the result of the decline of a species. We approached this problem by studying species' characteristics on specimens that were collected before the onset of their decline and preserved in natural history museums. In northwestern Europe, some bumble bee species declined dramatically during the 20th century whereas other, ecologically similar, species maintained stable populations. A long-standing debate focuses on whether this is caused by declining species having stricter host plant preferences. We compared the composition of pollen loads of five bumble bee species with stable populations and five with declining populations using museum specimens collected before 1950 in Belgium, England, and The Netherlands. Prior to 1950, the number of plant taxa in pollen loads of declining species was almost one-third lower than that in stable species even though individuals of stable and declining species generally originated from the same areas. There were no systematic differences in the composition of pollen loads between stable and declining species, but the plant taxa preferred by declining species before 1950 had experienced a stronger decline in the 20th century than those preferred by stable species. In 2004 and 2005, we surveyed the areas where bumble bees had been caught in the past and compared the composition of past and present pollen loads of the stable, but not of the by now locally extinct declining species. The number of collected pollen taxa was similar, but the composition differed significantly between the two periods. Differences in composition reflected the major changes in land use in northwestern Europe but also the spread of the invasive plant species Impatiens glandulifera. The main question now is why declining species apparently were not able to switch to less preferred food plants when stable species were. This study shows that natural history collections can play an important role in improving our understanding of the ecological mechanisms driving species population change.

Impact of rare diseases in oral health

PubMed Central

Molina-García, Ana; Castellanos-Cosano, Lizett; Posada-de la Paz, Manuel

2016-01-01

Background Rare diseases (RD) are those that present a lower prevalence than 5 cases per 10.000 population. The main objective of this review was to study the effect on oral health in rare diseases, while the secondary objective of the study is theme upgrade. Material and Methods Comparative observational case-control studies were analysed and a systematic review was conducted in PubMed. Each rare disease listed on the statistical data record of the Health Portal of the Ministry of Equality, Health and Social Policies Board of Andalusia was associated with “oral health”. The variables studied included dental, oral mucosa and occlusion alterations, oral pathologies (caries, periodontal disease) and other alterations (mouth breathing, parafunctional habits, etc). A bias analysis of the variable caries was conducted. Results Six RD were selected through our inclusion and exclusion criteria (hypogammaglobulinemia, Rett syndrome, Marfan syndrome, Prader-Willi syndrome, cystic fibrosis and Cri du chat syndrome) in a total of 8 publications, of which four trials were classified as high risk of bias and one of them as medium risk. There were not trials with low risk of bias. Conclusions The main statistically significant differences found by Syndrome compared to a control group were in Hypogammaglobulinemia with a greater tendency to enamel hypoplasia and dry mouth. The Rett syndrome had, as well, a greater tendency to an anterior open bite, ogival palate, bruxism, mouth breathing and tongue thrusting. Prader-Willi syndrome had a tendency of dental erosion, and Cri du chat syndrome showed a higher association to Tannerella forsythia. Key words:Rare diseases, oral health. PMID:27475682

Lunar atmosphere. How surface composition and meteoroid impacts mediate sodium and potassium in the lunar exosphere.

PubMed

Colaprete, A; Sarantos, M; Wooden, D H; Stubbs, T J; Cook, A M; Shirley, M

2016-01-15

Despite being trace constituents of the lunar exosphere, sodium and potassium are the most readily observed species due to their bright line emission. Measurements of these species by the Ultraviolet and Visible Spectrometer (UVS) on the Lunar Atmosphere and Dust Environment Explorer (LADEE) have revealed unambiguous temporal and spatial variations indicative of a strong role for meteoroid bombardment and surface composition in determining the composition and local time dependence of the Moon's exosphere. Observations show distinct lunar day (monthly) cycles for both species as well as an annual cycle for sodium. The first continuous measurements for potassium show a more repeatable variation across lunations and an enhancement over KREEP (Potassium Rare Earth Elements and Phosphorus) surface regions, revealing a strong dependence on surface composition. Copyright © 2016, American Association for the Advancement of Science.

Development of Tandem, Double-Focusing, Electron Impact, Gas Source Mass Spectrometer for Measurement of Rare Double-Substituted Isotoplogues in Geochemistry

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

Young, Edward D.

This project culminated in construction and delivery of the world’s first large-radius gas-source isotope ratio mass spectrometer that permits unparalleled analyses of the stable isotopic composition of methane gas. The instrument, referred to as the “Panorama” and installed at UCLA in March 2015, can now be used to determine the relative abundances of rare isotopic species of methane that serve as tracers of temperature of formation and/or subsequent processing of gas. With this technology we can begin to delineate different sources and sinks of methane isotopically in ways not possible until now.

Rare gases and Ca, Sr, and Ba in Apollo 17 drill-core fines

NASA Technical Reports Server (NTRS)

Pepin, R. O.; Dragon, J. C.; Johnson, N. L.; Bates, A.; Coscio, M. R., Jr.; Murthy, V. R.

1975-01-01

Trapped gas isotopic compositions and spallation gas concentrations as functions of depth in the Apollo 17 drill core were determined from mass spectrometer studies by means of correlation techniques. The distribution of He, Ne, Ar, Kr, and Xe as well as Ca, Sr, and Ba was investigated, and rare-gas spallation and neutron capture profiles are compared with attention to proposed depositional models for the Taurus-Littrow regolith. The data exclude a sedimentation pattern similar to that found at the Apollo 15 site but are possibly compatible with long-term continuous accretion models or models of very recent rapid accumulation of regolith.

Rare earth doped zinc oxide varistors

DOEpatents

McMillan, A.D.; Modine, F.A.; Lauf, R.J.; Alim, M.A.; Mahan, G.D.; Bartkowiak, M.

1998-12-29

A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2--4.0% oxide of at least one rare earth element, 0.5--4.0% Co{sub 3}O{sub 4}, 0.05--0.4% K{sub 2}O, 0.05--0.2% Cr{sub 2}O{sub 3}, 0--0.2% CaO, 0.00005--0.01% Al{sub 2}O{sub 3}, 0--2% MnO, 0--0.05% MgO, 0--0.5% TiO{sub 3}, 0--0.2% SnO{sub 2}, 0--0.02% B{sub 2}O{sub 3}, balance ZnO. 4 figs.

Rare isotope studies involving catalytic oxidation of CO over platinum-tin oxide

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Wood, George M., Jr.; Hess, Robert V.; Hoyt, Ronald F.

1987-01-01

Results of studies utilizing normal and rare oxygen isotopes in the catalytic oxidation of carbon monoxide over a platinum-tin oxide catalyst substrate are presented. Chemisorption of labeled carbon monoxide on the catalyst followed by thermal desorption yielded a carbon dioxide product with an oxygen-18 composition consistent with the formation of a carbonate-like intermediate in the chemisorption process. The efficacy of a method developed for the oxygen-18 labeling of the platinum-tin oxide catalyst surface for use in closed cycle pulsed care isotope carbon dioxide lasers is demonstrated for the equivalent of 10 to the 6th power pulses at 10 pulses per second.

Rare earth doped zinc oxide varistors

DOEpatents

McMillan, April D.; Modine, Frank A.; Lauf, Robert J.; Alim, Mohammad A.; Mahan, Gerald D.; Bartkowiak, Miroslaw

1998-01-01

A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2-4.0% oxide of at least one rare earth element, 0.5-4.0% Co.sub.3 O.sub.4, 0.05-0.4% K.sub.2 O, 0.05-0.2% Cr.sub.2 O.sub.3, 0-0.2% CaO, 0.00005-0.01% Al.sub.2 O.sub.3, 0-2% MnO, 0-0.05% MgO, 0-0.5% TiO.sub.3, 0-0.2% SnO.sub.2, 0-0.02% B.sub.2 O.sub.3, balance ZnO.

[Study on species and distribution of flora of national rare and endangered medicinal plant in the Three Gorges area].

PubMed

Chen, Shao-Cheng

2013-04-01

According to the China Plant Red Data Book and National Key Protected Wild Plants, the distribution of the rare and endangered plants and national conservative plants in the Three Gorges area were investigated and statistically analyzed. Its floristic composition and characteristics of geographical distribution were explored. As a result, a total of 97 species of medicinal flora belonging to rare and endangered national protection plants were found in the Three Gorges area. They come from 81 genera of 46 families. Their vertical distribution is obvious and horizontal distribution has discontinuous overlap. There are many ancient relict medicinal plants in the Three Gorges area. These medicinal plants have obvious temperate characteristics, and are easily found at warm and moist ravines and hillsides; The proportion of tree is much higher than that of herb, vine, shrub and fern. Most of them belong to specific and monotypic genera.

Extraction processes and solvents for recovery of cesium, strontium, rare earth elements, technetium and actinides from liquid radioactive waste

DOEpatents

Zaitsev, Boris N.; Esimantovskiy, Vyacheslav M.; Lazarev, Leonard N.; Dzekun, Evgeniy G.; Romanovskiy, Valeriy N.; Todd, Terry A.; Brewer, Ken N.; Herbst, Ronald S.; Law, Jack D.

2001-01-01

Cesium and strontium are extracted from aqueous acidic radioactive waste containing rare earth elements, technetium and actinides, by contacting the waste with a composition of a complex organoboron compound and polyethylene glycol in an organofluorine diluent mixture. In a preferred embodiment the complex organoboron compound is chlorinated cobalt dicarbollide, the polyethylene glycol has the formula RC.sub.6 H.sub.4 (OCH.sub.2 CH.sub.2).sub.n OH, and the organofluorine diluent is a mixture of bis-tetrafluoropropyl ether of diethylene glycol with at least one of bis-tetrafluoropropyl ether of ethylene glycol and bis-tetrafluoropropyl formal. The rare earths, technetium and the actinides (especially uranium, plutonium and americium), are extracted from the aqueous phase using a phosphine oxide in a hydrocarbon diluent, and reextracted from the resulting organic phase into an aqueous phase by using a suitable strip reagent.

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

Prodius, D.; Smetana, V.; Steinberg, S.

A family of bis(trifluoromethanesulfonyl)amide-based ionic liquids of composition [RE 5(C 2H 5-C 3H 3N 2-CH 2COO) 16(H 2O) 8](Tf 2N) 15 (RE = Er, Ho, Tm; C 3H 3N 2 ≡ imidazolium moiety) featuring the cationic, record quindecim {15+} charged pentanuclear rare earth (RE)-containing ion [RE 5(C 2H 5-C 3H 3N 2-CH 2COO) 16(H 2O) 8] 15+ has been synthesized and characterized. In addition, due to the presence of rare earth ions, these ionic liquids show a response to magnetic fields with the highest effective magnetic moment observed so far for an ionic liquid and are rare examples of ionicmore » liquids showing luminescence in the near-infrared. As a result, these ionic liquids also were successfully employed in a three-component synthesis of 2-pyrrolo-3'-yloxindole with an extremely low (<0.035 mol%) catalyst loading rate.« less

Rare earth-doped lead borate glasses and transparent glass-ceramics: structure-property relationship.

PubMed

Pisarski, W A; Pisarska, J; Mączka, M; Lisiecki, R; Grobelny, Ł; Goryczka, T; Dominiak-Dzik, G; Ryba-Romanowski, W

2011-08-15

Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu(3+) and Er(3+) ions. The observed BO(3)↔BO(4) conversion strongly depends on the relative PbO/B(2)O(3) ratios in glass composition, giving important contribution to the luminescence intensities associated to (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+). The near-infrared luminescence and up-conversion spectra for Er(3+) ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er(3+) ions into the orthorhombic PbF(2) crystalline phase, which was identified using X-ray diffraction analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

A study on the utilization of advanced composites in commercial aircraft wing structure: Executive summary

NASA Technical Reports Server (NTRS)

Watts, D. J.

1978-01-01

The overall wing study objectives are to study and plan the effort by commercial transport aircraft manufacturers to accomplish the transition from current conventional materials and practices to extensive use of advanced composites in wings of aircraft that will enter service in the 1985-1990 time period. Specific wing study objectives are to define the technology and data needed to support an aircraft manufacturer's commitment to utilize composites primary wing structure in future production aircraft and to develop plans for a composite wing technology program which will provide the needed technology and data.

Nanoporous carbon actuator and methods of use thereof

DOEpatents

Biener, Juergen [San Leandro, CA; Baumann, Theodore F [Discovery Bay, CA; Shao, Lihua [Karlsruhe, DE; Weissmueller, Joerg [Stutensee, DE

2012-07-31

An electrochemically driveable actuator according to one embodiment includes a nanoporous carbon aerogel composition capable of exhibiting charge-induced reversible strain when wetted by an electrolyte and a voltage is applied thereto. An electrochemically driven actuator according to another embodiment includes a nanoporous carbon aerogel composition wetted by an electrolyte; and a mechanism for causing charge-induced reversible strain of the composition. A method for electrochemically actuating an object according to one embodiment includes causing charge-induced reversible strain of a nanoporous carbon aerogel composition wetted with an electrolyte to actuate the object by the strain.

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

Charkin, Dmitri O.; Black, Cameron; Downie, Lewis J.

Two new rare-earth – alkali – tellurium oxide halides were synthesized by a salt flux technique and characterized by single-crystal X-ray diffraction. The structures of the new compounds Cs{sub 7}Sm{sub 11}[TeO{sub 3}]{sub 12}Cl{sub 16} (I) and Rb{sub 7}Nd{sub 11}[TeO{sub 3}]{sub 12}Br{sub 16} (II) (both tetragonal, space group I4/mcm) correspond to the sequence of [MLn{sub 11}(TeO{sub 3}){sub 12}] and [M{sub 6}X{sub 16}] layers and bear very strong similarities to those of known selenite analogs. We discuss the trends in similarities and differences in compositions and structural details between the Se and Te compounds; more members of the family are predicted. -more » Graphical abstract: Two new rare-earth – alkali – tellurium oxide halides were predicted and synthesized. - Highlights: • Two new rare-earth – alkali – tellurium oxide halides were synthesized. • They adopt slab structure of rare earth-tellurium-oxygen and CsCl-like slabs. • The Br-based CsCl-like slabs have been observed first in this layered family.« less

Exposure histories of lunar rocks 71135 and 71569

NASA Technical Reports Server (NTRS)

Niemeyer, S.

1977-01-01

Rare-gas isotopic analyses have been performed on lunar rocks 71135 and 71569. The conventional (Kr-81)-Kr cosmic-ray exposure ages are 103 + or - 3 m.y. for 71135 and 134 + or - 7 m.y. for 71569. An approach is outlined to deducing complex exposure histories from rare-gas data using depth profiles of the production rates of the cosmogenic rare-gas isotopes. Examination of the Xe isotopes by means of a 'concordia' plot suggests that 71569 may have a simple one-stage exposure history whereas 71135 has a more complex history. An attempt is made to construct exposure models for these two rocks which account for the abundances of all the cosmogenic rare gases, the Xe isotopic compositions, and the apparent (Kr-81)-Kr exposure ages. This study demonstrates the depreciation of (Kr-81)-Kr ages for rocks exposed at shallow depths, caused by the relatively rapid variation of the Kr-81 production as the rock is eroded. Possible implications of the tentative results for the formation age of the Central Cluster unit are discussed.

Granitoids of different geodynamic settings of Baikal region (Russia) their geochemical evolution and origin

NASA Astrophysics Data System (ADS)

Antipin, Viktor; Sheptyakova, Natalia

2016-04-01

In the southern folded framing of the Siberian craton the granitoid magmatism of different ages involves batholiths, small low-depth intrusions and intrusion-dyke belts with diverse mineral and geochemical characteristics of rocks. Granitoid formation could be related to the Early Paleozoic collision stage and intra-plate magmatism of the Late Paleozoic age of the geologic development of Baikal area. The Early Paleozoic granitoids of Khamar-Daban Ridge and Olkhon region revealed their closeness in age and composition. They were referred to syncollision S-type formations derived from gneiss-schistose substratum of metamorphic sequences. The magmatic rocks were classified into various geochemical types comprising formations of normal Na-alkalinity (migmatites and plagiogranites), calc-alkaline and subalkaline (K-Na granitoids, granosyenites and quartz syenites) series. It is significant, that plagiomigmatites and plagiogranites in all elements repeat the shape of the chart of normalized contents marked for trend of K-Na granitoids, but at considerably lower level of concentrations of all elements. This general pattern of element distribution might indicate similar anatectic origin of both granitoid types, but from crustal substrata distinguished by composition and geochemical features. Comparative geochemical analysis pointed out that the source of melts of the Early Paleozoic granitoids of the Olkhon (505-477 Ma) and Khamar-Daban (516-490 Ma) complexes of the Baikal region could be the crustal substratum, which is obviously the criterion for their formation in the collisional geodynamic setting. Using the Late Paleozoic subalkaline magmatism proceeding at the Khamar-Daban Range (Khonzurtay pluton, 331 Ma) as an example, it was found that the formation of monzodiorite-syenite-leucogranite series was considerably contributed by the processes of hybridism and assimilation through mixing of the upper mantle basaltoid magma derived melts of granitic composition. The involvement of the deep source is indicated by low Rb/Sr ratios and 87Sr/86Sr ratio (0.70592±0.00021) in rocks (Kazimirovskiy, 2006). The intra-plate biotite granites and leucogranites are represented by rare-metal geochemical type of rocks (311-321 Ma). Geochemical evolution promoted an increase of F, Li, Rb, Cs, Sn, Be, Ta, and Pb and a decrease of Ba, Sr, Zn, Zr, Th, and U contents in rare-metal granites, that reflects their formation from deeply differentiated residual magma. The substance of the lower crust could have the composition of biotite-bearing granulites rich in lithophyle rare elements. It is noteworthy, that the composition and isotope-geochemical features of the supposed magma-forming substratum correspond to the characteristics of the ancient Precambrian continental crust of the Southern Baikal region. These conclusions agree with the results of preceding studies of rare-metal granites in the other regions of Central Asia (Kovalenko et al, 1999). Research has been supported by RNF grant № 15-17-10010.

Contact in an Expanding Universe: An Instructive Exercise in Dynamic Geometry

ERIC Educational Resources Information Center

Zimmerman, Seth

2010-01-01

The particular problem solved in this paper is that of calculating the time required to overtake a distant object receding under cosmic expansion, and the speed at which that object is passed. This is a rarely investigated problem leading to some interesting apparent paradoxes. We employ the problem to promote a deeper understanding of the dynamic…

Gravitational Lensing by Clusters of Galaxies

NASA Astrophysics Data System (ADS)

Tyson, J.; Murdin, P.

2000-11-01

CLUSTERS OF GALAXIES are massive and relatively rare objects containing hundreds of galaxies. Their huge mass—dominated by DARK MATTER—bends light from all background objects, systematically distorting the images of thousands of distant galaxies (shear). This observed gravitational lens distortion can be inverted to produce an `image' of the mass in the foreground cluster of galaxies. Most of the...

Education and Coronary Heart Disease Risk: Potential Mechanisms Such as Literacy, Perceived Constraints, and Depressive Symptoms

ERIC Educational Resources Information Center

Loucks, Eric B.; Gilman, Stephen E.; Howe, Chanelle J.; Kawachi, Ichiro; Kubzansky, Laura D.; Rudd, Rima E.; Martin, Laurie T.; Nandi, Arijit; Wilhelm, Aude; Buka, Stephen L.

2015-01-01

Objective: Education is inversely associated with coronary heart disease (CHD) risk; however the mechanisms are poorly understood. The study objectives were to evaluate the extent to which rarely measured factors (literacy, time preference, sense of control) and more commonly measured factors (income, depressive symptomatology, body mass index) in…

Integrating the Epistemic and Ontological Aspects of Content Knowledge in Science Teaching and Learning

ERIC Educational Resources Information Center

Papadouris, Nicos; Constantinou, Constantinos P.

2017-01-01

Promoting facility with content knowledge is one of the most important objectives of science teaching. Conventionally, the focus for this objective is placed on the substantive side of content knowledge (e.g. science concepts/laws), whereas its epistemic or ontological aspects (e.g. why do we construct concepts?) rarely receive explicit attention.…

Earth-approaching asteroids: Populations, origin, and compositional types

NASA Technical Reports Server (NTRS)

Shoemaker, E. M.; Helin, E. F.

1978-01-01

Origin, physical properties, and discovery history of smaller asteroids are reviewed. They appear to link the main belt objects, namely the comets and meteorites. Physical observations suggest that a wide variety of compositional types are represented among the near-earth asteroids; the apparent rarity of carbonaceous objects is stated.

Acquisition and Early Losses of Rare Gases from the Deep Earth

NASA Technical Reports Server (NTRS)

Porcelli, D.; Cassen, P.; Woolum, D.; Wasserburg, G. J.

1998-01-01

Direct observations show that the deep Earth contains rare gases of solar composition distinct from those in the atmosphere. We examine the implications of mantle rare gas characteristics on acquisition of rare gases from the solar nebula and subsequent losses due to a large impact. Deep mantle rare gas concentrations and isotopic compositions can be obtained from a model of transport and distribution of mantle rare gases. This model assumes the lower mantle closed early, while the upper mantle is open to subduction from the atmosphere and mass transfer from the lower mantle. Constraints are derived that can be incorporated into models for terrestrial volatile acquisition: (1) Calculated lower-mantle Xe-isotopic ratios indicate that the fraction of radiogenic Xe produced by I-129 and Pu-244 during the first about 10(exp 8) yr was lost, a conclusion also drawn for atmospheric Xe. Thus, either the Earth was made from materials that had lost >99% of rare gases about (0.7-2) x 10(exp 8) yr after the solar system formed, or gases were then lost from the fully formed Earth. (2) Concentrations of 3He and 20Ne in the lower mantle were established after these losses. (3) Neon-isotopic data indicates that mantle Ne has solar composition. The model allows for solar Ar/Ne and Xe/Ne in the lower mantle if a dominant fraction of upper mantle Ar and Xe are subduction-derived. If Earth formed in the presence of the solar nebula, it could have been melted by accretional energy and the blanketing effect of a massive, nebula-derived atmosphere. Gases from this atmosphere would have been sequestered within the molten Earth by dissolution at the surface and downward mixing. It was found that too much Ne would be dissolved in the Earth unless the atmosphere began to escape when the Earth was only partially assembled. Here we consider conditions required to initially dissolve sufficient rare gases to account for the present lower mantle concentrations after subsequent losses at 10(exp 8) yr. It is assumed that equilibration of the atmosphere with a thoroughly molten mantle was rapid, so that initial abundances of gases retained in any mantle layer reflected surface conditions when the layer solidified. For subsequent gas loss of 99.5% and typical solubility coefficients, a total pressure of 100 atm was required for an atmosphere of solar composition. Calculations of the pressure at the base of a primordial atmosphere indicate that this value might be exceeded by an order of magnitude or more for an atmosphere supported by accretional energy. Surface temperatures of about 4000 K would have been produced, probably high enough to melt the deep mantle. Initial distributions of retained rare gases would then be determined by the history of surface pressure and temperature during mantle cooling and solidification, i.e., the coupled cooling of Earth and atmosphere. The Earth's thermal state was determined by its surface temperature and the efficiency of convection in the molten mantle, estimated to be sufficient to maintain an adiabatic gradient. Because the melting curve is steeper than the adiabat, solidification of the mantle proceeded outward from the interior. Incorporation of atmospheric gases in the mantle therefore occurred over a range in surface temperature of a few thousand degrees Kelvin. The thermal state of the atmosphere was controlled by total luminosity of the Earth (energy) released by accreting planetesimals and the cooling Earth), nebular temperature and pressure, and atmospheric opacity. The energy released by accretion declined with time as did nebular pressure. Analytical solutions for an idealized (constant opacity radiative atmosphere show that declining energy sources under constant nebular conditions result in slowly diminishing surface temperature but dramatically increasing surface pressure. For such an atmosphere with declining nebular pressure but constant total luminosity, surface pressure decreases gradually with decreasing temperaure. A decline in accretion luminosity might be compensated by energy released as the mantle cools for about 10(exp 5) year, after which luminosity must decline. The total complement of dissolved rare gases will depend on the particular evolutionary path determined by the declining accretional luminosity, the Earth thermal history, removal of the nebula, and opacity variations of the atmosphere. Models for these coupled evolutionary histories for Earth's acquisition of nebular-derived noble gases are in progress. The later losses required at about 10(exp 8) yr (depleting the interior concentrations of the sequestered solar gases by a factor of > 100) were presumably related to the major impact in which the Moon formed.

Final Report - Enhanced LAW Glass Property - Composition Models - Phase 1 VSL-13R2940-1, Rev. 0, dated 9/27/2013

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

Kruger, Albert A.; Muller, I.; Gilbo, K.

2013-11-13

The objectives of this work are aimed at the development of enhanced LAW propertycomposition models that expand the composition region covered by the models. The models of interest include PCT, VHT, viscosity and electrical conductivity. This is planned as a multi-year effort that will be performed in phases with the objectives listed below for the current phase.  Incorporate property- composition data from the new glasses into the database.  Assess the database and identify composition spaces in the database that need augmentation.  Develop statistically-designed composition matrices to cover the composition regions identified in the above analysis.  Preparemore » crucible melts of glass compositions from the statistically-designed composition matrix and measure the properties of interest.  Incorporate the above property-composition data into the database.  Assess existing models against the complete dataset and, as necessary, start development of new models.« less

Fe-U-PGE-Au-Ag-Cu Deposits of the Udokan-Chiney Region (East Siberia, Russia)

NASA Astrophysics Data System (ADS)

Gongalskiy, B.; Krivolutskaya, N.; Murashov, K.; Nistratov, S.; Gryazev, S.

2012-04-01

Introduction. Cupriferous sandstones-shales and magmatic copper-nickel deposits mark out the western and southern boundaries of the Siberian Craton accordingly. Of special interest are the Paleoproterozoic deposits of the Udokan-Chiney mining district (Gongalskiy, Krivolutskaya, 2008). Copper reserves and resources of this region are estimated at more than 50 Mt. Half of them is concentrated at the unique Udokan Deposit and the second half is distributed among sedimentary (Unkur, Pravoingamakitskoye, Sakinskoye, Krasnoye, Burpala) and magmatic deposits of the Chiney (Rudnoye, Verkhnechineyskoye, Kontaktovoye), Luktur and Maylav massifs. Results. It was established that the ores are characterized by similarity in chemical composition (main, major and rare elements that are Ag, Au, PGE) and mineral assemblages with varying proportions. It is important to emphasize that Fe role in mineralization was previously ignored. Meanwhile the Udokan deposit contains 10 Mt of magnetite metacrystals so as chalcocite ores may contain up to 50% magnetite too. It has been recently found that the Chiney titanomagnetite ores comprise commercially significant uranium and rare-earth metal concentrations (Makaryev et al., 2011). Thus the Udokan-Chiney region comprises Cu, Fe, Ti, V, U, REE, Ag, Au, PGE. These deposits differ from similar objects, the Olympic Dam in particular, by a much smaller content of fluid-bearing minerals. Copper mineralization at the Udokan is represented by chalcocite-bornite ores. They occur as ore beds conformable with sedimentary structures or as cross-cutting veins. The central zones of the former are often brecciated. They are rimmed by fine magnetite, bornite, and chalcocite dissemination. Bornite-chalcopyrite and chalcopyrite-pyrite veins are known at the lower levels of the Udokan ore bed. Such ore compositions are predominant in other ore deposits in sedimentary rocks (Pravoingamakitskoye, Unkur) and have a hydrothermal origin. Silver grades are up to 370 g/t in grab samples (Gongalskiy et al., 2008a). The long-lived Udokan-Chiney ore-magmatic has small areal extent of explosive rocks and breccias (n*10 m) with massive sulfide veins (chalcopyrite, pyrrhotite) which are similar to Sudbury offset dikes. While the same vertical zones at the Rudnoye deposit have been confirmed over 0.5 km downward from the lower contact of the Chiney massif. Conclusions. Multielement and similar mineralogical composition ores of different deposits in the Udokan-Chiney area reflect long evolution of ore processes in very movable block of the crust. Observed combination of magmatic, sedimentary and partially hydrothermal deposits is a result of the telescoping of a wide range of metals into a limited area.

CoMiniGut-a small volume in vitro colon model for the screening of gut microbial fermentation processes.

PubMed

Wiese, Maria; Khakimov, Bekzod; Nielsen, Sebastian; Sørensen, Helena; van den Berg, Frans; Nielsen, Dennis Sandris

2018-01-01

Driven by the growing recognition of the influence of the gut microbiota (GM) on human health and disease, there is a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this purpose. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increased throughput, we have developed a prototype in vitro parallel gut microbial fermentation screening tool with a working volume of only 5 ml consisting of five parallel reactor units that can be expanded with multiples of five to increase throughput. This allows e.g., the investigation of interpersonal variations in gut microbial dynamics and the acquisition of larger data sets with enhanced statistical inference. The functionality of the in vitro colon model, Copenhagen MiniGut (CoMiniGut) was first demonstrated in experiments with two common prebiotics using the oligosaccharide inulin and the disaccharide lactulose at 1% (w/v). We then investigated fermentation of the scarce and expensive human milk oligosaccharides (HMOs) 3-Fucosyllactose, 3-Sialyllactose, 6-Sialyllactose and the more common Fructooligosaccharide in fermentations with infant gut microbial communities. Investigations of microbial community composition dynamics in the CoMiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing showed excellent experimental reproducibility and allowed us to extract significant differences in gut microbial composition after 24 h of fermentation for all investigated substrates and fecal donors. Furthermore, short chain fatty acids (SCFAs) were quantified for all treatments and donors. Fermentations with inulin and lactulose showed that inulin leads to a microbiota dominated by obligate anaerobes, with high relative abundance of Bacteroidetes, while the more easily fermented lactulose leads to higher relative abundance of Proteobacteria. The subsequent study on the influence of HMOs on two infant GM communities, revealed the strongest bifidogenic effect for 3'SL for both infants. Inter-individual differences of infant GM, especially with regards to the occurrence of Bacteroidetes and differences in bifidobacterial species composition, correlated with varying degrees of HMO utilization foremost of 6'SL and 3'FL, indicating species and strain related differences in HMO utilization which was also reflected in SCFAs concentrations, with 3'SL and 6'SL resulting in significantly higher butyrate production compared to 3'FL. In conclusion, the increased throughput of CoMiniGut strengthens experimental conclusions through elimination of statistical interferences originating from low number of repetitions. Its small working volume moreover allows the investigation of rare and expensive bioactives.

Integrating microbial diversity in soil carbon dynamic models parameters

NASA Astrophysics Data System (ADS)

Louis, Benjamin; Menasseri-Aubry, Safya; Leterme, Philippe; Maron, Pierre-Alain; Viaud, Valérie

2015-04-01

Faced with the numerous concerns about soil carbon dynamic, a large quantity of carbon dynamic models has been developed during the last century. These models are mainly in the form of deterministic compartment models with carbon fluxes between compartments represented by ordinary differential equations. Nowadays, lots of them consider the microbial biomass as a compartment of the soil organic matter (carbon quantity). But the amount of microbial carbon is rarely used in the differential equations of the models as a limiting factor. Additionally, microbial diversity and community composition are mostly missing, although last advances in soil microbial analytical methods during the two past decades have shown that these characteristics play also a significant role in soil carbon dynamic. As soil microorganisms are essential drivers of soil carbon dynamic, the question about explicitly integrating their role have become a key issue in soil carbon dynamic models development. Some interesting attempts can be found and are dominated by the incorporation of several compartments of different groups of microbial biomass in terms of functional traits and/or biogeochemical compositions to integrate microbial diversity. However, these models are basically heuristic models in the sense that they are used to test hypotheses through simulations. They have rarely been confronted to real data and thus cannot be used to predict realistic situations. The objective of this work was to empirically integrate microbial diversity in a simple model of carbon dynamic through statistical modelling of the model parameters. This work is based on available experimental results coming from a French National Research Agency program called DIMIMOS. Briefly, 13C-labelled wheat residue has been incorporated into soils with different pedological characteristics and land use history. Then, the soils have been incubated during 104 days and labelled and non-labelled CO2 fluxes have been measured at ten sampling time in order to follow the dynamic of residue and soil organic matter mineralization. Diversity, structure and composition of microbial communities have been characterized before incubation time. The dynamic of carbon fluxes through CO2 emissions has been modelled through a simple model. Using statistical tools, relations between parameters of the model and microbial diversity indexes and/or pedological characteristics have been developed and integrated to the model. First results show that global diversity has an impact on the models parameters. Moreover, larger fungi diversity seems to lead to larger parameters representing decomposition rates and/or carbon use efficiencies than bacterial diversity. Classically, pedological factors such as soil pH and texture must also be taken into account.

Hydrodynamic Modeling of the Deep Impact Mission into Comet Tempel 1

NASA Astrophysics Data System (ADS)

Sorli, Kya; Remington, Tané; Bruck Syal, Megan

2018-01-01

Kinetic impact is one of the primary strategies to deflect hazardous objects off of an Earth-impacting trajectory. The only test of a small-body impact is the 2005 Deep Impact mission into comet Tempel 1, where a 366-kg mass impactor collided at ~10 km/s into the comet, liberating an enormous amount of vapor and ejecta. Code comparisons with observations of the event represent an important source of new information about the initial conditions of small bodies and an extraordinary opportunity to test our simulation capabilities on a rare, full-scale experiment. Using the Adaptive Smoothed Particle Hydrodynamics (ASPH) code, Spheral, we explore how variations in target material properties such as strength, composition, porosity, and layering affect impact results, in order to best match the observed crater size and ejecta evolution. Benchmarking against this unique small-body experiment provides an enhanced understanding of our ability to simulate asteroid or comet response to future deflection missions. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-739336-DRAFT.

The Detection of Collisional and Scattering Processes in the Asteroid-Meteoroid Continuum

NASA Astrophysics Data System (ADS)

Lai, H. R.; Connos, M. A.; Russell, C. T.; Wei, H. Y.

2014-04-01

Optical and radar observations have enabled the compilation of a useful inventory of near-Earth objects down to a diameter of approximately 500m, but at smaller diameters the catalogue is sparse. This is unacceptable for several reasons. First, the most hazardous size range based on damage per impact on Earth times expected impact rate is near 50m and second, we do not know if either the spatial distribution of objects or their behavior is similar to that of the larger objects. We have reason to believe they are importantly different. Near Earth Objects evolve due to collisions with other objects. Disruptive collisions of large objects say 200m in diameter are rare because such objects are "rare" and the impactors that could disrupt a 200m class object are rare. However, near the Earth, collisions are expected to occur at relative velocities of near 20 km/sec and such a speed could disrupt a body 106 times more massive (100 times larger diameter). Our studies show that collisions that can produce objects in the range 10 to 100m in diameter are "frequent" in near-Earth space. Our studies of the asteroid 2201 Oljato at Venus and asteroid 138175 near Earth indicates that both asteroids have coorbital debris clouds presumably caused by a past non-disruptive but debris-producing collision. This has the effect of spreading the hazardous material out of the known orbit so that a false sense of security is had when the parent body is safely past the Earth. We can detect a subset of the debris trail by their destructive impacts because they create a cloud of charged nanoscale dust which in turn creates a magnetic "cloud" that enables the dust cloud to be weighed and its location roughly identified. This shows spreading in longitude, latitude, and heliocentric radius from the parent on a time scale of decades. This is much faster than some modelers have expected and over a broader range, suggesting that the debris trail receives more of the impactor momentum than anticipated. This possibly depends on the elasticity of the target asteroid. In any event, we now have a new qualitative method of tracking debris tails of hazardous materials using existing assets in space

Disturbance and temporal partitioning of the activated sludge metacommunity

PubMed Central

Vuono, David C; Benecke, Jan; Henkel, Jochen; Navidi, William C; Cath, Tzahi Y; Munakata-Marr, Junko; Spear, John R; Drewes, Jörg E

2015-01-01

The resilience of microbial communities to press disturbances and whether ecosystem function is governed by microbial composition or by the environment have not been empirically tested. To address these issues, a whole-ecosystem manipulation was performed in a full-scale activated sludge wastewater treatment plant. The parameter solids retention time (SRT) was used to manipulate microbial composition, which started at 30 days, then decreased to 12 and 3 days, before operation was restored to starting conditions (30-day SRT). Activated sludge samples were collected throughout the 313-day time series in parallel with bioreactor performance (‘ecosystem function'). Bacterial small subunit (SSU) rRNA genes were surveyed from sludge samples resulting in a sequence library of >417 000 SSU rRNA genes. A shift in community composition was observed for 12- and 3-day SRTs. The composition was altered such that r-strategists were enriched in the system during the 3-day SRT, whereas K-strategists were only present at SRTs⩾12 days. This shift corresponded to loss of ecosystem functions (nitrification, denitrification and biological phosphorus removal) for SRTs⩽12 days. Upon return to a 30-day SRT, complete recovery of the bioreactor performance was observed after 54 days despite an incomplete recovery of bacterial diversity. In addition, a different, yet phylogenetically related, community with fewer of its original rare members displaced the pre-disturbance community. Our results support the hypothesis that microbial ecosystems harbor functionally redundant phylotypes with regard to general ecosystem functions (carbon oxidation, nitrification, denitrification and phosphorus accumulation). However, the impacts of decreased rare phylotype membership on ecosystem stability and micropollutant removal remain unknown. PMID:25126758

An investigation into heterogeneity in a single vein-type uranium ore deposit: Implications for nuclear forensics.

PubMed

Keatley, A C; Scott, T B; Davis, S; Jones, C P; Turner, P

2015-12-01

Minor element composition and rare earth element (REE) concentrations in nuclear materials are important as they are used within the field of nuclear forensics as an indicator of sample origin. However recent studies into uranium ores and uranium ore concentrates (UOCs) have shown significant elemental and isotopic heterogeneity from a single mine site such that some sites have shown higher variation within the mine site than that seen between multiple sites. The elemental composition of both uranium and gangue minerals within ore samples taken along a single mineral vein in South West England have been measured and reported here. The analysis of the samples was undertaken to determine the extent of the localised variation in key elements. Energy Dispersive X-ray spectroscopy (EDS) was used to analyse the gangue mineralogy and measure major element composition. Minor element composition and rare earth element (REE) concentrations were measured by Electron Probe Microanalysis (EPMA). The results confirm that a number of key elements, REE concentrations and patterns used for origin location do show significant variation within mine. Furthermore significant variation is also visible on a meter scale. In addition three separate uranium phases were identified within the vein which indicates multiple uranium mineralisation events. In light of these localised elemental variations it is recommended that representative sampling for an area is undertaken prior to establishing the REE pattern that may be used to identify the originating mine for an unknown ore sample and prior to investigating impact of ore processing on any arising REE patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

The formation of crystals in glasses containing rare earth oxides

NASA Astrophysics Data System (ADS)

Fadzil, Syazwani Mohd; Hrma, Pavel; Crum, Jarrod; Siong, Khoo Kok; Ngatiman, Mohammad Fadzlee; Said, Riduan Mt

2014-02-01

Korean spent nuclear fuel will reach the capacity of the available temporary storage by 2016. Pyroprocessing and direct disposal seems to be an alternative way to manage and reuse spent nuclear fuel while avoiding the wet reprocessing technology. Pyroprocessing produces several wastes streams, including metals, salts, and rare earths, which must be converted into stabilized form. A suitable form for rare earth immobilization is borosilicate glass. The borosilicate glass form exhibits excellent durability, allows a high waste loading, and is easy to process. In this work, we combined the rare earths waste of composition (in wt%) 39.2Nd2O3-22.7CeO2-11.7La2O3-10.9PrO2-1.3Eu2O3-1.3Gd2O3-8.1Sm2O3-4.8Y2O3 with a baseline glass of composition 60.2SiO2-16.0B2O3-12.6Na2O-3.8Al2O3-5.7CaO-1.7ZrO2. Crystallization in waste glasses occurs as the waste loading increases. It may produce complicate glass processing and affect the product quality. To study crystal formation, we initially made glasses containing 5%, 10% and 15% of La2O3 and then glasses with 5%, 10% and 15% of the complete rare earth mix. Samples were heat-treated for 24 hours at temperatures 800°C to 1150°C in 50°C increments. Quenched samples were analyzed using an optical microscope, scanning electron microscope with energy dispersive spectroscopy, and x-ray diffraction. Stillwellite (LaBSiO5) and oxyapatite (Ca2La8Si6O26) were found in glasses containing La2O3, while oxyapatite (Ca2La8Si6O26 and NaNd9Si6O26) precipitated in glasses with additions of mixed rare earths. The liquidus temperature (TL) of the glasses containing 5%, 10% and 15% La2O3 were 800°C, 959°C and 986°C, respectively; while TL was 825°C, 1059°C and 1267°C for glasses with 5%, 10% and 15% addition of mixed rare earth oxides. The component coefficients TB2O3, TSiO2, TCaO, and TRE2O3 were also evaluated using a recently published study.

Synthesis of functional materials in combustion reactions

NASA Astrophysics Data System (ADS)

Zhuravlev, V. D.; Bamburov, V. G.; Ermakova, L. V.; Lobachevskaya, N. I.

2015-12-01

The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating-reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al2O3, YSZ composites, uranium oxides, nickel powder, NiO and NiO: YSZ composite, TiO2, and manganites, cobaltites, and aluminates of rare earth elements.

Qualitative and quantitative studies of chemical composition of sandarac resin by GC-MS.

PubMed

Kononenko, I; de Viguerie, L; Rochut, S; Walter, Ph

2017-01-01

The chemical composition of sandarac resin was investigated qualitatively and quantitatively by gas chromatography-mass spectrometry (GC-MS). Six compounds with labdane and pimarane skeletons were identified in the resin. The obtained mass spectra were interpreted and the mass spectrometric behaviour of these diterpenoids under EI conditions was described. Quantitative analysis by the method of internal standard revealed that identified diterpenoids represent only 10-30% of the analysed sample. The sandarac resin from different suppliers was analysed (from Kremer, Okhra, Color Rare, La Marchande de Couleurs, L'Atelier Montessori, Hevea). The analysis of different lumps of resins showed that the chemical composition differs from one lump to another, varying mainly in the relative distributions of the components.

Rare earth element transport in the western North Atlantic inferred from Nd isotopic observations

NASA Technical Reports Server (NTRS)

Piepgras, D. J.; Wasserburg, G. J.

1987-01-01

The relationship between the Nd isotopic composition in the Atlantic waters and the origin and circulation of the water masses was investigated. Samples were collected in the western North Atlantic between 7 and 54 deg N. The isotopic composition (Nd-143/Nd-144 ratios) showed extensive vertical structure at all locations. In regions where a thermocline was well-developed, large isotopic shifts were observed across the base of the thermocline, while regions without a thermocline were characterized by much more gradual shifts in isotopic composition with depth. The data reveal an excellent correlation between the Nd isotopic distribution in the western North Atlantic water column and the distribution of water masses identified from temperature and salinity measurements.

A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape.

PubMed

Egan, J Franklin; Graham, Ian M; Mortensen, David A

2014-03-01

Declining plant biodiversity in agroecosystems has often been attributed to escalating use of chemical herbicides, but other changes in farming systems, including the clearing of seminatural habitat fragments, confound the influence of herbicides. The present study introduces a new approach to evaluate the impacts of herbicide pollution on plant communities at landscape or regional scales. If herbicides are in fact a key factor shaping agricultural plant diversity, one would expect to see the signal of past herbicide impacts in the current plant community composition of an intensively farmed region, with common, successful species more tolerant to widely used herbicides than rare or declining species. Data from an extensive field survey of plant diversity in Lancaster County, Pennsylvania, USA, were compared with herbicide bioassay experiments in a greenhouse to test the hypothesis that common species possess higher herbicide tolerances than rare species. Five congeneric pairs of rare and common species were treated with 3 commonly used herbicide modes of action in bioassay experiments, and few significant differences were found in the tolerances of rare species relative to common species. These preliminary results suggest that other factors beyond herbicide exposure may be more important in shaping the distribution and abundance of plant species diversity across an agricultural landscape. © 2014 SETAC.

The OASIS Mission

NASA Technical Reports Server (NTRS)

Adams, James H., Jr.; Barghouty, Abdulnasser F.; Binns, W. robert; Christl, Mark; Cosse, Charles B.; Guzik, T. Gregory; deNolfo, Georgia A.; Hams,Thomas; Isbert, Joachim; Israel, Martin H.;

Pollination ecology of the rare orchid, Spiranthes diluvialis: Implications for conservation

Treesearch

Kim Pierson; Vincent J. Tepedino; Sedonia Sipes; Kim Kuta

2001-01-01

We examined the pollination ecology of Spiranthes diluvialis Sheviak, Ute ladies-tresses, a federally listed, threatened orchid species known only from small, isolated populations in the western United States. The pollinator composition, male and female reproductive success, and demography of S. diluvialis populations were examined in 1995,1997, and 1999. Spiranthes...

Medical Documentation: An English Composition Professor's Perspective.

ERIC Educational Resources Information Center

Freeman, Mary G.

Nursing textbooks which address the subject of medical documentation tend to equate good documentation of a patient's behavior and state with strong interpersonal skills on the part of the nurse. Rarely do they point out the importance of developing a deep concentrated attention to the sensory world around oneself in order to be a good medical…

Short-term response of ground-dwelling macroarthropods to shelterwood harvests in a productive Southern Appalachian upland hardwood forest

Treesearch

Jr. Westby-Gibson; Cathryn H. Greenberg; Christopher E. Moorman; T.G. Forrest; Tara L. Keyser; Dean M. Simon; Gordon S. Warburton

2017-01-01

 Macroarthropods rarely are considered in forest management decisions, despite their ecological importance as decomposers, herbivores, pollinators, predators, and nutrient cyclers, and potential of some taxa as indicators of forest condition. We used a replicated design to experimentally determine if, and how, community composition,...

Krypton and xenon in lunar fines

NASA Technical Reports Server (NTRS)

Basford, J. R.; Dragon, J. C.; Pepin, R. O.; Coscio, M. R., Jr.; Murthy, V. R.

1973-01-01

Data from grain-size separates, stepwise-heated fractions, and bulk analyses of 20 samples of fines and breccias from five lunar sites are used to define three-isotope and ordinate intercept correlations in an attempt to resolve the lunar heavy rare gas system in a statistically valid approach. Tables of concentrations and isotope compositions are given.

Mapping Habitat Connectivity for Multiple Rare, Threatened, and Endangered Species on and Around Military Installations

DTIC Science & Technology

2011-05-01

choice model based on foraying behavior to predict natal dispersal destinations. We counted instances in which a female occupied the breeding position...movement for pollen dispersal by honey bees. Ecology 74:493-500. Müller, J., J. Stadler, R. Brandl., 2009. Composition versus physiognomy of vegetation

Simulating the phase partitioning of NH3, HNO3, and HCl with size-resolved particles over northern Colorado in winter

EPA Science Inventory

Numerical modeling of inorganic aerosol processes is useful in air quality management, but comprehensive evaluation of modeled aerosol processes is rarely possible due to the lack of comprehensive datasets. During the Nitrogen, Aerosol Composition, and Halogens on a Tall Tower (N...

Growth, nutritional, and gastrointestinal aspects of focal dermal hypoplasia (Goltz-Gorlin syndrome)

USDA-ARS?s Scientific Manuscript database

Focal dermal hypoplasia (FDH) is a rare genetic disorder caused by mutations in the PORCN gene located on the X-chromosome. In the present study, we characterized the pattern of growth, body composition, and the nutritional and gastrointestinal aspects of children and adults (n'='19) affected with t...

Composition and evolution of the eucrite parent body - Evidence from rare earth elements. [extraterrestrial basaltic melts

NASA Technical Reports Server (NTRS)

Consolmagno, G. J.; Drake, M. J.

1977-01-01

Quantitative modeling of the evolution of rare earth element (REE) abundances in the eucrites, which are plagioclase-pigeonite basalt achondrites, indicates that the main group of eucrites (e.g., Juvinas) might have been produced by approximately 10% equilibrium partial melting of a single type of source region with initial REE abundances which were chondritic relative and absolute. Since the age of the eucrites is about equal to that of the solar system, extensive chemical differentiation of the eucrite parent body prior to the formation of eucrites seems unlikely. If homogeneous accretion is assumed, the bulk composition of the eucrite parent body can be estimated; two estimates are provided, representing different hypotheses as to the ratio of metal to olivine in the parent body. Since a large number of differentiated olivine meteorites, which would represent material from the interior of the parent body, have not been detected, the eucrite parent body is thought to be intact. It is suggested that the asteroid 4 Vesta is the eucrite parent body.

Structure-property-composition relationships in doped zinc oxides: enhanced photocatalytic activity with rare earth dopants.

PubMed

Goodall, Josephine B M; Illsley, Derek; Lines, Robert; Makwana, Neel M; Darr, Jawwad A

2015-02-09

In this paper, we demonstrate the use of continuous hydrothermal flow synthesis (CHFS) technology to rapidly produce a library of 56 crystalline (doped) zinc oxide nanopowders and two undoped samples, each with different particle properties. Each sample was produced in series from the mixing of an aqueous stream of basic zinc nitrate (and dopant ion or modifier) solution with a flow of superheated water (at 450 °C and 24.1 MPa), whereupon a crystalline nanoparticle slurry was rapidly formed. Each composition was collected in series, cleaned, freeze-dried, and then characterized using analytical methods, including powder X-ray diffraction, transmission electron microscopy, Brunauer-Emmett-Teller surface area measurement, X-ray photoelectron spectroscopy, and UV-vis spectrophotometry. Photocatalytic activity of the samples toward the decolorization of methylene blue dye was assessed, and the results revealed that transition metal dopants tended to reduce the photoactivity while rare earth ions, in general, increased the photocatalytic activity. In general, low dopant concentrations were more beneficial to having greater photodecolorization in all cases.

Multi-objective optimization for the economic production of d-psicose using simulated moving bed chromatography.

PubMed

Wagner, N; Håkansson, E; Wahler, S; Panke, S; Bechtold, M

2015-06-12

The biocatalytic production of rare carbohydrates from available sugar sources rapidly gains interest as a route to acquire industrial amounts of rare sugars for food and fine chemical applications. Here we present a multi-objective optimization procedure for a simulated moving bed (SMB) process for the production of the rare sugar d-psicose from enzymatically produced mixtures with its epimer d-fructose. First, model parameters were determined using the inverse method and experimentally validated on a 2-2-2-2 lab-scale SMB plant. The obtained experimental purities (PUs) were in excellent agreement with the simulated data derived from a transport-dispersive true-moving bed model demonstrating the feasibility of the proposed design. In the second part the performance of the separation was investigated in a multi-objective optimization study addressing the cost-contributing performance parameters productivity (PR) and desorbent requirement (DR) as a function of temperature. While rare sugar SMB operation under conditions of low desorbent consumption was found to be widely unaffected by temperature, SMB operation focusing on increased PR significantly benefited from high temperatures, with possible productivities increasing from 3.4kg(Lday)(-1) at 20°C to 5kg(Lday)(-1) at 70°C, indicating that decreased selectivity at higher temperatures could be fully compensated for by the higher mass transfer rates, as they translate into reduced switch times and hence higher PR. A DR/PR Pareto optimization suggested a similar but even more pronounced trend also under relaxed PU requirements, with the PR increasing from 4.3kg(Lday)(-1) to a maximum of 7.8kg(Lday)(-1) for SMB operation at 50°C when the PU of the non-product stream was reduced from 99.5% to 90%. Based on the in silico optimization results experimental SMB runs were performed yielding considerable PRs of 1.9 (30°C), 2.4 (50°C) and 2.6kg(Lday)(-1) (70°C) with rather low DR (27L per kg of rare sugar produced) on a lab-scale SMB installation. Copyright © 2015. Published by Elsevier B.V.

Contribution of Electronic Medical Records to the Management of Rare Diseases.

PubMed

Bremond-Gignac, Dominique; Lewandowski, Elisabeth; Copin, Henri

2015-01-01

Electronic health record systems provide great opportunity to study most diseases. Objective of this study was to determine whether electronic medical records (EMR) in ophthalmology contribute to management of rare eye diseases, isolated or in syndromes. Study was designed to identify and collect patients' data with ophthalmology-specific EMR. Ophthalmology-specific EMR software (Softalmo software Corilus) was used to acquire ophthalmological ocular consultation data from patients with five rare eye diseases. The rare eye diseases and data were selected and collected regarding expertise of eye center. A total of 135,206 outpatient consultations were performed between 2011 and 2014 in our medical center specialized in rare eye diseases. The search software identified 29 congenital aniridia, 6 Axenfeld/Rieger syndrome, 11 BEPS, 3 Nanophthalmos, and 3 Rubinstein-Taybi syndrome. EMR provides advantages for medical care. The use of ophthalmology-specific EMR is reliable and can contribute to a comprehensive ocular visual phenotype useful for clinical research. Routinely EMR acquired with specific software dedicated to ophthalmology provides sufficient detail for rare diseases. These software-collected data appear useful for creating patient cohorts and recording ocular examination, avoiding the time-consuming analysis of paper records and investigation, in a University Hospital linked to a National Reference Rare Center Disease.

Contribution of Electronic Medical Records to the Management of Rare Diseases

PubMed Central

Bremond-Gignac, Dominique; Lewandowski, Elisabeth; Copin, Henri

2015-01-01

Purpose. Electronic health record systems provide great opportunity to study most diseases. Objective of this study was to determine whether electronic medical records (EMR) in ophthalmology contribute to management of rare eye diseases, isolated or in syndromes. Study was designed to identify and collect patients' data with ophthalmology-specific EMR. Methods. Ophthalmology-specific EMR software (Softalmo software Corilus) was used to acquire ophthalmological ocular consultation data from patients with five rare eye diseases. The rare eye diseases and data were selected and collected regarding expertise of eye center. Results. A total of 135,206 outpatient consultations were performed between 2011 and 2014 in our medical center specialized in rare eye diseases. The search software identified 29 congenital aniridia, 6 Axenfeld/Rieger syndrome, 11 BEPS, 3 Nanophthalmos, and 3 Rubinstein-Taybi syndrome. Discussion. EMR provides advantages for medical care. The use of ophthalmology-specific EMR is reliable and can contribute to a comprehensive ocular visual phenotype useful for clinical research. Conclusion. Routinely EMR acquired with specific software dedicated to ophthalmology provides sufficient detail for rare diseases. These software-collected data appear useful for creating patient cohorts and recording ocular examination, avoiding the time-consuming analysis of paper records and investigation, in a University Hospital linked to a National Reference Rare Center Disease. PMID:26539543

Rare earth elements in the sedimentary cycle - A pilot study of the first leg

NASA Technical Reports Server (NTRS)

Basu, A.; Blanchard, D. P.; Brannon, J. C.

1982-01-01

The effects of source rock composition and climate on the natural abundances of rare elements (REE) in the first leg of the sedimentary cycle are evaluated using a study with Holocene fluvia sands. The medium grained sand fraction of samples collected from first order streams exclusively draining granitic plutons in Montana (semi-arid), Georgia (humid), and South Carolina (humid) are analyzed. It is found that the REE distribution patterns (but not the total absolute abundances) of the daughter sands are very similar, despite compositional differences between parent plutons. Averages of the three areas are determined to have a La/Lu ratio of about 103, showing a depletion of heavy REE with respect to an average granite (La/Lu = 79) or the composition of North American Shales (La/Lu = 55). However, the Eu/Sm ratio in sands from these areas is about 0.22, which is very close to this ratio in North American Shales (0.21), although the overall REE distribution of these sands is not similar to that of the North American Shales in any way. It is concluded that the major rock type, but neither its minor subdivisions nor the climate, controls the REE distribution patterns in first cycle daughter sands, although the total and the parent rock-normalized abundances of REE in sands from humid areas are much lower than those in sands from arid areas.

Effect of space exposure of some epoxy matrix composites on their thermal expansion and mechanical properties (A0138-8)

NASA Technical Reports Server (NTRS)

Elberg, R.

1984-01-01

This experiment has three objectives. The first and main objective is to detect a possible variation in the coefficient of thermal expansion of composite samples during a 1-year exposure to the near-Earth orbital environment. A second objective is to detect a possible change in the mechanical integrity of composite products, both simple elements and honeycomb sandwich assemblies. A third objective is to compare the behavior of two epoxy resins commonly used in space structural production. The experimental approach is to passively expose samples of epoxy matrix composite materials to the space environment and to compare preflight and postflight measurements of mechanical properties. The experiment will be located in one of the three FRECOPA (French cooperative payload) boxes in a 12-in.-deep peripheral tray that contains nine other experiments from France. The FRECOPA box will protect the samples from contamination during the launch and reentry phases of the mission. The coefficients of thermal expansion are measured on Earth before and after space exposure.

Rare disease: a national survey of paediatricians’ experiences and needs

PubMed Central

Zurynski, Yvonne; Gonzalez, Aranzazu; Deverell, Marie; Phu, Amy; Leonard, Helen; Christodoulou, John; Elliott, Elizabeth

2017-01-01

Objective To describe the experiences of Australian paediatricians while caring for children with rare diseases, and their educational and resource needs. Design A brief online survey was developed and deployed to a representative sample of 679 paediatricians from the Australian Paediatric Surveillance Unit database. Results Of the 679 paediatricians, 242 (36%) completed the survey. The respondents were representative of all states and territories of Australia, urban and rural regions, and hospital and private practice. Almost all respondents (93%) had seen children with one or more of >350 different rare diseases during their career; 74% had seen a new patient with rare disease in the last 6 months. The most common problems encountered while caring for patients were: diagnostic delays (65%), lack of available treatments (40%), clinical guidelines (36%) and uncertainty where to refer for peer support (35%). Few paediatricians said that rare diseases were adequately covered during university (40%) or the Fellowship of the Royal Australasian College of Physicians (50%) training, and 28% felt unprepared to care for patients with rare diseases. Paediatricians wanted lists of specialist referral services (82%) and online educational modules about rare diseases (78%) that could be accessed via one online portal that consolidated multiple resources. Smartphone applications on rare diseases were favoured by paediatricians aged <50 years and by female paediatricians. Conclusions An online educational portal should be developed and maintained for accuracy and currency of information to support dissemination of rare disease guidelines, referral pathways and coordination services relevant to Australian paediatricians and other health professionals who care for children with rare diseases. PMID:29637168

High-Speed, Three Dimensional Object Composition Mapping Technology

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

Ishikawa, M Y

2001-02-14

This document overviews an entirely new approach to determining the composition--the chemical-elemental, isotopic and molecular make-up--of complex, highly structured objects, moreover with microscopic spatial resolution in all 3 dimensions. The front cover depicts the new type of pulsed laser system at the heart of this novel technology under adjustment by Alexis Wynne, and schematically indicates two of its early uses: swiftly analyzing the 3-D composition governed structure of a transistor circuit with both optical and mass-spectrometric detectors, and of fossilized dinosaur and turtle bones high-speed probed by optical detection means. Studying the composition-cued 3-D micro-structures of advanced composite materials andmore » the microscopic scale composition-texture of biological tissues are two near-term examples of the rich spectrum of novel applications enabled by this field-opening analytic tool-set.« less

Stand-off molecular composition analysis

NASA Astrophysics Data System (ADS)

Hughes, Gary B.; Lubin, Philip; Meinhold, Peter; O'Neill, Hugh; Brashears, Travis; Zhang, Qicheng; Griswold, Janelle; Riley, Jordan; Motta, Caio

2015-09-01

Molecular composition of distant stars is explored by observing absorption spectra. The star produces blackbody radiation that passes through the molecular cloud of vaporized material surrounding the star. Characteristic absorption lines are discernible with a spectrometer, and molecular composition is investigated by comparing spectral observations with known material profiles. Most objects in the solar system—asteroids, comets, planets, moons—are too cold to be interrogated in this manner. Molecular clouds around cold objects consist primarily of volatiles, so bulk composition cannot be probed. Additionally, low volatile density does not produce discernible absorption lines in the faint signal generated by low blackbody temperatures. This paper describes a system for probing the molecular composition of cold solar system targets from a distant vantage. The concept utilizes a directed energy beam to melt and vaporize a spot on a distant target, such as from a spacecraft orbiting the object. With sufficient flux (~10 MW/m2), the spot temperature rises rapidly (to ~2 500 K), and evaporation of all materials on the target surface occurs. The melted spot creates a high-temperature blackbody source, and ejected material creates a molecular plume in front of the spot. Bulk composition is investigated by using a spectrometer to view the heated spot through the ejected material. Spatial composition maps could be created by scanning the surface. Applying the beam to a single spot continuously produces a borehole, and shallow sub-surface composition profiling is also possible. Initial simulations of absorption profiles with laser heating show great promise for molecular composition analysis.

Feasibility and Scaling of Composite Based Additive Manufacturing

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

Nuttall, David; Chen, Xun; Kunc, Vlastimil

2016-04-27

Engineers and Researchers at Oak Ridge National Lab s Manufacturing Demonstration Facility (ORNL MDF) collaborated with Impossible Objects (IO) in the characterization of PEEK infused carbon fiber mat manufactured by means of CBAM composite-based additive manufacturing, a first generation assembly methodology developed by Robert Swartz, Chairman, Founder, and CTO of Impossible Objects.[1] The first phase of this project focused on demonstration of CBAM for composite tooling. The outlined steps focused on selecting an appropriate shape that fit the current machine s build envelope, characterized the resulting form, and presented next steps for transitioning to a Phase II CRADA agreement. Phasemore » I of collaborative research and development agreement NFE-15-05698 was initiated in April of 2015 with an introduction to Impossible Objects, and concluded in March of 2016 with a visitation to Impossible Objects headquarters in Chicago, IL. Phase II as discussed herein is under consideration by Impossible Objects as of this writing.« less

Automated Tow Placement Processing and Characterization of Composites

NASA Technical Reports Server (NTRS)

Prabhakaran, R.

2004-01-01

The project had one of the initial objectives as automated tow placement (ATP), in which a robot was used to place a collimated band of pre-impregnated ribbons or a wide preconsolidated tape onto a tool surface. It was proposed to utilize the Automated Tow Placement machine that was already available and to fabricate carbon fiber reinforced PEEK (polyether-ether-ketone) matrix composites. After initial experiments with the fabrication of flat plates, composite cylinders were to be fabricated. Specimens from the fabricated parts were to be tested for mechanical characterization. A second objective was to conduct various types of tests for characterizing composite specimens cured by different fabrication processes.

Development, characterization and dissolution behavior of calcium-aluminoborate glass wasteforms to immobilize rare-earth oxides.

PubMed

Kim, Miae; Corkhill, Claire L; Hyatt, Neil C; Heo, Jong

2018-03-28

Calcium-aluminoborate (CAB) glasses were developed to sequester new waste compositions made of several rare-earth oxides generated from the pyrochemical reprocessing of spent nuclear fuel. Several important wasteform properties such as waste loading, processability and chemical durability were evaluated. The maximum waste loading of the CAB compositions was determined to be ~56.8 wt%. Viscosity and the electrical conductivity of the CAB melt at 1300 °C were 7.817 Pa·s and 0.4603 S/cm, respectively, which satisfies the conditions for commercial cold-crucible induction melting (CCIM) process. Addition of rare-earth oxides to CAB glasses resulted in dramatic decreases in the elemental releases of B and Ca in aqueous dissolution experiments. Normalized elemental releases from product consistency standard chemical durability test were <3.62·10 -5  g·m -2 for Nd, 0.009 g·m -2 for Al, 0.067 g·m -2 for B and 0.073 g·m -2 for Ca (at 90, after 7 days, for SA/V = 2000m -1 ); all meet European and US regulation limits. After 20 d of dissolution, a hydrated alteration layer of ~ 200-nm-thick, Ca-depleted and Nd-rich, was formed at the surface of CAB glasses with 20 mol% Nd 2 O 3 whereas boehmite [AlO(OH)] secondary crystalline phases were formed in pure CAB glass that contained no Nd 2 O 3 .

Petrological processes in mantle plume heads: Evidence from study of mantle xenoliths in the late Cenozoic alkali Fe-Ti basalts in Western Syria

NASA Astrophysics Data System (ADS)

Sharkov, Evgenii

2015-04-01

It is consensus now that within-plate magmatism is considered with ascending of mantle plumes and adiabatic melting of their head. At the same time composition of the plumes' matter and conditions of its adiabatic melting are unclear yet. The major source of objective information about it can be mantle xenoliths in alkali basalts and basanites which represent fragments of material of the plume heads above magma-generation zone. They are not represent material in melting zone, however, carry important information about material of modern mantle plumes, its phase composition and components, involved in melting. Populations of mantle xenoliths in basalts are characterized by surprising sameness in the world and represented by two major types: (1) dominated rocks of ``green'' series, and (2) more rare rocks of ``black'' series, which formed veins in the ``green'' series matrix. It can evidence about common composition of plume material in global scale. In other words, the both series of xenoliths represent two types of material of thermochemical mantle plumes, ascended from core-mantle boundary (Maruyama, 1994; Dobretsov et al., 2001). The same types of xenoliths are found in basalts and basanites of Western Syria (Sharkov et al., 1996). Rocks of ``green'' series are represented by Sp peridotites with cataclastic and protogranular structures and vary in composition from dominated spinel lherzolites to spinel harzburgites and rare spinel pyroxenites (websterites). It is probably evidence about incomplete homogenizing of the plume head matter, where material, underwent by partial melting, adjoins with more fertile material. Such heterogeneity was survived due to quick cooling of upper rim of the plume head in contact with relatively cold lithosphere. Essential role among xenoliths of the ``black'' series play Al-Ti-augite and water-bearing phases like hornblende (kaersutute) and Ti-phlogopite. Rocks of this series are represented by wehrlite, clinopyroxenite, amphibole clinopyroxenite, hornbledite, etc. as well as megacrysts of Al-Ti-augite, kaersutite, ilmenite, sanidine, etc. Numerous vesicles often occurred in megacrysts, especially in kaersurtite. Sp peridotites of the matrix are sharply different on their geochemical features from the ``black series'' rocks (in this case, megacrysts of kaersutite) which are the most close to composition of xenoliths-bearing alkali basalts. From this follows that geochemistry of plume-related basalts was determined by mantle fluids which occurred in magma-generation zone. Very likely, that these fluids, enriched in Fe, Ti, LREE, alkalis, and incompatible elements, initially were parts of intergranular material of original mantle plume material and were released due to its decompression. Because their high mobility, the fluids percolated upwards and accumulated in the upper part of the mantle plume head, where promoted its melting by lowering of solidus of the matter. Excess of the fluids gathered beneath the cooled upper rim and penetrated in its rocks which led to appearance of centers of secondary melting (melt-pockets). Very likely, that these secondary melts formed rocks of the ``black series'' (Ismail et al., 2008;Ryabchkov et al., 2011; Ma et al., 2014). According to geobarometric estimations, Sp peridotite xenoliths from Syria derived from depths 24-42 km (0.8-1.4 GPa) under temperatures 896-980oC; formation of melt-pockets, enriched in volatiles, occurred at the depths 21-27 km (0.7-0.9 GPa) under 826-981oC (Sharkov et al., 1996; Ismail et al., 2008; Ma et al., 2014). From this follows that plumeheads reached depths approximately 21-30 km which is in agree with practically absence of lower-crustal xenoliths in the populations. One of the problems of plume-related magmatism is coexisting of alkali and tholeiitic basalts, which origin often considered with different PT conditions. However, these basalt not rarely interlayered, especially at low and middle levels of LIPs or in single volcanoes (Hawaii, Etna, etc.) which is not in a good agreement with such idea. We suggest that the situation can be more likely explained by nonuniform impregnation of peridotite matrix with fluid components which composition and/or quantity can play essential role in composition of smeltings. It is especially important because even small differences in their ñomposition near to plane of SiO2 saturation in ``basalt tetrahedron'' (Yoder and Tilley, 1962) lead to appearance of Ne-normative or Ne-free melts at practically similar PT conditions. Thus, judging on composition of the mantle xenoliths in basalts of all occurrences in the world, quite possible that Sp peridotites (mainly lherzolites) together with intergranular geochemical-enriched fluid components represent the matter of the modern thermochemical mantle plumes. Origin of two major types of the plume-related magmas, probably, considered with fluid regime in the plume head.

Determining and analyzing the strength and impact resistance of high modulus glass

NASA Technical Reports Server (NTRS)

Bacon, J. F.

1972-01-01

A number of new glass compositions have been prepared with increased emphasis on compositions without beryllia. Glass preparations have been much more broadly based and have included the eutectic glass fields, and the mullite-rare earth glass systems. Of the new glasses, the best non-toxic composition is UARL 472 with a bulk modulus of only 18.20 million psi. A second experimental glass, UARL 417, was chosen for research in making large quantities of fiber in monofilament form. Tests of these UARL 417 epoxy resin samples in comparison to similar composites made with the DuPont organic fiber, PRD-49-1, show that the UARL composites have a compressive strength 41/2 times higher and a specific compressive strength at least 21/2 times greater. Much of the research effort attempted to answer the question of why a given glass should have an impact strength superior to other glasses. No definitive answer to the question was found.

CEMARA: a Web dynamic application within a N-tier architecture for rare diseases.

PubMed

Messiaen, Claude; Le Mignot, Loïc; Rath, Ana; Richard, Jean-Baptiste; Dufour, Eric; Ben Said, Mohamed; Jais, Jean-Philippe; Verloes, Alain; Le Merrer, Martine; Bodemer, Christine; Baujat, Geneviève; Gerard-Blanluet, Marion; Bourdon-Lanoy, Eva; Salomon, Rémi; Ayme, Ségolène; Landais, Paul

2008-01-01

Rare diseases include a group of conditions characterized by a prevalence lower than 5 per 10,000 in the community. In France, any rare disease affects less than 30,000 patients and often much less. Three to 4% of children and 6% of the population in Europe are affected. It is a true public health stake since most diseases do not have any curative treatment. In France, the Ministry of Health has initiated a National Rare Diseases Plan. Twenty five out of 132 labelled Reference Centres (RC) decided to share a common Information System named CEMARA. It is dedicated to collect continuous and complete records of all patients presenting with a rare disease, and their follow-up. The main objective of CEMARA is to contribute to the missions of the RC regarding the registration and description of their activities, coordination of the network of their correspondents, organization of the follow-up of rare diseases, and analysis of the epidemiological patterns. A description of CEMARA is provided as well as its cooperation with Orphanet and Genatlas, and a presentation of 11803 current records collected by more than 300 health care professionals belonging to more than 70 sites.

Traumatic aortic injury: CT findings, mimics, and therapeutic options

PubMed Central

Lantz, Eric J.; Johnson, C. Michael; Young, Philip M.

2014-01-01

Objective Traumatic aortic injury (TAI) is rare, but frequently lethal. However, with prompt diagnosis, patients can undergo life-saving open or endovascular repair. Unfortunately, because these injuries are relatively rare, subtle forms of these injuries may be missed, and normal variants may mimic TAI leading to misdiagnosis. Conclusions We will discuss computed tomography findings of typical injury patterns of traumatic aortic injuries as well as treatment options, diagnostic pitfalls and injury mimics. These are highlighted with clinical case examples. PMID:25009793

A Rare Case of Bilateral Agenesis of Central Lower Incisors Associated With Upper Impacted Canine- A Case Report

PubMed Central

PORUMB, Anca; IGNAT ROMANUL, Ioana; DALAI, Camelia; CIAVOI, Gabiela; TIG, Ioan Andrei

2016-01-01

This case of a female patient, 14 yr old with association of the two anomalies, which we came across with in 2014, is rarely met in the specialty practice. The impacted canines are part of the group of dental anomalies of position, while the agenesis is part of the group of dental number anomalies. The orthodontic treatment in the two arches has to be differentiated, the therapeutic objectives being, also different in the two arches. PMID:27141502

A Rare Case of Bilateral Agenesis of Central Lower Incisors Associated With Upper Impacted Canine- A Case Report.

PubMed

Porumb, Anca; Ignat Romanul, Ioana; Dalai, Camelia; Ciavoi, Gabiela; Tig, Ioan Andrei

2016-03-01

This case of a female patient, 14 yr old with association of the two anomalies, which we came across with in 2014, is rarely met in the specialty practice. The impacted canines are part of the group of dental anomalies of position, while the agenesis is part of the group of dental number anomalies. The orthodontic treatment in the two arches has to be differentiated, the therapeutic objectives being, also different in the two arches.

Fen ecohydrologic trajectories in response to groundwater drawdown with edaphic, floristic, and hydrologic feedbacks

NASA Astrophysics Data System (ADS)

Booth, E.; Steven, L. I.; Bart, D.

2017-12-01

Calcareous fens are unique and often isolated ecosystems of high conservation value worldwide because they provide habitat for many rare plant and animal species. Their identity is inextricably linked to an absolute dependence on a consistent discharge of groundwater that saturates the near surface for most of the growing season leading to the accumulation of carbon as peat or tufa and sequestration of nutrients. The stresses resulting from consistent saturation and low-nutrient availability result in high native plant diversity including very high rare species richness compared to other ecosystems. Decreases in the saturation stress by reduced groundwater inputs (e.g., from nearby pumping) can result in losses of native diversity, decreases in rare-species abundance, and increased invasion by non-native species. As such, fen ecosystems are particularly susceptible to changes in groundwater conditions including reduction in water levels due to nearby groundwater pumping. Trajectories of degradation are complex due to feedbacks between loss of soil organic carbon, changes in soil properties, and plant water use. We present a model of an archetype fen that couples a hydrological niche model with a variably-saturated groundwater flow model to predict changes in vegetation composition in response to different groundwater drawdown scenarios (step change, declining trend, and periodic drawdown during dry periods). The model also includes feedbacks among vegetation composition, plant water use, and soil properties. The hydrological niche models (using surface soil moisture as predictor) and relationships between vegetation composition, plant water use (via stomatal conductance and leaf-area index), and soil hydraulic properties (van Genuchten parameters) were determined based on data collected from six fens in Wisconsin under various states of degradation. Results reveal a complex response to drawdown and provide insight into other ecosystems with linkages between the hydrologic regime, plants, water use, and soil properties.

Phase composition and magnetic properties in nanocrystalline permanent magnets based on misch-metal

NASA Astrophysics Data System (ADS)

Ma, Q.; Wang, J.; Zhang, Z. Y.; Zhang, X. F.; Liu, F.; Liu, Y. L.; Jv, X. M.; Li, Y. F.; Wang, G. F.

2017-09-01

The magnetic properties and phase composition of magnets based on misch-metal (MM) with nominal composition of MM13+xFe84-xB6.5 with x = 0.5, 1, 1.5, 2 and 2.5 using melt-spinning method were investigated. For x = 1.5, it could exhibit best magnetic properties (Hcj = 753.02 kA m-1, (BH)max = 70.77 kJ m-3). X-ray diffraction and energy dispersive spectroscopy show that the multi hard magnetic phase of RE2Fe14B (RE = La, Ce, Pr, Nd) existed in the magnets. The domain wall pinning effect and the exchange coupling interaction between grains are dependent on the abnormal RE-rich phase composition. Optimizing the phase constitution is necessary to improve magnetic properties in MM-Fe-B magnets for utilizing the rare earth resource in a balanced manner.

Efficient and Stable CsPb(Br/I)3@Anthracene Composites for White Light-Emitting Devices.

PubMed

Shen, Xinyu; Sun, Chun; Bai, Xue; Zhang, Xiaoyu; Wang, Yu; Wang, Yiding; Song, Hongwei; Yu, William W

2018-05-16

Inorganic perovskite quantum dots bear many unique properties that make them potential candidates for optoelectronic applications, including color display and lighting. However, the white emission with inorganic perovskite quantum dots has rarely been realized due to the anion-exchange reaction. Here, we proposed a one-pot preparation to fabricate inorganic perovskite quantum dot-based white light-emitting composites by introducing anthracene as a blue emission component. The as-prepared white light-emitting composite exhibited a photoluminescence quantum yield of 41.9%. By combining CsPb(Br/I) 3 @anthracene composites with UV light-emitting device (LED) chips, white light-emitting devices with a color rendering index of 90 were realized with tunable color temperature from warm white to cool white. These results can promote the application of inorganic perovskite quantum dots in the field of white LEDs.

Development of Advanced Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites: Path Toward 2700 F Temperature Capability and Beyond

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Hurst, Janet B.; Good, Brian; Costa, Gustavo; Bhatt, Ramakrishna T.; Fox, Dennis S.

2017-01-01

Advanced environmental barrier coating systems for SiC-SiC Ceramic Matrix Composite (CMC) turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant coating development challenges is to achieve prime-reliant environmental barrier coating systems to meet the future 2700F EBC-CMC temperature stability and environmental durability requirements. This presentation will emphasize recent NASA environmental barrier coating system testing and down-selects, particularly the development path and properties towards 2700-3000F durability goals by using NASA hafnium-hafnia-rare earth-silicon-silicate composition EBC systems for the SiC-SiC CMC turbine component applications. Advanced hafnium-based compositions for enabling next generation EBC and CMCs capabilities towards ultra-high temperature ceramic coating systems will also be briefly mentioned.

Processing of strong flux trapping high T(subc) oxide superconductors: Center director's discretionary fund

NASA Technical Reports Server (NTRS)

Wu, M. K.; Higgins, C. A.; Leong, P. T.; Chou, H.; Loo, B. H.; Curreri, P. A.; Peters, P. N.; Sisk, R. C.; Huang, C. Y.; Shapira, Y.

1989-01-01

Magnetic suspension effect was first observed in samples of YBa2Cu3O7/AgO(Y-123/AgO) composites. Magnetization measurements of these samples show a much larger hysteresis which corresponds to a large critical current density. In addition to the Y-123AgO composites, recently similar suspension effects in other RE-123/AgO, where RE stands for rare-Earth elements, were also observed. Some samples exhibit even stronger flux pinning than that of the Y-123/AgO sample. An interesting observation was that in order to form the composite which exhibits strong flux trapping effect the sintering temperature depends on the particular RE-123 compound used. The paper presents the detailed processing conditions for the formation of these RE-123/AgO composites, as well as the magnetization and critical field data.

The impact of common and rare EGFR mutations in response to EGFR tyrosine kinase inhibitors and platinum-based chemotherapy in patients with non-small cell lung cancer.

PubMed

Arrieta, Oscar; Cardona, Andrés Felipe; Corrales, Luis; Campos-Parra, Alma Delia; Sánchez-Reyes, Roberto; Amieva-Rivera, Eduardo; Rodríguez, July; Vargas, Carlos; Carranza, Hernán; Otero, Jorge; Karachaliou, Nikki; Astudillo, Horacio; Rosell, Rafael

2015-02-01

In non-small cell lung cancer (NSCLC), the association between common EGFR mutations (Del EX19/L858R) with EGFR tyrosine kinase inhibitors (EGFR-TKIs) has been well established. However, this has not been investigated for rare EGFR mutations or their impact on treatment response and outcome to EGFR TKIs (primary objective) and chemotherapy (secondary objective). In an observational prospective cohort, we analyzed 188 NSCLC patients from Mexico, Colombia and Costa Rica with EGFR mutations. As a first line of treatment, 66.5% received platinum-based chemotherapy. All patients received TKIs in first-line treatment or after progression to chemotherapy. The clinical-pathological characteristics as well as the f of common and rare EGFR mutations associated with treatment response were analyzed. Of all patients, 79.5% had common and 20.5% had rare EGFR mutations. Lepidic and acinar adenocarcinomas were associated with common EGFR mutations (p=0.010). Patients with common EGFR mutations had higher response rates to EGFR-TKIs than those who had rare EGFR mutations (63.8 vs 32.4%, p<0.001). Women had increased progression-free survival (PFS) to EGFR-TKIs than men (16.4 vs 9.5 months, p=0.02). The median PFS and overall survival (OS) were better in patients with common EGFR mutations (15.5 vs 3.9 months, p<0.001; and 37.3 vs 17.4 months, p<0.001) respectively. Our findings suggested that only patients with rare EGFR mutations could receive platinum-based chemotherapy as a first-line treatment, due to their low response rates and short PFS in response to EGFR-TKIs. Consequently, EGFR-TKIs could be reserved as a second- or third-line treatment. In patients with EGFR mutations, women have better PFS to EGFR-TKIs than men, and rare EGFR mutations are more frequent in high grade adenocarcinomas than in low grade tumors. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Obtaining of Nano Oxide Systems SiO2-REE with Alkoxide Technology

NASA Astrophysics Data System (ADS)

Amelina, Anna; Grinberg, Evgenii

A lot of oxides systems with REE as dopants are used in catalytic processes in organic synthesis. They are very perspectives as thermostable coating in aerospace technics. These systems are usually based on silicon or aluminium oxides and doped with rare-earth elements. This systems can be produced by different methods. One of the most perspective of them is “sol-gel”-method with silicium, aluminium and rare-earth alkoxides as a precursor of doped silica and alumina, or their derivatives. Thus the obtaining of composite SiO _{2} - REE oxide materials by the hydrolysis doped with rare-earth elements was suggested. Some of alcoholate derivatives such as El(OR)n were used in this processes. The SiO _{2}- REE oxides were precipitated during the sol-gel process, where tetraethoxysilane (TEOS) as used as SiO _{2} sources. Also it is known that alkoxides of alkali metals, including lithium alkoxides, are widely used in industry and synthetic chemistry, as well as a source of lithium in various mixed oxide compositions, such as lithium niobate, lithium tantalate or lithium silicate. Therefore, we attempted to obtain the lithium silicate, which is also doped with rare-earth elements. Lithium silicate was obtained by alkaline hydrolysis of tetraethoxysilane with lithium alkoxide. Lithium alkoxide were synthesized by dissolving at metal in the corresponding alcohol are examined. The dependence of the rate of dissolving of the metal on the method of mixing of the reaction mixture and the degree of metal dispersion was investigated. The mathematical model of the process was composed and also optimization of process was carried out. Some oxide SiO _{2}, Al _{2}O _{3} and rare-earth nanostructured systems were obtained by sol-gel-method. The size of particle was determined by electron and X-ray spectroscopy and was in the range of 5 - 15 nm. Purity of this oxide examples for contaminating of heavy metals consists n.(1E-4...1E-5) wt%. Sols obtained by this method may be used for producing of thin coats on ceramics and metallic surfaces.

Magmatic Complexes of the Vetlovaya Marginal Sea Paleobasin (Kamchatka): Composition and Geodynamic Setting

NASA Astrophysics Data System (ADS)

Tsukanov, N. V.; Saveliev, D. P.; Kovalenko, D. V.

2018-01-01

This study presents new geochemical and isotope data on igneous rocks of the Vetlovaya marginal sea paleobasin (part of the Late Mesozoic-Cenozoic margin of the northwestern Pacific). The results show that the rock complexes of this marginal sea basin comprise igneous rocks with geochemical compositions similar to those of normal oceanic tholeiites, enriched transitional tholeiites, and ocean island and back-arc basin basalts. Island-arc tholeiitic basalts are present only rarely. The specific geochemical signatures of these rocks are interpreted as being related to mantle heterogeneity and the geodynamic conditions in the basin.

Novel Optical Fiber Materials With Engineered Brillouin Gain Coefficients SSL 1: Novel Fiber Lasers

DTIC Science & Technology

2015-12-29

strontium aluminosilicate glasses . A zero-p12 composition is calculated to be at a SiO2 content of about 41.5 mol%, SrO content of about 22.5 mol...ternary, glasses that are needed for this program. These include the BaO- SiO2 system as an example binary glass , and the MgO-Al2O3- SiO2 and BaO-Al2O3... SiO2 systems as example ternary glasses (with the addition of a rare earth 16 resulting in a quaternary glass ). Complex ternary compositions were

The rheology and composition of cryovolcanic flows on icy satellites

NASA Technical Reports Server (NTRS)

Kargel, Jeffrey S.

1993-01-01

The rheologic properties of terrestrial lavas have been related to morphologic features of their flows, such as levees, banked surfaces, multilobate structures, and compressible folds. These features also have been used to determine rheologies and constrain the compositions of extraterrestrial flows. However, with rare exceptions, such features are not resolvable in Voyager images of the satellites of outer planets. Often only flow length and edge thickness of cryovolcanic flows can be measured reasonably accurately from Voyager images. The semiempirical lava-flow model presented here is a renewed effort to extract useful information from such measurements.

Rhyolite, dacite, andesite, basaltic andesite, and basalt volcanism on the Alarcon Rise spreading-center, Gulf of California

NASA Astrophysics Data System (ADS)

Dreyer, B. M.; Portner, R. A.; Clague, D. A.; Castillo, P. R.; Paduan, J. B.; Martin, J. F.

2012-12-01

The Alarcon Rise is a ~50 km long intermediate-rate (~50mm/a) spreading segment at the southern end of the Gulf of California. The Rise is bounded by the Tamayo and Pescadero transforms to the south and north. In Spring 2012, an MBARI-led expedition mapped a ~1.5- 3km wide swath of the ridge axis at 1-m resolution and completed 9 ROV dives (Clague et al., this session). Sampling during the ROV dives was supplemented by use of a wax-tip corer to recover volcanic glass: 194 glassy lava samples were recovered from the Rise. The vast majority of lava flows along the axis are basalt and rare basaltic andesite. More than half the basalts are plagioclase-phyric to ultraphyric (Martin et al., this session), and the rest are aphyric. Rare samples also include olivine or olivine and clinopyroxene phenocrysts. Analyses of half of the recovered glass basalt rinds range in MgO from 4.3 to 8.5 wt.% and those with MgO > 6 wt % have K2O/TiO2 = 0.07-0.11. The basalts are broadly characterized as normal mid-ocean ridge basalts (N-MORB). E-MORB is also present near the center of the ridge segment, but has been found only as pyroclasts in sediment cores. A much greater range in lava composition is associated with an unusual volcanic dome-like edifice that lies ~9 km south of the Pescadero transform. Two dives in the vicinity of the dome collected lava and volcaniclastic samples consisting of moderately to sparsely phyric light brown to colorless volcanic glass. Feldspar is the dominant phase, but magnetite, fayalitic olivine, light tan and light green clinopyroxene, orthopyroxene, zircon, and rare pyrite blebs also occur. Melt-inclusions are common in many phenocrysts, especially of plagioclase. Hydrous mineral phases are not observed. These samples have rhyolitic glass compositions (75.8- 77.4 SiO2 wt %), but their whole-rock compositions will be somewhat less silicic. Pillow flows to the immediate west have dacitic glass compositions (67.4- 68.8 wt % SiO2). Basaltic andesitic glasses (~56% SiO2), and basaltic glasses, more typical of the rest of the ridge, occur within 100m of the dome. Flow(s) with andesite glass compositions (~62 wt % SiO2) are exposed in fault scarps ~1km SW of the dome. Minor seawater contamination in evolved lavas (> 53 wt % SiO2) is indicated by generally increasing Cl-/K2O with decreasing MgO and increasing SiO2. Three preliminary Sr-isotopic analyses indicate that crustal assimilation and assimilation of altered crustal rocks has been minimal. Major element trends, and a preliminary subset of laser-ablation ICP-MS data, are consistent with extended fractional crystallization from a multiply-saturated parental liquid(s) of limited compositional range. Rare earth element abundances range from 15-150x chondritic, and patterns are coarsely described as flat with moderate LREE-depletion (LaN/CeN ~ 0.8- 0.9). Differentiated lavas have distinct negative Eu-anomalies documenting extensive crystal fractionation of plagioclase in the generation of the more evolved lavas.

Luminescence properties of erbium doped sodium barium borate glass with silver nanoparticles

NASA Astrophysics Data System (ADS)

Rajeshree Patwari, D.; Eraiah, B.

2018-02-01

Alteration in the absorption features of rare earth (RE) doped glasses with silver nanoparticles is ever-challenging in photonics. Erbium (Er3+) doped glasses with composition (60-x-y)B2O3-30Na2CO3-10BaO-xEr2O3-yAgCl where (x=0.5, 1.0 and y=1.0 mol %) are synthesized using melt-quenching method. The density is determined by Archimedes principle and molar volumes are calculated. Glass samples were characterized by XRD and UV-Visible spectroscopy. UV-Visible spectra shows eleven prominent absorption peaks centred around 366, 378, 408, 442, 452, 489, 521, 547, 652, 800 and 977 nm equivalent to the rare earth (Er3+) ion transitions. The sample without rare earth shows no peaks which specifies that rare earth ion plays a spirited role in the glass matrix. The glass samples with silver and without rare earth ion shows plasmon peak on heat treatment. The energy band gap values calculated for direct and indirect transitions are in the range of 3.126-3.440eV and 2.58-3.177eV respectively. The refractive indices and Urbach energies are also determined. Photoluminescence spectra are recorded and studied for excitation of the most intense peaks of wavelengths 378 and 521nm. The luminescence of erbium ion is enhanced by the presence of silver when the concentration of rare earth ion is less than that of silver.

Pickup Ion Mass Spectrometry for Surface Bounded Exospheres and Composition Mapping of Lunar and Planetary Surfaces

NASA Technical Reports Server (NTRS)

Keller, J. W.; Zurbuchen, T. H.; Baragiola, R. A.; Cassidy, T. A.; Chornay, D. J.; Collier, M. R.; Hartle, R. E.; Johnson, R. E.; Killen, R. M.; Koehn, P.

2005-01-01

Many of the small to medium sized objects in the solar system can be characterized as having surface bounded exospheres, or atmospheres so tenuous that scale lengths for inter-particle collisions are much larger than the dimensions of the objects. The atmospheres of these objects are the product of their surfaces, both the surface composition and the interactions that occur on them and also their interiors when gases escape from there. Thus by studying surface bounded exospheres it is possible to develop insight into the composition and processes that are taking place on the surface and interiors of these objects. The Moon and Mercury are two examples of planetary bodies with surface bounded exospheres that have been studied through spectroscopic observations of sodium, potassium, and, on the moon, mass spectrometric measurements of lunar gases such as argon and helium.

Manufacturing issues and optical properties of rare-earth (Y, Lu, Sc, Nd) aluminate garnets composite transparent ceramics

NASA Astrophysics Data System (ADS)

Bonnet, Loïck; Boulesteix, Rémy; Maître, Alexandre; Sallé, Christian; Couderc, Vincent; Brenier, Alain

2015-12-01

In this work, a comparative study of reactive sintering and optical properties of three laser composite transparent ceramics doped with neodymium: Nd:YAG/Nd:YS1AG, Nd:YAG/Nd:LuAG and Nd:YS1AG/Nd:LuAG has been achieved. Samples were manufactured thanks to pressureless co-sintering under vacuum of bilayer powder compacts. The reaction sequence from primary oxides to final garnet phases has been investigated. Similar dilatometric behavior was observed during reactive-sintering for each composition. Differential shrinkage can be thus accommodated to some extent. Second, this work has shown that the intermediate zone at composites interface is composed of single-phased garnet solid-solution with continuous evolution from one side to the other. The thickness of the interdiffusion zone was found to be limited to about 100 μm in all cases and appeared to be well described by classical diffusion laws of Fick and Whipple-Le Claire. The analyses of spectroscopic properties of transparent ceramics composites have finally shown that composite ceramics should be suitable to produce dual wavelength emission for terahertz generation.

Distribution, Community Composition, and Potential Metabolic Activity of Bacterioplankton in an Urbanized Mediterranean Sea Coastal Zone.

PubMed

Richa, Kumari; Balestra, Cecilia; Piredda, Roberta; Benes, Vladimir; Borra, Marco; Passarelli, Augusto; Margiotta, Francesca; Saggiomo, Maria; Biffali, Elio; Sanges, Remo; Scanlan, David J; Casotti, Raffaella

2017-09-01

Bacterioplankton are fundamental components of marine ecosystems and influence the entire biosphere by contributing to the global biogeochemical cycles of key elements. Yet, there is a significant gap in knowledge about their diversity and specific activities, as well as environmental factors that shape their community composition and function. Here, the distribution and diversity of surface bacterioplankton along the coastline of the Gulf of Naples (GON; Italy) were investigated using flow cytometry coupled with high-throughput sequencing of the 16S rRNA gene. Heterotrophic bacteria numerically dominated the bacterioplankton and comprised mainly Alphaproteobacteria , Gammaproteobacteria , and Bacteroidetes Distinct communities occupied river-influenced, coastal, and offshore sites, as indicated by Bray-Curtis dissimilarity, distance metric (UniFrac), linear discriminant analysis effect size (LEfSe), and multivariate analyses. The heterogeneity in diversity and community composition was mainly due to salinity and changes in environmental conditions across sites, as defined by nutrient and chlorophyll a concentrations. Bacterioplankton communities were composed of a few dominant taxa and a large proportion (92%) of rare taxa (here defined as operational taxonomic units [OTUs] accounting for <0.1% of the total sequence abundance), the majority of which were unique to each site. The relationship between 16S rRNA and the 16S rRNA gene, i.e., between potential metabolic activity and abundance, was positive for the whole community. However, analysis of individual OTUs revealed high rRNA-to-rRNA gene ratios for most (71.6% ± 16.7%) of the rare taxa, suggesting that these low-abundance organisms were potentially active and hence might be playing an important role in ecosystem diversity and functioning in the GON. IMPORTANCE The study of bacterioplankton in coastal zones is of critical importance, considering that these areas are highly productive and anthropogenically impacted. Their richness and evenness, as well as their potential activity, are very important to assess ecosystem health and functioning. Here, we investigated bacterial distribution, community composition, and potential metabolic activity in the GON, which is an ideal test site due to its heterogeneous environment characterized by a complex hydrodynamics and terrestrial inputs of varied quantities and quality. Our study demonstrates that bacterioplankton communities in this region are highly diverse and strongly regulated by a combination of different environmental factors leading to their heterogeneous distribution, with the rare taxa contributing to a major proportion of diversity and shifts in community composition and potentially holding a key role in ecosystem functioning. Copyright © 2017 American Society for Microbiology.

Distribution, Community Composition, and Potential Metabolic Activity of Bacterioplankton in an Urbanized Mediterranean Sea Coastal Zone

PubMed Central

Richa, Kumari; Balestra, Cecilia; Piredda, Roberta; Benes, Vladimir; Borra, Marco; Passarelli, Augusto; Margiotta, Francesca; Saggiomo, Maria; Biffali, Elio; Sanges, Remo; Scanlan, David J.

2017-01-01

ABSTRACT Bacterioplankton are fundamental components of marine ecosystems and influence the entire biosphere by contributing to the global biogeochemical cycles of key elements. Yet, there is a significant gap in knowledge about their diversity and specific activities, as well as environmental factors that shape their community composition and function. Here, the distribution and diversity of surface bacterioplankton along the coastline of the Gulf of Naples (GON; Italy) were investigated using flow cytometry coupled with high-throughput sequencing of the 16S rRNA gene. Heterotrophic bacteria numerically dominated the bacterioplankton and comprised mainly Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes. Distinct communities occupied river-influenced, coastal, and offshore sites, as indicated by Bray-Curtis dissimilarity, distance metric (UniFrac), linear discriminant analysis effect size (LEfSe), and multivariate analyses. The heterogeneity in diversity and community composition was mainly due to salinity and changes in environmental conditions across sites, as defined by nutrient and chlorophyll a concentrations. Bacterioplankton communities were composed of a few dominant taxa and a large proportion (92%) of rare taxa (here defined as operational taxonomic units [OTUs] accounting for <0.1% of the total sequence abundance), the majority of which were unique to each site. The relationship between 16S rRNA and the 16S rRNA gene, i.e., between potential metabolic activity and abundance, was positive for the whole community. However, analysis of individual OTUs revealed high rRNA-to-rRNA gene ratios for most (71.6% ± 16.7%) of the rare taxa, suggesting that these low-abundance organisms were potentially active and hence might be playing an important role in ecosystem diversity and functioning in the GON. IMPORTANCE The study of bacterioplankton in coastal zones is of critical importance, considering that these areas are highly productive and anthropogenically impacted. Their richness and evenness, as well as their potential activity, are very important to assess ecosystem health and functioning. Here, we investigated bacterial distribution, community composition, and potential metabolic activity in the GON, which is an ideal test site due to its heterogeneous environment characterized by a complex hydrodynamics and terrestrial inputs of varied quantities and quality. Our study demonstrates that bacterioplankton communities in this region are highly diverse and strongly regulated by a combination of different environmental factors leading to their heterogeneous distribution, with the rare taxa contributing to a major proportion of diversity and shifts in community composition and potentially holding a key role in ecosystem functioning. PMID:28667110

Effect of silver nanoparticles on the fluorescence of Pb2+ and compositional dependence of Sm3+ fluorescence in borate glasses

NASA Astrophysics Data System (ADS)

Olumoroti, Akinloluwa T.

Borate glasses have been widely studied due to their good optical and mechanical properties. Lead and bismuth (PbO/Bi2O 3:B2O3) borate glasses belong to a family of heavy metal oxide (HMO) glasses which are well known to be chemically durable, stable against atmospheric moisture, have low melting temperatures and good corrosion resistance. The first part of this work deals with lead borate glasses with silver nanoparticles (NPs) introduced into the glass matrix. Transmission electron microscopy characterization is done to verify the nucleation of NPs. Fluorescence and optical absorption experiments are then carried out after different heat treatment duration to investigate the influence of silver NPs on the optical properties of lead (Pb2+) by comparing with a glass sample without silver NPs. Optical absorption experiments show that a well-defined surface plasmon resonance (SPR) peak due to Ag NPs can be observed only for samples that were annealed for 36 hrs. Pb2+ fluorescence spectra reveal that the presence of silver NPs creates new emission centers for Pb2+ ions by altering their chemical environment. The second part of the work involves the use of samarium (a rare earth ion) as a dopant in lead and bismuth borate glasses. The concentration of samarium (Sm3+) is fixed and the base glass composition is varied. The goal is to investigate the compositional dependence of optical properties of samarium in the base glass (PbO/Bi2O3:B 2O3). Optical absorption spectra have been collected and the oscillator strength of each transition - including the hypersensitive - is obtained. The Optical absorption edge is found to shift toward lower energies with increasing PbO/Bi2O3 concentration. Both the oscillator strength and the peak position of the hypersensitive transition show significant variation with glass composition. Strong interaction between Sm3+ ions and Pb2+/Bi3+ ions can also be seen from the variations in the fluorescence emission properties of Sm3+ as a function of base glass composition. Studying the variation of these optical properties will help to create the optimum rare-earth ion-host configuration for possible technological applications. This is the thrust of our future investigations of these glass systems. Keywords: Borate glasses, nanoparticles, fluorescence, transmission electron microscopy, optical absorption, surface plasmon resonance, rare-earth (RE) ions, oscillator strength, hypersensitive transition (HST).

Fiscal Year 1986 Technical Objective Document (TOD).

DTIC Science & Technology

1986-03-01

abilties superior to other IR and manual turrets. - START DATE: FY 88 END DATE: FY 90" PROJECT TITLE: COMPOSITE METAL FIRES EE 62:06 JON: 2673XXXX...TECHNOLOGY: FIRE ELEMENT: INTERACTION DESCRIPTION (TECHNICAL OBJECTIVE) Evaluate a new series of agents "BORALONS" capable of extinguishing metal fires and...PROJECT TITLE: COMPOSITE METAL FIRES PE: 63723 JON: 2104XXXX

Lumbar Pseudomeningocele Causing Hydronephrosis

PubMed Central

Hamilton, Rita G; Brown, Steven W; Goetz, Lance L; Miner, Michael

2009-01-01

Background/Objective: Pseudomeningocele is most commonly the result of a rent in the meninges during spine surgery. Noniatrogenic causes exist but are rare. Pseudomeningoceles may heal spontaneously, but they may also slowly enlarge. They rarely present as a mass within the abdomen. The objective of this study was to present the first case report of hydronephrosis secondary to lumbar pseudomeningocele. Design: Single case report and literature review. Methods: Single case report. Results: This man had undergone extensive lumbar spine surgery for pain and spondylolisthesis. He subsequently developed a pseudomeningocele that caused hydronephrosis of the left kidney. He was treated with surgical intervention and had resolution of his hydronephrosis and his flank and groin pain. He also had improvement of his back pain. Conclusions: This report shows an unusual cause of hydronephrosis—a pseudomeningocele presenting as an abdominal mass that compressed the ureter. PMID:19264055

Layered rare-earth hydroxide (LRH, R = Tb, Y) composites with fluorescein: delamination, tunable luminescence and application in chemosensoring for detecting Fe(iii) ions.

PubMed

Su, Feifei; Guo, Rong; Yu, Zihuan; Li, Jian; Liang, Zupei; Shi, Keren; Ma, Shulan; Sun, Genban; Li, Huifeng

2018-04-17

We demonstrate a novel example of tunable luminescence and the application of the delaminated FLN/OS-LRH composites (LRHs are layered rare-earth hydroxides, R = Tb, Y; FLN is the fluorescein named 2-(6-hydroxy-3-oxo-(3H)-xanthen-9-yl)benzoic acid; OS is the anionic surfactant 1-octane sulfonic acid sodium) in detecting Fe(iii) ions. The FLNxOS1-x species (x = 0.02, 0.05, 0.10, and 0.20) are intercalated into the LTbyY1-yH layers (y = 1, 0.9, 0.7, 0.5, 0.3, 0.1 and 0) by ion exchange reactions to yield the composites FLNxOS1-x-LTbyY1-yH. In the solid state, the LYH composites display green emission (564 nm) arising from the organic FLN, while in LTbH composites, the luminescence of the Tb3+ in the layers (545 nm) and the FLN in the interlayers is co-quenched. In the delaminated state in formamide (FM), FLNxOS1-x-LTbH composites display green to yellowish-green luminescence (540-574 nm) following the increasing FLN/OS ratio; while the FLN0.02OS0.98-LTbyY1-yH composites show green emission at ∼540 nm. The fluorescence lifetimes of the composites (4.22-4.63 ns) are comparable to the free FLN-Na, and the quantum yields (31.62-78.70%) of the composites especially that (78.70%) of the FLN0.02OS0.98-LYH are much higher than that (28.40%) of free FLN-Na. The recognition ability of the FLN0.02OS0.98-LYH composite for metal cations is researched. The delaminated FLN0.02OS0.98-LYH colloidal suspension exhibits high selectivity for Fe3+ over other ions (Mg2+, Al3+, Ni2+, Co2+, Cu2+, Zn2+, Mn2+, Pb2+, and Cd2+) with fluorescence quenching, which can work as a kind of turn-off fluorescence sensor for the detection of Fe3+. The detection limit of Fe3+ is determined to be 2.58 × 10-8 M and the quenching constant (Ksv) is 1.70 × 103 M-1. This is the first work on LRH materials working as a chemosensor for recognising metal cations. It provides a new approach for the design of LRH materials to be applied in fluorescence chemosensing.

The Mission Accessible Near-Earth Object Survey (MANOS): Project Status

NASA Astrophysics Data System (ADS)

Moskovitz, Nicholas; Thirouin, Audrey; Mommert, Michael; Thomas, Cristina A.; Skiff, Brian; Polishook, David; Burt, Brian; Trilling, David E.; DeMeo, Francesca E.; Binzel, Richard P.; Christensen, Eric J.; Willman, Mark; Hinkle, Mary

2017-10-01

The Mission Accessible Near-Earth Object Survey (MANOS) is a physical characterization survey of sub-km, low delta-v, newly discovered near-Earth objects (NEOs). MANOS aims to collect astrometry, lightcurve photometry, and reflectance spectra for a representative sample of these important target of opportunity objects in a rarely observed size range. We employ a diverse set of large aperture (2-8 meter) telescopes and observing modes (queue, remote, classical) to overcome the challenge of observing faint NEOs moving at high non-sidereal rates with short observing windows. We target approximately 10% of newly discovered NEOs every month for follow-up characterization.The first generation MANOS ran from late 2013 to early 2017, using telescopes at Lowell Observatory, NOAO, and the University of Hawaii. This resulted in the collection of data for over 500 targets. These data are continuing to provide new insights into the NEO population as a whole as well as for individual objects of interest. Science highlights include identification of the four fastest rotating minor planets found to date with rotation periods under 20 seconds, constraints on the distribution of NEO morphologies as quantified by de-biased estimates for lightcurve-derived axis ratios, and the compositional distribution of NEOs at sizes under 100 meters.The second generation MANOS will begin in late 2017 and will employ much of the same strategies while continuing to build a comprehensive dataset of NEO physical properties. This will grow the MANOS sample to ~1000 objects and provide the means to better address key questions related to understanding the physical properties of NEOs, their viability as exploration mission targets, and their relationship to Main Belt asteroids and meteorites. This continuation of MANOS will include an increased focus on spectroscopic observations at near-IR wavelengths using a new instrument called NIHTS (the Near-Infrared High-Throughput Spectrograph) at Lowell Observatory’s 4.3m Discovery Channel Telescope.We will present key results from the first generation survey and current status and plans for the second generation survey. MANOS is supported by the NASA SSO/NEOO program.

Sensitive Optical and Microfluidic Systems for Cellular Analyses

NASA Astrophysics Data System (ADS)

Schiro, Perry G.

Investigating rare cells and heterogeneous subpopulations is challenging for a myriad reasons. This dissertation describes novel techniques to analyze single molecules, synaptic vesicles, and rare circulating tumor cells. The eDAR platform for isolating rare cells in fluids provides a new method to monitor breast cancer status in patients as well as to guide research for personalized treatment and efficacy. In a side-by-side comparison with CellSearch, eDAR detected CTCs in all 20 Stage IV metastatic breast cancer patients while the CellSearch system found CTCs in just 8 patients. The single-molecule capillary electrophoresis technology is a method to characterize an entire sample one molecule at a time, providing detailed information about the absolute number and nature of molecules present in a sample. The nFASS platform has the potential to apply the advantages that currently exist in flow cytometry to the study of items on a much smaller scale such as subcellular organelles and nanometer-sized objects. For example, the isolation of subpopulations of synaptic vesicles will allow for detailed protein quantification and identification in the study of neurological diseases. These tools facilitate fundamental investigation of objects ranging from single molecules to single cells.

Influence of rare earth content on Mm-based AB 5 metal hydride alloys for Ni-MH batteries-An X-ray fluorescence study

NASA Astrophysics Data System (ADS)

Ananth, M. V.; Raju, M.; Manimaran, K.; Balachandran, G.; Nair, Lekshmi M.

AB 5-type MH alloys with Mm (Misch metal) as the A part (with varied rare earth contents in Mm) were investigated for rare earth by XRF analysis and battery performance by life cycle tests with an objective of understanding the influence of rare earth content on electrochemical hydrogen storage. The La/Ce ratio was found to vary from 0.51 to 18.73. The capacity output varied between 179 and 266 mAh g -1. The results show that the La/Ce ratio has a strong influence on the performance, with the best performance realized with samples having an La/Ce ratio of around 12. La enhancement facilitates easy activation due to refinement in grain size and interstitial dimensions. Also, an orderly influence on crystalline structure could be seen. The study demonstrates that the rare earth content is an essential factor in determining the maximum capacity output because of its influence on crystal orientation as well as an increase in the radius of the interstitials, lattice constants and cell volumes.

Conceptualization and Implementation of the Central Information Portal on Rare Diseases: Protocol for a Qualitative Study

PubMed Central

Hartz, Tobias; Göbel, Jens; Storf, Holger; Pauer, Frédéric; Babac, Ana; Lührs, Verena; Bruckner-Tuderman, Leena; Schauer, Franziska; Schmidtke, Jörg; Biehl, Lisa; Wagner, TOF; Graf von der Schulenburg, J-Matthias; Frank, Martin

2018-01-01

Background Recently, public and political interest has focused on people living with rare diseases and their health concerns. Due to the large number of different types of rare diseases and the sizable number of patients, taking action to improve the life of those affected is gaining importance. In 2013, the federal government of Germany adopted a national action plan for rare diseases, including the call to establish a central information portal on rare diseases (Zentrales Informationsportal über seltene Erkrankungen, ZIPSE). Objective The objective of this study, therefore, was to conduct scientific research on how such a portal must be designed to meet the needs of patients, their families, and medical professionals, and to provide high-quality information for information seekers. Methods We chose a 3-step procedure to develop a needs-based prototype of a central information portal. In the first step, we determined the information needs of patients with rare diseases, their relatives, and health care professionals by means of qualitative interviews and their content-analytical evaluation. On the basis of this, we developed the basic structure of the portal. In the second step, we identified quality criteria for websites on rare diseases to ensure that the information linked with ZIPSE meets the quality demands. Therefore, we gathered existing criteria catalogs and discussed them in an expert workshop. In the third step, we implemented and tested the developed prototypical information portal. Results A portal page was configured and made accessible on the Web. The structure of ZIPSE was based on the findings from 108 qualitative interviews with patients, their relatives, and health care professionals, through which numerous information needs were identified. We placed particularly important areas of information, such as symptoms, therapy, research, and advisory services, on the start page. Moreover, we defined 13 quality criteria, referring to factors such as author information, creation date, and privacy, enabling links with high-quality information. Moreover, 19 users tested all the developed routines based on usability and comprehensibility. Subsequently, we improved the visual presentation of search results and other important search functions. Conclusions The implemented information portal, ZIPSE, provides high-quality information on rare diseases from a central point of access. By integrating the targeted groups as well as different experts on medical information during the construction, the website can assure an improved search for information for users. ZIPSE can also serve as a model for other Web-based information systems in the field of rare diseases. Registered Report Identifier RR1-10.2196/7425 PMID:29752252

The Development of a New Analytical Model for the Identification of Saccharide Binders in Paint Samples

PubMed Central

Restivo, Annalaura; Colombini, Maria Perla; Bonaduce, Ilaria

2012-01-01

This paper describes a method for reliably identifying saccharide materials in paintings. Since the 3rd millennium B.C., polysaccharide materials such as plant gums, sugar, flour, and honey were used as binding media and sizing agents in paintings, illuminated manuscripts, and polychrome objects. Although it has been reported that plant gums have a stable composition, their identification in paint samples is often doubtful and rarely discussed. Our research was carried out independently at two different laboratories: the Getty Conservation Institute in Los Angeles, USA (GCI) and the Department of Chemistry and Industrial Chemistry of the University of Pisa, Italy (DCCI). It was shown in a previous stage of this research that the two methods give highly comparable data when analysing both reference paint samples and paint layers from art objects, thus the combined data was used to build a large database. In this study, the simultaneous presence of proteinaceous binders and pigments in fresh and artificially aged paint replicas was investigated, and it highlighted how these can affect the sugar profile of arabic, tragacanth, and fruit tree gums. The environmental contamination due to sugars from various plant tissues is also discussed. The results allowed the development of a new model for the reliable identification of saccharide binders in paintings based on the evaluation of markers that are stable to ageing and unaffected by pigments. This new model was applied to the sugar profiles obtained from the analysis of a large number of samples from murals, easel paintings, manuscripts, and polychrome objects from different geographical areas and dating from the 13th century BC to the 20th century AD, thus demonstrating its reliability. PMID:23166654

The development of a new analytical model for the identification of saccharide binders in paint samples.

PubMed

Lluveras-Tenorio, Anna; Mazurek, Joy; Restivo, Annalaura; Colombini, Maria Perla; Bonaduce, Ilaria

2012-01-01

This paper describes a method for reliably identifying saccharide materials in paintings. Since the 3(rd) millennium B.C., polysaccharide materials such as plant gums, sugar, flour, and honey were used as binding media and sizing agents in paintings, illuminated manuscripts, and polychrome objects. Although it has been reported that plant gums have a stable composition, their identification in paint samples is often doubtful and rarely discussed. Our research was carried out independently at two different laboratories: the Getty Conservation Institute in Los Angeles, USA (GCI) and the Department of Chemistry and Industrial Chemistry of the University of Pisa, Italy (DCCI). It was shown in a previous stage of this research that the two methods give highly comparable data when analysing both reference paint samples and paint layers from art objects, thus the combined data was used to build a large database. In this study, the simultaneous presence of proteinaceous binders and pigments in fresh and artificially aged paint replicas was investigated, and it highlighted how these can affect the sugar profile of arabic, tragacanth, and fruit tree gums. The environmental contamination due to sugars from various plant tissues is also discussed. The results allowed the development of a new model for the reliable identification of saccharide binders in paintings based on the evaluation of markers that are stable to ageing and unaffected by pigments. This new model was applied to the sugar profiles obtained from the analysis of a large number of samples from murals, easel paintings, manuscripts, and polychrome objects from different geographical areas and dating from the 13(th) century BC to the 20(th) century AD, thus demonstrating its reliability.

A Method for Evaluating Outcomes of Restoration When No Reference Sites Exist

Treesearch

J. Stephen Brewer; Timothy Menzel

2009-01-01

Ecological restoration typically seeks to shift species composition toward that of existing reference sites. Yet, comparing the assemblages in restored and reference habitats assumes that similarity to the reference habitat is the optimal outcome of restoration and does not provide a perspective on regionally rare off-site species. When no such reference assemblages of...

Using the Institutional Database to Examine Student Diversity by School

ERIC Educational Resources Information Center

Cerrito, Patricia B.; Hook, Arnold

2006-01-01

While it is common to report the percentage of minority and female students attending universities, it is rare to perform a detailed examination of the overall composition of the student body, particularly, the proportion of International students. It is the purpose of this study to examine the proportion of International Students by School from…

Writing and Writer Identity: The Poor Relation and The Search for Voice in "Personal Literacy"

ERIC Educational Resources Information Center

Gardner, Paul

2018-01-01

The teaching of writing has been a relatively neglected aspect of research in literacy. Cultural and socio-economic reasons for this are suggested. In addition, teachers often readily acknowledge themselves as readers, but rarely as writers. Without a solid grasp of compositional processes, teachers are perhaps prone to adopt schemes that promote…

Managing composition of piedmont forests with prescribed fire

Treesearch

Kenneth W. Outcalt

2006-01-01

Native Americans used frequent burning of forests in the South's Piedmont to maintain pine-dominated stands, to favor oak regeneration over other hardwoods, and to keep understories open. From 1950 to 1990, fire occurred rarely in the region, resulting in a gradual replacement of pines with hardwoods. More recently, however, prescribed burning has been used much...

Second Language Writing and Bidialectalism: A Case for African American Student Writers

ERIC Educational Resources Information Center

DePolo, Jason

2017-01-01

There has been much research conducted on second language writing. In addition, there exists a significant amount of studies conducted with African American student writers. However, the fields of Second Language Writing and Composition Studies rarely if ever dovetail in the research literature. The purpose of this article is to argue how English…

Growth, nutritional, and gastrointestinal aspects of ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC) syndrome

USDA-ARS?s Scientific Manuscript database

Ankyloblepharon-ectodermal defect-cleft lip and/or palate (AEC), is a rare genetic disorder due to mutations in the TP63 gene. In the present study, we characterized the pattern of growth and body composition, and the nutritional and gastrointestinal aspects of children and adults (n = 18) affected ...

Focal necrosis mimicking breast cancer following coronary bypass grafting.

PubMed

Coufal, Oldřich; Ostřížek, Tomáš; Krsička, Petr; Lžičařová, Eva; Nenutil, Rudolf; Procházková, Monika; Bencsiková, Beatrix; Grell, Peter; Šefr, Roman

2017-05-30

Breast cancer can be diagnosed easily in most cases. However, occasionally, we are faced with some conditions that can mimic it. These may include inflammations, benign tumors, cysts, hematomas, or, more rarely, focal necrosis. This report presents a case of focal breast necrosis following myocardial revascularization with the left internal mammary artery, which is a very rare condition, with only few cases described in the literature. The necrosis becomes usually apparent a few days or weeks after the surgery and is often coincidental with the dehiscence of sternotomy with necrosis of wound edges. As it mostly affects the skin, it can be easily recognized. Also, our patient developed a dehisced sternotomy shortly after the surgery but there were no obvious objective changes on the breast. The condition was first dominated only by non-specific subjective symptom-pain. Later, a lump in the breast occurred, when the sternotomy had already healed. Moreover, an enlarged lymph node was palpable in the axilla. Because of non-typical symptoms, the condition was suggestive of breast cancer for a relatively long time. The patient had suffered from a very strong pain until she was treated by mastectomy with a good clinical result. Mammary necrosis following the coronary artery bypass is rare. In most cases, it manifests on the skin shortly after the surgery concurrently with dehisced sternotomy, so it can be easily diagnosed. However, in sporadic cases, the symptoms may occur later and may mimic breast cancer. Our objective is to raise awareness of this rare condition.

Synthesis of functional materials in combustion reactions

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

Zhuravlev, V. D., E-mail: zhvd@ihim.uran.ru; Bamburov, V. G.; Ermakova, L. V.

2015-12-15

The conditions for obtaining oxide compounds in combustion reactions of nitrates of metals with organic chelating–reducing agents such as amino acids, urea, and polyvinyl alcohol are reviewed. Changing the nature of internal fuels and the reducing agent-to-oxidizing agent ratio makes possible to modify the thermal regime of the process, fractal dimensionality, morphology, and dispersion of synthesized functional materials. This method can be used to synthesize simple and complex oxides, composites, and metal powders, as well as ceramics and coatings. The possibilities of synthesis in combustion reactions are illustrated by examples of αand γ-Al{sub 2}O{sub 3}, YSZ composites, uranium oxides, nickelmore » powder, NiO and NiO: YSZ composite, TiO{sub 2}, and manganites, cobaltites, and aluminates of rare earth elements.« less

Review of the geochemistry and metallogeny of approximately 1.4 Ga granitoid intrusions of the conterminous United States

USGS Publications Warehouse

du Bray, Edward A.; Holm-Denoma, Christopher S.; Lund, Karen; Premo, Wayne R.

2018-03-27

The conterminous United States hosts numerous volumetrically significant and geographically dispersed granitoid intrusions that range in age from 1.50 to 1.32 billion years before present (Ga). Although previously referred to as A-type granites, most are better described as ferroan granites. These granitoid intrusions are distributed in the northern and central Rocky Mountains, the Southwest, the northern midcontinent, and a swath largely buried beneath Phanerozoic cover across the Great Plains and into the southern midcontinent. These intrusions, with ages that are bimodally distributed between about 1.455–1.405 Ga and 1.405–1.320 Ga, are dispersed nonsystematically with respect to age across their spatial extents. Globally, although A-type or ferroan granites are genetically associated with rare-metal deposits, most U.S. 1.4 Ga granitoid intrusions do not contain significant deposits. Exceptions are the light rare-earth element deposit at Mountain Pass, California, and the iron oxide-apatite and iron oxide-copper-gold deposits in southeast Missouri.Most of the U.S. 1.4 Ga granitoid intrusions are composed of hornblende ± biotite or biotite ± muscovite monzogranite, commonly with prominent alkali feldspar megacrysts; however, modal compositions vary widely. These intrusions include six of the eight commonly identified subtypes of ferroan granite: alkali-calcic and calc-alkalic peraluminous subtypes; alkalic, alkali-calcic, and calc-alkalic metaluminous subtypes; and the alkalic peralkaline subtype. The U.S. 1.4 Ga granitoid intrusions also include variants of these subtypes that have weakly magnesian compositions. Extreme large-ion lithophile element enrichments typical of ferroan granites elsewhere are absent among these intrusions. Chondrite-normalized rare-earth element patterns for these intrusions have modest negative slopes and moderately developed negative europium anomalies. Their radiogenic isotopic compositions are consistent with mixing involving primitive, mantle-derived components and evolved, crust-derived components.Each compositional subtype can be ascribed to a relatively unique petrogenetic history. The numerically dominant ferroan, peraluminous granites probably represent low-degree, relatively high-pressure partial melting of preexisting, crust-derived, intermediate-composition granitoids. The moderately numerous, weakly magnesian, peraluminous granites probably reflect similar partial melting but at a higher degree and in a lower pressure environment. In contrast, the ferroan but metaluminous granites may be the result of extensive differentiation of tholeiitic basalt. Finally, the peralkaline igneous rocks at Mountain Pass have compositions potentially derived by differentiation of alkali basalt. The varying alkalic character of each subtype probably reflects polybaric petrogenesis and the corresponding effect of diverse mineral stabilities on ultimate melt compositions. Mantle-derived mafic magma and variably assimilated partial melts of mainly juvenile Paleoproterozoic crustal components are required to generate the relatively low initial strontium (87Sr/86Sr) and distinctive neodymium isotope compositions characteristic of the U.S. 1.4 Ga granitoid intrusions. The characteristics of these intrusions are consistent with crustal melting in an extensional/decompressional, intracratonic setting that was triggered by mantle upwelling and emplacement of tholeiitic basaltic magma at or near the base of the crust. Composite magmas, formed by mingling and mixing mantle components with partial melts of Paleoproterozoic crust, produced variably homogenized storage reservoirs that continued polybaric evolution as intrusions lodged at various crustal depths.

Rare Disease Terminology and Definitions-A Systematic Global Review: Report of the ISPOR Rare Disease Special Interest Group.

PubMed

Richter, Trevor; Nestler-Parr, Sandra; Babela, Robert; Khan, Zeba M; Tesoro, Theresa; Molsen, Elizabeth; Hughes, Dyfrig A

2015-09-01

At present, there is no universal definition of rare disease. To provide an overview of rare disease definitions currently used globally. We systematically searched for definitions related to rare disease from organizations in 32 international jurisdictions. Descriptive statistics of definitions were generated and prevalence thresholds were calculated. We identified 296 definitions from 1109 organizations. The terms "rare disease(s)" and "orphan drug(s)" were used most frequently (38% and 27% of the definitions, respectively). Qualitative descriptors such as "life-threatening" were used infrequently. A prevalence threshold was specified in at least one definition in 88% of the jurisdictions. The average prevalence threshold across organizations within individual jurisdictions ranged from 5 to 76 cases/100,000 people. Most jurisdictions (66%) had an average prevalence threshold between 40 and 50 cases/100,000 people, with a global average of 40 cases/100,000 people. Prevalence thresholds used by different organizations within individual jurisdictions varied substantially. Across jurisdictions, umbrella patient organizations had the highest (most liberal) average prevalence threshold (47 cases/100,000 people), whereas private payers had the lowest threshold (18 cases/100,000 people). Despite variation in the terminology and prevalence thresholds used to define rare diseases among different jurisdictions and organizations, the terms "rare disease" and "orphan drug" are used most widely and the average prevalence threshold is between 40 and 50 cases/100,000 people. These findings highlight the existing diversity among definitions of rare diseases, but suggest that any attempts to harmonize rare disease definitions should focus on standardizing objective criteria such as prevalence thresholds and avoid qualitative descriptors. Copyright © 2015 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

The Rare Disease Bank of Japan: establishment, current status and future challenges.

PubMed

Tada, Mayako; Hirata, Makoto; Sasaki, Mitsuho; Sakate, Ryuichi; Kohara, Arihiro; Takahashi, Ichiro; Kameoka, Yosuke; Masui, Toru; Matsuyama, Akifumi

2018-04-02

Research on rare diseases cannot be performed without appropriate samples from patients with such diseases. Due to the limited number of such patients, securing biosamples of sufficient quality for extensive research is a challenge and represents an important barrier to the advancement of research on rare diseases. To tackle this problem, the Rare Disease Bank (RDB) was established in 2009 at the National Institute of Biomedical Innovation (NIBIO; currently, the National Institutes of Biomedical Innovation, Health and Nutrition in Japan). Since then, the RDB has focused on three objectives: (1) emphasizing the importance of collecting biosamples from patients with rare diseases, together with appropriate clinical information, from various medical facilities nationwide; (2) maintaining strict high-quality sample management standards; and (3) sharing biosamples with research scientists across Japan for the advancement of research on rare diseases. As of August 2017, the bank has collected 4147 biosamples from patients with rare diseases, including DNA, serum, plasma, and cell samples from various university hospitals and other medical institutions across the country, and provided various research institutions with 13,686 biosample aliquots from 2850 cases. In addition, the management committee has successfully established a bank system that provides high-quality biosamples together with the results of human leukocyte antigen analysis. It is anticipated that the RDB, through the collection and sharing of biosamples with the medical research community, will enhance the understanding, prevention, and treatment of rare diseases in Japan and the world at large.

Echocardiographic diagnosis of rare pathological patterns of sinus of Valsalva aneurysm

PubMed Central

Wang, Xinfang; Lü, Qing; He, Lin; Wang, Jing; Wang, Bin; Li, Ling; Yuan, Li; Liu, Jinfeng; Ge, Shuping; Xie, Mingxing

2017-01-01

Objective To evaluate the value and improve the diagnostic accuracy of echocardiography in the diagnosis of a sinus of Valsalva aneurysm (SVA) with rare pathological patterns. Methods Echocardiographic features and surgical findings from 270 Chinese patients with SVA treated in the last 18 years (1995–2013) at the Union Hospital were compared retrospectively; 22 of 270 cases had rare patterns. Results The patients with SVA, a rare origin, a rare extending position, or a rare course accounted for 3.4%, 7.4%, and 0.4% of the 270 cases, respectively. The three most common aneurysmal complications of the patients with rare patterns were severe aortic regurgitation (16), obstruction of the ventricular outflow tract or valvular orifice (3), and conduction disturbance (3). The origin, course, extending position and rupture status of the SVAs determined by echocardiography were entirely consistent with surgical findings in 81.8% of the 22 cases. With the exception of one failed diagnosis of an aneurysmal wall dissection and one misdiagnosis of a descending aortic dissection, the echocardiographic results of SVA complications and associated cardiovascular lesions were also confirmed. Conclusion We could accurately diagnose SVAs with rare pathological patterns by echocardiographic identification of distinguishing features. However, for several conditions, we could not accurately identify the origin or course of the aneurysm or define its relationship to adjacent structures using conventional echocardiography alone. Therefore, we recommend combining conventional echocardiography with different imaging techniques, such as transesophageal echocardiography, three-dimensional echocardiography, computed tomography angiography, and aortic angiography. PMID:28291779

Geochemical fractions of rare earth elements in soil around a mine tailing in Baotou, China

PubMed Central

Wang, Lingqing; Liang, Tao

2015-01-01

Rare earth mine tailing dumps are environmental hazards because tailing easily leaches and erodes by water and wind. To assess the influence of mine tailing on the geochemical behavior of rare earth elements (REEs) in soil, sixty-seven surface soil samples and three soil profile samples were collected from different locations near China’s largest rare earth mine tailing. The total concentration of REEs in surface soils ranged from 156 to 5.65 × 104 mg·kg−1 with an average value of 4.67 × 103 mg·kg−1, which was significantly higher than the average value in China (181 mg·kg−1). We found obvious fractionation of both light and heavy REEs, which was supported by the North American Shale Composite (NASC) and the Post-Archean Average Australian Shale (PAAS) normalized concentration ratios calculated for selected elements (LaN/YbN, LaN/SmN and GdN/YbN). A slightly positive Ce anomaly and a negative Eu anomaly were also found. For all 14 REEs in soils, enrichment was intensified by the mine tailing sources and influenced by the prevailing wind. PMID:26198417

A general route to hollow mesoporous rare-earth silicate nanospheres as a catalyst support.

PubMed

Jin, Renxi; Yang, Yang; Zou, Yongcun; Liu, Xianchun; Xing, Yan

2014-02-17

Hollow mesoporous structures have recently aroused intense research interest owing to their unique structural features. Herein, an effective and precisely controlled synthesis of hollow rare-earth silicate spheres with mesoporous shells is reported for the first time, produced by a simple hydrothermal method, using silica spheres as the silica precursors. The as-prepared hollow rare-earth silicate spheres have large specific surface area, high pore volume, and controllable structure parameters. The results demonstrate that the selection of the chelating reagent plays critical roles in forming the hollow mesoporous structures. In addition, a simple and low-energy-consuming approach to synthesize highly stable and dispersive gold nanoparticle-yttrium silicate (AuNPs/YSiO) hollow nanocomposites has also been developed. The reduction of 4-nitrophenol with AuNPs/YSiO hollow nanocomposites as the catalyst has clearly demonstrated that the hollow rare-earth silicate spheres are good carriers for Au nanoparticles. This strategy can be extended as a general approach to prepare multifunctional yolk-shell structures with diverse compositions and morphologies simply by replacing silica spheres with silica-coated nanocomposites. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Geochemical fractions of rare earth elements in soil around a mine tailing in Baotou, China.

PubMed

Wang, Lingqing; Liang, Tao

2015-07-22

Rare earth mine tailing dumps are environmental hazards because tailing easily leaches and erodes by water and wind. To assess the influence of mine tailing on the geochemical behavior of rare earth elements (REEs) in soil, sixty-seven surface soil samples and three soil profile samples were collected from different locations near China's largest rare earth mine tailing. The total concentration of REEs in surface soils ranged from 156 to 5.65 × 10(4) mg·kg(-1) with an average value of 4.67 × 10(3) mg·kg(-1), which was significantly higher than the average value in China (181 mg·kg(-1)). We found obvious fractionation of both light and heavy REEs, which was supported by the North American Shale Composite (NASC) and the Post-Archean Average Australian Shale (PAAS) normalized concentration ratios calculated for selected elements (La(N)/Yb(N), La(N)/Sm(N) and Gd(N)/Yb(N)). A slightly positive Ce anomaly and a negative Eu anomaly were also found. For all 14 REEs in soils, enrichment was intensified by the mine tailing sources and influenced by the prevailing wind.

[Mechanical property of tooth-like yttria-stabilized tetragonal zirconia polycrystal by adding rare earth oxide].

PubMed

Gao, Yan; Zhang, Fuqiang; Gao, Jianhua

2012-02-01

To evaluate the influence of mechanical property of tooth-like yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) by adding rare earth oxide as colorants. Six kinds of tooth-like Y-TZP were made by introducing internal coloration technology. The colorants included rare earth oxide (Pr6O11, CeO2, Er2O3) and transition element oxide (MnO2). Mechanical properties (flexural strength, vickers hardness and fracture toughness) were tested. Microstructure was examined by scanning electron microscope(SEM), and the fracture model was analyzed. The range of flexural strength of the six kinds of tooth-like Y-TZP were (792 +/- 20)-(960 +/- 17) MPa, the fracture toughness were (4.72 +/- 0.31)-(5.64 +/- 0.38) MPam(1/2), and the vickers hardness were (1332 +/- 19)-(1380 +/- 17) MPa. SEM observation on the cross section of the six kinds of sintered composites showed a relatively dense polycrystal structure, and the fracture models was mixed type. Tooth-like Y-TZP is acquired with better mechanical properties (fracture toughness and vickers hardness) by adding rare earth oxide as colorants. It is available for clinical application.

Design, fabrication and characterization of an arrayable all-polymer microfluidic valve employing highly magnetic rare-earth composite polymer

NASA Astrophysics Data System (ADS)

Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

2016-05-01

We present a new magnetically actuated microfluidic valve that employs a highly magnetic composite polymer (M-CP) containing rare-earth hard-magnetic powder for its actuating element and for its valve seat. The M-CP offers much higher magnetization compared to the soft-magnetic, ferrite-based composite polymers typically used in microfluidic applications. Each valve consists of a permanently magnetized M-CP flap and valve seat mounted on a microfluidic channel system fabricated in poly(dimethylsiloxane) (PDMS). Each valve is actuated under a relatively small external magnetic field of 80 mT provided by a small permanent magnet mounted on a miniature linear actuator. The performance of the valve with different flap thicknesses is characterized. In addition, the effect of the magnetic valve seat on the valve’s performance is also characterized. It is experimentally shown that a valve with a 2.3 mm flap thickness, actuated under an 80 mT magnetic field, is capable of completely blocking liquid flow at a flow rate of 1 ml min-1 for pressures up to 9.65 kPa in microfluidic channels 200 μm wide and 200 μm deep. The valve can also be fabricated into an array for flow switching between multiple microfluidic channels under continuous flow conditions. The performance of arrays of valves for flow routing is demonstrated for flow rates up to 5 ml min-1 with larger microfluidic channels of up to 1 mm wide and 500 μm deep. The design of the valves is compatible with other commonly used polymeric microfluidic components, as well as other components that use the same novel permanently magnetic composite polymer, such as our previously reported cilia-based mixing devices.

Medical imaging scintillators from glass-ceramics using mixed rare-earth halides

NASA Astrophysics Data System (ADS)

Beckert, M. Brooke; Gallego, Sabrina; Ding, Yong; Elder, Eric; Nadler, Jason H.

2016-10-01

Recent years have seen greater interest in developing new luminescent materials to replace scintillator panels currently used in medical X-ray imaging systems. The primary areas targeted for improvement are cost and image resolution. Cost reduction is somewhat straightforward in that less expensive raw materials and processing methods will yield a less expensive product. The path to improving image resolution is more complex because it depends on several properties of the scintillator material including density, transparency, and composition, among others. The present study focused on improving image resolution using composite materials, known as glass-ceramics that contain nanoscale scintillating crystallites formed within a transparent host glass matrix. The small size of the particles and in-situ precipitation from the host glass are key to maintaining transparency of the composite scintillator, which ensures that a majority of the light produced from absorbed X-rays can actually be used to create an image of the patient. Because light output is the dominating property that determines the image resolution achievable with a given scintillator, it was used as the primary metric to evaluate performance of the glass-ceramics relative to current scintillators. Several glass compositions were formulated and then heat treated in a step known as "ceramization" to grow the scintillating nanocrystals, whose light output was measured in response to a 65 kV X-ray source. Performance was found to depend heavily on the thermal history of the glass and glass-ceramic, and so additional studies are required to more precisely determine optimal process temperatures. Of the compositions investigated, an alumino-borosilicate host glass containing 56mol% scintillating rare-earth halides (BaF2, GdF3, GdBr3, TbF3) produced the highest recorded light output at nearly 80% of the value recorded using a commercially-available GOS:Tb panel as a reference.

Magnetic Partitioning Nanofluid for Rare Earth Extraction from Geothermal Fluids

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

McGrail, Bernard P.; Thallapally, Praveen K.; Liu, Jian

Rare earth metals are critical materials in a wide variety of applications in generating and storing renewable energy and in designing more energy efficient devices. Extracting rare earth metals from geothermal brines is a very challenging problem due to the low concentrations of these elements and engineering challenges with traditional chemical separations methods involving packed sorbent beds or membranes that would impede large volumetric flow rates of geothermal fluids transitioning through the plant. We are demonstrating a simple and highly cost-effective nanofluid-based method for extracting rare earth metals from geothermal brines. Core-shell composite nanoparticles are produced that contain a magneticmore » iron oxide core surrounded by a shell made of silica or metal-organic framework (MOF) sorbent functionalized with chelating ligands selective for the rare earth elements. By introducing the nanoparticles at low concentration (≈0.05 wt%) into the geothermal brine after it passes through the plant heat exchanger, the brine is exposed to a very high concentration of chelating sites on the nanoparticles without need to pass through a large and costly traditional packed bed or membrane system where pressure drop and parasitic pumping power losses are significant issues. Instead, after a short residence time flowing with the brine, the particles are effectively separated out with an electromagnet and standard extraction methods are then applied to strip the rare earth metals from the nanoparticles, which are then recycled back to the geothermal plant. Recovery efficiency for the rare earths at ppm level has now been measured for both silica and MOF sorbents functionalized with a variety of chelating ligands. A detailed preliminary techno-economic performance analysis of extraction systems using both sorbents showed potential to generate a promising internal rate of return (IRR) up to 20%.« less

Patterns and Processes in Marine Microeukaryotic Community Biogeography from Xiamen Coastal Waters and Intertidal Sediments, Southeast China

PubMed Central

Chen, Weidong; Pan, Yongbo; Yu, Lingyu; Yang, Jun; Zhang, Wenjing

2017-01-01

Microeukaryotes play key roles in the structure and functioning of marine ecosystems. Little is known about the relative importance of the processes that drive planktonic and benthic microeukaryotic biogeography in subtropical offshore areas. This study compares the microeukaryotic community compositions (MCCs) from offshore waters (n = 12) and intertidal sediments (n = 12) around Xiamen Island, southern China, using high-throughput sequencing of 18S rDNA. This work further quantifies the relative contributions of spatial and environmental variables on the distribution of marine MCCs (including total, dominant, rare and conditionally rare taxa). Our results showed that planktonic and benthic MCCs were significantly different, and the benthic richness (6627 OTUs) was much higher than that for plankton (4044 OTUs) with the same sequencing effort. Further, we found that benthic MCCs exhibited a significant distance-decay relationship, whereas the planktonic communities did not. After removing two unique sites (N2 and N3), however, 72% variation in planktonic community was explained well by stochastic processes. More importantly, both the environmental and spatial factors played significant roles in influencing the biogeography of total and dominant planktonic and benthic microeukaryotic communities, although their relative effects on these community variations were different. However, a high proportion of unexplained variation in the rare taxa (78.1–97.4%) and conditionally rare taxa (49.0–81.0%) indicated that more complex mechanisms may influence the assembly of the rare subcommunity. These results demonstrate that patterns and processes in marine microeukaryotic community assembly differ among the different habitats (coastal water vs. intertidal sediment) and different communities (total, dominant, rare and conditionally rare microeukaryotes), and provide novel insight on the microeukaryotic biogeography and ecological mechanisms in coastal waters and intertidal sediments at local scale. PMID:29075237

Historical Photos, Artwork, and Objects - Naval Oceanography Portal

Science.gov Websites

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Inhibited solid propellant composition containing beryllium hydride

NASA Technical Reports Server (NTRS)

Thompson, W. W. (Inventor)

1978-01-01

An object of this invention is to provide a composition of beryllium hydride and carboxy-terminated polybutadiene which is stable. Another object of this invention is to provide a method for inhibiting the reactivity of beryllium hydride toward carboxy-terminated polybutadiene. It was found that a small amount of lecithin inhibits the reaction of beryllium hydride with the acid groups in carboxy terminated polybutadiene.

Optimal dietary energy and amino acids for gilt development: Growth, body composition, feed intake, and carcass composition traits

USDA-ARS?s Scientific Manuscript database

The objective of this study was to manipulate the lean to fat ratio by feeding diets differing in lysine and metabolizable energy (ME) content to replacement gilts from 100 d to 260 d of age. A secondary objective was to evaluate lysine and caloric efficiency between dietary treatments fed to develo...

Fast processing of microscopic images using object-based extended depth of field.

PubMed

Intarapanich, Apichart; Kaewkamnerd, Saowaluck; Pannarut, Montri; Shaw, Philip J; Tongsima, Sissades

2016-12-22

Microscopic analysis requires that foreground objects of interest, e.g. cells, are in focus. In a typical microscopic specimen, the foreground objects may lie on different depths of field necessitating capture of multiple images taken at different focal planes. The extended depth of field (EDoF) technique is a computational method for merging images from different depths of field into a composite image with all foreground objects in focus. Composite images generated by EDoF can be applied in automated image processing and pattern recognition systems. However, current algorithms for EDoF are computationally intensive and impractical, especially for applications such as medical diagnosis where rapid sample turnaround is important. Since foreground objects typically constitute a minor part of an image, the EDoF technique could be made to work much faster if only foreground regions are processed to make the composite image. We propose a novel algorithm called object-based extended depths of field (OEDoF) to address this issue. The OEDoF algorithm consists of four major modules: 1) color conversion, 2) object region identification, 3) good contrast pixel identification and 4) detail merging. First, the algorithm employs color conversion to enhance contrast followed by identification of foreground pixels. A composite image is constructed using only these foreground pixels, which dramatically reduces the computational time. We used 250 images obtained from 45 specimens of confirmed malaria infections to test our proposed algorithm. The resulting composite images with all in-focus objects were produced using the proposed OEDoF algorithm. We measured the performance of OEDoF in terms of image clarity (quality) and processing time. The features of interest selected by the OEDoF algorithm are comparable in quality with equivalent regions in images processed by the state-of-the-art complex wavelet EDoF algorithm; however, OEDoF required four times less processing time. This work presents a modification of the extended depth of field approach for efficiently enhancing microscopic images. This selective object processing scheme used in OEDoF can significantly reduce the overall processing time while maintaining the clarity of important image features. The empirical results from parasite-infected red cell images revealed that our proposed method efficiently and effectively produced in-focus composite images. With the speed improvement of OEDoF, this proposed algorithm is suitable for processing large numbers of microscope images, e.g., as required for medical diagnosis.

Diversity of rare and abundant bacteria in surface waters of the Southern Adriatic Sea.

PubMed

Quero, Grazia Marina; Luna, Gian Marco

2014-10-01

Bacteria are fundamental players in the functioning of the ocean, yet relatively little is known about the diversity of bacterioplankton assemblages and the factors shaping their spatial distribution. We investigated the diversity and community composition of bacterioplankton in surface waters of the Southern Adriatic sub-basin (SAd) in the Mediterranean Sea, across an environmental gradient from coastal to offshore stations. Bacterioplankton diversity was investigated using a whole-assemblage genetic fingerprinting technique (Automated Ribosomal Intergenic Spacer Analysis, ARISA) coupled with 16S rDNA amplicon pyrosequencing. The main physico-chemical variables showed clear differences between coastal and offshore stations, with the latter displaying generally higher temperature, salinity and oxygen content. Bacterioplankton richness was higher in coastal than offshore waters. Bacterial community composition (BCC) differed significantly between coastal and offshore waters, and appeared to be influenced by temperature (explaining up to 30% of variance) and by the trophic state. Pyrosequencing evidenced dominance of Alphaproteobacteria (SAR11 cluster), uncultured Gammaproteobacteria (Rhodobacteraceae) and Cyanobacteria (Synechococcus). Members of the Bacteroidetes phylum were also abundant, and accounted for 25% in the station characterized by the higher organic carbon availability. Bacterioplankton assemblages included a few dominant taxa and a very large proportion (85%) of rare (<0.1%) bacteria, the vast majority of which was unique to each sampling station. The first detailed census of bacterioplankton taxa in the SAd sub-basin, performed using next generation sequencing, indicates that assemblages are highly heterogeneous, spatially structured according to the environmental conditions, and comprise a large number of rare taxa. The high turnover diversity, particularly evident at the level of the rare taxa, suggests to direct future investigations toward larger spatial or temporal scales, to better understand the role of bacterioplankton in the ecosystem functioning and the biogeochemistry of the basin. Copyright © 2014 Elsevier B.V. All rights reserved.

Species undersampling in tropical bat surveys: effects on emerging biodiversity patterns.

PubMed

Meyer, Christoph F J; Aguiar, Ludmilla M S; Aguirre, Luis F; Baumgarten, Julio; Clarke, Frank M; Cosson, Jean-François; Estrada Villegas, Sergio; Fahr, Jakob; Faria, Deborah; Furey, Neil; Henry, Mickaël; Jenkins, Richard K B; Kunz, Thomas H; Cristina MacSwiney González, M; Moya, Isabel; Pons, Jean-Marc; Racey, Paul A; Rex, Katja; Sampaio, Erica M; Stoner, Kathryn E; Voigt, Christian C; von Staden, Dietrich; Weise, Christa D; Kalko, Elisabeth K V

2015-01-01

Undersampling is commonplace in biodiversity surveys of species-rich tropical assemblages in which rare taxa abound, with possible repercussions for our ability to implement surveys and monitoring programmes in a cost-effective way. We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness (SR) and compositional variation across sites. For 27 bat assemblage data sets from across the tropics, we used correlations between original data sets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in SR and composition in data subsets are congruent with those in the initial data set. We then examined to what degree high sample representativeness (r ≥ 0·8) was influenced by biogeographic region, sampling method, sampling effort or structural assemblage characteristics. For SR, correlations between random subsets and original data sets were strong (r ≥ 0·8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among-site variation. For nonrandom subsets, removing only the rarest species (on average c. 10% of the full data set) yielded strong correlations (r > 0·95) for both SR and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among data sets. Species subsets that comprised ca. 85% of the original set can be considered reliable surrogates, capable of adequately revealing patterns of SR and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost-effectiveness in tropical bat surveys or monitoring programmes. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site by site basis based on pilot surveys. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Impact of weighted composite compared to traditional composite endpoints for the design of randomized controlled trials.

PubMed

Bakal, Jeffrey A; Westerhout, Cynthia M; Armstrong, Paul W

2015-12-01

Composite endpoints are commonly used in cardiovascular clinical trials. When using a composite endpoint a subject is considered to have an event when the first component endpoint has occurred. The use of composite endpoints offers the ability to incorporate several clinically important endpoint events thereby augmenting the event rate and increasing statistical power for a given sample size. One assumption of the composite is that all component events are of equal clinical importance. This assumption is rarely achieved given the diversity of component endpoints included. One means of adjusting for this diversity is to adjust the outcomes using severity weights determined a priori. The use of a weighted endpoint also allows for the incorporation of multiple endpoints per patient. Although weighting the outcomes lowers the effective number of events, it offers additional information that reduces the variance of the estimate. We created a series of simulation studies to examine the effect on power as the individual components of a typical composite were changed. In one study, we noted that the weighted composite was able to offer discriminative power when the component outcomes were altered, while the traditional method was not. In the other study, we noted that the weighted composite offered a similar level of power to the traditional composite when the change was driven by the more severe endpoints. © The Author(s) 2011.

Breaking the paradigm: Record quindecim charged magnetic ionic liquids

DOE PAGES

Prodius, D.; Smetana, V.; Steinberg, S.; ...

2016-12-08

A family of bis(trifluoromethanesulfonyl)amide-based ionic liquids of composition [RE 5(C 2H 5-C 3H 3N 2-CH 2COO) 16(H 2O) 8](Tf 2N) 15 (RE = Er, Ho, Tm; C 3H 3N 2 ≡ imidazolium moiety) featuring the cationic, record quindecim {15+} charged pentanuclear rare earth (RE)-containing ion [RE 5(C 2H 5-C 3H 3N 2-CH 2COO) 16(H 2O) 8] 15+ has been synthesized and characterized. In addition, due to the presence of rare earth ions, these ionic liquids show a response to magnetic fields with the highest effective magnetic moment observed so far for an ionic liquid and are rare examples of ionicmore » liquids showing luminescence in the near-infrared. As a result, these ionic liquids also were successfully employed in a three-component synthesis of 2-pyrrolo-3'-yloxindole with an extremely low (<0.035 mol%) catalyst loading rate.« less

Rare earth elements minimal harvest year variation facilitates robust geographical origin discrimination: The case of PDO "Fava Santorinis".

PubMed

Drivelos, Spiros A; Danezis, Georgios P; Haroutounian, Serkos A; Georgiou, Constantinos A

2016-12-15

This study examines the trace and rare earth elemental (REE) fingerprint variations of PDO (Protected Designation of Origin) "Fava Santorinis" over three consecutive harvesting years (2011-2013). Classification of samples in harvesting years was studied by performing discriminant analysis (DA), k nearest neighbours (κ-NN), partial least squares (PLS) analysis and probabilistic neural networks (PNN) using rare earth elements and trace metals determined using ICP-MS. DA performed better than κ-NN, producing 100% discrimination using trace elements and 79% using REEs. PLS was found to be superior to PNN, achieving 99% and 90% classification for trace and REEs, respectively, while PNN achieved 96% and 71% classification for trace and REEs, respectively. The information obtained using REEs did not enhance classification, indicating that REEs vary minimally per harvesting year, providing robust geographical origin discrimination. The results show that seasonal patterns can occur in the elemental composition of "Fava Santorinis", probably reflecting seasonality of climate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Possible lunar ores

NASA Technical Reports Server (NTRS)

Gillett, Stephen L.

1991-01-01

Despite the conventional wisdom that there are no lunar ores, geochemical considerations suggest that local concentrations of useful rare elements exist on the Moon in spite of its extreme dryness. The Moon underwent protracted igneous activity in its history, and certain magmatic processes can concentrate incompatible elements even if anhydrous. Such processes include: (1) separation of a magma into immiscible liquid phases (depending on composition, these could be silicate-silicate, silicate-oxide, silicate-sulfide, or silicate-salt); (2) cumulate deposits in layered igneous intrusions; and (3) concentrations of rare, refractory, lithophile elements (e.g., Be, Li, Zr) in highly differentiated, silica-rich magmas, as in the lunar granites. Terrestrial mining experience indicates that the single most important characteristic of a potential ore is its concentration of the desire element. The utility of a planet as a resource base is that the welter of interacting processes over geologic time can concentrate rare element automatically. This advantage is squandered if adequate exploration for ores is not first carried out.

Date prints on stranded macroplastics: Exploring the potential of marine litter assemblages as chronological markers in recent coastal deposit

NASA Astrophysics Data System (ADS)

Sander, L.

2016-12-01

Plastic is a collective term describing a group of synthetic materials developed from the early 1900s onward. The mass production of plastics began in the 1950s and already in the 1970s, the magnitude of plastic pollution has been recognized as an issue of concern for the global marine environment. Today, it is no longer a rare event to encounter plastic fragments and objects in modern coastal deposits. The presence of any form of plastic holds in itself a chronological indication (i.e. the deposit is younger than the invention of plastic). Larger items can be surveyed as discrete objects and allow the retrieval of more precise, though indirect age-information, such as production-date prints (i.e. the deposit is younger than the encountered litter item). The potential of this approach was tested in an investigation into the spatial distribution of stranded macroplastics in recent overwash deposits in SW Denmark. An amount of >110 georeferenced surface samples containing date prints were surveyed in summer 2015. Objects with ages from the late 1970s until 2014 were encountered. The distribution of the litter was clearly non-random in relation to overwash morphology, and based on the collected samples, it was possible to reconstruct indication on both the timing and the extent of extreme events since the 1990s. These observations were cross-compared with a dense time series of satellite images and orthophotos. It is proposed that an improved interpretation of indications from the plastic record may be obtained by broader surveys including additional parameters, such as the exact location, elevation, chemical composition, assemblage, origin, product design, decay, fracturing or the colonization by marine sessile organisms, from all encountered macroplastic objects. If calibrated properly, the plastic assemblages may serve as fast, cheap and reliable chronological markers in recent coastal deposits.

Euhedral metallic-Fe-Ni grains in extraterrestrial samples

NASA Technical Reports Server (NTRS)

Rubin, Alan E.

1993-01-01

Metallic Fe-Ni is rare in terrestrial rocks, being largely restricted to serpentinized peridotites and volcanic rocks that assimilated carbonaceous material. In contrast, metallic Fe-Ni is nearly ubiquitous among extraterrestrial samples (i.e., meteorites, lunar rocks, and interplanetary dust particles). Anhedral grains are common. For example, in eucrites and lunar basalts, most of the metallic Fe-Ni occurs interstitially between silicate grains and thus tends to have irregular morphologies. In many porphyritic chondrules, metallic Fe-Ni and troilite form rounded blebs in the mesostasis because their precursors were immiscible droplets. In metamorphosed ordinary chondrites, metallic Fe-Ni and troilite form coarse anhedral grains. Some of the metallic Fe-Ni and troilite grains has also been mobilized and injected into fractures in adjacent silicate grains where local shock-reheating temperatures reached the Fe-FeS eutectic (988 C). In interplanetary dust particles metallic Fe-Ni most commonly occurs along with sulfide as spheroids and fragments. Euhedral metallic Fe-Ni grains are extremely rare. Several conditions must be met before such grains can form: (1) grain growth must occur at free surfaces, restricting euhedral metallic Fe-Ni grains to systems that are igneous or undergoing vapor-deposition; (2) the metal (+/-) sulfide assemblage must have an appropriate bulk composition so that taenite is the liquidus phase in igneous systems or the stable condensate phase in vapor-deposition systems; and (3) metallic Fe-Ni grains must remain underformed during subsequent compaction, thermal metamorphism, and shock. Because of these restrictions, the occurrence of euhedral metallic Fe-Ni grains in an object can potentially provide important petrogenetic information. Despite its rarity, euhedral metallic Fe-Ni occurs in a wide variety of extraterrestrial materials. Some of these materials formed in the solar nebula; others formed on parent body surfaces by meteoroid impacts.

Characterization of frictional melting processes in subduction zone faults by trace element and isotope analyses

NASA Astrophysics Data System (ADS)

Ishikawa, T.; Ujiie, K.

2017-12-01

Pseudotachylytes found in exhumed accretionary complexes, which are considered to be formed originally at seismogenic depths, are of great importance for elucidating frictional melting and concomitant dynamic weakening of the fault during earthquake in subduction zones. However, fluid-rich environment of the subduction zone faults tends to cause extensive alteration of the pseudotachylyte glass matrix in later stages, and thus it has been controversial that pseudotachylytes are rarely formed or rarely preserved. Chemical analysis of the fault rocks, especially on fluid-immobile trace elements and isotopes, can be a useful means to identify and quantify the frictional melting occurred in subduction zone faults. In this paper, we report major and trace element and Sr isotope compositions for pseudotachylyte-bearing dark veins and surrounding host rocks from the Mugi area of the Shimanto accretionary complex (Ujiie et al., J. Struct. Geol. 2007). Samples were collected from a rock chip along the microstructure using a micro-drilling technique, and then analyzed by ICP-MS and TIMS. Major element compositions of the dark veins showed a clear shift from the host rock composition toward the illite composition. The dark veins, either unaltered or completely altered, were also characterized by extreme enrichment in some of the trace elements such as Ti, Zr, Nb and Th. These results are consistent with disequilibrium melting of the fault zone. Model calculations revealed that the compositions of the dark veins can be produced by total melting of clay-rich matrix in the source rock, leaving plagioclase and quartz grains almost unmolten. The calculations also showed that the dark veins are far more enriched in melt component than that expected from the source rock compositions, suggesting migration and concentration of frictional melt during the earthquake faulting. Furthermore, Sr isotope data of the dark veins implied the occurrence of frictional melting in multiple stages. These results demonstrate that trace element and isotope analyses are useful not only to detect preexistence of pseudotachylytes but also to evaluate the frictional melting in subduction zone faults quantitatively.

Filigree burn of lightning: two case reports.

PubMed

Kumar, Virendra

2007-04-01

Lightning is a powerful natural electrostatic discharge produced during a thunderstorm. The electric current passing through the discharge channels is direct with a potential of 1000 million volts or more. Lightning can kill or injure a person by a direct strike, a side-flash, or conduction through another object. Lightning can cause a variety of injuries in the skin and the cardiovascular, neurological and ophthalmic systems. Filigree burn of lightning is a superficial burn and very rare. Two cases of death from lightning which have this rare finding are reported and discussed.

Application of multi-objective optimization to pooled experiments of next generation sequencing for detection of rare mutations.

PubMed

Zilinskas, Julius; Lančinskas, Algirdas; Guarracino, Mario Rosario

2014-01-01

In this paper we propose some mathematical models to plan a Next Generation Sequencing experiment to detect rare mutations in pools of patients. A mathematical optimization problem is formulated for optimal pooling, with respect to minimization of the experiment cost. Then, two different strategies to replicate patients in pools are proposed, which have the advantage to decrease the overall costs. Finally, a multi-objective optimization formulation is proposed, where the trade-off between the probability to detect a mutation and overall costs is taken into account. The proposed solutions are devised in pursuance of the following advantages: (i) the solution guarantees mutations are detectable in the experimental setting, and (ii) the cost of the NGS experiment and its biological validation using Sanger sequencing is minimized. Simulations show replicating pools can decrease overall experimental cost, thus making pooling an interesting option.

Resource potential for commodities in addition to Uranium in sandstone-hosted deposits: Chapter 13

USGS Publications Warehouse

Breit, George N.

2016-01-01

Sandstone-hosted deposits mined primarily for their uranium content also have been a source of vanadium and modest amounts of copper. Processing of these ores has also recovered small amounts of molybdenum, rhenium, rare earth elements, scandium, and selenium. These deposits share a generally common origin, but variations in the source of metals, composition of ore-forming solutions, and geologic history result in complex variability in deposit composition. This heterogeneity is evident regionally within the same host rock, as well as within districts. Future recovery of elements associated with uranium in these deposits will be strongly dependent on mining and ore-processing methods.

Loparite-(Ce) from the Khibiny Alkaline Pluton, Kola Peninsula, Russia

NASA Astrophysics Data System (ADS)

Konopleva, N. G.; Ivanyuk, G. Yu.; Pakhomovsky, Ya. A.; Yakovenchuk, V. N.; Mikhailova, Yu. A.

2017-12-01

Data on the occurrence, morphology, anatomy, composition, and formation conditions of loparite-(Ce) in the Khibiny alkaline pluton are given. Loparite-(Ce), (Na,Ce,Sr)(Ce,Th)(Ti,Nb)2O6, resulted from metasomatic alteration and assimilation of metamorphic host rocks at the contact with foyaite as well as foyaite on the contact with foidolite. This alteration was the highest in pegmatite, and albitite developed there. A decrease in temperature resulted in enrichment of the perovskite and tausonite endmembers in loparite-(Ce) owing to a decrease in the loparite and lueshite endmembers. La and Ce sharply predominate among rare earth elements in the composition of loparite-(Ce).

Geologic map of the Simcoe Mountains Volcanic Field, main central segment, Yakama Nation, Washington

USGS Publications Warehouse

Hildreth, Wes; Fierstein, Judy

2015-01-01

Lava compositions other than various types of basalt are uncommon here. Andesite is abundant on and around Mount Adams but is very rare east of the Klickitat River. The only important nonbasaltic composition in the map area is rhyolite, which crops out in several patches around the central highland of the volcanic field, mainly in the upper canyons of Satus and Kusshi Creeks and Wilson Charley canyon. Because the rhyolites were some of the earliest lavas erupted here, they are widely concealed by later basalts and therefore crop out only in local windows eroded by canyons that cut through the overlying basalts.

Standards in C.S.E. and G.C.E.: English and Mathematics. Working Paper No. 9.

ERIC Educational Resources Information Center

Schools Council, London (England).

Attainment tests in English and mathematics were administered to a total sample of 2,011/15-year old students. The English test consisted of a composition and a test battery of objective items. Marking of the composition was made by the test designer on a rapid first-impression reading. The objective test battery consisted of a comprehension test,…

Fundamental Movement Skill Proficiency and Body Composition Measured by Dual Energy X-Ray Absorptiometry in Eight-Year-Old Children

ERIC Educational Resources Information Center

Slotte, Sari; Sääkslahti, Arja; Metsämuuronen, Jari; Rintala, Pauli

2015-01-01

Objective: The main aim was to examine the association between fundamental movement skills (FMS) and objectively measured body composition using dual energy X-ray absorptiometry (DXA). Methods: A study of 304 eight-year-old children in Finland. FMS were assessed with the "Test of gross motor development," 2nd ed. Total body fat…

Asteroid taxonomy

NASA Technical Reports Server (NTRS)

Tholen, David J.; Barucci, M. Antonietta

1989-01-01

The spectral reflectivity of asteroid surfaces over the wavelength range of 0.3 to 1.1 micron can be used to classify these objects into several broad groups with similar spectral characteristics. The three most recently developed taxonomies group the asteroids into 9, 11, or 14 different clases, depending on the technique used to perform the analysis. The distribution of the taxonomic classes shows that darker and redder objects become more dominant at larger heliocentric distances, while the rare asteroid types are found more frequently among the small objects of the planet-crossing population.

The effects of canopy openings and population size on the persistence of Southwest columbines at risk of extinction

Treesearch

Kelly G. Gallagher; Brook G. Milligan

2001-01-01

The habitat associated with riparian, understory, rare and endangered plant populations of the Southwest includes rocky places in high-altitude canyons, mostly along shady streams, pools, and dripping cliffs. The composition of these insular plant populations, which are separated by intervening desert, is influenced by several local environmental conditions. The...

Habitat-associated and temporal patterns of bat activity in a diverse forest landscape of southern New England, USA

Treesearch

Robert T. Brooks

2009-01-01

The development and use of acoustic recording technology, surveys have revealed the composition, relative levels of activity, and preliminary habitat use of bat communities of various forest locations. However, detailed examinations of acoustic surveys results to investigate temporal patterns of bat activity are rare. Initial active acoustic surveys of bat activity on...

Natural canopy damage and the ecological restoration of fire-indicative groundcover vegetation in an oak-pine forest

Treesearch

J. Stephen Brewer

2016-01-01

An important goal of restoring fire to upland oak-dominated communities that have experienced fire exclusion is restoring groundcover plant species diversity and composition indicative of fire-maintained habitats. Several studies have shown that fire alone, however, may not be sufficient to accomplish this goal. Furthermore, treatment-driven declines in rare forest...

Interaction of ectoparasites in cohabitating colonies of pond bats Myotis dasycneme (Boie, 1825) and species of genus Pipistrellus from northern Poland.

PubMed

Orlova, Maria V; Zapart, Aneta

2012-01-01

The article presents data on ectoparasites of pond bat (rare in Europe bat species) in northern Poland region. We discuss the species composition and relationship between ectoparasites of several bat species in mixed colonies. Temporary ectoparasites of pipistrelle bats suppress permanent ectoparasites of pond bats it the cohabitating colonies.

Effects of fire frequency on long-term development of an oak-hickory forest in Missouri, U.S.A.

Treesearch

Benjamin O. Knapp; Michael A. Hullinger; John M. Kabrick

2017-01-01

Repeated prescribed burning over long timescales has some predictable effects on forest structure and composition, but multi-decadal patterns of stand dynamics and successional change with different fire frequencies have rarely been described. We used longitudinal data from a prescribed burning study conducted over a 63-year period to quantify stand structure (stem...

An Old-Growth Definition for Dry and Dry-Mesic Oak-Pine Forests.

Treesearch

David L. White; F. Thomas Lloyd

1998-01-01

Dry and dry-mesic oak-pine forests are widely distributed from New Jersey to Texas, but representative old-growth stands are rare. Historical accounts of composition, along with information from existing old-growth stands, were used to characterize this type. Shortleaf pine and white oak were the most widely distributed trees across all old-growth stands. Shortleaf was...

Spatial and Temporal Variability of Zooplankton Thin Layers: The Effects of Composition and Orientation on Acoustic Detection of Layers

DTIC Science & Technology

2008-01-01

whereas the pump collected more rare taxa (cladocerans and siphonophores ). These differences could be due to the volume sampled. ZOOVIS-SC imaged...Larvaceans 3016 1.3x 4102 3.5x Siphonophores 85 0.2x 215 0.14x 11 IMPACT/APPLICATIONS The image data from ZOOVIS-SC can

A metabolomics-based approach identifies changes in the small molecular weight compound composition of the peanut as a result of dry-roasting

USDA-ARS?s Scientific Manuscript database

Peanut production in the United States is a $1.12 billion industry. United States peanut production is primarily focused on the edibles market. Peanut seeds are included in a variety of snack and confectionary products. Raw peanuts are rarely consumed in the United States. Instead, peanut seeds are ...

The Design and Synthesis of Epoxy Matrix Composites Curable by Electron Beam Induced Cationic Polymerization

NASA Technical Reports Server (NTRS)

Crivello, James V.

2000-01-01

Several new series of novel, high reactivity epoxy resins are described which are designed specifically for the fabrication of high performance carbon fiber reinforced composites for commercial aircraft structural applications using cationic UV and e-beam curing. The objective of this investigation is to provide resin matrices which rapidly and efficiently cure under low e-beam doses which are suitable to high speed automated composite fabrication techniques such as automated tape and tow placement. It was further the objective of this work to provide resins with superior thermal, oxidative and atomic oxygen resistance.

Analysis of Online Composite Mirror Descent Algorithm.

PubMed

Lei, Yunwen; Zhou, Ding-Xuan

2017-03-01

We study the convergence of the online composite mirror descent algorithm, which involves a mirror map to reflect the geometry of the data and a convex objective function consisting of a loss and a regularizer possibly inducing sparsity. Our error analysis provides convergence rates in terms of properties of the strongly convex differentiable mirror map and the objective function. For a class of objective functions with Hölder continuous gradients, the convergence rates of the excess (regularized) risk under polynomially decaying step sizes have the order [Formula: see text] after [Formula: see text] iterates. Our results improve the existing error analysis for the online composite mirror descent algorithm by avoiding averaging and removing boundedness assumptions, and they sharpen the existing convergence rates of the last iterate for online gradient descent without any boundedness assumptions. Our methodology mainly depends on a novel error decomposition in terms of an excess Bregman distance, refined analysis of self-bounding properties of the objective function, and the resulting one-step progress bounds.

Neutron resonance spectroscopy for the characterization of materials and objects

NASA Astrophysics Data System (ADS)

Schillebeeckx, P.; Borella, A.; Emiliani, F.; Gorini, G.; Kockelmann, W.; Kopecky, S.; Lampoudis, C.; Moxon, M.; Perelli Cippo, E.; Postma, H.; Rhodes, N. J.; Schooneveld, E. M.; Van Beveren, C.

2012-03-01

The resonance structure in neutron induced reaction cross sections can be used to determine the elemental compositions of materials or objects. The occurrence of resonances is the basis of neutron resonance capture analysis (NRCA) and neutron resonance transmission analysis (NRTA). NRCA and NRTA are fully non-destructive methods to determine the bulk elemental composition without the need of any sample preparation and resulting in a negligible residual activity. They have been applied to determine the elemental composition of archaeological objects and to characterize reference materials used for cross section measurements. For imaging applications a position sensitive neutron detector has been developed within the ANCIENT CHARM project. The detector is based on a 10 × 10 array of 6Li-glass scintillators mounted on a pitch of 2.5 mm, resulting in a 25 × 25 mm2 active area. The detector has been tested at the time-of-flight facility GELINA and used at the ISIS spallation source to study cultural heritage objects.

Transport properties of Y1-xNdxCo2 compounds

NASA Astrophysics Data System (ADS)

Uchima, K.; Takeda, M.; Zukeran, C.; Nakamura, A.; Arakaki, N.; Komesu, S.; Takaesu, Y.; Hedo, M.; Nakama, T.; Yagasaki, K.; Uwatoko, Y.; Burkov, A. T.

2012-12-01

Electrical resistivity ρ and thermopower S of light rare earth-based pseudo-binary Y1-xNdxCo2 alloys have been measured at temperatures from 2 K to 300 K and under pressures up to 3.5 GPa. The Curie temperature of the alloys, TC, determined from characteristic features in the temperature dependences of the transport properties, decreases with decreasing Nd concentration x and vanishes around xc = 0.3. The residual resistivity has a pronounced maximum at x = xc. The temperature coefficient of thermopower dS/dT at low temperature limit shows a complex dependence on alloy composition: it changes its sign from negative to positive at x ≍ 0.2, having a maximum at x = xc, and is nearly composition independent at x > 0.5. The pressure dependences of TC and ρ0 of Yo.6Ndo.4Co2 reveal the behavior similar to that observed in the Y1-xRxHCo2 (RH = heavy rare earth) alloy systems, which implies that the magnetic state of the Co-3d electron subsystem is responsible for the transport properties in the Y1-xNdxCo2 alloys.

High- and low-Am RE inclusion phases in a U-Np-Pu-Am-Zr alloy

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

Janney, Dawn E.; Madden, James W.; O'Holleran, Thomas P.

2015-03-01

Structural, microstructural, and microchemical data were collected from rare-earth inclusions in an as-cast U-Pu-Zr alloy with ~3 at% Am, 2% Np, and 9% rare-earth elements (La, Ce, Pr, and Nd). Two RE phases with different concentrations of Am were identified. The composition of high-Am RE inclusions is ~2-5 at% La, 15-20 % Ce, 5-10% Pr, 25-45% Nd, 1% Np, 5-10% Pu, and 10-20% Am. Some areas also have O, although this does not appear to be an essential part of the high-Am RE phase. The inclusions have a face-centered cubic structure with a lattice parameter a ~ 0.54 nm. Themore » composition of the only low-Am RE inclusion studied in detail is ~~35-40 at% O, 40-45 % Nd, 1-2% Zr, 4-5% La, 9-10% Ce, and 6-7% Pr. This inclusion is an oxide with a crystal structure similar to the room-temperature structure of Nd 2O 3. Microstructural features suggest that oxidation occurred during casting, and that early crystallization of high-temperature oxides led to formation of two distinct RE phases.« less

Geochemistry of the Neoproterozoic metabasic rocks from the Negele area, southern Ethiopia: Tectonomagmatic implications

NASA Astrophysics Data System (ADS)

Yihunie, Tadesse; Adachi, Mamoru; Yamamoto, Koshi

2006-03-01

Neoproterozoic metabasic rocks along with metasediments and ultramafic rocks constitute the Kenticha and Bulbul lithotectonic domains in the Negele area. They occur as amphibolite and amphibole schist in the Kenticha, and amphibole schist and metabasalt in the Bulbul domains. These rocks are dominantly basaltic in composition and exhibit low-K tholeiitic characteristics. They are slightly enriched in large ion lithophile (LIL) and light rare earth (LRE) elements and depleted in high field strength (HFS) and heavy rare earth (HRE) elements. They exhibit chemical characteristics similar to back-arc basin and island-arc basalts, but include a few samples with slightly higher Y, Zr and Nb contents. Initial Sr isotopic ratios and ɛNd values for the Kenticha metabasic rocks range from 0.7048 to 0.7051 and from 4.7 to 9.6 whereas for the Bulbul metabasic rocks they range from 0.7032 to 0.7055 and from -0.1 to 5.5, respectively. The trace elements and Sr-Nd isotope compositions of samples from the Kenticha and Bulbul domains suggest similar, but isotopically heterogeneous magma sources. The magma is inferred to have derived from depleted source with a contribution from an enriched mantle source component.

The scramble for Africa: pan-temperate elements on the African high mountains.

PubMed

Gehrke, Berit; Linder, H Peter

2009-07-22

The composition of isolated floras has long been thought to be the result of relatively rare long-distance dispersal events. However, it has recently become apparent that the recruitment of lineages may be relatively easy and that many dispersal events from distant but suitable habitats have occurred, even at an infraspecific level. The evolution of the flora on the high mountains of Africa has been attributed to the recruitment of taxa not only from the African lowland flora or the Cape Floristic Region, but also to a large extent from other areas with temperate climates. We used the species rich, pan-temperate genera Carex, Ranunculus and Alchemilla to explore patterns in the number of recruitment events and region of origin. Molecular phylogenetic analyses, parametric bootstrapping and ancestral area optimizations under parsimony indicate that there has been a high number of colonization events of Carex and Ranunculus into Africa, but only two introductions of Alchemilla. Most of the colonization events have been derived from Holarctic ancestors. Backward dispersal out of Africa seems to be extremely rare. Thus, repeated colonization from the Northern Hemisphere in combination with in situ radiation has played an important role in the composition of the flora of African high mountains.

Binary rare earth element-Ni/Co metallic glasses with distinct β-relaxation behaviors

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

Zhu, Z. G.; Wang, Z.; Wang, W. H., E-mail: whw@iphy.ac.cn

2015-10-21

We report the formation of a series of rare earth element (RE)-Ni/Co binary metallic glasses (MGs) with unusual distinct β-relaxation peak compared with that of most of the reported MGs which usually exhibit as an excess wing or a shoulder. The β-relaxation behavior of RE-Ni/Co MGs is sensitive to the composition and the atomic radii of the RE and can be tuned through changing the fraction of RE-Ni (or Co) atomic pairs. The novel RE-Ni/Co MGs with distinct β-relaxation can serve as model system to investigate the nature of the β-relaxation as well as its relations with other physical andmore » mechanical properties of MGs.« less

Catalytic recombination of dissociation products with Pt/SnO2 for rare and common isotope long-life, closed-cycle CO2 lasers

NASA Technical Reports Server (NTRS)

Brown, Kenneth G.; Sidney, B. D.; Schryer, D. R.; Upchurch, B. T.; Miller, I. M.

1986-01-01

This paper reports results on recombination of pulsed CO2 laser dissociation products with Pt/SnO2 catalysts, and supporting studies in a surrogate laboratory catalyst reactor. The closed-cycle, pulsed CO2 laser has been continuously operated for one million pulses with an overall power degradation of less than 5 percent by flowing the laser gas mixture through a 2-percent Pt/SnO2 catalyst bed. In the surrogate laboratory reactor, experiments have been conducted to determine isotopic exchange with the catalyst when using rare-isotope gases. The effects of catalyst pretreatment, sample weight, composition, and temperature on catalyst efficiency have also been determined.

Predicting locations of rare aquatic species’ habitat with a combination of species-specific and assemblage-based models

USGS Publications Warehouse

McKenna, James E.; Carlson, Douglas M.; Payne-Wynne, Molly L.

2013-01-01

Aim: Rare aquatic species are a substantial component of biodiversity, and their conservation is a major objective of many management plans. However, they are difficult to assess, and their optimal habitats are often poorly known. Methods to effectively predict the likely locations of suitable rare aquatic species habitats are needed. We combine two modelling approaches to predict occurrence and general abundance of several rare fish species. Location: Allegheny watershed of western New York State (USA) Methods: Our method used two empirical neural network modelling approaches (species specific and assemblage based) to predict stream-by-stream occurrence and general abundance of rare darters, based on broad-scale habitat conditions. Species-specific models were developed for longhead darter (Percina macrocephala), spotted darter (Etheostoma maculatum) and variegate darter (Etheostoma variatum) in the Allegheny drainage. An additional model predicted the type of rare darter-containing assemblage expected in each stream reach. Predictions from both models were then combined inclusively and exclusively and compared with additional independent data. Results Example rare darter predictions demonstrate the method's effectiveness. Models performed well (R2 ≥ 0.79), identified where suitable darter habitat was most likely to occur, and predictions matched well to those of collection sites. Additional independent data showed that the most conservative (exclusive) model slightly underestimated the distributions of these rare darters or predictions were displaced by one stream reach, suggesting that new darter habitat types were detected in the later collections. Main conclusions Broad-scale habitat variables can be used to effectively identify rare species' habitats. Combining species-specific and assemblage-based models enhances our ability to make use of the sparse data on rare species and to identify habitat units most likely and least likely to support those species. This hybrid approach may assist managers with the prioritization of habitats to be examined or conserved for rare species.

Comparison of the LEW88516 and ALHA77005 martian meteorites: Similar but distinct

NASA Technical Reports Server (NTRS)

Treiman, A. H.; Mckay, G. A.; Bogard, D. D.; Mittlefehldt, D. W.; Wang, M.-S.; Keller, L.; Lipschutz, M. E.; Lindstrom, M. M.; Garrison, D.

1994-01-01

By mineral and bulk compositions, the Lewis Cliff (LEW) 88516 meteorite is quite similar to the ALHA77005 martian meteorite. These two meteorites are not paired because their mineral compositions are distinct, they were found 500 km apart in ice fields with different sources for meteorites, and their terrestrial residence ages are different. Minerals in LEW88516 include: olivine, pyroxenes (low- and high-Ca), and maskelynite (ater plagioclase); and the minor minerals chromite, whitlockite, ilmenite, and pyrrhotite. Mineral grains in LEW88516 range up to a few mm. Texturally, the meteorite is complex, with regions of olivine and chromite poikilitically enclosed in pyroxene, regions of interstitial basaltic texture, and glass-rich (shock) veinlets. Olivine compositions range from Fo(sub 64) to Fo(sub 70), (avg. Fo(sub 67)), more ferroan and with more variation than in ALHA77005 (Fo(sub 69) to Fo(sub 73)). Pyroxene compositions fall between En(sub 77)Wo(sub 4) and En(sub 65)Wo(sub 15) and in clusters near En(sub 63)Wo(sub 9) and En(sub 53)Wo(sub 33), on average more magnesian and with more variation than in ALHA77005. Shock features in LEW88516 range from weak deformation through complete melting. Bulk chemical analyses by modal recombination of electron microprobe analyses, instrumental neutron activation, and radiochemical neutron activation confirm that LEW88516 is more closely related to ALHA77005 than to other known martian meteorites. Key element abundance ratios are typical of martian meteorites, as is it nonchondritic rare earth pattern. Differences between the chemical compositions of LEW88516 and ALHA77005 are consistent with slight differences in the proportions of their constituent minerals and not from fundamental petrogenetic differences. Noble gas abundances in LEW88516, like those in ALHA77005, show modest excesses of Ar-40 and Xe-129 from trapped (shock-implanted) gas. As with other ALHA77005 and the shergottite martian meteorites (except EETA79001), noble gas isotope abundances in LEW88516 are consistent with exposure to cosmic rays for 2.5-3 Ma. The absence of substantial effects of shielding from cosmic rays suggest LEW88516 spent this time as an object no larger than a few cm in diameter.

The effect of lanthanum on the fabrication of ZrB{sub 2}-ZrC composites by spark plasma sintering

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

Kim, Kyoung Hun; Shim, Kwang Bo

2003-01-15

The effect of the addition of the rare earth element, lanthanum, on the sintering characteristics of ZrB{sub 2}-ZrC composites has been analyzed during a spark plasma sintering (SPS) process. Microscopic observation confirmed that lanthanum accelerated mass transport by the formation of the liquid phase between the particles induced by the spark plasma in the initial stage of the SPS process, and then these were recrystallized to form a lanthanum-containing secondary phase at the grain boundaries and at the grain boundary triple junctions. In spite of the strong covalent bonding characteristics of the ZrB{sub 2}-ZrC composite there are many well-developed dislocationmore » structures observed. The fracture toughness of the lanthanum-containing ZrB{sub 2}-ZrC is about 2.56 MPa m{sup 1/2}, which is comparable to that of the pure composite. Therefore, it is concluded that lanthanum is very effective as a sintering aid for the ZrB{sub 2}-ZrC composite without any degradation of the mechanical properties.« less

Setting objective thresholds for rare event detection in flow cytometry

PubMed Central

Richards, Adam J.; Staats, Janet; Enzor, Jennifer; McKinnon, Katherine; Frelinger, Jacob; Denny, Thomas N.; Weinhold, Kent J.; Chan, Cliburn

2014-01-01

The accurate identification of rare antigen-specific cytokine positive cells from peripheral blood mononuclear cells (PBMC) after antigenic stimulation in an intracellular staining (ICS) flow cytometry assay is challenging, as cytokine positive events may be fairly diffusely distributed and lack an obvious separation from the negative population. Traditionally, the approach by flow operators has been to manually set a positivity threshold to partition events into cytokine-positive and cytokine-negative. This approach suffers from subjectivity and inconsistency across different flow operators. The use of statistical clustering methods does not remove the need to find an objective threshold between between positive and negative events since consistent identification of rare event subsets is highly challenging for automated algorithms, especially when there is distributional overlap between the positive and negative events (“smear”). We present a new approach, based on the Fβ measure, that is similar to manual thresholding in providing a hard cutoff, but has the advantage of being determined objectively. The performance of this algorithm is compared with results obtained by expert visual gating. Several ICS data sets from the External Quality Assurance Program Oversight Laboratory (EQAPOL) proficiency program were used to make the comparisons. We first show that visually determined thresholds are difficult to reproduce and pose a problem when comparing results across operators or laboratories, as well as problems that occur with the use of commonly employed clustering algorithms. In contrast, a single parameterization for the Fβ method performs consistently across different centers, samples, and instruments because it optimizes the precision/recall tradeoff by using both negative and positive controls. PMID:24727143

Phosphate-Silicate Inclusions in Chaunskij: How Diverse are They?

NASA Astrophysics Data System (ADS)

Petaev, M. I.; Clarke, R. S., Jr.; Jarosewich, E.; Lipschutz, M. E.; Wang, M.-S.; Davis, A. M.; Steele, I. M.; Olsen, E. J.; Wood, J. A.

1993-07-01

The Chaunskij meteorite was found in 1985 and was recently classified as the most highly metamorphosed, shock-modified, and metal-rich mesosiderite [1]. It contains ~10 vol% mono- and polymineralic troilite-phosphate-silicate inclusions, micrometers to centimeters in size. Metal in Chaunskij displays a mesosiderite structure and is described in some detail in an accompanying paper [2]. Here we present new data on polymineralic inclusions that shed additional light on their origin. Two dominant silicate lithologies have been found in the inclusions. One, making up the largest inclusion (2.2 x 1.7 cm), consists of a fine-grained (20-30 micrometers) aggregate of anhedral pyroxene, subhedral plagioclase laths, and silica, with larger poikilitic grains of the first two minerals. Whitlockite is minor. Textures vary from microophitic to xenoblastic. This lithology, called "igneous," also contains rare primary clasts enriched in pyroxene, whose boundaries are almost unresolvable from the ground mass in transmitted light. The second, "metamorphic" lithology occurs as separate small inclusions and as larger areas in intimate contact with the "igneous" lithology in the largest inclusion. This lithology is a fine-grained (typically 30-50 micrometers) xenoblastic intergrowth of low-Ca pyroxene, whitlockite, and cordierite, with rare larger porphyritic grains of the first two minerals. Porphyritic pyroxene grain edges are generally irregular, indicative of reaction with the ground mass. Plagioclase is present only as a rare accessory mineral. Minor minerals in both lithologies are silica, kamacite, taenite, troilite, chromite, ilmenite, and rutile. Rare grains of pyrophanite, zircon, alabandite, stanfieldite, and a graftonite-farringtonite mineral are also present in the inclusions. Mineral compositions of small inclusions are more diverse than those characteristic of the "igneous" and "metamorphic" lithologies. Many of them consist of cordierite, pyroxene, and whitlockite intergrowths, with or without silica and opaque minerals. However, some inclusions do not match the mineralogies of "igneous" or "metamorphic" lithologies. They consist of cordierite only (inclusion #1-10); cordierite and silica (#1-18); silica, whitlockite, and troilite with minor Al-rich chromite and rare pyroxene (#4- 5A); plagioclase and whitlockite (#4-5D); and silica and whitlockite (#4-6E). Mineral compositions vary considerably both between and within all inclusions. No systematic differences between separate inclusions were found. Compositions of pyroxene and plagioclase match those of mesosideritic minerals. The chromite and ilmenite display systematic variations in MgO, MnO, Al(sub)2O(sub)3 and V(sub)2O(sub)3 contents, suggestive of a precursor material consisting of a series of basaltic rocks. The bulk chemical composition of the largest silicate inclusion, recalculated to the silicate fraction only, is very close to that of eucrites and mesosiderites except for a large enrichment in P and volatile chalcophiles. Major-element and REE chemistry and bulk mineralogy point to cumulate eucrites as the precursor of the silicate inclusions. This precursor was apparently slightly fractionated during the remelting event inferred by the structure of the "igneous" lithology. The "metamorphic" lithology apparently was formed due to reaction between silicates and phosphorus dissolved in the metal: Px + An + P + O --> Cord + Q + Whit. This reaction took place under ~700 degrees C and ~4 kbar [3] in the interior of the Chaunskij parent body. Compositions and textures of small inclusions suggest that the metamorphic reaction took place before the incorporation of the inclusions into the piece of metal making up the Chaunskij main mass. References: [1] Petaev M. I. et al. (1993) LPS XXIV, 1131-1132. [2] Clarke R. S. Jr. et al., this volume. [3] Petaev M. I. et al. (1992) Meteoritics, 27, 276-277.

Coordinates Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

NASA Technical Reports Server (NTRS)

Keller, L. P.; Snead, C.; McKeegan, K. D.

2016-01-01

Interplanetary dust particles (IDPs) collected in the stratosphere fall into two major groups: an anhydrous group termed the "chondritic-porous (CP) IDPs and a hydrated group, the "chondritic-smooth (CS) IDPs, although rare IDPs with mineralogies intermediate between these two groups are known [1]. The CP-IDPs are widely believed to be derived from cometary sources [e.g. 2]. The hydrated CS-IDPs show mineralogical similarities to heavily aqueously altered carbonaceous chondrites (e.g. CI chondrites), but only a few have been directly linked to carbonaceous meteorite parent bodies [e.g. 3, 4]. Most CS-IDPs show distinct chemical [5] and oxygen isotopic composition differences [6-8] from primitive carbonaceous chondrites. Here, we report on our coordinated analyses of a suite of carbon-rich CS-IDPs focusing on their bulk compositions, mineralogy, mineral chemistry, and isotopic compositions.

Procurement Practices for the Composite Armored Vehicle and Composite Affordability Initiative Programs

DTIC Science & Technology

1999-10-26

The audit objective was to determine whether violations of procurement regulations occurred regarding procurement of selected components of the Army...Crusader vehicle and the Joint Strike Fighter aircraft. However, during the audit , we determined that the allegations involved the Army Composite

Recycling of Aluminum Alloy with Dimox and Rheocasting Functionalize High Performance Structural Foam Composite

NASA Astrophysics Data System (ADS)

Rabeeh, Bakr Mohamed

Great efforts aiming towards the synthesis and the development of structural composite materials. Direct metal oxidation, DIMOX introduced for hybrid composite processing. However, oxidation temperatures around 1100°C lead to the formation of porous ceramic materials. To utilize this porosity intentionally for foam production, a new approach based on synergetic effect of alloying elements, DIMOX and semisolid (rheocsting) processing is developed. A semisolid reaction, rheocasting is introduced to control porosity shape and size. Aluminum alloy 6xxx (automobile scrap pistons) is recycled for this objective and DIMOX at 1100°C for 30 min, then rheocasting, at 750°C for 30 minutes. The effect of α-Fe powder, Mg powder, and Boric acid powder established for the objective of a hybrid structural metal matrix composite in bulk foam matrix. The kinetic of formation of hybrid metal matrix foam composite is introduced. Microstructural and mechanical characterization established for high performance Aluminum foam hybrid composite materials.

Fingerprints of carbon, nitrogen, and silicon isotopes in small interstellar SiC grains from the Murchison meteorite

NASA Technical Reports Server (NTRS)

Hoppe, Peter; Geiss, Johannes; Buehler, Fritz; Neuenschwander, Juerg; Amari, Sachiko; Lewis, Roy S.

1993-01-01

We report ion microprobe determinations of the carbon, nitrogen, and silicon isotopic compositions of small SiC grains from the Murchison CM2 chondrite. Analyses were made on samples containing variable numbers of grains and on 14 individual grains. In some cases the multiple-grain sample compositions were probably dominated by only one or two grains. Total ranges observed are given. Only a few grains show values near the range limits. Both the total ranges of carbon and nitrogen isotopic compositions, and even the narrower ranges typical for the majority of the grains, are similar to those observed for larger SiC grains. Two rare components appear to be present in the smaller-size fraction, one characterized by C-12/C-13 about 12-16 and the other by very heavy nitrogen. The carbon and nitrogen isotopic compositions qualitatively may reflect hydrostatic H-burning via the CNO cycle and He-burning in red giants, as well as explosive H-burning in novae. The silicon isotopic compositions of most grains qualitatively show what is the signature of He-burning. The silicon isotopic composition of one grain, however, suggests a different process.

[Sea star (Asteroidea) association structures on the rocky reef in the Gulf of California, Mexico].

PubMed

Reyes Bonilla, Héctor; González Azcárraga, Adriana; Rojas Sierra, Aracely

2005-12-01

Sea stars are invertebrates that play relevant roles in rocky and coral reefs: they occupy different levels in food webs and may act as top predators. There are numerous studies on taxonomy and biogeography of the class in the eastern tropical Pacific, but information about the attributes and composition of its assemblages is scant. The objectives of this study were the examination and comparison of asteroid community structure from four regions of the Gulf of California, Mexico, characterized by the presence of rocky reefs, and the search for possible associations between pairs of species. In August 2004 we visited four locations in the western gulf: Bahia de Los Angeles (29 degrees N), Santa Rosalia (27 degrees N), Loreto (26 degrees N) and La Paz (24 degrees N), and censuses sea stars using 50 m2 belt transects (N=93). Abundance and species richness was estimated, as well as diversity (H'), evenness (J') and taxonomic distinctness (delta*); then, all variables were compared among regions with analysis of variance. In addition, an ordination analysis was run looking for groups of locations with similar faunistic composition. Our results showed that Loreto Bay had the highest richness and abundance of asteroids, probably because it presents a large number of habitats and multiple food sources; these conditions seem to favor the occurrence of rare species and of detritivores. However, there were no significant interregional differences among ecological indices, nor we detected groups of locations singled out because of its species composition. Thus, community structure of sea stars in rocky areas of the Gulf of California is quite homogeneous and do not change with latitude. This is a consequence of the fact that all regions under analysis had the species Phataria unifascialis and Pharia pyramidatus as dominant in number. There were significant positive associations between three pairs of species: apparently competition is not particularly relevant to control sea star community structure in the Gulf.

The Rest-frame Ultraviolet Spectra of UV-selected Active Galactic Nuclei at z ~ 2-3

NASA Astrophysics Data System (ADS)

Hainline, Kevin N.; Shapley, Alice E.; Greene, Jenny E.; Steidel, Charles C.

2011-05-01

We present new results for a sample of 33 narrow-lined UV-selected active galactic nuclei (AGNs), identified in the course of a spectroscopic survey for star-forming galaxies at z ~ 2-3. The rest-frame UV composite spectrum for our AGN sample shows several emission lines characteristic of AGNs, as well as interstellar absorption features detected in star-forming Lyman break galaxies (LBGs). We report a detection of N IV] λ1486, which has been observed in high-redshift radio galaxies, as well as in rare optically selected quasars. The UV continuum slope of the composite spectrum is significantly redder than that of a sample of non-AGN UV-selected star-forming galaxies. Blueshifted Si IV absorption provides evidence for outflowing highly ionized gas in these objects at speeds of ~103 km s-1, quantitatively different from what is seen in the outflows of non-AGN LBGs. Grouping the individual AGNs by parameters such as the Lyα equivalent width, redshift, and UV continuum magnitude allows for an analysis of the major spectroscopic trends within the sample. Stronger Lyα emission is coupled with weaker low-ionization absorption, which is similar to what is seen in the non-AGN LBGs, and highlights the role that cool interstellar gas plays in the escape of Lyα photons. However, the AGN composite does not show the same trends between Lyα strength and extinction seen in the non-AGN LBGs. These results represent the first such comparison at high redshift between star-forming galaxies and similar galaxies that host AGN activity. Based, in part, on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Potential disruption of seed dispersal in the absence of a native Kauai thrush

PubMed Central

Pejchar, Liba; Crampton, Lisa H.

2018-01-01

Hawaii has experienced a catastrophic decline in frugivorous native birds coupled with the introduction of non-native species. Puaiohi (Myadestes palmeri), a critically endangered thrush, is the sole extant native songbird capable of dispersing fleshy fruited plants in the rainforest of Kauai island, Hawaii. As this species has declined to occupy a small proportion of its original range, a suite of largely omnivorous non-native birds have been introduced to this region, including the common and widespread Japanese White-eye (Zosterops japonicus). This reshuffling of the bird community could have long-term implications for plant community composition if introduced birds incompletely replace the ecological role of native species. The objective of this study was to evaluate the potential consequences of the local extirpation of Puaiohi for seed dispersal. Specifically, we compared the diet of Puaiohi and Japanese White-eye, vegetation characteristics, and seed rain at sites with and without Puaiohi in the Na Pali-Kona Forest Reserve on the island of Kauai. We found high overlap in the composition of seeds consumed by the two bird species, but differences in the characteristics of seeds consumed; Japanese White-eye appeared more likely to consume smaller seeded species compared with Puaiohi. Sites with Puaiohi received substantially higher seed rain during the study period, despite no significant differences in overall fruit abundance. Our results suggest that non-native birds are unlikely to completely replace the seed dispersal services provided by Puaiohi. If Puaohi continue to be rare and range restricted, we predict a shift in plant community composition through an increase in non-native and small-seeded plants, and possible dispersal failure of other native species. Our findings lend further support to efforts to conserve Puaiohi across its current and former range, and to consider introductions to other suitable areas to ensure the persistence not only of the species and but also its functional role in Hawaii’s montane ecosystems. PMID:29381764

[Effect of forest management on the herpetofauna of a temperate forest of western Oaxaca, Mexico].

PubMed

Aldape-López, César Tonatiuh; Santos-Moreno, Antonio

2016-09-01

The development of silvicultural techniques has as main objective to maximize the production of timber, whereas at the same time minimize the impact generated during and after forest intervention in the local diversity. However, these activities change local climate, and this, in turn, alter the composition of natural communities. The effect of these changes may be greater in those taxonomic groups with high sensitivity to habitat disturbance, such as amphibians and reptiles, which are the unique terrestrial ectothermic vertebrates. The present study aims to know the differences in diversity of amphibians and reptiles in a temperate forest under two silvicultural treatments, one of low and the other of high intensity, as well as from one, five and ten years of regeneration since the last logging event, Sierra Sur of Oaxaca, Mexico. Records of 21 species of herpetofauna (six amphibians and 15 reptiles) were obtained. The total species richness was similar in both treatments; however, the composition varied between sites with different recovery times. Higher abundance of amphibian was presented on sites with the low-intensity treatment, while reptiles were more abundant at sites with intensive treatment. Compared to a mature forest without management, sites with intensive treatment have more rare species, although the values of true diversity of amphibians were similar between treatments with different intensities, while for reptiles sites under treatment showed less diversity that unmanaged site: 33 % for intensive treatment and 28 % at sites with low intensity with respect to one control site. Complementary Analysis showed a difference of 86 % between the compositions of species in sites with intensive treatment. The treatment intensity was associated with an increase in the number of species, but the way they respond to changes in habitat depends largely on the population characteristics of each species and its ability to adapt to new conditions.

Fine-Scale Vertical Stratification and Guild Composition of Saproxylic Beetles in Lowland and Montane Forests: Similar Patterns despite Low Faunal Overlap

PubMed Central

Weiss, Matthias; Procházka, Jiří; Schlaghamerský, Jiří; Cizek, Lukas

2016-01-01

Objective The finer scale patterns of arthropod vertical stratification in forests are rarely studied and poorly understood. Further, there are no studies investigating whether and how altitude affects arthropod vertical stratification in temperate forests. We therefore investigated the fine-scale vertical stratification of diversity and guild structure of saproxylic beetles in temperate lowland and montane forests and compared the resulting patterns between the two habitats. Methods The beetles were sampled with flight intercept traps arranged into vertical transects (sampling heights 0.4, 1.2, 7, 14, and 21 m). A triplet of such transects was installed in each of the five sites in the lowland and in the mountains; 75 traps were used in each forest type. Results 381 species were collected in the lowlands and 236 species in the mountains. Only 105 species (21%) were found at both habitats; in the montane forest as well as in the lowlands, the species richness peaked at 1.2 m, and the change in assemblage composition was most rapid near the ground. The assemblages clearly differed between the understorey (0.4 m, 1.2 m) and the canopy (7 m, 14 m, 21 m) and between the two sampling heights within the understorey, but less within the canopy. The stratification was better pronounced in the lowland, where canopy assemblages were richer than those near the forest floor (0.4 m). In the mountains the samples from 14 and 21 m were more species poor than those from the lower heights. The guild structure was similar in both habitats. Conclusions The main patterns of vertical stratification and guild composition were strikingly similar between the montane and the lowland forest despite the low overlap of their faunas. The assemblages of saproxylic beetles were most stratified near ground. The comparisons of species richness between canopy and understorey may thus give contrasting results depending on the exact sampling height in the understorey. PMID:26978783

Development of stitching reinforcement for transport wing panels

NASA Technical Reports Server (NTRS)

Palmer, Raymond J.; Dow, Marvin B.; Smith, Donald L.

1991-01-01

The NASA Advanced Composites Technology (ACT) program has the objective of providing the technology required to obtain the full benefit of weight savings and performance improvements offered by composite primary aircraft structures. Achieving the objective is dependent upon developing composite materials and structures which are damage tolerant and economical to manufacture. Researchers are investigating stitching reinforcement combined with resin transfer molding to produce materials meeting the ACT program objective. Research is aimed at materials, processes, and structural concepts for application in both transport wings and fuselages, but the emphasis to date has been on wing panels. Empirical guidelines are being established for stitching reinforcement in structures designed for heavy loads. Results are presented from evaluation tests investigating stitching types, threads, and density (penetrations per square inch). Tension strength, compression strength, and compression after impact data are reported.

Communication strategies employed by rare disease patient organizations in Spain.

PubMed

Castillo-Esparcia, Antonio; López-Villafranca, Paloma

2016-08-01

The current study focuses on communication strategies employed by rare disease patient organizations. The aims of these organizations are: educate and inform the public about rare diseases, raise awareness of the problems related to rare diseases, and achieve social legitimacy in order give visibility to their demands. We analyzed the portrayal of rare disease and patient organizations by Spain's major media organizations in terms of circulation and viewership - the press (El País, El Mundo, La Vanguardia,ABC and El Periódico), radio (CadenaSer, Onda Cero, Cope and RNE), and television (Telecinco, Antena 3, La 1, La Sexta, Cuatro) -between 2012 and 2014.We then carried out a descriptive analysis of communication activities performed via the World Wide Web and social networks by 143 national organizations. Finally, we conducted a telephone questionnaire of a representative sample of 90 organizations in order to explore the association between media presence and funding and public image. The triangulation of quantitative and qualitative methods allowed us to meet the study's objectives. Increased visibility of the organizations afforded by an increase in the coverage of the topic by the medialed to an increase in membership - but not in donations - and increased awareness of these diseases.

Les xénolites ultramafiques du volcanisme alcalin quaternaire d'Oranie (Tell, Algérie occidentale), témoins d'une lithosphère cisaillée et enrichieUltramafic xenoliths from Quaternary alkali volcanism from Oranie (Tell, western Algeria): witnesses of a sheared and enriched lithosphere

NASA Astrophysics Data System (ADS)

Zerka, Mohamed; Cottin, Jean-Yves; Grégoire, Michel; Lorand, Jean-Pierre; Megartsi, M'Hamed; Midoun, Mohamed

Numerous ultramafic xenoliths occur within the Aı̈n-Temouchent volcanic complex (Northwestern Oranie, Algeria). Most of them are type I mantle tectonites (lherzolites and harzburgites) and composite xenoliths (harzburgite/clinopyroxenite) are rare. Only a few samples of spinel lherzolites display relatively fertile compositions when the major part of type I xenoliths have refractory major element compositions but enriched LREE contents showing that they have been affected by mantle metasomatism. The composite xenoliths are witnesses of reactions of alkaline magmas with the upper mantle. An asthenospheric rising, in relation with the large strike slip fault affecting the North African plate margin at Trias time is proposed as a possible geodynamical setting. To cite this article: M. Zerka et al., C. R. Geoscience 334 (2002) 387-394.

Making Early Modern Medicine: Reproducing Swedish Bitters.

PubMed

Ahnfelt, Nils-Otto; Fors, Hjalmar

2016-05-01

Historians of science and medicine have rarely applied themselves to reproducing the experiments and practices of medicine and pharmacy. This paper delineates our efforts to reproduce "Swedish Bitters," an early modern composite medicine in wide European use from the 1730s to the present. In its original formulation, it was made from seven medicinal simples: aloe, rhubarb, saffron, myrrh, gentian, zedoary and agarikon. These were mixed in alcohol together with some theriac, a composite medicine of classical origin. The paper delineates the compositional history of Swedish Bitters and the medical rationale underlying its composition. It also describes how we go about to reproduce the medicine in a laboratory using early modern pharmaceutical methods, and analyse it using contemporary methods of pharmaceutical chemistry. Our aim is twofold: first, to show how reproducing medicines may provide a path towards a deeper understanding of the role of sensual and practical knowledge in the wider context of early modern medical culture; and second, how it may yield interesting results from the point of view of contemporary pharmaceutical science.

Effects of machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites

NASA Astrophysics Data System (ADS)

Azmi, A. I.; Syahmi, A. Z.; Naquib, M.; Lih, T. C.; Mansor, A. F.; Khalil, A. N. M.

2017-10-01

This article presents an approach to evaluate the effects of different machining conditions on the specific cutting energy of carbon fibre reinforced polymer composites (CFRP). Although research works in the machinability of CFRP composites have been very substantial, the present literature rarely discussed the topic of energy consumption and the specific cutting energy. A series of turning experiments were carried out on two different CFRP composites in order to determine the power and specific energy constants and eventually evaluate their effects due to the changes in machining conditions. A good agreement between the power and material removal rate using a simple linear relationship. Further analyses revealed that a power law function is best to describe the effect of feed rate on the changes in the specific cutting energy. At lower feed rate, the specific cutting energy increases exponentially due to the nature of finishing operation, whereas at higher feed rate, the changes in specific cutting energy is minimal due to the nature of roughing operation.

Novel characterization of landscape-level variability in historical vegetation structure.

PubMed

Collins, Brandon M; Lydersen, Jamie M; Everett, Richard G; Fry, Danny L; Stephens, Scott L

2015-07-01

We analyzed historical timber inventory data collected systematically across a large mixed-conifer-dominated landscape to gain insight into the interaction between disturbances and vegetation structure and composition prior to 20th century land management practices. Using records from over 20 000 trees, we quantified historical vegetation structure and composition for nine distinct vegetation groups. Our findings highlight some key aspects of forest structure under an intact disturbance regime: (1) forests were low density, with mean live basal area and tree density ranging from 8-30 m2 /ha and 25-79 trees/ha, respectively; (2) understory and overstory structure and composition varied considerably across the landscape; and (3) elevational gradients largely explained variability in forest structure over the landscape. Furthermore, the presence of large trees across most of the surveyed area suggests that extensive stand-replacing disturbances were rare in these forests. The vegetation structure and composition characteristics we quantified, along with evidence of largely elevational control on these characteristics, can provide guidance for restoration efforts in similar forests.

The compositional diversity of non-Vesta basaltic asteroids

NASA Astrophysics Data System (ADS)

Leith, Thomas B.; Moskovitz, Nicholas A.; Mayne, Rhiannon G.; DeMeo, Francesca E.; Takir, Driss; Burt, Brian J.; Binzel, Richard P.; Pefkou, Dimitra

2017-10-01

We present near-infrared (0.78-2.45 μm) reflectance spectra for nine middle and outer main belt (a > 2.5 AU) basaltic asteroids. Three of these objects are spectrally distinct from all classifications in the Bus-DeMeo system and could represent spectral end members in the existing taxonomy or be representatives of a new spectral type. The remainder of the sample are classified as V- or R-type. All of these asteroids are dynamically detached from the Vesta collisional family, but are too small to be intact differentiated parent bodies, implying that they originated from differentiated planetesimals which have since been destroyed or ejected from the solar system. The 1- and 2-μm band centers of all objects, determined using the Modified Gaussian Model (MGM), were compared to those of 47 Vestoids and fifteen HED meteorites of known composition. The HEDs enabled us to determine formulas relating Band 1 and Band 2 centers to pyroxene ferrosilite (Fs) compositions. Using these formulas we present the most comprehensive compositional analysis to date of middle and outer belt basaltic asteroids. We also conduct a careful error analysis of the MGM-derived band centers for implementation in future analyses. The six outer belt V- and R-type asteroids show more dispersion in parameter space than the Vestoids, reflecting greater compositional diversity than Vesta and its associated bodies. The objects analyzed have Fs numbers which are, on average, between five and ten molar percent lower than those of the Vestoids; however, identification and compositional analysis of additional outer belt basaltic asteroids would help to confirm or refute this result. Given the gradient in oxidation state which existed within the solar nebula, these results tentatively suggest that these objects formed at either a different time or location than 4 Vesta.

CoMiniGut—a small volume in vitro colon model for the screening of gut microbial fermentation processes

PubMed Central

Khakimov, Bekzod; Nielsen, Sebastian; Sørensen, Helena; van den Berg, Frans; Nielsen, Dennis Sandris

2018-01-01

Driven by the growing recognition of the influence of the gut microbiota (GM) on human health and disease, there is a rapidly increasing interest in understanding how dietary components, pharmaceuticals and pre- and probiotics influence GM. In vitro colon models represent an attractive tool for this purpose. With the dual objective of facilitating the investigation of rare and expensive compounds, as well as an increased throughput, we have developed a prototype in vitro parallel gut microbial fermentation screening tool with a working volume of only 5 ml consisting of five parallel reactor units that can be expanded with multiples of five to increase throughput. This allows e.g., the investigation of interpersonal variations in gut microbial dynamics and the acquisition of larger data sets with enhanced statistical inference. The functionality of the in vitro colon model, Copenhagen MiniGut (CoMiniGut) was first demonstrated in experiments with two common prebiotics using the oligosaccharide inulin and the disaccharide lactulose at 1% (w/v). We then investigated fermentation of the scarce and expensive human milk oligosaccharides (HMOs) 3-Fucosyllactose, 3-Sialyllactose, 6-Sialyllactose and the more common Fructooligosaccharide in fermentations with infant gut microbial communities. Investigations of microbial community composition dynamics in the CoMiniGut reactors by MiSeq-based 16S rRNA gene amplicon high throughput sequencing showed excellent experimental reproducibility and allowed us to extract significant differences in gut microbial composition after 24 h of fermentation for all investigated substrates and fecal donors. Furthermore, short chain fatty acids (SCFAs) were quantified for all treatments and donors. Fermentations with inulin and lactulose showed that inulin leads to a microbiota dominated by obligate anaerobes, with high relative abundance of Bacteroidetes, while the more easily fermented lactulose leads to higher relative abundance of Proteobacteria. The subsequent study on the influence of HMOs on two infant GM communities, revealed the strongest bifidogenic effect for 3′SL for both infants. Inter-individual differences of infant GM, especially with regards to the occurrence of Bacteroidetes and differences in bifidobacterial species composition, correlated with varying degrees of HMO utilization foremost of 6′SL and 3′FL, indicating species and strain related differences in HMO utilization which was also reflected in SCFAs concentrations, with 3′SL and 6′SL resulting in significantly higher butyrate production compared to 3′FL. In conclusion, the increased throughput of CoMiniGut strengthens experimental conclusions through elimination of statistical interferences originating from low number of repetitions. Its small working volume moreover allows the investigation of rare and expensive bioactives. PMID:29372119

An overview of the impact of rare disease characteristics on research methodology.

PubMed

Whicher, Danielle; Philbin, Sarah; Aronson, Naomi

2018-01-19

About 30 million individuals in the United States are living with a rare disease, which by definition have a prevalence of 200,000 or fewer cases in the United States ([National Organization for Rare Disorders], [About NORD], [2016]). Disease heterogeneity and geographic dispersion add to the difficulty of completing robust studies in small populations. Improving the ability to conduct research on rare diseases would have a significant impact on population health. The purpose of this paper is to raise awareness of methodological approaches that can address the challenges to conducting robust research on rare diseases. We conducted a landscape review of available methodological and analytic approaches to address the challenges of rare disease research. Our objectives were to: 1. identify algorithms for matching study design to rare disease attributes and the methodological approaches applicable to these algorithms; 2. draw inferences on how research communities and infrastructure can contribute to the efficiency of research on rare diseases; and 3. to describe methodological approaches in the rare disease portfolio of the Patient-Centered Outcomes Research Institute (PCORI), a funder promoting both rare disease research and research infrastructure. We identified three algorithms for matching study design to rare disease or intervention characteristics (Gagne, et.al, BMJ 349:g6802, 2014); (Gupta, et.al, J Clin Epidemiol 64:1085-1094, 2011); (Cornu, et. al, Orphet J Rare Dis 8:48,2012) and summarized the applicable methodological and analytic approaches. From this literature we were also able to draw inferences on how an effective research infrastructure can set an agenda, prioritize studies, accelerate accrual, catalyze patient engagement and terminate poorly performing studies. Of the 24 rare disease projects in the PCORI portfolio, 11 are randomized controlled trials (RCTs) using standard designs. Thirteen are observational studies using case-control, prospective cohort, or natural history designs. PCORI has supported the development of 9 Patient-Powered Research Networks (PPRNs) focused on rare diseases. Matching research design to attributes of rare diseases and interventions can facilitate the completion of RCTs that are adequately powered. An effective research infrastructure can improve efficiency and avoid waste in rare disease research. Our review of the PCORI research portfolio demonstrates that it is feasible to conduct RCTs in rare disease. However, most of these studies are using standard RCT designs. This suggests that use of a broader array of methodological approaches to RCTs --such as adaptive trials, cross-over trials, and early escape designs can improve the productivity of robust research in rare diseases.

Rare Variants in RTEL1 Are Associated with Familial Interstitial Pneumonia

PubMed Central

Cogan, Joy D.; Zhao, Min; Mitchell, Daphne B.; Rives, Lynette; Markin, Cheryl; Garnett, Errine T.; Montgomery, Keri H.; Mason, Wendi R.; McKean, David F.; Powers, Julia; Murphy, Elissa; Olson, Lana M.; Choi, Leena; Cheng, Dong-Sheng; Blue, Elizabeth Marchani; Young, Lisa R.; Lancaster, Lisa H.; Steele, Mark P.; Brown, Kevin K.; Schwarz, Marvin I.; Fingerlin, Tasha E.; Schwartz, David A.; Lawson, William E.; Loyd, James E.; Zhao, Zhongming; Phillips, John A.; Blackwell, Timothy S.

2015-01-01

Rationale: Up to 20% of cases of idiopathic interstitial pneumonia cluster in families, comprising the syndrome of familial interstitial pneumonia (FIP); however, the genetic basis of FIP remains uncertain in most families. Objectives: To determine if new disease-causing rare genetic variants could be identified using whole-exome sequencing of affected members from FIP families, providing additional insights into disease pathogenesis. Methods: Affected subjects from 25 kindreds were selected from an ongoing FIP registry for whole-exome sequencing from genomic DNA. Candidate rare variants were confirmed by Sanger sequencing, and cosegregation analysis was performed in families, followed by additional sequencing of affected individuals from another 163 kindreds. Measurements and Main Results: We identified a potentially damaging rare variant in the gene encoding for regulator of telomere elongation helicase 1 (RTEL1) that segregated with disease and was associated with very short telomeres in peripheral blood mononuclear cells in 1 of 25 families in our original whole-exome sequencing cohort. Evaluation of affected individuals in 163 additional kindreds revealed another eight families (4.7%) with heterozygous rare variants in RTEL1 that segregated with clinical FIP. Probands and unaffected carriers of these rare variants had short telomeres (<10% for age) in peripheral blood mononuclear cells and increased T-circle formation, suggesting impaired RTEL1 function. Conclusions: Rare loss-of-function variants in RTEL1 represent a newly defined genetic predisposition for FIP, supporting the importance of telomere-related pathways in pulmonary fibrosis. PMID:25607374

The Space Infrared Interferometric Telescope (SPIRIT): High-Resolution Imaging and Spectroscopy in the Far-Infrared (Preprint)

DTIC Science & Technology

2007-01-01

primary scientific objectives: (1) Learn how planetary systems form from protostellar disks , and how they acquire their inhomogeneous composition; (2...characterize the family of extrasolar planetary systems by imaging the structure in debris disks to understand how and where planets of different...scientific objectives: (1) Learn how planetary systems form from protostellar disks , and how they acquire their inhomogeneous composition; (2

Content metamorphosis in synthetic holography

NASA Astrophysics Data System (ADS)

Desbiens, Jacques

2013-02-01

A synthetic hologram is an optical system made of hundreds of images amalgamated in a structure of holographic cells. Each of these images represents a point of view on a three-dimensional space which makes us consider synthetic holography as a multiple points of view perspective system. In the composition of a computer graphics scene for a synthetic hologram, the field of view of the holographic image can be divided into several viewing zones. We can attribute these divisions to any object or image feature independently and operate different transformations on image content. In computer generated holography, we tend to consider content variations as a continuous animation much like a short movie. However, by composing sequential variations of image features in relation with spatial divisions, we can build new narrative forms distinct from linear cinematographic narration. When observers move freely and change their viewing positions, they travel from one field of view division to another. In synthetic holography, metamorphoses of image content are within the observer's path. In all imaging Medias, the transformation of image features in synchronisation with the observer's position is a rare occurrence. However, this is a predominant characteristic of synthetic holography. This paper describes some of my experimental works in the development of metamorphic holographic images.

Effects of aquatic exercise on physical function and fitness among people with spinal cord injury

PubMed Central

Li, Chunxiao; Khoo, Selina; Adnan, Athirah

2017-01-01

Abstract Objective: The aim of this review is to synthesize the evidence on the effects of aquatic exercise interventions on physical function and fitness among people with spinal cord injury. Data source: Six major databases were searched from inception till June 2015: MEDLINE, CINAHL, EMBASE, PsychInfo, SPORTDiscus, and Cochrane Center Register of Controlled Trials. Study appraisal and synthesis methods: Two reviewers independently rated methodological quality using the modified Downs and Black Scale and extracted and synthesized key findings (i.e., participant characteristics, study design, physical function and fitness outcomes, and adverse events). Results: Eight of 276 studies met the inclusion criteria, of which none showed high research quality. Four studies assessed physical function outcomes and 4 studies evaluated aerobic fitness as outcome measures. Significant improvements on these 2 outcomes were generally found. Other physical or fitness outcomes including body composition, muscular strength, and balance were rarely reported. Conclusions and implications of key findings: There is weak evidence supporting aquatic exercise training to improve physical function and aerobic fitness among adults with spinal cord injury. Suggestions for future research include reporting details of exercise interventions, evaluating other physical or fitness outcomes, and improving methodological quality. PMID:28296754

Dual noise-like pulse and soliton operation of a fiber ring cavity

NASA Astrophysics Data System (ADS)

Bracamontes Rodríguez, Y. E.; Pottiez, O.; García Sanchez, E.; Lauterio Cruz, J. P.; Ibarra-Villalón, H.; Hernandez-Garcia, J. C.; Bello-Jimenez, M.; Beltrán-Pérez, G.; Ibarra-Escamilla, B.; Kuzin, E. A.

2017-03-01

Passively mode-locked fiber lasers (PML-FLs) are versatile sources that are capable of generating a broad variety of short and ultrashort optical pulses. Besides conservative solitons, PML-FLs allow the generation of different kinds of dissipative structures, usually called dissipative solitons, a concept that also encompasses more complex structures and collective behaviors such as soliton molecules, gas, rain of solitons, etc. In addition to this, PML-FLs are also able to generate even more complex objects, the so-called noise-like pulses (NLPs). A few recent research results revealed a connection between NLPs and solitons, a sign that deterministic ingredients enter into the composition of NLPs, whose nature is traditionally assumed to be random. Although it is usual that a fiber laser is able to generate either solitons or noise-like pulses, depending on pump power and adjustments in the cavity, these two regimes are rarely observed simultaneously. In this paper, a PML-FL in a ring configuration is presented, in which it is possible to observe and verify experimentally the simultaneous presence of NLPs and solitons. Interestingly, these two components are found in different spectral regions, which greatly facilitates their separation and individual study and characterization.

An engineering approach for the application of textile composites to a structural component

NASA Technical Reports Server (NTRS)

Baldwin, Jack W.; Gracias, Brian K.; Clark, Steven R.

1993-01-01

An engineering approach for the application of textile composites to a structural component is addressed. The main objective is to improve impact resistance of composite blades by using some form of 3-D reinforcement. Project goals, results, and conclusions are discussed.

Composite scintillators for detection of ionizing radiation

DOEpatents

Dai, Sheng [Knoxville, TN; Stephan, Andrew Curtis [Knoxville, TN; Brown, Suree S [Knoxville, TN; Wallace, Steven A [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

2010-12-28

Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

THE ROTTEN EGG NEBULA A PLANETARY NEBULA IN THE MAKING

NASA Technical Reports Server (NTRS)

2002-01-01

The object shown in these NASA/ESA Hubble Space Telescope images is a remarkable example of a star going through death throes just as it dramatically transforms itself from a normal red giant star into a planetary nebula. This process happens so quickly that such objects are quite rare, even though astronomers believe that most stars like the Sun will eventually go through such a phase. This star, with the prosaic name of OH231.8+4.2, is seen in these infrared pictures blowing out gas and dust in two opposite directions. So much dust has been cast off and now surrounds the star that it cannot be seen directly, only its starlight that is reflected off the dust. The flow of gas is very fast, with a velocity up to 450,000 mph (700,000 km/h). With extreme clarity, these Hubble Near Infrared Camera and Multi-Object Spectrometer (NICMOS) images reveal that the fast-moving gas and dust are being collimated into several thin streamers (on the right) and a jet-like structure (on the left), which can be seen extending away from the centers of both pictures. On the right, wisps of material in jet-like streamers appear to strike some dense blobs of gas. This interaction must produce strong shock waves in the gas. The pictures represent two views of the object. The color image is a composite of four images taken with different NICMOS infrared filters on March 28, 1998. It shows that the physical properties of the material, both composition and temperature, vary significantly throughout the outflowing material. The black-and-white image was taken with one NICMOS infrared filter. That image is able to show more clearly the faint detail and structure in the nebula than can be achieved with the color composites. Observations by radio astronomers have found many unusual molecules in the gas around this star, including many containing sulfur, such as hydrogen sulfide and sulfur dioxide. These sulfur compounds are believed to be produced in the shock waves passing through the gas. Because of the large amount of sulfur compounds, this object has earned the nickname 'The Rotten Egg' Nebula. It resides in the constellation Puppis. These NICMOS data pose a serious challenge to astrophysical theorists: How can a star generate such tightly collimated streams of gas and dust and accelerate them to such very high velocities? William B. Latter from the California Institute of Technology and his group are using these data to obtain a better understanding of the detailed structure in the outflowing material, look for evidence for the origin of the thin streamers and jets, and learn more about the star itself. This information will give astronomers a more complete understanding of the final stages in the lives of stars like our Sun. These results were presented at a conference called 'Asymmetrical Planetary Nebulae II: From Origins to Microstructures,' Aug. 3 to 6, 1999 at the Massachusetts Institute of Technology. The results also will be published in the Astrophysical Journal. Credit: NASA, ESA, William B. Latter (SIRTF Science Center/California Institute of Technology), John H. Bieging (University of Arizona), Casey Meakin (University of Arizona), A.G.G.M. Tielens (Kapteyn Astronomical Institute), Aditya Dayal (IPAC/NASA Jet Propulsion Laboratory), Joseph L. Hora (Center for Astrophysics), and Douglas M. Kelly (University of Arizona).

Effects of Fiber/Matrix Interface and its Composition on Mechanical Properties of Hi Nicalon/Celsian Composites

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.; Eldridge, Jeffrey I.

1998-01-01

Fiber-reinforced ceramic matrix composites (CMC) are prospective candidate materials for high temperature structural applications in aerospace, energy conservation, power generation, nuclear, petrochemical, and other industries. At NASA Lewis, we are investigating celsian matrix composites reinforced with various types of silicon carbide fibers. The objective of the present study was to investigate the effects of fiber/matrix interface and its composition on the mechanical properties of silicon carbide (Hi-Nicalon) fiber-reinforced celsian matrix composites.

Method and apparatus for evaluating structural weakness in polymer matrix composites

DOEpatents

Wachter, E.A.; Fisher, W.G.

1996-01-09

A method and apparatus for evaluating structural weaknesses in polymer matrix composites is described. An object to be studied is illuminated with laser radiation and fluorescence emanating therefrom is collected and filtered. The fluorescence is then imaged and the image is studied to determine fluorescence intensity over the surface of the object being studied and the wavelength of maximum fluorescent intensity. Such images provide a map of the structural integrity of the part being studied and weaknesses, particularly weaknesses created by exposure of the object to heat, are readily visible in the image. 6 figs.

Method and apparatus for evaluating structural weakness in polymer matrix composites

DOEpatents

Wachter, Eric A.; Fisher, Walter G.

1996-01-01

A method and apparatus for evaluating structural weaknesses in polymer matrix composites is described. An object to be studied is illuminated with laser radiation and fluorescence emanating therefrom is collected and filtered. The fluorescence is then imaged and the image is studied to determine fluorescence intensity over the surface of the object being studied and the wavelength of maximum fluorescent intensity. Such images provide a map of the structural integrity of the part being studied and weaknesses, particularly weaknesses created by exposure of the object to heat, are readily visible in the image.

Strengthening bridges using composite materials.

DOT National Transportation Integrated Search

1998-03-01

The objective of this research project is to outline methodologies for using Fiber Reinforced Polymer (FRP) composites to strengthen and rehabilitate reinforced concrete bridge elements. : Infrastructure deterioration and bridge strengthening techniq...

Structure and Evolution of Kuiper Belt Objects: The Case for Compositional Classes

NASA Astrophysics Data System (ADS)

McKinnon, William B.; Prialnik, D.; Stern, S. A.

2007-10-01

Kuiper belt objects (KBOs) accreted from a mélange of ices, carbonaceous matter, and rock of mixed interstellar and solar nebular provenance. The transneptunian region, where this accretion took place, was likely more radially compact than today. This and the influence of gas drag during the solar nebula epoch argue for more rapid KBO accretion than usually considered. Early evolution of KBOs was largely the result of radiogenic heating, with both short-term and long-term contributions being potentially important. Depending on rock content and porous conductivity, KBO interiors may have reached relatively high temperatures. Models suggest that KBOs likely lost very volatile ices during early evolution, whereas less volatile ices should be retained in cold, less altered subsurface layers; initially amorphous ice may have crystallized in the interior as well, releasing trapped volatiles. Generally, KBOs should be stratified in terms of composition and porosity, albeit subject to impact disruption and collisional stripping. KBOs are thus unlikely to be "the most pristine objects in the Solar System.” Large (dwarf planet) KBOs may be fully differentiated. KBO surface color and compositional classes are usually discussed in terms of "nature vs. nurture,” i.e., a generic primordial composition vs. surface processing, but the true nature of KBOs also depends on how they have evolved. The broad range of albedos now found in the Kuiper belt, deep water-ice absorptions on some objects, evidence for differentiation of Pluto and 2003 EL61, and a range of densities incompatible with a single, primordial composition and variable porosity strongly imply significant, intrinsic compositional differences among KBOs. The interplay of formation zone (accretion rate), body size, and dynamical (collisional) history may yield KBO compositional classes (and their spectral correlates) that recall the different classes of asteroids in the inner Solar System, but whose members are broadly distributed among the KBO dynamical subpopulations.

Biotechnological approaches for conservation and improvement of rare and endangered plants of Saudi Arabia.

PubMed

Khan, Salim; Al-Qurainy, Fahad; Nadeem, Mohammad

2012-01-01

Genetic variation is believed to be a prerequisite for the short-and long-term survival of the plant species in their natural habitat. It depends on many environmental factors which determine the number of alleles on various loci in the genome. Therefore, it is important to understand the genetic composition and structure of the rare and endangered plant species from their natural habitat to develop successful management strategies for their conservation. However, rare and endangered plant species have low genetic diversity due to which their survival rate is decreasing in the wilds. The evaluation of genetic diversity of such species is very important for their conservation and gene manipulation. However, plant species can be conserved by in situ and in vitro methods and each has advantages and disadvantages. DNA banking can be considered as a means of complimentary method for the conservation of plant species by preserving their genomic DNA at low temperatures. Such approach of preservation of biological information provides opportunity for researchers to search novel genes and its products. Therefore, in this review we are describing some potential biotechnological approaches for the conservation and further manipulation of these rare and endangered plant species to enhance their yield and quality traits.

Chemical speciation and bioavailability of rare earth elements (REEs) in the ecosystem: a review.

PubMed

Khan, Aysha Masood; Bakar, Nor Kartini Abu; Bakar, Ahmad Farid Abu; Ashraf, Muhammad Aqeel

2017-10-01

Rare earths (RE), chemically uniform group of elements due to similar physicochemical behavior, are termed as lanthanides. Natural occurrence depends on the geological circumstances and has been of long interest for geologist as tools for further scientific research into the region of ores, rocks, and oceanic water. The review paper mainly focuses to provide scientific literature about rare earth elements (REEs) with potential environmental and health effects in understanding the research. This is the initial review of RE speciation and bioavailability with current initiative toward development needs and research perceptive. In this paper, we have also discussed mineralogy, extraction, geochemistry, analytical methods of rare earth elements. In this study, REEs with their transformation and vertical distribution in different environments such as fresh and seawater, sediments, soil, weathering, transport, and solubility have been reported with most recent literature along key methods of findings. Speciation and bioavailability have been discussed in detail with special emphasis on soil, plant, and aquatic ecosystems and their impacts on the environment. This review shows that REE gained more importance in last few years due to their detrimental effects on living organisms, so their speciation, bioavailability, and composition are much more important to evaluate their health risks and are discussed thoroughly as well.

Defect Clustering and Nano-Phase Structure Characterization of Multi-Component Rare Earth Oxide Doped Zirconia-Yttria Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Chen, Yuan L.; Miller, Robert A.

2003-01-01

Advanced oxide thermal barrier coatings have been developed by incorporating multi-component rare earth oxide dopants into zirconia-yttria to effectively promote the creation of the thermodynamically stable, immobile oxide defect clusters and/or nano-scale phases within the coating systems. The presence of these nano-sized defect clusters has found to significantly reduce the coating intrinsic thermal conductivity, improve sintering resistance, and maintain long-term high temperature stability. In this paper, the defect clusters and nano-structured phases, which were created by the addition of multi-component rare earth dopants to the plasma-sprayed and electron-beam physical vapor deposited thermal barrier coatings, were characterized by high-resolution transmission electron microscopy (TEM). The defect cluster size, distribution, crystallographic and compositional information were investigated using high-resolution TEM lattice imaging, selected area diffraction (SAD), electron energy-loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) analysis techniques. The results showed that substantial defect clusters were formed in the advanced multi-component rare earth oxide doped zirconia- yttria systems. The size of the oxide defect clusters and the cluster dopant segregation was typically ranging from 5 to 50 nm. These multi-component dopant induced defect clusters are an important factor for the coating long-term high temperature stability and excellent performance.

Defect Clustering and Nano-Phase Structure Characterization of Multi-Component Rare Earth Oxide Doped Zirconia-Yttria Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Chen, Yuan L.; Miller, Robert A.

1990-01-01

Advanced oxide thermal barrier coatings have been developed by incorporating multi- component rare earth oxide dopants into zirconia-yttria to effectively promote the creation of the thermodynamically stable, immobile oxide defect clusters and/or nano-scale phases within the coating systems. The presence of these nano-sized defect clusters has found to significantly reduce the coating intrinsic thermal conductivity, improve sintering resistance, and maintain long-term high temperature stability. In this paper, the defect clusters and nano-structured phases, which were created by the addition of multi-component rare earth dopants to the plasma- sprayed and electron-beam physical vapor deposited thermal barrier coatings, were characterized by high-resolution transmission electron microscopy (TEM). The defect cluster size, distribution, crystallographic and compositional information were investigated using high-resolution TEM lattice imaging, selected area diffraction (SAD), and energy dispersive spectroscopy (EDS) analysis techniques. The results showed that substantial defect clusters were formed in the advanced multi-component rare earth oxide doped zirconia-yttria systems. The size of the oxide defect clusters and the cluster dopant segregation was typically ranging fiom 5 to 50 nm. These multi-component dopant induced defect clusters are an important factor for the coating long-term high temperature stability and excellent performance.

Techno-Economic Assessment for Integrating Biosorption into Rare Earth Recovery Process

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

Jiao, Yongqin; Sutherland, John; Jin, Hongyue

The current uncertainty in the global supply of rare earth elements (REEs) necessitates the development of novel extraction technologies that utilize a variety of REE source materials. Herein, we examined the techno-economic performance of integrating a biosorption approach into a large-scale process for producing salable total rare earth oxides (TREOs) from various feedstocks. An airlift bioractor is proposed to carry out a biosorption process mediated by bioengineered rare earth-adsorbing bacteria. Techno-econmic asssements were compared for three distinctive categories of REE feedstocks requiring different pre-processing steps. Key parameters identified that affect profitability include REE concentration, composition of the feedstock, and costsmore » of feedstock pretreatment and waste management. Among the 11 specific feedstocks investigated, coal ash from the Appalachian Basin was projected to be the most profitable, largely due to its high-value REE content. Its cost breakdown includes pre-processing (primarily leaching) (8077.71%), biosorption (1619.04%), and oxalic acid precipitation and TREO roasting (3.35%). Surprisingly, biosorption from the high-grade Bull Hill REE ore is less profitable due to high material cost and low production revenue. Overall, our results confirmed that the application of biosorption to low-grade feedstocks for REE recovery is economically viable.« less

Biotechnological approaches for conservation and improvement of rare and endangered plants of Saudi Arabia

PubMed Central

Khan, Salim; Al-Qurainy, Fahad; Nadeem, Mohammad

2011-01-01

Genetic variation is believed to be a prerequisite for the short-and long-term survival of the plant species in their natural habitat. It depends on many environmental factors which determine the number of alleles on various loci in the genome. Therefore, it is important to understand the genetic composition and structure of the rare and endangered plant species from their natural habitat to develop successful management strategies for their conservation. However, rare and endangered plant species have low genetic diversity due to which their survival rate is decreasing in the wilds. The evaluation of genetic diversity of such species is very important for their conservation and gene manipulation. However, plant species can be conserved by in situ and in vitro methods and each has advantages and disadvantages. DNA banking can be considered as a means of complimentary method for the conservation of plant species by preserving their genomic DNA at low temperatures. Such approach of preservation of biological information provides opportunity for researchers to search novel genes and its products. Therefore, in this review we are describing some potential biotechnological approaches for the conservation and further manipulation of these rare and endangered plant species to enhance their yield and quality traits. PMID:23961155

Determination of rare earth elements concentration at different depth profile of Precambrian pegmatites using instrumental neutron activation analysis.

PubMed

Sadiq Aliyu, Abubakar; Musa, Yahaya; Liman, M S; Abba, Habu T; Chaanda, Mohammed S; Ngene, Nnamani C; Garba, N N

2018-01-01

The Keffi area hosts abundant pegmatite bodies as a result of the surrounding granitic intrusions. Keffi is part of areas that are geologically classified as North Central Basement Complex. Data on the mineralogy and mineralogical zonation of the Keffi pegmatite are scanty. Hence the need to understand the geology and mineralogical zonation of Keffi pegmatites especially at different depth profiles is relevant as a study of the elemental composition of the pegmatite is essential for the estimation of its economic viability. Here, the relative standardization method of instrumental neutron activation analysis (INAA) has been used to investigate the vertical deviations of the elemental concentrations of rare earth elements (REEs) at different depth profile of Keffi pegmatite. This study adopted the following metrics in investigating the vertical variations of REEs concentrations. Namely, the total contents of rare earth elements (∑REE); ratio of light to heavy rare earth elements (LREE/HREE), which defines the enrichment or depletion of REEs; europium anomaly (Eu/Sm); La/Lu ratio relative to chondritic meteorites. The study showed no significant variations in the total content of rare elements between the vertical depth profiles (100-250m). However, higher total concentrations of REEs (~ 92.65ppm) were recorded at the upper depth of the pegmatite and the europium anomaly was consistently negative at all the depth profiles suggesting that the Keffi pegmatite is enriched with light REEs. Copyright © 2017 Elsevier Ltd. All rights reserved.

SAMPLE COLLECTION AND HANDLING FOR MICROBIOLOGICAL EXAMINATION OF BIOSOLIDS

EPA Science Inventory

The objective of this presentation is to discuss sample collection and handling methods currently in use for detection and enumeration of microorganisms in biosolids and municipal wastewater sludges. Untreated sludges and biosolids are rarely homogeneous and present a challenge ...

Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition.

PubMed

Allan, Eric; Manning, Pete; Alt, Fabian; Binkenstein, Julia; Blaser, Stefan; Blüthgen, Nico; Böhm, Stefan; Grassein, Fabrice; Hölzel, Norbert; Klaus, Valentin H; Kleinebecker, Till; Morris, E Kathryn; Oelmann, Yvonne; Prati, Daniel; Renner, Swen C; Rillig, Matthias C; Schaefer, Martin; Schloter, Michael; Schmitt, Barbara; Schöning, Ingo; Schrumpf, Marion; Solly, Emily; Sorkau, Elisabeth; Steckel, Juliane; Steffen-Dewenter, Ingolf; Stempfhuber, Barbara; Tschapka, Marco; Weiner, Christiane N; Weisser, Wolfgang W; Werner, Michael; Westphal, Catrin; Wilcke, Wolfgang; Fischer, Markus

2015-08-01

Global change, especially land-use intensification, affects human well-being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real-world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land-use intensity. We also introduce five multifunctionality measures in which ecosystem services were weighted according to realistic land-use objectives. We found that indirect land-use effects, i.e. those mediated by biodiversity loss and by changes to functional composition, were as strong as direct effects on average. Their strength varied with land-use objectives and regional context. Biodiversity loss explained indirect effects in a region of intermediate productivity and was most damaging when land-use objectives favoured supporting and cultural services. In contrast, functional composition shifts, towards fast-growing plant species, strongly increased provisioning services in more inherently unproductive grasslands. © 2015 The Authors Ecology Letters published by John Wiley & Sons Ltd and CNRS.

SPATIALLY EXTENDED 21 cm SIGNAL FROM STRONGLY CLUSTERED UV AND X-RAY SOURCES IN THE EARLY UNIVERSE

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

Ahn, Kyungjin; Xu, Hao; Norman, Michael L.

2015-03-20

We present our prediction for the local 21 cm differential brightness temperature (δT{sub b}) from a set of strongly clustered sources of Population III (Pop III) and II (Pop II) objects in the early universe, by a numerical simulation of their formation and radiative feedback. These objects are located inside a highly biased environment, which is a rare, high-density peak (“Rarepeak”) extending to ∼7 comoving Mpc. We study the impact of ultraviolet and X-ray photons on the intergalactic medium (IGM) and the resulting δT{sub b}, when Pop III stars are assumed to emit X-ray photons by forming X-ray binaries verymore » efficiently. We parameterize the rest-frame spectral energy distribution of X-ray photons, which regulates X-ray photon-trapping, IGM-heating, secondary Lyα pumping and the resulting morphology of δT{sub b}. A combination of emission (δT{sub b} > 0) and absorption (δT{sub b} < 0) regions appears in varying amplitudes and angular scales. The boost of the signal by the high-density environment (δ ∼ 0.64) and on a relatively large scale combines to make Rarepeak a discernible, spatially extended (θ ∼ 10′) object for 21 cm observation at 13 ≲ z ≲ 17, which is found to be detectable as a single object by SKA with integration time of ∼1000 hr. Power spectrum analysis by some of the SKA precursors (Low Frequency Array, Murchison Widefield Array, Precision Array for Probing the Epoch of Reionization) of such rare peaks is found to be difficult due to the rarity of these peaks, and the contribution only by these rare peaks to the total power spectrum remains subdominant compared to that by all astrophysical sources.« less

Composite structural materials

NASA Technical Reports Server (NTRS)

Ansell, G. S.; Wiberley, S. E.

1978-01-01

The purpose of the RPI composites program is to develop advanced technology in the areas of physical properties, structural concepts and analysis, manufacturing, reliability and life prediction. Concommitant goals are to educate engineers to design and use composite materials as normal or conventional materials. A multifaceted program was instituted to achieve these objectives.

Firefighting and Emergency Response Study of Advanced Composites Aircraft. Objective 2: Firefighting Effectiveness of Technologies and Agents on Composite Aircraft Fires

DTIC Science & Technology

2011-12-31

current methods used for aluminum-skinned aircraft. To this end, a series of medium-scale fire experiments were performed on aerospace composite materials...History.....................................................................................................................4 3. METHODS , ASSUMPTIONS AND...4.3. Agent Cost Analysis ..........................................................................................................21 5. CONCLUSIONS

Wood-thermoplastic composites manufactured using beetle-killed spruce from Alaska

Treesearch

V. Yadama; Eini Lowell; N. Petersen; D. Nicholls

2009-01-01

The primary objectives of the study were to characterize the critical properties of wood flour produced using highly deteriorated beetle-killed spruce for wood-plastic composite (WPC) production and evaluate important mechanical and physical properties of WPC extruded using an industry standard formulation. Chemical composition analysis indicated no significant...

Choosing Aggregation Rules for Composite Indicators

ERIC Educational Resources Information Center

Munda, Giuseppe

2012-01-01

From a formal point of view, a composite indicator is an aggregate of all dimensions, objectives, individual indicators and variables used for its construction. This implies that what defines a composite indicator is the set of properties underlying its mathematical aggregation convention. In this article, I try to revise the theoretical debate on…

The Use of Lead Isotope and Rare Earth Element Geochemistry for Forensic Geographic Provenancing

NASA Astrophysics Data System (ADS)

Carey, A.; Darrah, T.; Harrold, Z.; Prutsman-Pfeiffer, J.; Poreda, R.

2008-12-01

Lead isotope and rare earth element composition of modern human bones are analyzed to explore their utility for geographical provenancing. DNA analysis is the standard for identification of individuals. DNA analysis requires a DNA match for comparison. Thus, DNA analysis is of limited use in cases involving unknown remains. Trace elements are incorporated into bones and teeth during biomineralization, recording the characteristics of an individual's geochemical environment. Teeth form during adolescence, recording the geochemical environment of an individual's youth. Bones remodel throughout an individual's lifetime. Bones consist of two types of bone tissue (cortical and trabecular) that remodel at different rates, recording the geochemical environment at the time of biomineralization. Cortical bone tissue, forming the outer surface of bones, is dense, hard tissue that remodels in 25-30 yrs. Conversely, trabecular bone tissue, the inner cavity of bones, is low density, porous and remodels in 2-5 years. Thus, analyzing teeth and both bone tissues allows for the development of a geographical time line capable of tracking immigration patterns through time instead of only an individual's youth. Geochemical isotopic techniques (Sr, O, C, N) have been used for geographical provenancing in physical anthropology. The isotopic values of Sr, C, O, N are predominantly a function of soil compositions in areas where food is grown or water is consumed. Application of these provenancing techniques has become difficult as an individual's diet may reflect the isotopic composition of foods obtained at the local grocer as opposed to local soil compositions. Thus, we explore the use of REEs and Pb isotopes for geographical provenancing. Pb and REEs are likely more reliable indicators of modern geographical location as their composition are high in bio-available sources such as local soils, atmospheric aerosols, and dust as opposed to Sr, C, O, N that are controlled by food and drinking water. Lead isotope and REE analysis of trabecular and cortical bone tissue of 60 femoral heads resected during hip replacement surgery at the Univ. of Roch. Medical Center were analyzed by a combination of TIMS and ICP-MS. Results show that Pb compositions are consistent with local soil with variable inputs from known environmental sources. Several samples demonstrate inputs from known environmental sources (e.g. Mississippi Valley ore) that was used in paint, solder, and US gasoline. Additionally, results suggest bioincorporation of Pb with isotopic composition consistent with that observed for Canadian gasoline aerosols. Immigrants included in the study show Pb compositions distinctly different than local residents.

Anti-buckling design of variable stiffness composite cylinder under combined loading based on the multi-objective optimization method

NASA Astrophysics Data System (ADS)

Zheng, Y.; Chen, J.

2018-06-01

Variable stiffness composite structures take full advantages of composite’s design ability. An enlarged design space will make the structure’s performance more excellent. Through an optimal design of a variable stiffness cylinder, the buckling capacity of the cylinder will be increased as compared with its constant stiffness counterpart. In this paper, variable stiffness composite cylinders sustaining combined loadings are considered, and the optimization is conducted based on the multi-objective optimization method. The results indicate that variable stiffness cylinder’s loading capacity is increased significantly as compared with the constant stiffness, especially when an inhomogeneous loading is considered.

Age of A2 Horizon Charcoal and Forest Structure near Porto Trombetas, Pará , Brazil

Treesearch

John K. Francis; Oliver Henry Knowles

2001-01-01

To study the structure and composition of old-growth forest in the Saracá-Taquera National Forest near Porto Trombetas, Brazil, we established 36 0.25 ha plots and described the vegetation. We collected charcoal from the A2 soil horizon of each plot for radiocarbon dating. Although fires have been very rare in this forest during historic times, the...

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

P.E.D. Morgan; R.M. Housley; J.B. Davis

A very import, extremely-long-term, use for monazite as a radwaste encapsulant has been proposed. THe use of ceramic La-monazite for sequestering actinides (isolating them from the environment), especially plutonium and some other radioactive elements )e.g., fission-product rare earths), had been especially championed by Lynn Boatner of ORNL. Monazite may be used alone or, copying its compatibility with many other minerals in nature, may be used in diverse composite combinations.

Spatial and Temporal Variability of Zooplankton Thin Layers: The Effects of Composition and Orientation on Acoustic Detection of Layers

DTIC Science & Technology

2010-09-30

abundant taxa (copepods and larvaceans), whereas the pump collected more rare taxa (cladocerans and siphonophores ). These differences could be due...4.2x 14848 6.8x Cladocerans 199 0.3x 195 0.88x Larvaceans 3016 1.3x 4102 3.5x Siphonophores 85 0.2x 215 0.14x

Survival of Hardwood Regeneration During Prescribed Fires: The Importance of Root Development and Root Collar Location

Treesearch

Patrick Brose; David Van Lear

2004-01-01

Fire ecology studies in eastern hardwood forests usually use plot-based inventory methods and focus on sprouting stems to detect changes in vegetative composition and structure. Rarely are individual stems studied and stems that fail to sprout are usually ignored. In this study, an individual stem mortality approach was employed. Four hundred fifty stems of eight...

Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas

Treesearch

Adrian G. Grell; Michael G. Shelton; Eric Heitzman

2005-01-01

Old-growth bottomland hardwood-Pinus taeda L. forests are rare in Arkansas, and the complex relationships between plant communities and environmental conditions have not been well described in these forests. To investigate these relationships, a digital elevation model was developed for a 16.2 ha old-growth bottomland hardwood-Pinus taeda forest in...

Development and Performance Evaluations of HfO2-Si and Rare Earth-Si Based Environmental Barrier Bond Coat Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si based EBC bond coat systems for SiCSiC CMC combustor and turbine airfoil applications are investigated. The coating design approach and stability requirements are specifically emphasized, with the development and implementation focusing on Plasma Sprayed (PS) and Electron Beam-Physic Vapor Deposited (EB-PVD) coating systems and the composition optimizations. High temperature properties of the HfO2-Si based bond coat systems, including the strength, fracture toughness, creep resistance, and oxidation resistance were evaluated in the temperature range of 1200 to 1500 C. Thermal gradient heat flux low cycle fatigue and furnace cyclic oxidation durability tests were also performed at temperatures up to 1500 C. The coating strength improvements, degradation and failure modes of the environmental barrier coating bond coat systems on SiCSiC CMCs tested in simulated stress-environment interactions are briefly discussed and supported by modeling. The performance enhancements of the HfO2-Si bond coat systems with rare earth element dopants and rare earth-silicon based bond coats are also highlighted. The advanced bond coat systems, when integrated with advanced EBC top coats, showed promise to achieve 1500 C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and long-term durability.

Preliminary Study on the Dissolutions of Ce, Nd, Y and La from Mineral Cassiterite by Acid and Alkaline Leaching

NASA Astrophysics Data System (ADS)

Firdiyono, F.; Andriyah, L.; Aini, F. N.; Arini, T.; Lalasari, L. H.

2018-03-01

Rare Earth Metal is a rare element that its availability in nature is very small. In Indonesia, the potential of rare earth metals is generally found as the associated mineral in major commodities, especially gold and alluvial tin. These associated minerals can be processed using a particular technology so that the result is a by-product that can increase the added value of the mineral. This purpose of this research was to investigate the dissolution of Cerium (Ce), Neodymium (Nd), Yttrium (Y) and Lanthanum (La) from mineral cassiterite by leaching process using dilute hydrochloric acid (HCl), sulfate acid (H2SO4) and sodium hydroxide (NaOH). Firstly, cassiterite was grinded to -100 mesh of particle size and characterized by X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) techniques. Secondly, 10 gram of cassiterite was leached in 100 ml solution of 3.26 N HCl, H2SO4 and NaOH at variation leaching time of 2, 4, 6, 24 and 48 hours in atmospheric conditions. The products were then filtered to separate filtrate and residue of cassiterite. Finally, to investigate the dissolution of Ce, La, Nd and Y, filtrate from dissolved cassiterite was analyzed by Induced Coupled Plasma-Optical Emission Spectrometry (ICP-OES), while to know the chemical composition of cassiterite leached by dilute HCl, H2SO4 and NaOH, residue products of cassiterite was characterized by XRF analysis. The result of ICP-OES analysis showed the dissolution of Ce element higher than Nd, Y and La elements for leaching cassiterite using HCl, H2SO4 and NaOH. The increase of leaching time was accompanied by the rise in the amount of dissolved elements from cassiterite. The result of XRF analysis showed the chemistry composition of Ce, Nd, Y and La elements on residue decreased insignificantly from chemistry composition of cassiterite (raw mineral) in all conditions. However, the dissolution of Ce, La, Nd and Y was insignificant in all conditions.

Computing return times or return periods with rare event algorithms

NASA Astrophysics Data System (ADS)

Lestang, Thibault; Ragone, Francesco; Bréhier, Charles-Edouard; Herbert, Corentin; Bouchet, Freddy

2018-04-01

The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agencies may be interested by the return time of a 10 m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein–Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

Isolated Traumatic Bilateral First Rib Fracture: A Rare Entity

PubMed Central

Chatterjee, Souvik; Dey, Rajesh; Ray, Ramdip; Sinha, Santanu

2011-01-01

Since the first rib is protected very well by the overlying soft tissue and bones, its fracture is a major injury and a considerable force is required to do it. Therefore, an isolated fracture of this rib is unusual. A 28-year-old healthy female had an accident while crossing the road and a heavy object fell on her. She had severe pain behind her clavicle region and was immediately hospitalized and examined. Thorough clinical examination and different relevant investigations surprisingly disclosed isolated bilateral first rib fracture which is a very rare clinical condition. PMID:25191390

Tuberculous Otitis Media with Facial Paralysis Combined with Labyrinthitis

PubMed Central

Hwang, Gyu Ho; Jung, Jong Yoon; Yum, Gunhwee

2013-01-01

Tuberculosis otitis media is a very rare cause of otorrhea, so that it is infrequently considered in differential diagnosis because clinical symptoms are nonspecific, and standard microbiological and histological tests for tuberculosis often give false-negative results. We present a rare case presenting as a rapidly progressive facial paralysis with severe dizziness and hearing loss on the ipsilateral side that was managed with facial nerve decompression and anti-tuberculosis therapy. The objective of this article is to create an awareness of ear tuberculosis, and to consider tuberculosis in the differential diagnosis of chronic otitis media with complications. PMID:24653900

Tuberculous otitis media with facial paralysis combined with labyrinthitis.

PubMed

Hwang, Gyu Ho; Jung, Jong Yoon; Yum, Gunhwee; Choi, June

2013-04-01

Tuberculosis otitis media is a very rare cause of otorrhea, so that it is infrequently considered in differential diagnosis because clinical symptoms are nonspecific, and standard microbiological and histological tests for tuberculosis often give false-negative results. We present a rare case presenting as a rapidly progressive facial paralysis with severe dizziness and hearing loss on the ipsilateral side that was managed with facial nerve decompression and anti-tuberculosis therapy. The objective of this article is to create an awareness of ear tuberculosis, and to consider tuberculosis in the differential diagnosis of chronic otitis media with complications.

Response of composite plates subjected to acoustic loading

NASA Technical Reports Server (NTRS)

Moyer, E. Thomas, Jr.

1989-01-01

The objectives of the project were to investigate numerical methodology for the determination of narrowband response in the geometrically nonlinear regime, to determine response characteristics for geometrically nonlinear plates subjected to random loading and to compare the predictions with experiments to be performed at NASA-Langley. The first two objectives were met. The response of composite plates subjected to both narrowband and broadband excitation were studied and the results are presented and discussed.

Context Influences Holistic Processing of Non-face Objects in the Composite Task

PubMed Central

Richler, Jennifer J.; Bukach, Cindy M.; Gauthier, Isabel

2013-01-01

We explore whether holistic-like effects can be observed for non-face objects in novices as a result of the task context. We measure contextually-induced congruency effects for novel objects (Greebles) in a sequential matching selective attention task (composite task). When format at study was blocked, congruency effects were observed for study-misaligned, but not study-aligned, conditions (Experiment 1). However, congruency effects were observed in all conditions when study formats were randomized (Experiment 2), revealing that the presence of certain trial types (study-misaligned) in an experiment can induce congruency effects. In a dual task, a congruency effect for Greebles was induced in trials where a face was first encoded, only if it was aligned (Experiment 3). Thus, congruency effects can be induced by context that operates at the scale of the entire experiment or within a single trial. Implications for using the composite task to measure holistic processing are discussed. PMID:19304644

A Multi-Objective Advanced Design Methodology of Composite Beam-to-Column Joints Subjected to Seismic and Fire Loads

NASA Astrophysics Data System (ADS)

Pucinotti, Raffaele; Ferrario, Fabio; Bursi, Oreste S.

2008-07-01

A multi-objective advanced design methodology dealing with seismic actions followed by fire on steel-concrete composite full strength joints with concrete filled tubes is proposed in this paper. The specimens were designed in detail in order to exhibit a suitable fire behaviour after a severe earthquake. The major aspects of the cyclic behaviour of composite joints are presented and commented upon. The data obtained from monotonic and cyclic experimental tests have been used to calibrate a model of the joint in order to perform seismic simulations on several moment resisting frames. A hysteretic law was used to take into account the seismic degradation of the joints. Finally, fire tests were conducted with the objective to evaluate fire resistance of the connection already damaged by an earthquake. The experimental activity together with FE simulation demonstrated the adequacy of the advanced design methodology.

Oxycarbonitride phosphors and light emitting devices using the same

DOEpatents

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2013-10-08

Disclosed herein is a novel family of oxycarbidonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbidonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

Oxycarbonitride phosphors and light emitting devices using the same

DOEpatents

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2014-07-08

Disclosed herein is a novel family of oxycarbonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

[Effect of nutritional quality of diet on chemical composition of organs and their interrelations in Bombyx mori L].

PubMed

Calvez, B

1975-01-01

Changing the qualitative and quantitative level of diet may affect the physiology of the insects. However only the total growth of the larvae is generally pointed out. Biochemical changes in undernourished larvae have been rarely investigated. For this purpose Bombyx mori larvae reared upon Spring leaves are compared to larvae reared upon Autumn leaves (poor nutritional value because of their Chemical composition). In both cases the analyses were carried out from the fourth larval ecdysis to the beginning of spinning. Three measurements indicate the development of larvae growth:--the mean weight of the larvae;--the fresh and dry weight of fat body;--the hemolymph volume.

Lightweight, Room-Temperature CO2 Gas Sensor Based on Rare-Earth Metal-Free Composites—An Impedance Study

PubMed Central

2017-01-01

We report a light, flexible, and low-power poly(ionic liquid)/alumina composite CO2 sensor. We monitor the direct-current resistance changes as a function of CO2 concentration and relative humidity and demonstrate fast and reversible sensing kinetics. Moreover, on the basis of the alternating-current impedance measurements we propose a sensing mechanism related to proton conduction and gas diffusion. The findings presented herein will promote the development of organic/inorganic composite CO2 gas sensors. In the future, such sensors will be useful for numerous practical applications ranging from indoor air quality control to the monitoring of manufacturing processes. PMID:28726384

Designing typefaces for maps. A protocol of tests.

NASA Astrophysics Data System (ADS)

Biniek, Sébastien; Touya, Guillaume; Rouffineau, Gilles; Huot-Marchand, Thomas

2018-05-01

The text management in map design is a topic generally linked to placement and composition issues. Whereas the type design issue is rarely addressed or at least only partially. Moreover the typefaces especially designed for maps are rare. This paper presents a protocol of tests to evaluate characters for digital topographic maps and fonts that were designed for the screen through the use of geographical information systems using this protocol. It was launched by the Atelier National de Recherche Typographique Research (ANRT, located in Nancy, France) and took place over his `post-master' course in 2013. The purpose is to isolate different issues inherent to text in a topographic map: map background, nonlinear text placement and toponymic hierarchies. Further research is necessary to improve this kind of approach.

Partition coefficients for REE between garnets and liquids - Implications of non-Henry's Law behaviour for models of basalt origin and evolution

NASA Technical Reports Server (NTRS)

Harrison, W. J.

1981-01-01

An experimental investigation of Ce, Sm and Tm rare earth element (REE) partition coefficients between coexisting garnets (both natural and synthetic) and hydrous liquids shows that Henry's Law may not be obeyed over a range of REE concentrations of geological relevance. Systematic differences between the three REE and the two garnet compositions may be explained in terms of the differences between REE ionic radii and those of the dodecahedral site into which they substitute, substantiating the Harrison and Wood (1980) model of altervalent substitution. Model calculations demonstrate that significant variation can occur in the rare earth contents of melts produced from a garnet lherzolite, if Henry's Law partition coefficients do not apply for the garnet phase.

Resequencing of the CETP gene in American whites and African blacks: Association of rare and common variants with HDL-cholesterol levels

PubMed Central

Pirim, Dilek; Wang, Xingbin; Niemsiri, Vipavee; Radwan, Zaheda H.; Bunker, Clareann H.; Hokanson, John E.; Hamman, Richard F.; Barmada, M. Michael; Demirci, F. Yesim; Kamboh, M. Ilyas

2015-01-01

Background Cholesteryl ester transfer protein (CETP) plays a crucial role in lipid metabolism. Associations of common CETP variants with variation in plasma lipid levels, and/or CETP mass/activity have been extensively studied and well-documented; however, the effects of uncommon/rare CETP variants on plasma lipid profile remain undefined. Hence, resequencing of the gene in extreme phenotypes and follow-up rare-variant association analyses are essential to fill this gap. Objective To identify common and uncommon/rare variants in the CETP gene by resequencing the entire gene and test the effects of both common and uncommon/rare CETP variants on plasma lipid traits in two genetically distinct populations. Methods and Results The entire CETP gene plus flanking regions were resequenced in 190 individuals comprising 95 non-Hispanic Whites (NHWs) and 95 African blacks with extreme HDL-C levels. A total of 279 sequence variants were identified, of which 25 were novel. Selected variants were genotyped in the entire samples of 623 NHWs and 788 African blacks and 184 QC-passed variants were tested in relation to plasma lipid traits by using gene-based, single-site, haplotype and rare variant association analyses (SKAT-O). Two novel and independent associations of rs1968905 and rs289740 with HDL-C were identified in African blacks. Using SKAT-O analysis, we also identified rare variants with minor allele frequency <0.01 to be associated with HDL-C in both NHWs (P=0.024) and African blacks (P=0.009). Conclusions Our results point out that in addition to the common CETP variants, rare genetic variants in the CETP gene also contribute to the phenotypic variation of HDL-C in the general population. PMID:26683795

Societal views on orphan drugs: cross sectional survey of Norwegians aged 40 to 67

PubMed Central

Gyrd-Hansen, Dorte; Olsen, Jan Abel; Grepperud, Sverre; Kristiansen, Ivar Sønbø

2010-01-01

Objective To determine whether a general societal preference for prioritising treatment of rare diseases over common ones exists and could provide a justification for accepting higher cost effectiveness thresholds for orphan drugs. Design Cross sectional survey using a web based questionnaire. Setting Norway. Participants Random sample of 1547 Norwegians aged 40-67. Main outcome measure Choice between funding treatment for a rare disease versus a common disease and how funds should be allocated if it were not possible to treat all patients, for each of two scenarios: identical treatment costs per patient and higher costs for the rare disease. Respondents rated five statements concerning attitudes to equity on a five point Likert scale (5=completely agree). Results For the equal cost scenario, 11.2% (9.6% to 12.8%) of respondents favoured treating the rare disease, 24.9% (21.7% to 26.0%) the common disease, and 64.9% (62.6% to 67.3%) were indifferent. When the rare disease was four times more costly to treat, the results were, respectively, 7.4% (6.1% to 8.7%), 45.3% (42.8% to 47.8%), and 47.3% (44.8% to 49.8%). Rankings for attitude on a Likert scale indicated strong support for the statements “rare disease patients should have the right to treatment even if more expensive” (mean score 4.5, SD 0.86) and “resources should be used to provide the greatest possible health benefits” (3.9, 1.23). Conclusions Despite strong general support for statements expressing a desire for equal treatment rights for patients with rare diseases, there was little evidence that a societal preference for rarity exists if treatment of patients with rare diseases is at the expense of treatment of those with common diseases. PMID:20861122

[Hungarian national plan and strategy for rare diseases].

PubMed

Kosztolányi, György

2014-03-02

The rarity of low prevalence diseases and the lack of information, research, diagnosis, treatment and expert availability may mean that the people affected do not benefit from the health resources and services they need. Rare diseases are considered to have little impact on society as a whole, yet they pose serious difficulties for sufferers and their families. By the end of the last century, two robust achievements in science and technology, i.e. the biotechnological and informatics revolutions, have created a real base for global approach to rare diseases by coordinating the capacities for health care, biomedical research and drug development and pooling the very limited resources available both nationally and transnationally. The European Commission has taken a number of actions which help patients and professionals to share expertise and information across borders with the objective of reducing the number of people suffering from these types of diseases. These actions together form the legal basis of the European Union policy on rare diseases. Orphan or rare diseases are now one of the priorities in the public health programmes in European Union. In 2009, the document "European Union Council Recommendation on an action in the field of rare diseases" was released with the main goal to provide national health authorities with supporting tools for the development and implementation of national plans and strategies for rare diseases by the end of 2013. This recommendation adopted by European Union Member States, allows common policy guidelines to be shared everywhere in Europe. By September 2013 the Hungarian National Plan for Rare Diseases, a health policy strategy until 2020 was finalized. The present report gives a short view on the document.

Rare earth indates (RE: La-Yb): influence of the synthesis route and heat treatment on the crystal structure.

PubMed

Shukla, Rakesh; Grover, Vinita; Srinivasu, Kancharlapalli; Paul, Barnita; Roy, Anushree; Gupta, Ruma; Tyagi, Avesh Kumar

2018-05-15

Rare earth indates are an interesting class of compounds with rich crystallography. The present study explores the crystallographic phases observed in REInO3 (RE: La-Yb) systems and their dependence on synthesis routes and annealing temperature. All REInO3 compositions were synthesized by a solid state route as well as gel-combustion synthesis (GC) followed by annealing at different temperatures. The systems were well characterized by powder XRD studies and were analysed by Rietveld refinement for the structural parameters. The cell parameters were observed to decrease in accordance with the trend in ionic radii on proceeding from lighter to heavier rare earth ions. Interestingly, the synthesis route and the annealing temperature had a profound bearing on the phase relationships observed in the REInO3 series. The solid state synthesized samples depicted an orthorhombic phase (Pbnm) field for LaInO3 to SmInO3, followed by a hexagonal-type phase (P63cm) for GdInO3 to DyInO3. However, the phase field distribution was greatly influenced upon employing gel-combustion (GC) wherein both single-phasic hexagonal and orthorhombic phase fields were found to shrink. Annealing the GC-synthesized compositions to still higher temperatures (1250 °C) further evolved the phase boundaries. An important outcome of the study is observance of polymorphism in SmInO3 which crystallized in the hexagonal phase when synthesized by GC and orthorhombic phase by solid state synthesis. This reveals the all-important role played by synthesis conditions. The existence and energetics of the two polymorphs have been elucidated and discussed with the aid of theoretical studies.

Metabolic Characterization of a Rare Genetic Variation Within APOC3 and Its Lipoprotein Lipase-Independent Effects.

PubMed

Drenos, Fotios; Davey Smith, George; Ala-Korpela, Mika; Kettunen, Johannes; Würtz, Peter; Soininen, Pasi; Kangas, Antti J; Dale, Caroline; Lawlor, Debbie A; Gaunt, Tom R; Casas, Juan-Pablo; Timpson, Nicholas J

2016-06-01

Plasma triglyceride levels have been implicated in atherosclerosis and coronary heart disease. Apolipoprotein C-III (APOC3) plays a key role in the hydrolysis of triglyceride-rich lipoproteins to remnant particles by lipoprotein lipase (LPL) and their uptake by the liver. A rare variant in APOC3(rs138326449) has been associated with triglyceride, very low-density lipoprotein, and high-density lipoprotein levels, as well as risk of coronary heart disease. We aimed to characterize the impact of this locus across a broad set of mainly lipids-focused metabolic measures. A high-throughput serum nuclear magnetic resonance metabolomics platform was used to quantify 225 metabolic measures in 13 285 participants from 2 European population cohorts. We analyzed the effect of the APOC3 variant on the metabolic measures and used the common LPL(rs12678919) polymorphism to test for LPL-independent effects. Eighty-one metabolic measures showed evidence of association with APOC3(rs138326449). In addition to previously reported triglyceride and high-density lipoprotein associations, the variant was also associated with very low-density lipoprotein and high-density lipoprotein composition measures, other cholesterol measures, and fatty acids. Comparison of the APOC3 and LPL associations revealed that APOC3 association results for medium and very large very low-density lipoprotein composition are unlikely to be solely predictable by the action of APOC3 through LPL. We characterized the effects of the rare APOC3(rs138326449) loss of function mutation in lipoprotein metabolism, as well as the effects of LPL(rs12678919). Our results improve our understanding of the role of APOC3 in triglyceride metabolism, its LPL independent action, and the complex and correlated nature of human metabolites. © 2016 The Authors.

Metabolic Characterization of a Rare Genetic Variation Within APOC3 and Its Lipoprotein Lipase–Independent Effects

PubMed Central

Davey Smith, George; Ala-Korpela, Mika; Kettunen, Johannes; Würtz, Peter; Soininen, Pasi; Kangas, Antti J.; Dale, Caroline; Lawlor, Debbie A.; Gaunt, Tom R.; Casas, Juan-Pablo

2016-01-01

Background— Plasma triglyceride levels have been implicated in atherosclerosis and coronary heart disease. Apolipoprotein C-III (APOC3) plays a key role in the hydrolysis of triglyceride-rich lipoproteins to remnant particles by lipoprotein lipase (LPL) and their uptake by the liver. A rare variant in APOC3(rs138326449) has been associated with triglyceride, very low–density lipoprotein, and high-density lipoprotein levels, as well as risk of coronary heart disease. We aimed to characterize the impact of this locus across a broad set of mainly lipids-focused metabolic measures. Methods and Results— A high-throughput serum nuclear magnetic resonance metabolomics platform was used to quantify 225 metabolic measures in 13 285 participants from 2 European population cohorts. We analyzed the effect of the APOC3 variant on the metabolic measures and used the common LPL(rs12678919) polymorphism to test for LPL-independent effects. Eighty-one metabolic measures showed evidence of association with APOC3(rs138326449). In addition to previously reported triglyceride and high-density lipoprotein associations, the variant was also associated with very low–density lipoprotein and high-density lipoprotein composition measures, other cholesterol measures, and fatty acids. Comparison of the APOC3 and LPL associations revealed that APOC3 association results for medium and very large very low–density lipoprotein composition are unlikely to be solely predictable by the action of APOC3 through LPL. Conclusions— We characterized the effects of the rare APOC3(rs138326449) loss of function mutation in lipoprotein metabolism, as well as the effects of LPL(rs12678919). Our results improve our understanding of the role of APOC3 in triglyceride metabolism, its LPL independent action, and the complex and correlated nature of human metabolites. PMID:27114411

Structural flexibility in magnetocaloric RE 5T 4 (RE=rare-earth; T=Si,Ge,Ga) materials: Effect of chemical substitution on structure, bonding and properties

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

Misra, Sumohan

The binary, ternary and multicomponent intermetallic compounds of rare-earth metals (RE) with group 14 elements (Tt) at the RE 5Tt 4 stoichiometry have been known for over 30 years, but only in the past decade have these materials become a gold mine for solid-state chemistry, materials science and condensed matter physics. It all started with the discovery of a giant magnetocaloric effect in Gd 5Si 2Ge 2, along with other extraordinary magnetic properties, such as a colossal magnetostriction and giant magnetoresistance. The distinctiveness of this series is in the remarkable flexibility of the chemical bonding between well-defined, subnanometer-thick slabs andmore » the resultant magnetic, transport, and thermodynamic properties of these materials. This can be controlled by varying either or both RE and Tt elements, including mixed rare-earth elements on the RE sites and different group 14 (or T = group 13 or 15) elements occupying the Tt sites. In addition to chemical means, the interslab interactions are also tunable by temperature, pressure, and magnetic field. Thus, this system provides a splendid 'playground' to investigate the interrelationships among composition, structure, physical properties, and chemical bonding. The work presented in this dissertation involving RE 5T 4 materials has resulted in the successful synthesis, characterization, property measurements, and theoretical analyses of various new intermetallic compounds. The results provide significant insight into the fundamental magnetic and structural behavior of these materials and help us better understand the complex link between a compound's composition, its observed structure, and its properties.« less

Modeling Pair Distribution Functions of Rare-Earth Phosphate Glasses Using Principal Component Analysis.

PubMed

Cole, Jacqueline M; Cheng, Xie; Payne, Michael C

2016-11-07

The use of principal component analysis (PCA) to statistically infer features of local structure from experimental pair distribution function (PDF) data is assessed on a case study of rare-earth phosphate glasses (REPGs). Such glasses, codoped with two rare-earth ions (R and R') of different sizes and optical properties, are of interest to the laser industry. The determination of structure-property relationships in these materials is an important aspect of their technological development. Yet, realizing the local structure of codoped REPGs presents significant challenges relative to their singly doped counterparts; specifically, R and R' are difficult to distinguish in terms of establishing relative material compositions, identifying atomic pairwise correlation profiles in a PDF that are associated with each ion, and resolving peak overlap of such profiles in PDFs. This study demonstrates that PCA can be employed to help overcome these structural complications, by statistically inferring trends in PDFs that exist for a restricted set of experimental data on REPGs, and using these as training data to predict material compositions and PDF profiles in unknown codoped REPGs. The application of these PCA methods to resolve individual atomic pairwise correlations in t(r) signatures is also presented. The training methods developed for these structural predictions are prevalidated by testing their ability to reproduce known physical phenomena, such as the lanthanide contraction, on PDF signatures of the structurally simpler singly doped REPGs. The intrinsic limitations of applying PCA to analyze PDFs relative to the quality control of source data, data processing, and sample definition, are also considered. While this case study is limited to lanthanide-doped REPGs, this type of statistical inference may easily be extended to other inorganic solid-state materials and be exploited in large-scale data-mining efforts that probe many t(r) functions.

A Phyletically Rare Gene Promotes the Niche-specific Fitness of an E. coli Pathogen during Bacteremia

PubMed Central

Wiles, Travis J.; Lewis, Adam J.; Mobley, Harry L. T.; Casjens, Sherwood R.; Mulvey, Matthew A.

2013-01-01

In bacteria, laterally acquired genes are often concentrated within chromosomal regions known as genomic islands. Using a recently developed zebrafish infection model, we set out to identify unique factors encoded within genomic islands that contribute to the fitness and virulence of a reference urosepsis isolate—extraintestinal pathogenic Escherichia coli strain CFT073. By screening a series of deletion mutants, we discovered a previously uncharacterized gene, neaT, that is conditionally required by the pathogen during systemic infections. In vitro assays indicate that neaT can limit bacterial interactions with host phagocytes and alter the aggregative properties of CFT073. The neaT gene is localized within an integrated P2-like bacteriophage in CFT073, but was rarely found within other proteobacterial genomes. Sequence-based analyses revealed that neaT homologues are present, but discordantly conserved, within a phyletically diverse set of bacterial species. In CFT073, neaT appears to be unameliorated, having an exceptionally A+T-rich composition along with a notably altered codon bias. These data suggest that neaT was recently brought into the proteobacterial pan-genome from an extra-phyletic source. Interestingly, even in G+C-poor genomes, as found within the Firmicutes lineage, neaT-like genes are often unameliorated. Sequence-level features of neaT homologues challenge the common supposition that the A+T-rich nature of many recently acquired genes reflects the nucleotide composition of their genomes of origin. In total, these findings highlight the complexity of the evolutionary forces that can affect the acquisition, utilization, and assimilation of rare genes that promote the niche-dependent fitness and virulence of a bacterial pathogen. PMID:23459509

Electromagnetic wave absorbing properties of amorphous carbon nanotubes.

PubMed

Zhao, Tingkai; Hou, Cuilin; Zhang, Hongyan; Zhu, Ruoxing; She, Shengfei; Wang, Jungao; Li, Tiehu; Liu, Zhifu; Wei, Bingqing

2014-07-10

Amorphous carbon nanotubes (ACNTs) with diameters in the range of 7-50 nm were used as absorber materials for electromagnetic waves. The electromagnetic wave absorbing composite films were prepared by a dip-coating method using a uniform mixture of rare earth lanthanum nitrate doped ACNTs and polyvinyl chloride (PVC). The microstructures of ACNTs and ACNT/PVC composites were characterized using transmission electron microscope and X-ray diffraction, and their electromagnetic wave absorbing properties were measured using a vector-network analyzer. The experimental results indicated that the electromagnetic wave absorbing properties of ACNTs are superior to multi-walled CNTs, and greatly improved by doping 6 wt% lanthanum nitrate. The reflection loss (R) value of a lanthanum nitrate doped ACNT/PVC composite was -25.02 dB at 14.44 GHz, and the frequency bandwidth corresponding to the reflector loss at -10 dB was up to 5.8 GHz within the frequency range of 2-18 GHz.

Abrasive wear behavior of in-situ RZ5-10wt%TiC composite

NASA Astrophysics Data System (ADS)

Mehra, Deepak; Mahapatra, M. M.; Harsha, S. P.

2018-05-01

RZ5 Magnesium alloys containing zinc, rare earth and zirconium are well-known to have high specific strength, good creep resistance widely used in aerospace components. The incorporation of hard ceramic strengthens RZ5 mg alloy. The RZ5-10wt%TiC composite has been fabricated in situ using RZ5 mg alloy as matrix and TiC as reinforcement by self propagating high temperature synthesis (SHS) technique. This paper investigates the abrasive wear behavior of RZ5-10wt%TiC. Tests were performed using pin-on-disc apparatus against 600 grit abrasive paper by varying the sliding distance and applied load. The results showed improvement in the wear resistance of testing composite as compared to the unreinforced RZ5 Mg alloy. The coefficient of friction and weight loss increased linearly as applied load and sliding distance increased. The field emission scanning electron microscopic (FESEM) showed dominate wear mechanisms: abrasion, ploughing grooves.

Volatility in the lunar crust: Trace element analyses of lunar minerals by PIXE proton microprobe

NASA Technical Reports Server (NTRS)

Norman, M. D.; Griffin, W. L.; Ryan, C. G.

1993-01-01

In situ determination of mineral compositions using microbeam techniques can characterize magma compositions through mineral-melt partitioning, and be used to investigate fine-grained or rare phases which cannot be extracted for analysis. Abundances of Fe, Mn, Sr, Ga, Zr, Y, Nb, Zn, Cu, Ni, Se, and Sb were determined for various mineral phases in a small number of lunar highlands rocks using the PIXE proton microprobe. Sr/Ga ratios of plagioclase and Mn/Zn ratios of mafic silicates show that the ferroan anorthosites and Mg-suite cumulates are depleted in volatile lithophile elements to about the same degree compared with chondrites and the Earth. This links the entire lunar crust to common processes or source compositions. In contrast, secondary sulfides in Descartes breccia clasts are enriched in chalcophile elements such as Cu, Zn, Ni, Se, and Sb, and represent a potential resource in the lunar highlands.